When the James Webb Space Telescope started collecting data, it gave us an unprecedented view of the distant cosmos. Faint, redshifted galaxies seen by Hubble as mere smudges of light were revealed as objects of structure and form. And astronomers were faced with a bit of a problem. Those earliest galaxies seemed too developed and too large to have formed within the accepted timeline of the universe. This triggered a flurry of articles claiming boldly that JWST had disproven the big bang. Now a new article in the Monthly Notices of the Royal Astronomical Society argues that the problem isn’t that galaxies are too developed, but rather that the universe is twice as old as we’ve thought. A whopping 26.7 billion years old to be exact. It’s a bold claim, but does the data really support it?
The model proposed in the paper begins with something known as tired light. In the tired light model, light spontaneously loses energy over time. So as photons travel billions of light years through the cosmos, they become redshifted. Thus, the light of distant galaxies is redshifted not because of cosmic expansion, but because of the inherent reddening of light over time. The idea of tired light has been around since Edwin Hubble first observed cosmic expansion as a way to maintain the idea of a steady-state universe. It lost popularity as the evidence for cosmic expansion became clear, and regained some popularity as the Webb observations started rolling in.
We’ve long known that tired light doesn’t work on its own, so this paper adds a new twist dealing with universal physical constants. Quantities such as the speed of light, the charge of an electron, or the gravitational constant seem to be built into the structure of the universe. They have the values they do because of the way the universe formed, and it’s generally assumed they don’t change over time. We have geological and astronomical observations that show physical constants haven’t changed for at least several few billion years.
But this new paper argues that if you combine tired light and changing physical constants, you can get a universe that appears younger than it actually is. Basically, tired light gives you the cosmological redshift you observe, and gradually shifting physical constants means those mature distant galaxies aren’t just 100 million years old, they are billions of years old. By tweaking tired light and variable physical constants just so to match the data, you get a universe that is 26.7 billion years old.
Does the model work? Yes, but there are two problems with it. The first is that tweak theories are weak theories. While this model can be made to fit observational data, there’s no physical motivation for doing it. There are lots of models that can be tweaked to fit data, which is not the same as having a robust physical model. The author of the work argues that there could be some underlying mechanism that causes tired light and the physical constants to shift in just the right way, but there is still a lot of fudging in the model.
The second problem is that JWST’s observations don’t rule out the standard 13.7 billion-year-old universe. The galaxies are more complex than some computer simulations have predicted, but that’s not surprising given the limits of large structure models. There are plenty of ways early galaxies could have evolved quickly that don’t require rewriting cosmology.
But even without a strong physical motivation to create this model, the work is still useful. It’s the kind of paper that thinks outside the box, which is a great way to make sure we aren’t locked into old models just because they’ve worked so far. It isn’t likely that this new model overturns standard cosmology, but as long as ideas are testable and disprovable, as this model is, there is no harm in adding it to the pile of ideas.
Reference: Gupta, R. “JWST early Universe observations and ?CDM cosmology.” Monthly Notices of the Royal Astronomical Society (2023): stad2032.
After traveling for billions of years, it wouldn’t surprise me that light, after arcing around who knows how many large galaxies, gets a bit redder. But why would constants change? Can a constant somehow redshift,too?
Recently it has been discovered that sound waves share more similarities with light than first thought. Think of the sound of a jet at 40,000ft and one up close – is that happening to light? If it is then it suggest light is a wavicle moving in a medium, that’s a big upset to established thought and also throws a lot of distance measurements out, not to mention the concept of the expanding universe.
Light doesn’t travel over time. Time doesn’t exist when you travel at the speed of light, according to special relativity. Putting it like that sounds like denying the most solidly proven part of modern physics.
The abstract says that they combined tired light with conventional metric expansion. So it’s more of an open-ended suggestion about fitting observations to new forces causing additional redshift.
If the Big Bang was an energy jet from a humongous black hole with the mass of a universe, that could explain the young galaxies spotted by JWST being so well developed.
Our present estimates of the moment of the Big Bang would still be valid but categorised as a generalised moment of cooling, diffusion, and coalescing nucleosynthesis via that energy jet.
As a generalised moment it means that the Big Bang jet would be extended over a very long distance, hence a duration of time that can extrapolated. In contrast, present black hole theory states that the Big Bang happened at a prescise moment in time from an initial singularity. If the duration of the development of the young galaxies works out to be longer than the age of this Universe, it could mean that.
Dark energy would be the result of having other universe sized black holes at a huge distance, gravitationally attracting the nucleosynthetic products of the Big Bang energy jet, thus the accelerating of the jet’s initial expansion by its own impetus as it shot out of the black hole over time.
Gosh, made a typo there, meant in the 3rd paragraph “present big Bang theory”
One of the main arguments against “tired light” hypotheses is that they would cause frequency diffusion, also called Compton scattering. This would cause blurring as the light frequencies diffuse with distance travelled, and is not observed. In fact, we wouldn’t get the fantastic images from JWST if Compton scattering had set in.
I do not see any mention of how R. Gupta deals with Compton scattering in the new paper. Surely this is a major flaw?
Since I can’t get access I have to agree with Steen Kastoft Hansen. I’m not sure that the paper adress the main problem with tired light that its “this could have been an explanation for redshift but isn’t” proposer Zwicky noted. Astronomers have too crisp images of distant objects for tired light (say, from dust obscuration) would work. “Zwicky himself acknowledged that any sort of scattering of light would blur the images of distant objects more than what is seen.” [“Tired light”, Wikipedia.]
That said, astrophysicist Becky Smethurst promised to soon put up a video of this paper in yesterday’s weekly update of astronomy she puts up on her Youtube channel.
@SteveZodiac: Photons are ripples (wavepackets of wavefunctions) in modern quantum field theory. Contrary to your own expectation that is in fact how redshift indicates expansion and apparent time dilation, since wavepackets traveling through expanding space will lose energy and redshift as well as be stretched out and appear emitted by a slower process. A recent paper found that the apparent time dilation of ~ 5 times fits the emission redshifts at z ~ 5.
@Potatoswatter: That is correct in a very simple older quantum mechanical model of photons as particles, but it doesn’t explain their redshifts and other field interactions seen in quantum field physics. There a photon can at times fluctuate into the other fields it interacts with, so for instance within quantum uncertainty rules a brief moment appear as an electron and an positron pair. (See Feynman diagrams for what is happening more often and what is “forbiddingly” rare.)
So well before a far field photon gets caught in a nearfield “antenna” interaction it experiences time in the quantum physics that within a decade or so replaced quantum mechanics (which is still used to elucidate the basics). Notably quantum particle field physics is precisely what you get – and have to resort to – when you apply special relativity to quantum mechanics, you introduce the field and from low energy perturbation techniques you get localized particles.
@Andrew Planet: It should be obvious to all, not only astronomers, that since the discovery of the cosmic background radiation in sufficient detail the idea of a “big bang” space expansion cannot be an explosion. The observed radiation is too smooth for that. It has fluctuations of order 10^-5 instead of the order 1 that a chaotic “explosion” process would give.
[If you want to dig into the physics of that, see the other big theory (alongside dark energy-dark matter LCDM theory) of modern big bang cosmology, inflation theory. It describes how the fluctuations appear and what distribution they have. And also remaining observations of uniformity – the homogeneous and isotropic universe with the roughly the same temperature in the opposite ends of the observable universe of volumes that *could never have been in contact by light and equilibrated* unless inflation happened. Inflation is still part of the larger “big bang expansion” process, just a very different era than the later hot big bang era which it ushered in. It was the inflation potential energy that goes into heating the universe so immensely that radiation and particles result.]
Oops. I should perhaps note that I came to the same conclusion as Steen independently. Which should point to that this, at least for outsiders with no paper access, can be a serious criticism.
Thanks @Torbjorn , will dig into that, did not go in for the Big Bang as an explosion either.
While emptying my mailbox I found another article where professional criticism has come in, and they don’t buy it [“Why It’s Extremely Unlikely The Universe Is 26.7 Billion Years Old”, IFLScience].
It is possible the tired light problem has not at all been addressed.
““The other issue is that they’ve fitted their model to the supernova data alone,” Davis continued. “It’s just not good enough to fit it to one set of data and ignore all the rest.” She compared this to previous attempts to use supernova data to discredit dark energy, without testing the consequences. “They don’t seem to have done even simple things like see whether their new theory of gravity breaks what we know about the orbits of planets in the solar system,” she added.”
Another large issue is that the work doesn’t seem to move all the age estimates.
““There are many, many measurements that suggest the age of the universe is about 14 billion years,” Professor Tamara Davis of the University of Queensland told IFLScience. “Not just the cosmic microwave background, not just the expansion rate measured using supernovas, there’s also the large-scale structure of the universe and the measured age of the oldest stars.” At one point these appeared to be in conflict, Davis explained, with some pointing to a universe 9-10 billion years old, while others suggested 14 billion years. Now, with some reconsideration, all approximately agree.”