Introduction
Lisle's ASC model is a proposed solution to the distant starlight problem in YEC. It is a physical model, which is identical in just about every way to the standard cosmology model (LambdaCDM, built on the FLRW metric) after creation. It posits a mature creation of galaxies and stars and the earth, and it is designed to remove the need for created light in transit. In this model, any light that reaches earth had its origin in light-emitting physical objects like stars at most 6,000 years ago, rather than being created in space, containing properties about objects that the light never actually left. So long as there is no light created in transit, this model turns out to also make specific predictions and is falsifiable.
Proponents of this model claim the solution is a synchrony convention: by choosing a different convention (ASC) than what is typically used (ESC), we arrive at a universe that aligns with the biblical chronology and is 6,000 years old. By this convention, any light from stars we see can be considered to be happening instantaneously with when it was emitted by the star: the light we see gives us a real-time picture of what is going on at the stars right now. Statements are made about the one-way light speed being infinite towards earth, while c/2 away from earth, and we can choose the one-way speed of light to be whatever we want it to be. It is furthermore said that this model beat standard physical models by prediction of early mature galaxies that were discovered by the JWST data. All of this resulting from the use of a synchrony convention.
If you are puzzled how a mere change in convention can change the age of the universe or any of these other phenomena, you are not alone. In fact, you are correct that a convention cannot change physics or observations, and proponents of the ASC model will tell you the same. A convention is not like changing a reference frame or time dilation, which have physical causes and effects. So then, does this model actually solve the distant starlight problem? And if so, how? Is there a secret 13.8 billion years still in this model hiding somewhere?
It turns out that this model does indeed solve the distant starlight problem for the earth, and the answer turns out to not lie in convention: the real physical content of Lisle's theory that solves the distant starlight problem is not the ASC. Rather, he has an implied cosmology where the entire universe was created in causal connection with the earth on the earth's Day 4 (technically, their creation is placed on a null surface centered on earth). This means that any light arriving from galaxies contains information about events that actually occurred in history (technically, events that are on the galaxy's worldline). This is not a convention: it is the physical, falsifiable content of the model. In this article, I will disentangle convention from physics to show how this model solves the distant starlight problem, and I will observe and explain various implications of the model so that the costs of adopting it are clear: these are not primarily meant as critiques of the model, though some are. I also will show some physical predictions of the model that can actually be tested: one of these may have already falsified the model.
I will need a definition of created light in transit, so here is a definition upfront (briefly described above): light that is created with information about objects that it never left; light that is created with properties that it would have received from its source but did not because the source did not emit it.
It will be also helpful to define a few terms for any readers with less background in relativity. Proper time is what an observer's clock reads, and it is independent of convention and reference frame. A worldline is the path of an object through spacetime (strictly speaking, of a point-like object; extended objects like galaxies make tubes through spacetime, but we can treat them as points at the scales we are dealing with). It looks like a line when drawn through spacetime on a 2D plane/piece of paper: 1D for time, 1D for space—we call that (1+1)D spacetime. A coordinate system is a grid and set of labels that we assign to physical reality, so we can describe it mathematically. Physical reality does not have grid lines, so it doesn't care what grid lines we use, and so any coordinate system we use to describe it is physically just as good as any other: every physical quantity will have the same value independent of the coordinate system. A reference frame is a set of observers with clocks and rulers able to make measurements: imagine these observers filling every point of space, ready to take measurements. Anything physical determined by these measurements is independent of the coordinate system used by the reference frame. An event is the time and location of something that happens—when and where it occurred, and it is a point in spacetime. A metric is a mathematical object that tells us how to calculate physical distances and times from the space and time coordinates in our coordinate system, turning coordinate differences between nearby events into the physical times and distances that clocks and rulers measure, and it directly represents the physical spacetime geometry: the metric encodes the geometry. The metric will change its mathematical form in different coordinate systems, but the times and distances it computes remain the same because the geometry stays the same regardless of the grid we lay over it.
A few cosmology terms too. The FLRW (Friedmann–Lemaître–Robertson–Walker) metric is the spacetime geometry of the homogeneous, isotropic, and expanding universe. A static universe is one without expansion. A homogeneous universe is one that has no preferred center for its matter and energy content: the universe has the same matter and energy distribution on a large scale everywhere. An isotropic universe means no preferred direction for its matter and energy content: the universe looks the same on a large scale in all directions from every location. Note: "Homogeneous" and "Isotropic" here are about geometry and the matter and energy distribution, not the one-way speed of light. LambdaCDM is the standard cosmology model, which is the FLRW geometry plus a specific matter and energy content (including dark matter and dark energy). Lisle's model keeps LambdaCDM's features, expansion included, but not LambdaCDM's origin. Redshift, z, is the observable measure of expansion: 1 + z is the factor by which the universe has expanded since the light left its source to when it reaches the earth. Comoving distance is distance with the expansion divided out, so that galaxies carried along by the expansion keep the same comoving distance from one another as time passes; some of my figures use it for the horizontal axis. The Cosmic Microwave Background radiation (CMB) is the faint light in the microwave range that fills the sky in every direction.
Synchrony Conventions
I will not go into all the details about the conventionality of simultaneity, but a few points are good to review. Relativity introduces the conventionality of simultaneity: we cannot synchronize distant clocks independent of a convention—physics does not force one. This freedom arises because distant events in relativity cannot influence us, and they lie neither in our past nor future, but in our "elsewhere." The set of events that lie in our "elsewhere" come from the max speed of causal influence being the speed of light: events that are too far for light to reach us in our present time—our "now"—cannot causally influence us, and we cannot causally influence them.
As a result of the lack of physical influence and being neither in our past nor future, when we consider those events to occur (in our past, future, or "now") will have no physical or observable consequence. This also means the range of events we can causally influence and can causally influence us—we say that these events are in causal connection with us—is limited by the speed of light, forming a cone in spacetime, which we call the light cone. Events within the cone are "Future" (in the future light cone) or "Past" (in the past light cone) while events outside the cone are "elsewhere." The paths that light travels on through spacetime are null paths, and a surface made out of null paths is a null surface. The light cone is a null surface: it is the set of events that can send a light signal to, or receive one from, a given event. Null paths are very specific paths through spacetime: light cannot take any other path. Spacetime diagrams are typically scaled (years on one axis, light years on the other) so that null paths are always lines at 45 degrees; in some of my figures with expansion, the null paths curve instead. In either case, the light rays in my figures are the paths light has to take. See the spacetime diagram of the radar ranging figure, the lightcone, and the later figure for the earth and a distant galaxy.
We can then perform a radar experiment to bounce a light signal off somewhere and receive the light signal back again. Every event on earth's worldline between sending the signal and receiving it back lies in the "elsewhere" of the bounce, with no causal connection to it. We therefore have freedom, by setting our clocks, to label the bounce as occurring at any of those moments. Note: since the roundtrip—the two-way—speed of light is always c, we can use that and the time it took for the light to leave and return to us again (the roundtrip time) to find the distance to events from us. This distance is convention independent, since c and proper time are convention independent, and it is called the radar distance. It can be calculated from 2*radar distance = c*roundtrip time (2*distance cause the light travelled distance d to the object and distance d back to you). Although it is convention-independent, it should be noted that since it is a distance from a particular observer, it is observer-dependent.
A synchrony convention's meaning comes from the time assigned to the start of the light's return journey. Suppose your clock reads t = 0 when the light begins its journey to the distant object, and the roundtrip time is T. The ASC says, "If your clock reads t = T when light arrives, label the light to have left the distant object at t = T." The ESC says, "If your clock reads t = T when light arrives, label the light to have left the distant object at t = (1/2) T." In general, we use epsilon to keep track of the synchrony convention. Epsilon is the fraction of the roundtrip time we use for the label: we label the light to have left the distant object at t = epsilon*T. So for example, ASC is epsilon = 1, ESC is epsilon = 1/2, and any value in between is an equally possible convention.
As you might imagine, simply setting our clocks differently shouldn't have any physical effects. A synchrony convention amounts to a choice of coordinate system, though not all coordinate systems should be interpreted as defining a surface of simultaneity (as I will explain soon). This also means that one-way trip speeds of all objects—not just the one-way speed of light—are determined by when we set our clocks. If we use ASC, then the one-way speed = radar distance/time travelled is undefined (considered infinite) on the trip toward us, because we have stipulated that the time travelled from source to us is 0 from the labels we have applied; on the outbound trip away from us, the labels give c/2. If we use ESC, then the time travelled from source to us is half the roundtrip time from us to the source and back again, giving c in both directions. In general, we can consider the distant event of when the light leaves the distant object to be synchronized with any event between the time it takes for the light to leave and return again. Or equivalently, we can consider any event in the "elsewhere" to be happening at our "now:" see the figure of the earth and a distant galaxy. The purple lines of the lightcone can be considered the result of a hypothetical radar trip for light leaving and returning to the galaxy, and the earth's "now" is the moment that light arrives and leaves the earth.
A note on the figures here and in much of what follows: they ignore expansion and are in earth's frame. The galaxies' worldlines are drawn parallel to earth's because their motions relative to us are at most about 0.5% of c, which is a tilt of about 0.3° on the diagram, so essentially parallel. I will explain what expansion changes about this picture later on.
Clearly, the movement of light and other objects does not care about how we set our clocks: they will move how they will move, regardless of how we synchronize our clocks, and how we synchronize our clocks has zero effect on how they move. This then raises the obvious question: Why not synchronize our clocks so that they represent how the objects actually move? This is the heart of the conventionality thesis debate. The conventionality thesis says that we cannot measure how objects move without a convention, so such an exercise is circular: we have chosen our convention in the act of attempting to synchronize our clocks to how objects actually move. This is the point that is under contention and disputed with no final resolution, though many (most?) physicists would agree the conventionality thesis is correct.
The important point to grasp here is: the synchrony convention-dependent one-way speed of light, or one-way speed of anything, is not physical. We should not think of light as physically travelling with infinite speed towards earth and c/2 away. That is a conceptual mistake that is easy to make when thinking about this model, especially since we can picture light behaving that way and get correct physical results (recall that we get correct physical results regardless of coordinate system!). I will not say more on the one-way speed of light lest I get off track, except to note that we can define a different kind of one-way speed that is convention-free for objects with mass, but we cannot do that for light.
I refer the reader to the following articles for further reading on synchrony conventions and the one-way speed of light.
Is there a Preferred Epsilon?
One more point before turning to how Lisle's model uses a convention. Although they are just conventions, that does not mean there is no natural choice of synchrony convention, and it turns out that there are reasons to prefer ESC aside from making the math simple. One of them is that the matter distribution of the universe and the CMB provide a natural foliation: a slicing of spacetime that picks out what is known as cosmic time (the time kept by clocks at rest with the local matter and the CMB). These slices are surfaces on which density, temperature, expansion scale factor, and expansion rate are constant, orthogonal to the matter's own worldlines. This structure is the same that provides the CMB rest frame. And it turns out that the local synchrony convention that tracks cosmic time at the location of each observer moving with the matter is epsilon = 1/2. Cosmic time does not force us to use epsilon = 1/2, but it does mean epsilon = 1/2 is a convention picked out by matter and energy, giving epsilon = 1/2 a physical and natural preference.
Also, epsilon = 1/2 is the unique convention where the calculated distance to galaxies under the convention (i.e., the distance computed by the metric) is the same as their invariant "radar" distance (determined by half the time of a two-way light signal trip and multiplying by the invariant two-way speed of light). Among conventions that use the same epsilon in every direction, as both ESC and ASC do, it is the unique convention where "simultaneous" can be defined for an entire reference frame instead of per observer in a reference frame: all observers share the same simultaneity surfaces, instead of each observer having their own simultaneity surface. And if the universe had a physical one-way light speed, c—to which the epsilon = 1/2 convention corresponds—would be the only speed that could avoid creating a preferred reference frame. (A preferred frame is one in which the laws of physics take a different form, e.g., maybe the two-way light speed is c in this frame but different in every other frame. The CMB rest frame noted above is not preferred in that way: the laws of physics are the same in that frame as in any other; the CMB rest frame is just singled out by the contents of the universe.)
It is the unique choice where the simultaneity surface is orthogonal to the observer's worldline, which mathematically makes it the unique choice where a simultaneity surface doesn't need to have an extra parameter—a direction—supplied to specify the surface. Any other angle gives rise to a multitude of possible directions, and so an extra parameter is needed to specify which one. Extra parameters require additional explanation for their appearance in a model, and there is no physical explanation provided for this parameter. Imagine that the surface is a plane that should be tilted at 10 degrees to the worldline coming out of the xy plane...10 degrees toward the positive x axis? Towards the positive y axis? In general, there are 360 degrees of choices—a full circle (in three spatial dimensions, a sphere), so a direction must be specified. Meanwhile, if the surface is perpendicular to the worldline, no extra direction is needed to make that happen. See the figure illustrating this concept.
The ASC does escape the need for a direction by making its surface a cone around earth instead of a tilted plane. However, it requires a preferred center, since every other location's surface tilts toward earth. The same is true of any other epsilon that is the same in every direction, like epsilon = 1/4: each needs a preferred center, which is an extra parameter.
An analogy for this preferred epsilon choice may help: consider latitude and longitude. We could in theory put the poles wherever we want on the globe—like New York and the opposite point on the other side of the globe—and create a valid system of latitude and longitude. This is a valid coordinate system that we could use to calculate distances and specify locations. However, no one does this because the earth's rotation axis provides real structure that has poles on it. We therefore place the poles of our coordinate system at those locations to match the physical structure. Our coordinate system is adapted to the earth's physical structure. Setting epsilon = 1/2 is like placing our coordinate system's poles on the rotation axis. It is a choice, but a natural one.
One caveat: what I have said about a preferred epsilon is true for a static universe. With expansion, a few details change. Epsilon = 1/2 would only track cosmic time locally, for observers moving with the matter; this requires labeling events by cosmic time when speaking of ESC in the expanding universe as I will later on. Also, the calculated distance along a constant cosmic time slice would no longer be radar distance, but it would still be a physical distance: it would be the sum of the radar distances made at short distances and at the same cosmic time (called proper distance). Finally, if the matter in the universe turned out to not be at rest with respect to the CMB, i.e., the CMB and the matter in the universe have different rest frames, then there would no longer be one cosmic time but two separate natural clocks: one for observers moving with the matter and the other for observers at rest with the CMB. Observers would have to pick whether to sync their clocks to the matter or to the CMB, but it turns out that epsilon = 1/2 would still be the natural clock in either case.
We see then reasons to prefer epsilon = 1/2: that it is distinguished, natural, or adapted to the geometric structure and matter/energy of the universe.
The Model's Convention
First, we should note that not all time labelings are a simultaneity convention. Take timezones for an example. 9a New York time and 9a China time have the same t value, but no one would consider those events to be at the same time. The label is allowable, as all coordinates and labels are allowable, but t does not pick out a simultaneous moment: something more is needed for the definition. This is an important point because a few will argue that the same t label (plus the requirement that t always increases along a single observer's worldline) is a simultaneity convention. This is a different definition of what it means to be simultaneous from what people and most physicists mean by it. Nothing wrong with choosing that coordinate system or definition, but the meaning of "space at a moment in time" is lost under it.
The ASC's t coordinate is a label of this kind: it is not a time coordinate, it is what's called a null coordinate. The induced metric on the 3d surface is degenerate in the radial direction, meaning that this slice is not a space: it only has two defined dimensions. Its surfaces of constant t therefore do not represent all of space at a moment of time. This is related to the causal structure of relativity: if A causes B, A must come before B in time, and because A and B on the light cone are causally connected, assigning the same t coordinate to those events creates a mismatch with the causal structure. The degenerate spatial slice is another expression of that same structure. Another way to think of it: they are not in each others' "elsewhere," which is what gave freedom to assign simultaneity labels freely. Note that this causal structure also prevents instantaneous causation (i.e., cause and effect at the same moment, zero temporal separation).
None of this means that the ASC is an invalid coordinate system, or that its t coordinate is invalid to use or has no physical meaning. The t coordinate retains a physical meaning in terms of the radar definition and proper time: it represents the proper time of earth when light arrives. It represents when light is observed, without any further physical meaning. What it loses is what a time coordinate has: a time coordinate's level sets (sets given the same time value) are an instant, all of space at a moment of time. This is important because this is what Lisle's model needs the convention to supply: "all of creation made on Day 4" is a simultaneity claim, which this convention does not provide. Same with "that galaxy over there is 6,000 years old right now"—a simultaneity claim.
It is because of these considerations, and the way the interpretation breaks down when doing otherwise, that the simultaneity convention is understood to truly be a simultaneity convention with epsilon in (0, 1), i.e., between 0 and 1, excluding 0 and 1 (epsilon = 0 results in a degenerate metric also). For these values only does the surface contain only spacelike separated events, i.e., events that are not causally connected/cannot influence each other (what is called acausal). In relativity, the spacelike events do not lie in your future or past, so that results in freedom to choose a simultaneity convention within those values. We are free to use other coordinate systems if we want, but the coordinate system in Lisle’s case fails to describe a part of reality the model needs and which most would agree really exists in the universe (space at a moment).
We could adopt epsilon = 1 – delta, where delta is very small. Let's call this convention the nearly ASC. For this convention, this structural problem goes away: we can define simultaneity in this coordinate system and thereby represent reality again. In his 2010 paper, Lisle likewise sees the problem with epsilon = 1 and adopts a spacelike simultaneity surface just off earth's past light cone, which amounts to this nearly ASC. I will return to it in detail later. Note for now, though, that delta would have to be chosen small enough to have the same practical effect as epsilon = 1 in labeling time values to match the biblical chronology, and without any justification for a particular delta value other than that it makes the model match the chronology, the value is contrived.
Moreover, the point of ASC is to speak about the creation events in the way that the Bible speaks of them, aligning what we say about the universe’s age and its origin with the Biblical chronology. However, the fact remains that any epsilon in (0, 1) is just as valid. It is just as valid to speak of the creation as progressively occurring over a billion years as progressively occurring much more quickly with epsilon = 1 – delta. The two universes are physically equivalent. Saying the objects in the universe that we see are 6,000 years old right now is just convention; saying the objects in the universe that we see are billions of years old right now is just convention. Saying whether that distant galaxy that we see is 6,000 years or 1 billion years old right now is just convention.
That is in fact all that ASC does: it has nothing to do with physics, as we would expect to be the case from merely changing our clock times. Whether light has to be created in transit, and whether distant stars become visible all at once or progressively, does not depend on the convention at all. It depends on the creation surface—the geometry of creation in spacetime—which is what we shall look at next.
Geometry: The Creation Surface
When God created galaxies, they were created at particular locations of space at particular times. We can visualize their created positions and created times—these events—in a spacetime diagram. Connecting these creation events together forms a surface in spacetime (looks like a line in this (1+1)D spacetime diagram). This surface is what I call the creation surface.
One of the nice things about spacetime diagrams is that the objects drawn on them are invariant to conventions and coordinate systems, which will be helpful as we continue to discuss this model. The geometry a diagram shows is invariant, e.g., which events lie on which light rays, where worldlines cross, and how much proper time elapses along them.
In Lisle's model, all the light from all the galaxies reaches the earth simultaneously on Day 4. This means that the creation surface must be a null surface that lies on earth's past lightcone, i.e., all the galaxies and objects in space must be created at points on this spacetime surface. Light only ever takes null paths through spacetime, so all the galaxies must be on these null paths through spacetime for their light emitted upon creation to reach earth by Day 4. Everything on one branch of this surface can send a light signal and reach the earth (and each object in space on the way to earth) by earth's Day 4. We see then also that earth is in causal connection with these objects in space on earth's Day 4. By contrast, standard cosmology has all objects created on a spacelike horizontal surface. See the figure to illustrate the creation surfaces.
The null surface is also forced in this model because it is the only surface for which one could say that each galaxy has 6,000 years of proper time from creation until their most recent light is emitted that earth views (i.e., 6,000 years of proper time from creation until the galaxies' worldlines intersect earth's past light cone). That is, their age when they emitted the light that we see is 6,000 years. Another choice of creation surface will end up having some galaxies invisible until later: due to their great distances, a light ray from them doesn't reach earth until billions of years later on earth.
Moreover, Lisle's use of the ASC in his model labels events with the same time value in the shape of a null surface, as we already spoke about. The only way to say "All galaxies were created on Day 4" with the ASC is if the creation surface matches the shape of the ASC surface: any galaxies off the surface could not be said to be created on Day 4 in the ASC. With galaxies lying on the null surface, they can be given a single time label of ASC, and we are able to say, "Day 4 is when the galaxy emitted light; Day 4 is when earth received the light" for every galaxy.
However, we should be careful about what "forces" means here. The convention determines what Lisle can say about creation: the convention is what pushes the galaxies onto a null surface, if all of them are to be called created on Day 4. However, the convention does nothing to get their light to earth. That is geometry: light rays can be drawn from each of the galaxies on the null surface to reach earth on earth's Day 4, and that stays true under any convention.
See the figures below for an illustration of the creation surfaces, and the conventions overlaid on them.
To see that the convention does none of the work, let's look at the combinations. Apply ESC to LambdaCDM with its spacelike horizontal creation surface, and light of course doesn't need to be created in transit; apply ASC to LambdaCDM, and light still doesn't need to be created in transit — there are still 13.8 billion years of proper time elapsed along the worldline earth is on, though distant events are assigned the label "now." Take instead a horizontal spacelike creation surface with only 6,000 years of proper time on earth, and light will need to be created in transit under ASC and ESC alike: many galaxies would not be visible yet, their light rays not reaching earth's worldline until billions of years later, and under either convention stars progressively become visible on earth. The distant starlight problem returns. Take Lisle's null surface, and under either convention the light arrives on Day 4, with just 6,000 years of proper time elapsed for each galaxy from creation to when it emits the light that reaches earth now, i.e., to earth's past light cone. All the conventions do is change the time labels.
But how does changing time labels with a change of convention move billions of years? Where does the time go? Let's take Lisle's model with the null creation surface, suppose t = 0 is Day 4 of Creation, and look at a galaxy created a billion light years away. Under the ESC epsilon = 1/2, the galaxy's creation is assigned a time label of a billion years prior, t = –1 billion; the light then travels at speed c to reach the earth at t = 0, and all other galaxies and objects are created in a staggered fashion so that their light also reaches earth at t = 0. Under the ASC, that same creation event is assigned t = 0, the same label as the light's arrival at earth. The same billion years that sat in earth's past under ESC — the galaxy's history from emission until its worldline meets earth's past light cone again — is reassigned to t = 1 billion, in earth's future.
We see this reassignment in standard cosmology too. Under ASC, light emitted from any galaxy is assigned the same time label as when the light is received by the earth: at any given time, all the light we see is assigned a time label of "now." Suppose a distant galaxy a billion light years away emits light when 12.8 billion years of proper time have elapsed for a worldline from the singularity to the galaxy. Under ASC, that emission is labeled t = 13.8 billion, while the next billion years of the galaxy's history get assigned a value in earth's future, t = 14.8 billion. Under ESC, that same emission would be labeled t = 12.8 billion, with the billion years after it assigned 13.8 billion.
We see now then what the conventions are doing: they pick out which events are simultaneous with earth's Day 4. By a different choice, a billion years of the galaxy's worldline goes in earth's past or in earth's future, but the billion years of elapsed time for the galaxy still remains. Physics hasn't changed; the time labels have. See the figure for an illustration.
The null creation surface is what solves the distant starlight problem. The ASC in Lisle's model then just plays the role of synchronizing our clocks in accordance with the convention that God intended us to use when thinking about Creation. It is in accordance with and respect to this convention that God created all things in the space of six days. On this model, the ASC lets us use the correct clock to think about the creation events—a clock that dates the events we see by light rays to occur when we see them.
Geometry: things independent of convention
Let’s look at and recap some of the things in Lisle’s model that are not specific to the time conventions but are due to the geometry of the model. None of these claims have anything to do with ASC/nearly ASC or ESC and are true under any of them.
1) We have the null or (as we shall see) nearly null creation surface. All objects are created on this surface so that light from them arrives on Day 4.
2) The 6,000 years elapsed of proper time for earth since creation is there, and as can be seen by the even spacing between the null creation surface and earth's past light cone, the same 6,000 years elapses from creation to any light that has entered earth's view. Expansion makes it less than 6,000 years: 6,000/(1+z), in fact, where z is the redshift. By contrast, standard cosmology would have 13.8 billion years of proper time for worldlines through various locations (including the earth).
3) It turns out that the inwardly radial direction, i.e., radial direction towards the earth, is the only one where light does not in theory need to be created in transit. It’s not just the transverse direction that has a problem here but every other direction. For example, galaxies on separate arms of the null creation surface are initially space-like separated, requiring well over 6,000 years for light to travel from one to the other. This can be mathematically shown, or you can imagine drawing a light ray from one corner of the null surface to a galaxy right near the apex where earth is: the light ray will not reach on Day 4 but some time afterwards; see the figure below. The consequence is that light needs to be created in transit if light is to reach much of the universe that does not lie along a radial line with the earth and towards the earth. However, see what I say about voids and observational evidence below that will qualify this statement to narrow cones about the radial path and local bubbles.
4) This cosmology is geocentric. Earth is at the preferred and privileged center of the universe in the sense that it is the only place in the universe where the light from all the universe and in every direction arrives at all times from Day 4 onward. And all the gravitational waves too, for that matter. Other locations have to wait: see the discussion of voids later.
ASC vs ESC's Creation Story in Lisle's Model and Nearly Null Creation Surface
As noted earlier, the two conventions give a different story of Creation in this model, and I have partly explained the stories they give. Both of these are equally legitimate ways to describe the Creation week in this model, since they are conventions. I will lay out what the creation week looks like under these conventions in more detail here.
ESC's story.
In the furthest reaches of space where Galaxy A will be created on Day 4, Day 1 occurs and whatever creation of Day 1 that needs to happen at this location, happens. This location then proceeds through the week to Day 4, and Galaxy A is created, emitting photons in all directions. This location continues on to proceed to Day 6 and ending with Day 7.
We now look nearby Galaxy A at a location a little closer to earth and on a radial line connecting Galaxy A to earth. At this location, Day 1 happens a little later than Day 1 at Galaxy's A location. Day 1 happens at just the right time, so that on Day 4, light from Galaxy A will reach Galaxy B, which has yet to be created. Day 1 proceeds to Day 4. Galaxy B is created. Light from Galaxy A arrives.
We repeat this story along this radial line moving closer and closer to earth: each location has their creation week that begins in a staggered way such that light from the previous location arrives on Day 4 of the next location. This happens until earth is reached, and it has its Day 1 so that on Day 4, light from all these Galaxy A, B, and the rest arrive.
This story is likewise repeated for every location along every other radial line to earth with Day 1 happening at the same time for all galaxies equally distant from the earth.
This process takes a long time—13.8 billion years. But each location has its own 6 day Creation week followed by Day 7. See figure panel a below for a spacetime diagram to illustrate this. Note the shaded in "elsewhere:" those locations have no causal connection with earth on Day 4. As the earth proceeds through time, its slanted down lines (its past light cone) sweep through the elsewhere, and more of the universe comes in causal contact with the earth.
ASC's story.
Day 1 begins simultaneously for the future locations of Galaxy A, B, and all the rest on that radial line toward earth. Likewise for all the other locations on other radial lines toward earth. Day 1 on earth also begins at the same time as Day 1 at all these other locations. And then all the locations, including earth, proceed through the 6 day creation week, followed by Day 7, all at the same time. On Day 4, all the galaxies are created and their light instantly reaches earth on earth's Day 4: Day 4 occurs at the same time in all locations. At the end of the creation week, including Day 7, all locations in the universe have proceeded through 7 days of time at the same time. See figure panel b below for an illustration of ASC.
Do you see what happened here? The six day creation week's beginning is staggered and each day of the creation week is staggered for the various locations in ESC, while in ASC, they all happen at the same time. These are the exact same events: we just either consider them staggered or all happening at the same time. This is precisely what a simultaneity convention does: it relabels the same events to be simultaneous or to not be.
Of course, we should be careful here: I was deliberately crude with my telling of the ASC story for the sake of simplicity. As I noted earlier, ASC's days should not actually be understood to be simultaneous. More properly, all locations in the universe are assigned Day 1 for which light (hypothetical light signal sent or real light ray emitted) from them arrive at earth's Day 1. And Day 4 is the label given to the locations for which all the light from all the galaxies and stars arrive on earth's Day 4.
Nearly null surface, ESC, and nearly ASC
However, as I also noted earlier, we can restore a true sense of simultaneity—all of space at a moment of time—by changing the convention to epsilon = 1 - delta with delta very small (the nearly ASC, as we called it earlier). We can then change the creation surface so that events on this creation surface will be considered simultaneous under the nearly ASC, thereby restoring the intent of Lisle's model for creation to happen everywhere at the same time. This creation surface is the surface picked out by epsilon = 1 - delta, where delta is the same value as the delta we choose in the nearly ASC. Because this will be a very small delta, epsilon = 1 - delta is nearly equal to 1, i.e., the creation surface is nearly null.
The delta for the nearly null surface can be picked to be small enough so that all the light will arrive on earth during earth's Day 4. The light will not all arrive simultaneously on Day 4 anymore, but it will arrive some time during Day 4. Because delta is very small, any statements I have made in this post about the null surface will approximately apply to the nearly null surface (delta is very small!), including nearly 6,000 years of proper time from the creation surface to earth's past light cone (neglecting redshift).
A quick caution before we keep going: remember that statements about the surface are independent of the convention used. So for example, even if we do not use the nearly ASC with the nearly null creation surface, light will still arrive at their same times on earth, sometime during Day 4 and not arriving to earth at the same time on Day 4. And if we used the nearly ASC with the null creation surface, light will still arrive to earth simultaneously on Day 4 (while the regions of space pick up a staggering of the same kind as ESC, but much smaller—each Day's beginning nearly simultaneous). When light reaches the earth on its local Day 4 is a property of the creation surface, not the convention. The convention just specifies what events throughout space are considered to be simultaneous with events on earth.
The two stories (ESC and nearly ASC) will proceed in nearly the same way as with the null creation surface, the only difference being that for ESC, the beginning of the creation week at each location is staggered so that light's arrival at each location on a radial line happens sometime during that location's Day 4, rather than all at once on that location's Day 4. And for nearly ASC, the same thing: light arrives at each location, including earth, sometime during Day 4—nearer galaxies first, more distant last—no longer simultaneously on Day 4. But now, creation truly simultaneously occurs throughout the whole universe: the creation week begins and proceeds at the same time throughout the universe.
See the following figures for the spacetime diagrams with the nearly null creation surface under ESC and nearly ASC (epsilon = 1 - delta convention), including a zoomed in figure to see the light rays arriving on earth at different times during Day 4.
Another caveat I should make: the stories I have told have been simplified to what would be the case in a static universe—no expansion. For the expanding universe that we have, each location still gets its creation week, still defined as the creation events on the six creation surfaces at each location. However, the duration of the creation week—the time from the Day 1 surface to the Day 6 surface—changes at each location (about 6/(1+z) days), taking closer to the full 6 earth days for locations near earth and getting as short as hours long at locations far from earth. This happens with the null creation surface: every location would get the same six days for a horizontal spacelike creation surface.
Of course, this assumes that each location has Day 1 to Day 6 creation events and therefore Day 1 to Day 6 creation surfaces: there is only a guarantee of a Day 4 creation surface at each location in the universe. Without a creation event to physically mark time, each location's week is just a label, and that is the week that gets shortened. One physical statement that can be made though is that the galaxy's proper time measured from its creation to earth's past light cone will be shortened during that week. See the figures below to illustrate expansion and the shortening of the week with expansion.
The important point: these are two different stories of the creation week—ESC and ASC/nearly ASC. On Lisle's model, both stories are equally true: which one you end up telling is just a matter of convention.
Which brings us back to the preferred epsilon. It could be argued that ASC and nearly ASC have a preference of their own, since they match their creation surfaces. But that preference only exists where those creation surfaces exist: it is a preference for describing the creation week or elapsed time from it. Everywhere else, the physical and structural reasons to prefer epsilon = 1/2 remain. Lisle's model requires creating galaxies of varying maturity at the same redshift (else his model is falsified; see later discussion), as well as the CMB, such that the final result is the same observed matter and energy distribution that we see today and would observe under FLRW's history. So there is nothing in our observations that points to ASC: the universe is observationally identical to one with an ESC preference, and the creation surfaces that would ground the ASC preference cannot be observed. The preference for ASC instead comes solely from Scripture. Hence, on this model, the universe was created with its matter and radiation already synced to one clock (cosmic time, which reads billions of years), while the history that dates its creation is synced to another, and the two clock preferences conflict. This would be like putting the poles at points on the globe that Scripture identifies, though the globe does not mark them there. Nonetheless, the ASC is useful for speaking of creation happening in the space of six days and for speaking about 6,000 years of elapsed time from creation to now on earth and the maximum time from creation to when light from galaxies reaches earth.
What sort of mature creation is required
Mature creation is still required at points. These should not be viewed as unique requirements of the model but rather residual mature creation that is still required relative to a fully maturely created universe. Some of this may feel comfortable for some. Other parts, I don’t know, but they are requirements of the model. These are just examples: I'm sure there is more.
Predictions of the model
Both ASC and ESC give the same physical predictions for the null creation surface model, as would be expected, since they are just conventions. His model makes two in theory testable predictions.
As for 1, it is in principle impossible to measure elapsed proper time since creation, since the null creation surface is only visible for a brief moment of time on Day 4 of creation week. As for other events to measure the elapsed proper time and see how it differs from LambdaCDM, they take very long, and 6,000 years is short in comparison with that, making it practically impossible to distinguish Lisle’s model from standard LambdaCDM. Moreover, galaxies could just be created mature so that there is in fact no observable difference from LambdaCDM (see below).
One might think we could try to instead test the claim that galaxies at the same redshift are at the same maturity. This is falsified; galaxies of a variety of maturities are viewed at the same redshift. However, God could create galaxies at various stages of maturity on the null surface, with the variety at each redshift and the trend across redshifts matching what LambdaCDM's history would produce. This is a reasonable thing to say since Lisle has the galaxies created mature already anyway. Doing this makes the distinct redshift pattern of this model unobservable: the final product of creation would look identical to LambdaCDM.
Moreover, this is also the part that makes the difference in elapsed proper time not only impossible to measure in principle (because can't measure to the creation surface) but unobservable. Maturely created galaxy + 6,000/(1+z) years = same mature galaxy that developed over 13.8 billion years, where "maturely created galaxy" could be created at any stage of maturity to match the observed maturity of any galaxy.
It should be noted therefore: it is a mistake to say that this model inherently predicts galaxies at earlier redshifts remain fully formed and mature. Either galaxies must have the same maturity at the same redshift (falsified by the data), or galaxies are created at a variety of maturities at the same redshift in way that matches what LambdaCDM produces, in which case JWST actually did not confirm this model.
On 2, the only way to avoid the voids is to have light created in transit again, which would make the model unfalsifiable and defeat the purpose of adopting the model. So assuming no light in transit, what can we observe?
The voids would be quite distant from earth, so it is practically impossible to directly test this prediction, and in fact, without a warp drive or wormhole, for us a direct observation of a void is entirely impossible. However, it is possible we could indirectly see if there are voids. The idea is this: We should look where Lisle's model predicts a void. If we find material that is being illuminated, it means Lisle's model without light created in transit would be falsified. We might not be able to observe the voids directly, but we can observe other objects in the galaxy that are observing or not observing the voids themselves.
I asked Claude, and two tests came out of that conversation, along with two others that may falsify the model already. There may be other examples: Claude listed more, but I don’t understand them well enough to say whether they would indeed test the model.
Andromeda Galaxy. Dust cools down within hours. The dust needs light continuing to arrive to it to keep warm. Under Lisle's model, light from the central bulge would not be able to reach some of the dust at certain distances from the center (which can be calculated), i.e., a void is at that location, resulting in the dust on the far side being colder than dust the same distance from the center on the near side. If they have the same temperatures, then that light is reaching them. This means Lisle's model without created light in transit is falsified. It is also possible though there are other factors going on to explain the phenomenon, so one would want to see if the trend holds for other observations before declaring the model falsified.
Hanny's Voorwerp. This is a large cloud of gas near galaxy IC 2497. We see the cloud is ionized. If the electron number density is large enough, then any initial created ionized state would have faded by now unless light travelled from afar to keep it ionized. Under Lisle's model, this light would not be able to reach it, so it would have to have been created in transit, and Lisle's model without created light in transit would then be falsified. With low enough density, a created ionized state could still be glowing, so this test would not decide anything in that case. The electron number density has not currently been measured well enough to decide this.
The Third and Fourth Tests: CMB Falsifies?
Lisle's model without created light in transit may already be falsified by the SZ (Sunyaev–Zeldovich) effect of the CMB and CO gas molecule excitations. I would want to run this by someone in the field before being confident about it, but it seems plausible enough to me that I present it here.
The SZ effect of the CMB. The idea is that photons from the CMB pass through hot gases in galaxy clusters and get scattered by electrons. The scattering does two things: electrons scatter photons from the CMB out of their path that would reach earth, and photons from the CMB in other directions get scattered into the path toward earth. Because these photons are moving in all directions, the photons that get scattered into the path replace the ones that get scattered out of the path pretty much one-to-one: one photon scattered out, another photon scattered in. Due to their scattering with the electrons, the photons scattered into the path are at higher energy—higher frequencies—than the photons that were removed from the path. This results in an upshift of frequencies in the photons that we receive on earth from the CMB photons that pass through the gases: an upshifted frequency distribution.
The CMB surface is distant from galactic surfaces. Thus, there will be a big void at the location of these gases: the CMB photons arriving at the gas form a very narrow cone with a half-angle of about 0.09 degrees at 5 Gly away and 0.2 degrees at 1 Gly (0.2 degrees half-angle is 0.4 degrees wide). This is a best case calculation: expansion narrows the cone further. This means there are not CMB photons moving in all directions at that location, which means there are essentially no photons scattered into the path towards earth and so there is only really a scattering of photons to remove them from the path. The scattering is independent of frequency, so the scattering of photons to remove them from the path will result in no upshift of the photon frequencies: they will continue to have a frequency distribution matching the CMB but with significantly lower intensity. How low will depend on the electron column in the gas, rather than the gas pressure: photons that are scattered into the path—as in the case with photons in all directions—follow the pressure of the gas. So we have an effect here where in Lisle's model, the photons we observe correlate with the electron column, while in the photons in all directions model, the effect we see will correlate with the gas pressure.
Measurements have been made, and the data matches the upshifted distribution: a decrement (i.e., fewer photons at those frequencies) below about 217 GHz, zero at 217 GHz, and an increment above it (217 GHz is the frequency where the photons scattered out at that frequency are exactly replaced by photons scattered in and upshifted to it from lower frequencies; it is determined by the CMB spectrum's shape, not the gas). The data thereby apparently falsifies Lisle's model without created light in transit. Here is a figure of the theoretical frequency distribution under the all-directions light case (which matches the data) and the thin cone case of Lisle's model. They do not match in magnitude or shape, and you will see the removal-only curve (Lisle's thin cone case) does not cross zero at any point.
The only way out is through created light in transit. Either the photons from the CMB are created at the location of the gases to stream in all directions, in which case the effect we see is due to fabricated photons, since each of these photons are streaming to the gas with the properties they would have if they came from the CMB source.
Or the photons are given an initial state at the CMB source. This initial state would have to have just the right properties to have the right upshift as the photons get scattered out when passing through the gas. The photons would have to look like they had been scattered by the gas into the path toward earth, both in energy/frequency and in functional shape. The photons would have to have enough of them to compensate for when photons get scattered out of the path, and this would be correlated with the gas electron column, since out-scattering is correlated with that. The properties of the photons would have to correlate with the gas pressure, as they would if they had really been in-scattered by the gas in the all-directions case. And this initial state would have to match whatever gas it will arrive at in a very thin radial direction. In other words, the initial state would have photons with created properties that do not match photons coming from the blackbody CMB photons but of photons from scattering at the gas location plus compensation for any that will be scattered out. We therefore have photons with fabricated properties not matching their source, representing events that will never happen, and anticipating events in the future.
CO molecules excited by the CMB. CMB photons excite the Carbon Monoxide (CO) in distant, cold gas clouds. In a thin enough gas, this excitation will be way more than excitation from collisions. CO has a short relaxation period of about half a year, so it needs a steady supply of photons to stay excited: the excitation cannot be from an initial created state. We observe this excitation, do the math, and find that the excited temperature matches the predicted CMB temperature at that location, 2.725 K*(1+z). Also, any collisions with the surrounding gases would tend to drive the excitation temperature to the kinetic temperature of the gas, which is much bigger than the CMB temperature. This means the measured excitation temperature should be viewed as the upper bound on the CMB temperature. The close match and the much bigger temperature expected if collisions were significant sources of excitation means collisions contribute little. Meanwhile, the narrow beam of the CMB in Lisle's model means fewer photons arriving per second, which means more CO molecules will decay to a lower energy state before a photon can re-excite them. This means the CO molecules will pile up in a low energy state. So collisions would have to be nearly the whole source of excitation and happen to land near the CMB temperature 2.725 K*(1+z) in the many different clouds at different redshifts. Meanwhile, these gases are thin: low density, so there are few collisions; and the reason these CO populations are used as a CMB thermometer is due to few collisions in these gases.
Moreover, this CO excitation means that there needs to be photons there in all directions. Even if an initial state was created at the CMB source to match the SZ spectrum, the photons would still arrive in a narrow beam. So light would have to be created in transit to keep these molecules excited.
Conclusion
We have seen that this model solves the distant starlight problem by means of an implied spacetime creation surface, not through a convention, but the convention allows us to speak about Creation in a way that matches the Bible's chronology. We have also seen a number of implications of this model, including that viewing the universe as created over billions of years or a few days is a matter of clock convention. As for predictions, one of the predictions of the model that would falsify the model—direct observation of voids—is not practically testable at this time or in the foreseeable future (would need warp drive). Likewise, the distinct galaxy redshift turns out to be unobservable both in principle and because of mature creation, so it is not really a prediction. The prediction about voids could be observed indirectly and potentially falsify or support the model. If created light in transit is posited to fill in all the voids or places where it would be needed based on what we observe, then the model becomes unfalsifiable. It could be there are other things I have not noticed here pro or con for this model. My background is not in observations, so I easily could be unaware of something. But so far as I can see, the model without created light in transit is not clearly falsified yet: the two CMB tests appear to falsify it, but I would want someone in the field to confirm them before saying so with confidence.
Figures generated by Claude. Claude also assisted with review, calculations, and edits.
Lisle's ASC model is a proposed solution to the distant starlight problem in YEC. It is a physical model, which is identical in just about every way to the standard cosmology model (LambdaCDM, built on the FLRW metric) after creation. It posits a mature creation of galaxies and stars and the earth, and it is designed to remove the need for created light in transit. In this model, any light that reaches earth had its origin in light-emitting physical objects like stars at most 6,000 years ago, rather than being created in space, containing properties about objects that the light never actually left. So long as there is no light created in transit, this model turns out to also make specific predictions and is falsifiable.
Proponents of this model claim the solution is a synchrony convention: by choosing a different convention (ASC) than what is typically used (ESC), we arrive at a universe that aligns with the biblical chronology and is 6,000 years old. By this convention, any light from stars we see can be considered to be happening instantaneously with when it was emitted by the star: the light we see gives us a real-time picture of what is going on at the stars right now. Statements are made about the one-way light speed being infinite towards earth, while c/2 away from earth, and we can choose the one-way speed of light to be whatever we want it to be. It is furthermore said that this model beat standard physical models by prediction of early mature galaxies that were discovered by the JWST data. All of this resulting from the use of a synchrony convention.
If you are puzzled how a mere change in convention can change the age of the universe or any of these other phenomena, you are not alone. In fact, you are correct that a convention cannot change physics or observations, and proponents of the ASC model will tell you the same. A convention is not like changing a reference frame or time dilation, which have physical causes and effects. So then, does this model actually solve the distant starlight problem? And if so, how? Is there a secret 13.8 billion years still in this model hiding somewhere?
It turns out that this model does indeed solve the distant starlight problem for the earth, and the answer turns out to not lie in convention: the real physical content of Lisle's theory that solves the distant starlight problem is not the ASC. Rather, he has an implied cosmology where the entire universe was created in causal connection with the earth on the earth's Day 4 (technically, their creation is placed on a null surface centered on earth). This means that any light arriving from galaxies contains information about events that actually occurred in history (technically, events that are on the galaxy's worldline). This is not a convention: it is the physical, falsifiable content of the model. In this article, I will disentangle convention from physics to show how this model solves the distant starlight problem, and I will observe and explain various implications of the model so that the costs of adopting it are clear: these are not primarily meant as critiques of the model, though some are. I also will show some physical predictions of the model that can actually be tested: one of these may have already falsified the model.
I will need a definition of created light in transit, so here is a definition upfront (briefly described above): light that is created with information about objects that it never left; light that is created with properties that it would have received from its source but did not because the source did not emit it.
It will be also helpful to define a few terms for any readers with less background in relativity. Proper time is what an observer's clock reads, and it is independent of convention and reference frame. A worldline is the path of an object through spacetime (strictly speaking, of a point-like object; extended objects like galaxies make tubes through spacetime, but we can treat them as points at the scales we are dealing with). It looks like a line when drawn through spacetime on a 2D plane/piece of paper: 1D for time, 1D for space—we call that (1+1)D spacetime. A coordinate system is a grid and set of labels that we assign to physical reality, so we can describe it mathematically. Physical reality does not have grid lines, so it doesn't care what grid lines we use, and so any coordinate system we use to describe it is physically just as good as any other: every physical quantity will have the same value independent of the coordinate system. A reference frame is a set of observers with clocks and rulers able to make measurements: imagine these observers filling every point of space, ready to take measurements. Anything physical determined by these measurements is independent of the coordinate system used by the reference frame. An event is the time and location of something that happens—when and where it occurred, and it is a point in spacetime. A metric is a mathematical object that tells us how to calculate physical distances and times from the space and time coordinates in our coordinate system, turning coordinate differences between nearby events into the physical times and distances that clocks and rulers measure, and it directly represents the physical spacetime geometry: the metric encodes the geometry. The metric will change its mathematical form in different coordinate systems, but the times and distances it computes remain the same because the geometry stays the same regardless of the grid we lay over it.
A few cosmology terms too. The FLRW (Friedmann–Lemaître–Robertson–Walker) metric is the spacetime geometry of the homogeneous, isotropic, and expanding universe. A static universe is one without expansion. A homogeneous universe is one that has no preferred center for its matter and energy content: the universe has the same matter and energy distribution on a large scale everywhere. An isotropic universe means no preferred direction for its matter and energy content: the universe looks the same on a large scale in all directions from every location. Note: "Homogeneous" and "Isotropic" here are about geometry and the matter and energy distribution, not the one-way speed of light. LambdaCDM is the standard cosmology model, which is the FLRW geometry plus a specific matter and energy content (including dark matter and dark energy). Lisle's model keeps LambdaCDM's features, expansion included, but not LambdaCDM's origin. Redshift, z, is the observable measure of expansion: 1 + z is the factor by which the universe has expanded since the light left its source to when it reaches the earth. Comoving distance is distance with the expansion divided out, so that galaxies carried along by the expansion keep the same comoving distance from one another as time passes; some of my figures use it for the horizontal axis. The Cosmic Microwave Background radiation (CMB) is the faint light in the microwave range that fills the sky in every direction.
Synchrony Conventions
I will not go into all the details about the conventionality of simultaneity, but a few points are good to review. Relativity introduces the conventionality of simultaneity: we cannot synchronize distant clocks independent of a convention—physics does not force one. This freedom arises because distant events in relativity cannot influence us, and they lie neither in our past nor future, but in our "elsewhere." The set of events that lie in our "elsewhere" come from the max speed of causal influence being the speed of light: events that are too far for light to reach us in our present time—our "now"—cannot causally influence us, and we cannot causally influence them.
As a result of the lack of physical influence and being neither in our past nor future, when we consider those events to occur (in our past, future, or "now") will have no physical or observable consequence. This also means the range of events we can causally influence and can causally influence us—we say that these events are in causal connection with us—is limited by the speed of light, forming a cone in spacetime, which we call the light cone. Events within the cone are "Future" (in the future light cone) or "Past" (in the past light cone) while events outside the cone are "elsewhere." The paths that light travels on through spacetime are null paths, and a surface made out of null paths is a null surface. The light cone is a null surface: it is the set of events that can send a light signal to, or receive one from, a given event. Null paths are very specific paths through spacetime: light cannot take any other path. Spacetime diagrams are typically scaled (years on one axis, light years on the other) so that null paths are always lines at 45 degrees; in some of my figures with expansion, the null paths curve instead. In either case, the light rays in my figures are the paths light has to take. See the spacetime diagram of the radar ranging figure, the lightcone, and the later figure for the earth and a distant galaxy.
We can then perform a radar experiment to bounce a light signal off somewhere and receive the light signal back again. Every event on earth's worldline between sending the signal and receiving it back lies in the "elsewhere" of the bounce, with no causal connection to it. We therefore have freedom, by setting our clocks, to label the bounce as occurring at any of those moments. Note: since the roundtrip—the two-way—speed of light is always c, we can use that and the time it took for the light to leave and return to us again (the roundtrip time) to find the distance to events from us. This distance is convention independent, since c and proper time are convention independent, and it is called the radar distance. It can be calculated from 2*radar distance = c*roundtrip time (2*distance cause the light travelled distance d to the object and distance d back to you). Although it is convention-independent, it should be noted that since it is a distance from a particular observer, it is observer-dependent.
A synchrony convention's meaning comes from the time assigned to the start of the light's return journey. Suppose your clock reads t = 0 when the light begins its journey to the distant object, and the roundtrip time is T. The ASC says, "If your clock reads t = T when light arrives, label the light to have left the distant object at t = T." The ESC says, "If your clock reads t = T when light arrives, label the light to have left the distant object at t = (1/2) T." In general, we use epsilon to keep track of the synchrony convention. Epsilon is the fraction of the roundtrip time we use for the label: we label the light to have left the distant object at t = epsilon*T. So for example, ASC is epsilon = 1, ESC is epsilon = 1/2, and any value in between is an equally possible convention.
As you might imagine, simply setting our clocks differently shouldn't have any physical effects. A synchrony convention amounts to a choice of coordinate system, though not all coordinate systems should be interpreted as defining a surface of simultaneity (as I will explain soon). This also means that one-way trip speeds of all objects—not just the one-way speed of light—are determined by when we set our clocks. If we use ASC, then the one-way speed = radar distance/time travelled is undefined (considered infinite) on the trip toward us, because we have stipulated that the time travelled from source to us is 0 from the labels we have applied; on the outbound trip away from us, the labels give c/2. If we use ESC, then the time travelled from source to us is half the roundtrip time from us to the source and back again, giving c in both directions. In general, we can consider the distant event of when the light leaves the distant object to be synchronized with any event between the time it takes for the light to leave and return again. Or equivalently, we can consider any event in the "elsewhere" to be happening at our "now:" see the figure of the earth and a distant galaxy. The purple lines of the lightcone can be considered the result of a hypothetical radar trip for light leaving and returning to the galaxy, and the earth's "now" is the moment that light arrives and leaves the earth.
A note on the figures here and in much of what follows: they ignore expansion and are in earth's frame. The galaxies' worldlines are drawn parallel to earth's because their motions relative to us are at most about 0.5% of c, which is a tilt of about 0.3° on the diagram, so essentially parallel. I will explain what expansion changes about this picture later on.
Clearly, the movement of light and other objects does not care about how we set our clocks: they will move how they will move, regardless of how we synchronize our clocks, and how we synchronize our clocks has zero effect on how they move. This then raises the obvious question: Why not synchronize our clocks so that they represent how the objects actually move? This is the heart of the conventionality thesis debate. The conventionality thesis says that we cannot measure how objects move without a convention, so such an exercise is circular: we have chosen our convention in the act of attempting to synchronize our clocks to how objects actually move. This is the point that is under contention and disputed with no final resolution, though many (most?) physicists would agree the conventionality thesis is correct.
The important point to grasp here is: the synchrony convention-dependent one-way speed of light, or one-way speed of anything, is not physical. We should not think of light as physically travelling with infinite speed towards earth and c/2 away. That is a conceptual mistake that is easy to make when thinking about this model, especially since we can picture light behaving that way and get correct physical results (recall that we get correct physical results regardless of coordinate system!). I will not say more on the one-way speed of light lest I get off track, except to note that we can define a different kind of one-way speed that is convention-free for objects with mass, but we cannot do that for light.
I refer the reader to the following articles for further reading on synchrony conventions and the one-way speed of light.
Is there a Preferred Epsilon?
One more point before turning to how Lisle's model uses a convention. Although they are just conventions, that does not mean there is no natural choice of synchrony convention, and it turns out that there are reasons to prefer ESC aside from making the math simple. One of them is that the matter distribution of the universe and the CMB provide a natural foliation: a slicing of spacetime that picks out what is known as cosmic time (the time kept by clocks at rest with the local matter and the CMB). These slices are surfaces on which density, temperature, expansion scale factor, and expansion rate are constant, orthogonal to the matter's own worldlines. This structure is the same that provides the CMB rest frame. And it turns out that the local synchrony convention that tracks cosmic time at the location of each observer moving with the matter is epsilon = 1/2. Cosmic time does not force us to use epsilon = 1/2, but it does mean epsilon = 1/2 is a convention picked out by matter and energy, giving epsilon = 1/2 a physical and natural preference.
Also, epsilon = 1/2 is the unique convention where the calculated distance to galaxies under the convention (i.e., the distance computed by the metric) is the same as their invariant "radar" distance (determined by half the time of a two-way light signal trip and multiplying by the invariant two-way speed of light). Among conventions that use the same epsilon in every direction, as both ESC and ASC do, it is the unique convention where "simultaneous" can be defined for an entire reference frame instead of per observer in a reference frame: all observers share the same simultaneity surfaces, instead of each observer having their own simultaneity surface. And if the universe had a physical one-way light speed, c—to which the epsilon = 1/2 convention corresponds—would be the only speed that could avoid creating a preferred reference frame. (A preferred frame is one in which the laws of physics take a different form, e.g., maybe the two-way light speed is c in this frame but different in every other frame. The CMB rest frame noted above is not preferred in that way: the laws of physics are the same in that frame as in any other; the CMB rest frame is just singled out by the contents of the universe.)
It is the unique choice where the simultaneity surface is orthogonal to the observer's worldline, which mathematically makes it the unique choice where a simultaneity surface doesn't need to have an extra parameter—a direction—supplied to specify the surface. Any other angle gives rise to a multitude of possible directions, and so an extra parameter is needed to specify which one. Extra parameters require additional explanation for their appearance in a model, and there is no physical explanation provided for this parameter. Imagine that the surface is a plane that should be tilted at 10 degrees to the worldline coming out of the xy plane...10 degrees toward the positive x axis? Towards the positive y axis? In general, there are 360 degrees of choices—a full circle (in three spatial dimensions, a sphere), so a direction must be specified. Meanwhile, if the surface is perpendicular to the worldline, no extra direction is needed to make that happen. See the figure illustrating this concept.
The ASC does escape the need for a direction by making its surface a cone around earth instead of a tilted plane. However, it requires a preferred center, since every other location's surface tilts toward earth. The same is true of any other epsilon that is the same in every direction, like epsilon = 1/4: each needs a preferred center, which is an extra parameter.
An analogy for this preferred epsilon choice may help: consider latitude and longitude. We could in theory put the poles wherever we want on the globe—like New York and the opposite point on the other side of the globe—and create a valid system of latitude and longitude. This is a valid coordinate system that we could use to calculate distances and specify locations. However, no one does this because the earth's rotation axis provides real structure that has poles on it. We therefore place the poles of our coordinate system at those locations to match the physical structure. Our coordinate system is adapted to the earth's physical structure. Setting epsilon = 1/2 is like placing our coordinate system's poles on the rotation axis. It is a choice, but a natural one.
One caveat: what I have said about a preferred epsilon is true for a static universe. With expansion, a few details change. Epsilon = 1/2 would only track cosmic time locally, for observers moving with the matter; this requires labeling events by cosmic time when speaking of ESC in the expanding universe as I will later on. Also, the calculated distance along a constant cosmic time slice would no longer be radar distance, but it would still be a physical distance: it would be the sum of the radar distances made at short distances and at the same cosmic time (called proper distance). Finally, if the matter in the universe turned out to not be at rest with respect to the CMB, i.e., the CMB and the matter in the universe have different rest frames, then there would no longer be one cosmic time but two separate natural clocks: one for observers moving with the matter and the other for observers at rest with the CMB. Observers would have to pick whether to sync their clocks to the matter or to the CMB, but it turns out that epsilon = 1/2 would still be the natural clock in either case.
We see then reasons to prefer epsilon = 1/2: that it is distinguished, natural, or adapted to the geometric structure and matter/energy of the universe.
The Model's Convention
First, we should note that not all time labelings are a simultaneity convention. Take timezones for an example. 9a New York time and 9a China time have the same t value, but no one would consider those events to be at the same time. The label is allowable, as all coordinates and labels are allowable, but t does not pick out a simultaneous moment: something more is needed for the definition. This is an important point because a few will argue that the same t label (plus the requirement that t always increases along a single observer's worldline) is a simultaneity convention. This is a different definition of what it means to be simultaneous from what people and most physicists mean by it. Nothing wrong with choosing that coordinate system or definition, but the meaning of "space at a moment in time" is lost under it.
The ASC's t coordinate is a label of this kind: it is not a time coordinate, it is what's called a null coordinate. The induced metric on the 3d surface is degenerate in the radial direction, meaning that this slice is not a space: it only has two defined dimensions. Its surfaces of constant t therefore do not represent all of space at a moment of time. This is related to the causal structure of relativity: if A causes B, A must come before B in time, and because A and B on the light cone are causally connected, assigning the same t coordinate to those events creates a mismatch with the causal structure. The degenerate spatial slice is another expression of that same structure. Another way to think of it: they are not in each others' "elsewhere," which is what gave freedom to assign simultaneity labels freely. Note that this causal structure also prevents instantaneous causation (i.e., cause and effect at the same moment, zero temporal separation).
None of this means that the ASC is an invalid coordinate system, or that its t coordinate is invalid to use or has no physical meaning. The t coordinate retains a physical meaning in terms of the radar definition and proper time: it represents the proper time of earth when light arrives. It represents when light is observed, without any further physical meaning. What it loses is what a time coordinate has: a time coordinate's level sets (sets given the same time value) are an instant, all of space at a moment of time. This is important because this is what Lisle's model needs the convention to supply: "all of creation made on Day 4" is a simultaneity claim, which this convention does not provide. Same with "that galaxy over there is 6,000 years old right now"—a simultaneity claim.
It is because of these considerations, and the way the interpretation breaks down when doing otherwise, that the simultaneity convention is understood to truly be a simultaneity convention with epsilon in (0, 1), i.e., between 0 and 1, excluding 0 and 1 (epsilon = 0 results in a degenerate metric also). For these values only does the surface contain only spacelike separated events, i.e., events that are not causally connected/cannot influence each other (what is called acausal). In relativity, the spacelike events do not lie in your future or past, so that results in freedom to choose a simultaneity convention within those values. We are free to use other coordinate systems if we want, but the coordinate system in Lisle’s case fails to describe a part of reality the model needs and which most would agree really exists in the universe (space at a moment).
We could adopt epsilon = 1 – delta, where delta is very small. Let's call this convention the nearly ASC. For this convention, this structural problem goes away: we can define simultaneity in this coordinate system and thereby represent reality again. In his 2010 paper, Lisle likewise sees the problem with epsilon = 1 and adopts a spacelike simultaneity surface just off earth's past light cone, which amounts to this nearly ASC. I will return to it in detail later. Note for now, though, that delta would have to be chosen small enough to have the same practical effect as epsilon = 1 in labeling time values to match the biblical chronology, and without any justification for a particular delta value other than that it makes the model match the chronology, the value is contrived.
Moreover, the point of ASC is to speak about the creation events in the way that the Bible speaks of them, aligning what we say about the universe’s age and its origin with the Biblical chronology. However, the fact remains that any epsilon in (0, 1) is just as valid. It is just as valid to speak of the creation as progressively occurring over a billion years as progressively occurring much more quickly with epsilon = 1 – delta. The two universes are physically equivalent. Saying the objects in the universe that we see are 6,000 years old right now is just convention; saying the objects in the universe that we see are billions of years old right now is just convention. Saying whether that distant galaxy that we see is 6,000 years or 1 billion years old right now is just convention.
That is in fact all that ASC does: it has nothing to do with physics, as we would expect to be the case from merely changing our clock times. Whether light has to be created in transit, and whether distant stars become visible all at once or progressively, does not depend on the convention at all. It depends on the creation surface—the geometry of creation in spacetime—which is what we shall look at next.
Geometry: The Creation Surface
When God created galaxies, they were created at particular locations of space at particular times. We can visualize their created positions and created times—these events—in a spacetime diagram. Connecting these creation events together forms a surface in spacetime (looks like a line in this (1+1)D spacetime diagram). This surface is what I call the creation surface.
One of the nice things about spacetime diagrams is that the objects drawn on them are invariant to conventions and coordinate systems, which will be helpful as we continue to discuss this model. The geometry a diagram shows is invariant, e.g., which events lie on which light rays, where worldlines cross, and how much proper time elapses along them.
In Lisle's model, all the light from all the galaxies reaches the earth simultaneously on Day 4. This means that the creation surface must be a null surface that lies on earth's past lightcone, i.e., all the galaxies and objects in space must be created at points on this spacetime surface. Light only ever takes null paths through spacetime, so all the galaxies must be on these null paths through spacetime for their light emitted upon creation to reach earth by Day 4. Everything on one branch of this surface can send a light signal and reach the earth (and each object in space on the way to earth) by earth's Day 4. We see then also that earth is in causal connection with these objects in space on earth's Day 4. By contrast, standard cosmology has all objects created on a spacelike horizontal surface. See the figure to illustrate the creation surfaces.
The null surface is also forced in this model because it is the only surface for which one could say that each galaxy has 6,000 years of proper time from creation until their most recent light is emitted that earth views (i.e., 6,000 years of proper time from creation until the galaxies' worldlines intersect earth's past light cone). That is, their age when they emitted the light that we see is 6,000 years. Another choice of creation surface will end up having some galaxies invisible until later: due to their great distances, a light ray from them doesn't reach earth until billions of years later on earth.
Moreover, Lisle's use of the ASC in his model labels events with the same time value in the shape of a null surface, as we already spoke about. The only way to say "All galaxies were created on Day 4" with the ASC is if the creation surface matches the shape of the ASC surface: any galaxies off the surface could not be said to be created on Day 4 in the ASC. With galaxies lying on the null surface, they can be given a single time label of ASC, and we are able to say, "Day 4 is when the galaxy emitted light; Day 4 is when earth received the light" for every galaxy.
However, we should be careful about what "forces" means here. The convention determines what Lisle can say about creation: the convention is what pushes the galaxies onto a null surface, if all of them are to be called created on Day 4. However, the convention does nothing to get their light to earth. That is geometry: light rays can be drawn from each of the galaxies on the null surface to reach earth on earth's Day 4, and that stays true under any convention.
See the figures below for an illustration of the creation surfaces, and the conventions overlaid on them.
To see that the convention does none of the work, let's look at the combinations. Apply ESC to LambdaCDM with its spacelike horizontal creation surface, and light of course doesn't need to be created in transit; apply ASC to LambdaCDM, and light still doesn't need to be created in transit — there are still 13.8 billion years of proper time elapsed along the worldline earth is on, though distant events are assigned the label "now." Take instead a horizontal spacelike creation surface with only 6,000 years of proper time on earth, and light will need to be created in transit under ASC and ESC alike: many galaxies would not be visible yet, their light rays not reaching earth's worldline until billions of years later, and under either convention stars progressively become visible on earth. The distant starlight problem returns. Take Lisle's null surface, and under either convention the light arrives on Day 4, with just 6,000 years of proper time elapsed for each galaxy from creation to when it emits the light that reaches earth now, i.e., to earth's past light cone. All the conventions do is change the time labels.
But how does changing time labels with a change of convention move billions of years? Where does the time go? Let's take Lisle's model with the null creation surface, suppose t = 0 is Day 4 of Creation, and look at a galaxy created a billion light years away. Under the ESC epsilon = 1/2, the galaxy's creation is assigned a time label of a billion years prior, t = –1 billion; the light then travels at speed c to reach the earth at t = 0, and all other galaxies and objects are created in a staggered fashion so that their light also reaches earth at t = 0. Under the ASC, that same creation event is assigned t = 0, the same label as the light's arrival at earth. The same billion years that sat in earth's past under ESC — the galaxy's history from emission until its worldline meets earth's past light cone again — is reassigned to t = 1 billion, in earth's future.
We see this reassignment in standard cosmology too. Under ASC, light emitted from any galaxy is assigned the same time label as when the light is received by the earth: at any given time, all the light we see is assigned a time label of "now." Suppose a distant galaxy a billion light years away emits light when 12.8 billion years of proper time have elapsed for a worldline from the singularity to the galaxy. Under ASC, that emission is labeled t = 13.8 billion, while the next billion years of the galaxy's history get assigned a value in earth's future, t = 14.8 billion. Under ESC, that same emission would be labeled t = 12.8 billion, with the billion years after it assigned 13.8 billion.
We see now then what the conventions are doing: they pick out which events are simultaneous with earth's Day 4. By a different choice, a billion years of the galaxy's worldline goes in earth's past or in earth's future, but the billion years of elapsed time for the galaxy still remains. Physics hasn't changed; the time labels have. See the figure for an illustration.
The null creation surface is what solves the distant starlight problem. The ASC in Lisle's model then just plays the role of synchronizing our clocks in accordance with the convention that God intended us to use when thinking about Creation. It is in accordance with and respect to this convention that God created all things in the space of six days. On this model, the ASC lets us use the correct clock to think about the creation events—a clock that dates the events we see by light rays to occur when we see them.
Geometry: things independent of convention
Let’s look at and recap some of the things in Lisle’s model that are not specific to the time conventions but are due to the geometry of the model. None of these claims have anything to do with ASC/nearly ASC or ESC and are true under any of them.
1) We have the null or (as we shall see) nearly null creation surface. All objects are created on this surface so that light from them arrives on Day 4.
2) The 6,000 years elapsed of proper time for earth since creation is there, and as can be seen by the even spacing between the null creation surface and earth's past light cone, the same 6,000 years elapses from creation to any light that has entered earth's view. Expansion makes it less than 6,000 years: 6,000/(1+z), in fact, where z is the redshift. By contrast, standard cosmology would have 13.8 billion years of proper time for worldlines through various locations (including the earth).
3) It turns out that the inwardly radial direction, i.e., radial direction towards the earth, is the only one where light does not in theory need to be created in transit. It’s not just the transverse direction that has a problem here but every other direction. For example, galaxies on separate arms of the null creation surface are initially space-like separated, requiring well over 6,000 years for light to travel from one to the other. This can be mathematically shown, or you can imagine drawing a light ray from one corner of the null surface to a galaxy right near the apex where earth is: the light ray will not reach on Day 4 but some time afterwards; see the figure below. The consequence is that light needs to be created in transit if light is to reach much of the universe that does not lie along a radial line with the earth and towards the earth. However, see what I say about voids and observational evidence below that will qualify this statement to narrow cones about the radial path and local bubbles.
4) This cosmology is geocentric. Earth is at the preferred and privileged center of the universe in the sense that it is the only place in the universe where the light from all the universe and in every direction arrives at all times from Day 4 onward. And all the gravitational waves too, for that matter. Other locations have to wait: see the discussion of voids later.
ASC vs ESC's Creation Story in Lisle's Model and Nearly Null Creation Surface
As noted earlier, the two conventions give a different story of Creation in this model, and I have partly explained the stories they give. Both of these are equally legitimate ways to describe the Creation week in this model, since they are conventions. I will lay out what the creation week looks like under these conventions in more detail here.
ESC's story.
In the furthest reaches of space where Galaxy A will be created on Day 4, Day 1 occurs and whatever creation of Day 1 that needs to happen at this location, happens. This location then proceeds through the week to Day 4, and Galaxy A is created, emitting photons in all directions. This location continues on to proceed to Day 6 and ending with Day 7.
We now look nearby Galaxy A at a location a little closer to earth and on a radial line connecting Galaxy A to earth. At this location, Day 1 happens a little later than Day 1 at Galaxy's A location. Day 1 happens at just the right time, so that on Day 4, light from Galaxy A will reach Galaxy B, which has yet to be created. Day 1 proceeds to Day 4. Galaxy B is created. Light from Galaxy A arrives.
We repeat this story along this radial line moving closer and closer to earth: each location has their creation week that begins in a staggered way such that light from the previous location arrives on Day 4 of the next location. This happens until earth is reached, and it has its Day 1 so that on Day 4, light from all these Galaxy A, B, and the rest arrive.
This story is likewise repeated for every location along every other radial line to earth with Day 1 happening at the same time for all galaxies equally distant from the earth.
This process takes a long time—13.8 billion years. But each location has its own 6 day Creation week followed by Day 7. See figure panel a below for a spacetime diagram to illustrate this. Note the shaded in "elsewhere:" those locations have no causal connection with earth on Day 4. As the earth proceeds through time, its slanted down lines (its past light cone) sweep through the elsewhere, and more of the universe comes in causal contact with the earth.
ASC's story.
Day 1 begins simultaneously for the future locations of Galaxy A, B, and all the rest on that radial line toward earth. Likewise for all the other locations on other radial lines toward earth. Day 1 on earth also begins at the same time as Day 1 at all these other locations. And then all the locations, including earth, proceed through the 6 day creation week, followed by Day 7, all at the same time. On Day 4, all the galaxies are created and their light instantly reaches earth on earth's Day 4: Day 4 occurs at the same time in all locations. At the end of the creation week, including Day 7, all locations in the universe have proceeded through 7 days of time at the same time. See figure panel b below for an illustration of ASC.
Do you see what happened here? The six day creation week's beginning is staggered and each day of the creation week is staggered for the various locations in ESC, while in ASC, they all happen at the same time. These are the exact same events: we just either consider them staggered or all happening at the same time. This is precisely what a simultaneity convention does: it relabels the same events to be simultaneous or to not be.
Of course, we should be careful here: I was deliberately crude with my telling of the ASC story for the sake of simplicity. As I noted earlier, ASC's days should not actually be understood to be simultaneous. More properly, all locations in the universe are assigned Day 1 for which light (hypothetical light signal sent or real light ray emitted) from them arrive at earth's Day 1. And Day 4 is the label given to the locations for which all the light from all the galaxies and stars arrive on earth's Day 4.
Nearly null surface, ESC, and nearly ASC
However, as I also noted earlier, we can restore a true sense of simultaneity—all of space at a moment of time—by changing the convention to epsilon = 1 - delta with delta very small (the nearly ASC, as we called it earlier). We can then change the creation surface so that events on this creation surface will be considered simultaneous under the nearly ASC, thereby restoring the intent of Lisle's model for creation to happen everywhere at the same time. This creation surface is the surface picked out by epsilon = 1 - delta, where delta is the same value as the delta we choose in the nearly ASC. Because this will be a very small delta, epsilon = 1 - delta is nearly equal to 1, i.e., the creation surface is nearly null.
The delta for the nearly null surface can be picked to be small enough so that all the light will arrive on earth during earth's Day 4. The light will not all arrive simultaneously on Day 4 anymore, but it will arrive some time during Day 4. Because delta is very small, any statements I have made in this post about the null surface will approximately apply to the nearly null surface (delta is very small!), including nearly 6,000 years of proper time from the creation surface to earth's past light cone (neglecting redshift).
A quick caution before we keep going: remember that statements about the surface are independent of the convention used. So for example, even if we do not use the nearly ASC with the nearly null creation surface, light will still arrive at their same times on earth, sometime during Day 4 and not arriving to earth at the same time on Day 4. And if we used the nearly ASC with the null creation surface, light will still arrive to earth simultaneously on Day 4 (while the regions of space pick up a staggering of the same kind as ESC, but much smaller—each Day's beginning nearly simultaneous). When light reaches the earth on its local Day 4 is a property of the creation surface, not the convention. The convention just specifies what events throughout space are considered to be simultaneous with events on earth.
The two stories (ESC and nearly ASC) will proceed in nearly the same way as with the null creation surface, the only difference being that for ESC, the beginning of the creation week at each location is staggered so that light's arrival at each location on a radial line happens sometime during that location's Day 4, rather than all at once on that location's Day 4. And for nearly ASC, the same thing: light arrives at each location, including earth, sometime during Day 4—nearer galaxies first, more distant last—no longer simultaneously on Day 4. But now, creation truly simultaneously occurs throughout the whole universe: the creation week begins and proceeds at the same time throughout the universe.
See the following figures for the spacetime diagrams with the nearly null creation surface under ESC and nearly ASC (epsilon = 1 - delta convention), including a zoomed in figure to see the light rays arriving on earth at different times during Day 4.
Another caveat I should make: the stories I have told have been simplified to what would be the case in a static universe—no expansion. For the expanding universe that we have, each location still gets its creation week, still defined as the creation events on the six creation surfaces at each location. However, the duration of the creation week—the time from the Day 1 surface to the Day 6 surface—changes at each location (about 6/(1+z) days), taking closer to the full 6 earth days for locations near earth and getting as short as hours long at locations far from earth. This happens with the null creation surface: every location would get the same six days for a horizontal spacelike creation surface.
Of course, this assumes that each location has Day 1 to Day 6 creation events and therefore Day 1 to Day 6 creation surfaces: there is only a guarantee of a Day 4 creation surface at each location in the universe. Without a creation event to physically mark time, each location's week is just a label, and that is the week that gets shortened. One physical statement that can be made though is that the galaxy's proper time measured from its creation to earth's past light cone will be shortened during that week. See the figures below to illustrate expansion and the shortening of the week with expansion.
The important point: these are two different stories of the creation week—ESC and ASC/nearly ASC. On Lisle's model, both stories are equally true: which one you end up telling is just a matter of convention.
Which brings us back to the preferred epsilon. It could be argued that ASC and nearly ASC have a preference of their own, since they match their creation surfaces. But that preference only exists where those creation surfaces exist: it is a preference for describing the creation week or elapsed time from it. Everywhere else, the physical and structural reasons to prefer epsilon = 1/2 remain. Lisle's model requires creating galaxies of varying maturity at the same redshift (else his model is falsified; see later discussion), as well as the CMB, such that the final result is the same observed matter and energy distribution that we see today and would observe under FLRW's history. So there is nothing in our observations that points to ASC: the universe is observationally identical to one with an ESC preference, and the creation surfaces that would ground the ASC preference cannot be observed. The preference for ASC instead comes solely from Scripture. Hence, on this model, the universe was created with its matter and radiation already synced to one clock (cosmic time, which reads billions of years), while the history that dates its creation is synced to another, and the two clock preferences conflict. This would be like putting the poles at points on the globe that Scripture identifies, though the globe does not mark them there. Nonetheless, the ASC is useful for speaking of creation happening in the space of six days and for speaking about 6,000 years of elapsed time from creation to now on earth and the maximum time from creation to when light from galaxies reaches earth.
What sort of mature creation is required
Mature creation is still required at points. These should not be viewed as unique requirements of the model but rather residual mature creation that is still required relative to a fully maturely created universe. Some of this may feel comfortable for some. Other parts, I don’t know, but they are requirements of the model. These are just examples: I'm sure there is more.
- Mature creation of galaxies (built into the model at the null surface) and the earth.
- Mature creation of the CMB.
- The CMB (recall it is light in the microwave range) has marks in it from past scattering of photons in the form of polarizations. These marks would need to be created mature. Essentially, these “scars” of past scattering interactions would need to be part of the mature creation. Because the scattering interactions comes from light in all sorts of directions, including non-radial directions, these scars would also need to be created in CMB light arriving along the radial direction.
- Some supernova shells in mid-expansion will need to be maturely created (unless their standard ages are denied, as some YECs do).
Predictions of the model
Both ASC and ESC give the same physical predictions for the null creation surface model, as would be expected, since they are just conventions. His model makes two in theory testable predictions.
- Galaxies at the same redshift will have the same elapsed proper time since their creation. LambdaCDM also predicts this, but the elapsed proper time is both longer and results in a galaxy's maturity, so galaxy maturity is tied to redshift: galaxies can be no more mature than the implied age by their redshift. Meanwhile, the elapsed proper time in Lisle's model is too small to produce any significant maturity, so the galaxies of Lisle's model get their maturity from their created state and could therefore in theory be of any maturity.
- Assuming no light created in transit, there will be voids at locations in the universe. See the figures below. These voids are places where a hypothetical observer would see nothing because light from the stars has not reached them yet. At best (expansion makes the region of visibility smaller), they would only see a region of visibility shaped like a bowl opening away from earth reaching 3,000 light years in the direction of earth and about 6,000 light years off to the sides, bending into a cone in the anti-earth direction. The region of visibility forms a bubble for nearby light sources and a cone in the anti-earth direction—centered around light heading in the inwardly radial direction to the earth—for distant light sources. As the light reaches the location, the region of visibility expands (the bubble expands and the cone widens), and the void will get filled in over time. I am calling it a “void,” but it is really just a patch of the sky that looks empty of light; it should not be confused with the “voids” in cosmology. The first, more cartoonish figure draws a spherical portion of the local bubble, with a radius equal to the smallest radius of visibility (3,000 light years), but as explained and as can be seen in the next figure, the full local bubble reaches twice as far to the sides as it does toward the earth.
As for 1, it is in principle impossible to measure elapsed proper time since creation, since the null creation surface is only visible for a brief moment of time on Day 4 of creation week. As for other events to measure the elapsed proper time and see how it differs from LambdaCDM, they take very long, and 6,000 years is short in comparison with that, making it practically impossible to distinguish Lisle’s model from standard LambdaCDM. Moreover, galaxies could just be created mature so that there is in fact no observable difference from LambdaCDM (see below).
One might think we could try to instead test the claim that galaxies at the same redshift are at the same maturity. This is falsified; galaxies of a variety of maturities are viewed at the same redshift. However, God could create galaxies at various stages of maturity on the null surface, with the variety at each redshift and the trend across redshifts matching what LambdaCDM's history would produce. This is a reasonable thing to say since Lisle has the galaxies created mature already anyway. Doing this makes the distinct redshift pattern of this model unobservable: the final product of creation would look identical to LambdaCDM.
Moreover, this is also the part that makes the difference in elapsed proper time not only impossible to measure in principle (because can't measure to the creation surface) but unobservable. Maturely created galaxy + 6,000/(1+z) years = same mature galaxy that developed over 13.8 billion years, where "maturely created galaxy" could be created at any stage of maturity to match the observed maturity of any galaxy.
It should be noted therefore: it is a mistake to say that this model inherently predicts galaxies at earlier redshifts remain fully formed and mature. Either galaxies must have the same maturity at the same redshift (falsified by the data), or galaxies are created at a variety of maturities at the same redshift in way that matches what LambdaCDM produces, in which case JWST actually did not confirm this model.
On 2, the only way to avoid the voids is to have light created in transit again, which would make the model unfalsifiable and defeat the purpose of adopting the model. So assuming no light in transit, what can we observe?
The voids would be quite distant from earth, so it is practically impossible to directly test this prediction, and in fact, without a warp drive or wormhole, for us a direct observation of a void is entirely impossible. However, it is possible we could indirectly see if there are voids. The idea is this: We should look where Lisle's model predicts a void. If we find material that is being illuminated, it means Lisle's model without light created in transit would be falsified. We might not be able to observe the voids directly, but we can observe other objects in the galaxy that are observing or not observing the voids themselves.
I asked Claude, and two tests came out of that conversation, along with two others that may falsify the model already. There may be other examples: Claude listed more, but I don’t understand them well enough to say whether they would indeed test the model.
Andromeda Galaxy. Dust cools down within hours. The dust needs light continuing to arrive to it to keep warm. Under Lisle's model, light from the central bulge would not be able to reach some of the dust at certain distances from the center (which can be calculated), i.e., a void is at that location, resulting in the dust on the far side being colder than dust the same distance from the center on the near side. If they have the same temperatures, then that light is reaching them. This means Lisle's model without created light in transit is falsified. It is also possible though there are other factors going on to explain the phenomenon, so one would want to see if the trend holds for other observations before declaring the model falsified.
Hanny's Voorwerp. This is a large cloud of gas near galaxy IC 2497. We see the cloud is ionized. If the electron number density is large enough, then any initial created ionized state would have faded by now unless light travelled from afar to keep it ionized. Under Lisle's model, this light would not be able to reach it, so it would have to have been created in transit, and Lisle's model without created light in transit would then be falsified. With low enough density, a created ionized state could still be glowing, so this test would not decide anything in that case. The electron number density has not currently been measured well enough to decide this.
The Third and Fourth Tests: CMB Falsifies?
Lisle's model without created light in transit may already be falsified by the SZ (Sunyaev–Zeldovich) effect of the CMB and CO gas molecule excitations. I would want to run this by someone in the field before being confident about it, but it seems plausible enough to me that I present it here.
The SZ effect of the CMB. The idea is that photons from the CMB pass through hot gases in galaxy clusters and get scattered by electrons. The scattering does two things: electrons scatter photons from the CMB out of their path that would reach earth, and photons from the CMB in other directions get scattered into the path toward earth. Because these photons are moving in all directions, the photons that get scattered into the path replace the ones that get scattered out of the path pretty much one-to-one: one photon scattered out, another photon scattered in. Due to their scattering with the electrons, the photons scattered into the path are at higher energy—higher frequencies—than the photons that were removed from the path. This results in an upshift of frequencies in the photons that we receive on earth from the CMB photons that pass through the gases: an upshifted frequency distribution.
The CMB surface is distant from galactic surfaces. Thus, there will be a big void at the location of these gases: the CMB photons arriving at the gas form a very narrow cone with a half-angle of about 0.09 degrees at 5 Gly away and 0.2 degrees at 1 Gly (0.2 degrees half-angle is 0.4 degrees wide). This is a best case calculation: expansion narrows the cone further. This means there are not CMB photons moving in all directions at that location, which means there are essentially no photons scattered into the path towards earth and so there is only really a scattering of photons to remove them from the path. The scattering is independent of frequency, so the scattering of photons to remove them from the path will result in no upshift of the photon frequencies: they will continue to have a frequency distribution matching the CMB but with significantly lower intensity. How low will depend on the electron column in the gas, rather than the gas pressure: photons that are scattered into the path—as in the case with photons in all directions—follow the pressure of the gas. So we have an effect here where in Lisle's model, the photons we observe correlate with the electron column, while in the photons in all directions model, the effect we see will correlate with the gas pressure.
Measurements have been made, and the data matches the upshifted distribution: a decrement (i.e., fewer photons at those frequencies) below about 217 GHz, zero at 217 GHz, and an increment above it (217 GHz is the frequency where the photons scattered out at that frequency are exactly replaced by photons scattered in and upshifted to it from lower frequencies; it is determined by the CMB spectrum's shape, not the gas). The data thereby apparently falsifies Lisle's model without created light in transit. Here is a figure of the theoretical frequency distribution under the all-directions light case (which matches the data) and the thin cone case of Lisle's model. They do not match in magnitude or shape, and you will see the removal-only curve (Lisle's thin cone case) does not cross zero at any point.
The only way out is through created light in transit. Either the photons from the CMB are created at the location of the gases to stream in all directions, in which case the effect we see is due to fabricated photons, since each of these photons are streaming to the gas with the properties they would have if they came from the CMB source.
Or the photons are given an initial state at the CMB source. This initial state would have to have just the right properties to have the right upshift as the photons get scattered out when passing through the gas. The photons would have to look like they had been scattered by the gas into the path toward earth, both in energy/frequency and in functional shape. The photons would have to have enough of them to compensate for when photons get scattered out of the path, and this would be correlated with the gas electron column, since out-scattering is correlated with that. The properties of the photons would have to correlate with the gas pressure, as they would if they had really been in-scattered by the gas in the all-directions case. And this initial state would have to match whatever gas it will arrive at in a very thin radial direction. In other words, the initial state would have photons with created properties that do not match photons coming from the blackbody CMB photons but of photons from scattering at the gas location plus compensation for any that will be scattered out. We therefore have photons with fabricated properties not matching their source, representing events that will never happen, and anticipating events in the future.
CO molecules excited by the CMB. CMB photons excite the Carbon Monoxide (CO) in distant, cold gas clouds. In a thin enough gas, this excitation will be way more than excitation from collisions. CO has a short relaxation period of about half a year, so it needs a steady supply of photons to stay excited: the excitation cannot be from an initial created state. We observe this excitation, do the math, and find that the excited temperature matches the predicted CMB temperature at that location, 2.725 K*(1+z). Also, any collisions with the surrounding gases would tend to drive the excitation temperature to the kinetic temperature of the gas, which is much bigger than the CMB temperature. This means the measured excitation temperature should be viewed as the upper bound on the CMB temperature. The close match and the much bigger temperature expected if collisions were significant sources of excitation means collisions contribute little. Meanwhile, the narrow beam of the CMB in Lisle's model means fewer photons arriving per second, which means more CO molecules will decay to a lower energy state before a photon can re-excite them. This means the CO molecules will pile up in a low energy state. So collisions would have to be nearly the whole source of excitation and happen to land near the CMB temperature 2.725 K*(1+z) in the many different clouds at different redshifts. Meanwhile, these gases are thin: low density, so there are few collisions; and the reason these CO populations are used as a CMB thermometer is due to few collisions in these gases.
Moreover, this CO excitation means that there needs to be photons there in all directions. Even if an initial state was created at the CMB source to match the SZ spectrum, the photons would still arrive in a narrow beam. So light would have to be created in transit to keep these molecules excited.
Conclusion
We have seen that this model solves the distant starlight problem by means of an implied spacetime creation surface, not through a convention, but the convention allows us to speak about Creation in a way that matches the Bible's chronology. We have also seen a number of implications of this model, including that viewing the universe as created over billions of years or a few days is a matter of clock convention. As for predictions, one of the predictions of the model that would falsify the model—direct observation of voids—is not practically testable at this time or in the foreseeable future (would need warp drive). Likewise, the distinct galaxy redshift turns out to be unobservable both in principle and because of mature creation, so it is not really a prediction. The prediction about voids could be observed indirectly and potentially falsify or support the model. If created light in transit is posited to fill in all the voids or places where it would be needed based on what we observe, then the model becomes unfalsifiable. It could be there are other things I have not noticed here pro or con for this model. My background is not in observations, so I easily could be unaware of something. But so far as I can see, the model without created light in transit is not clearly falsified yet: the two CMB tests appear to falsify it, but I would want someone in the field to confirm them before saying so with confidence.
Figures generated by Claude. Claude also assisted with review, calculations, and edits.