New Evidence against the Standard Model of Cosmology

I thought Sabine Hossenfelder’s newest video was interesting. Also interested in any of your thoughts on it…

From the video transcript:

These recent developments make me think that in the next ten years or so, we will see a major paradigm shift in cosmology, where the current standard model will be replaced with another one. Just what the new model will be, and if it will still have dark energy, I don’t know.

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I didn’t watch the video, but I did read the transcript she provided. I’m not into communication via youtube video. I do regularly follow Hossenfelder’s blog posts.

I did think it interesting. But then I’ve been doubting the standard cosmological model for some time. However, I do not have any alternative to suggest.

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Calling all @physicists!

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I’m not even sure what the “standard model” of cosmology even is. Inflation? I’ve only heard the term standard model in the context of particle physics, not cosmology.

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It would be really interesting to be alive during a big change in cosmology. But then again, maybe it’s been happening throughout my whole life already and I haven’t noticed. :laughing:

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The “standard model” (sometimes called the “concordance” model) of cosmology posits that:

  1. General relativity is the correct theory of gravity

  2. There exist stuff that interacts purely (or almost purely) gravitationally called dark matter

  3. Further, these dark matter is cold, i.e., it does not move quickly (to understand this nomenclature you can think of hot air, for example, possessing particles that move faster than cold air)

  4. There exist stuff that interacts gravitationally to accelerate the expansion of the universe, this stuff is called dark energy

  5. Further, the amount of this dark energy is the same everywhere, i.e., a constant; this leads to the dark energy in this model being called a cosmological constant (the value of this constant is often written as the Greek letter lambda, Λ)

  6. Finally, there is all the usual matter and fields that we are used to (e.g., atoms, photons, etc)

Combining the stuff I wrote in bold leads to the official name for the “standard model” of cosmology, which is the ΛCDM-model (Λ for the cosmological constant dark energy and CDM being the abbreviation of “cold dark matter”).

Inflation is not technically part of this model, but an extension of it.

Edit: Whoops, of course I forgot the assumption of the ΛCDM-model that is most germane in this thread:

  1. The universe is, at large scales, the same everywhere (spatially homogenous) and the same in every direction (spatially isotropic)
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This is very interesting and right up my alley. Here is the paper for those who are interested.

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Is dark matter absorbed into black holes? If so, could one detect an excess of mass gain over known sources?

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Yes, and we expect them to contribute to the growth of supermassive black holes at the center of galaxies. There is even the possibility that the first supermassive black holes were formed by dark matter that collapses upon itself.

This is challenging, as it is difficult to measure the amount of dark matter (and its evolution over cosmic timescales) around a blackhole.

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That’s an interesting question. I don’t see why that shouldn’t happen but dark matter is very different from ‘normal’ matter, so we don’t know how it would behave.

Thanks for raising this interesting topic, Valerie. I hope you and the little one are doing well!

The failings of the Newtonian model gradually became apparent in the late 19th and early 20th centuries. The stage was set for Einstein’s general relativity, with which everyone in this thread is at least familiar, I’m sure.

Before general relativity was even introduced, however, the age of the universe was known to be at least tens of thousands of years old. In 1676, hundreds of years before Einstein, Ole Christensen Romer estimated the speed of light with an error of only about 20%. In 1729, James Bradley estimated the speed of light with an error of only 1.5%.

Given the speed of light and the distance that light has traveled, you can calculate when the light was emitted from its source. Well before the advent of general relativity, astronomers knew that the Milky Way has a span of at least 10s of thousands of light-years. This observation set a lower bound on the age of the universe at 10s of thousands of years.

Today, we have much better instruments and a much more accurate understanding of light travel in the universe. The Hubble is viewing electromagnetic radiation today that began its journey billions of years ago.

In the late 19th century, geophysicist John Perry estimated the age of the earth at 2 to 3 billion years based on heat dissipation equations. This sets a much larger lower bound on the age of the earth.

The next big cosmological theory will be fascinating, whatever it may be. It would be quite mistaken, in my opinion, to think that somehow the new theory will shrink the age of the universe from billions of years to mere thousands. The evidence for billions of years is overwhelmingly strong.

Hope this was helpful. Keep loving your little one!

Chris

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Thanks, but my interest I science is wider than the age of things. :slightly_smiling_face: I am curious how much others agree with Sabine on this based on the papers she cited.

After learning some about cosmology, I definitely thought it seemed poised to have some kind of fundamental change in the model. Whatever the change is it does seem like it what would have an effect on time in some way, even if it isn’t significant.

Anyway, I’m sure it would be an understatement to say that the vast majority of physicists would never consider a model without long ages given evolutionary models in other areas of science. If there was no widely accepted cosmological model, maybe some biologists would consider an alternative to the current understanding, and if the evolutionary model is overturned, maybe some cosmologists would consider an alternative. But otherwise I don’t expect anything to change soon. Even those kinds of changes would probably take decades.

Well…unless we soon get telescopes that are strong enough to consistently see objects farther back than the supposed age of the universe. :laughing:

I’m more sure that your wishful speculation is completely wrong. Scientists become famous by overturning dogma with new evidence, not by supporting it.

Our understanding is based on the biological data, not on any cosmological data.

I’m not a cosmologist, but I’m very confident that their positions are not based on biology.

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Don’t hold your breath waiting for that.

It is far easier to find flaws in the current model, than to come up with a good replacement.

The evidence for long ages from geology is independent of the cosmological model.

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10 posts were split to a new topic: On Consensus Science

It seems to me that would just force cosmologists to think the universe is even older than they already do. I can’t wait, however, for the launch and operation of the James Webb Space Telescope and the European Extremely Large Telescopes. We live in exciting times.

Is there anything in Valerie’s opening post to suggest that she was drawing that inference from Sabine Hossenfelder? If so, I didn’t see it. And certainly I’ve seen nothing in Hossenfelder’s writing that suggests she believes in a universe only thousands of years old.