This is a companion discussion topic for the original entry at https://biologos.org/blogs/deborah-haarsma-the-presidents-notebook/light-matters-is-einstein-a-friend-of-young-earth-creationism
I’ll be available here to respond to any further questions or remarks you might have. Especially to those without any background in physics, please don’t hesitate to ask for clarification.
Thank you for this contribution, Casper. I’m looking forward to the next installments.
I’ve become familiar with the rudimentary Lorentz contraction relationships and resolution of things like the twin paradox such that I can at least parrot facts (correctly I hope!) even if my understanding of the same isn’t very well embedded yet. Toward that end, could you clarify or correct the following as necessary?
My impression is that the relativistic universe does not have one absolute time that we could all set our clocks by. So the imagined “star date” that provides a semblance of unified chronology across all the galactically dispersed Star Trek events is really an impossible feature even in a science fiction galaxy with faster-than-light travel, right? Or perhaps I should say, it could only be done if one first agreed upon a same reference for motion (like the center of the galaxy?) Would that make such a thing realistic?
Thank you for a thought provoking article. While I have nothing to contribute about the physics, from the standpoint of looking at the nature of God and His desire to bring us all to Him, the concept of His creation of a universe that is not what it appears to be seems bizarre, and is one of the main reasons I trust that the universe as observed is the universe as created.
Thank you for this. Most of the physics are way above my understanding, as I am just a big science enthusiast, so I appreciate you explaining this on a level I can understand.
Hi Casper -
You have started a good series, and I look forward to the rest!
I am wondering if there are observations that could provide empirical evidence against “anisotropic synchrony convention.” For example, gravitational waves travel at the speed of light through a vacuum. The LIGO detectors in Washington state and Louisiana observed the gravitational waves from the black hole collision at different times (7 ms gap) from an earthbound reference frame. Perhaps this contradicts the notion that the speed of light is infinite when directed toward the center of the earth?
And what about transmissions from satellites or planetary probes to earth? If they have a timestamp for transmission time (in outer space) and reception time (on earth), could that provide empirical evidence?
I’m also wondering if the notion of an infinite speed of light (toward the earth) would have other testable implications? For example, would the gravitational effects of acceleration be cut in half while moving away from the center of the earth, and infinite when moving toward the earth?
This non-physicist is looking forward to the next articles. Again, I say thank you, Casper!
Thanks for your question Mervin, it’s a good one. I’m going to give it a try.
Within Special Relativity, there is indeed no absolute chronology of events. However there are still invariant quantities like the “space-time interval” that are the same in all reference frames, so it’s relatively easy to “translate” chronologies between reference frames. This doesn’t work anymore when we introduce curvature.
For our own universe we enter into the framework of General Relativity. There, energy content starts introducing curvature of spacetime into the story. This makes it impossible to compare chronologies with each other in a straightforward way… Fortunately, the universe also looks rather smooth (“homogeneous”) at very large scales. This makes it possible to define a universal rest frame, defined by the Cosmic Microwave Background. This background radiation was emitted when the universe had expanded enough for it to become transparent to light. That rest frame is the best tool we have for speaking in somewhat absolute terms about the “age” of the universe.
So my answer is: yes, there is some way to speak of “universal time”, but that only makes sense at extremely large scales where the universe looks smooth. So this still leaves our Star Trek civilizations with their events occurring at small scales without any absolute way of comparing their chronologies with each other.
BTW, Other sources state that Answers Research Journal published his paper in September 2010, not in 2012. It’s obviously not a big problem, but it might be worth removing even small, insignificant errors from “Light Matters.”
I’m struggling to wrap my mind around these things too.
So your answer seems to indicate that scaling up (to the level of the entire universe) gets one closer to being able to identify some absolute time. But scaling smaller brings out the relativistic difficulties. I would have guessed exactly opposite of that --that over large scales (e.g. between our galaxy and some other quite distant galaxy) there would be the greater relativistic differences due to radically different motion reference frames; and that, say, within our galaxy there would be smaller discrepancies between proposed “universal” clocks. But if I understand your answer correctly, we have more difficulties than ever with our closest neighbors. Logically extending that further in, shouldn’t globally agreed-upon “time stamps” be near impossible in the even smaller context of our planet? I think I’m misunderstanding your answer. But thanks in advance for your patience …
Fixed. Thanks for pointing this out.
How to explain red shift when c is infinite? Another question future articles might explore…
While we’re plying Instructor Hesp with the impossible demands to turn us all into relativity experts, I might as well throw this on the heap too.
How does the spatial geometry work for the CMB. I can visualize a big bang exploding (spherically) into space. [okay --I know there was no ‘space’ before that, and that the big bang is space itself expanding…] But still, I can visualize this blob getting bigger, no problems. Here’s my mental exit point, though: So the original ‘background’ microwave radiation is tied to this event and is busy going at the speed of light … where? Wouldn’t it be outward? And if we are all going roughly outward from the big bang but not at the speed of light, obviously, then wouldn’t all this radiation be long gone away from us traveling to (or along with) the expanding outer edges of space? How come we’re seeing it from all directions as if the stuff is (…lingering!) (…bouncing or swirling around!)? The geometry just doesn’t fit, and I suspect my problem is with time. Time too is tied to space and somehow that makes this cosmic “kablooie” into a timeless kind of thing. Kudoes to you if you can expand my mental horizons.
I also find background radiation to be a tricky concept. The only thing I can think of is that the Big Bang happened when the universe was infinitesimally small, so that the radiation was everywhere that was at the time. During the expansion phase, I have heard that space expanded faster than the speed of light, so that the radiation that was heading towards where the earth is now spread out along with the expanding universe, and has continued heading in our direction for the billions of years since the Big Bang. The Big Bang theory was considered unlikely until the cosmic background radiation was discovered in the early 60s, when the temperature represented by the radiation exactly matched predictions of the Big Bang theory.
That does make some sense to me. So as the big bang continues to happen, with us somewhere in it, we are still in the midst of the CMB that is also in it. But shouldn’t it not be isotropic? You would think it would be glowing brighter in the spot of the sky where the big bang originated. I guess if we are still in it, we can’t point to somewhere and say it started there. Because that would presume we could be in ‘pre-existing’ space watching real space expand from a definable location. And we can’t have space outside of space!
Maybe I should just dig up an old Keith Green album and see if the cosmic kablooie left any snacks in the cupboard.
My limited understanding is that right here is as much the origin of the big bang as anywhere else. It is sort of like blowing up a balloon and asking which point on the surface was the origin of the expansion of the balloon. All the points are where it began. And if there is someone in one what was one of those primordial galaxies 12 billion light years away seen by the Humble telescope looking our way, they will also see primordial galaxies.
That is not what I intended to say, so I’m happy that you ask this question. Einstein’s theory of General Relativity is actually defined in such a way that for very close neighbors the spacetime looks flat to first order approximation. So your initial intuition of close neighbors having less disagreements was correct.
The largest problems come in when we try to compare small regions of space that are far apart from each other. That could be a small region within our Milky Way compared to a small region in another galaxy. So there is some truth to your intuition that the problems exist at larger distances.
Now, if we look at sufficiently large scales, we essentially “lose” the resolution to distinguish galaxies from each other. Then the curvature of spacetime looks approximately the same everywhere. That makes it easier to compare clocks, as long as we don’t try to compare “zoomed in” regions with each other.
It might sound weird, but changing the synchrony convention actually does not change the physical properties of the system. Therefore it also leaves unchanged phenomena such as redshift.
Thanks for reminding me of the balloon comparison. I had heard that before and it too is helpful in picturing all this.
The “Humble” telescope! With all due respect to Edwin, I like it. Very fitting for these cosmological considerations.
Hi Chris, I’m glad you enjoyed the article!
The interesting thing about synchrony conventions is that they cannot be empirically verified or falsified.
For example, if you measure the speed of a ray of light travelling from a satellite (clock 1) to Earth (clock 2), you first need to decide what is an appropriate way to synchronize those two clocks.
Something similar holds for other possible effects. There is one very technical article that predicts a global shift in the gravitational potential as a result of anisotropic synchrony. However, global shifts are immeasurable.
Because of this, we will first be looking at theoretical considerations in the coming two posts. Most importantly, Maxwell’s theory of Electromagnetism describes light as electromagnetic waves always travelling at constant speed in vacuum.
Don’t worry, there will be enough opportunity to talk about the empirical issues when we start zooming in on the “ASC model” which Lisle proposed. His assumption that God used the ASC to describe a one-week creation event taking place 6,000 years ago does produce a number of serious conflicts with observations. Stay tuned for more .
Ha! Pesky letters!