The Crisis in Cosmology Just Got So Much Worse

In the past decade, astrophysicists have found a lot of evidence that our large-scale theory for how the universe works has some large-scale problems as well. It has, however, remained controversial whether this is a problem with data collection or whether it is indeed a problem with our understanding of the universe. In a new paper, astrophysicists now demonstrate that something is wrong with the theory indeed. It could be the first good evidence that “Einstein was wrong.” Let’s take a look.

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#science #sciencenews #physics #space

[SabineHossenfelder]

You can now also create your own quizzes on my website, it's free!

[troywahl]

Before one throws out general relativity, one needs to remember cosmological models, such as Lambda CDM, are models based on assumptions of how the universe works. If the assumptions are wrong, then the model is wrong and observations won't match predictions. One of the assumptions in Lambda CDM is the the universe has constant and isotropic curvature. General relativity does not actually require that the universe curves in the same way in all directions (the isotropic part). Nor does it require that the curvature is constant (it could vary from place to place). It is true that both cosmology and astrophysics become much more difficult if the constant and isotropic curvature assumption is wrong, but our job as scientists is to describe/explain the world as it is and not in a way that makes it easy for ourselves.

[GaryDew-np]

Hi Sabine, I’m an Aussie truck driver in my 60’s and a science tragic/lover since I care to remember. I will not waste your valuable time with a long post, just in case you read them, as it would detract from the time you have to do your incredibly important work.
I just want to let you know you are wonderful. I rank you as being alongside my heroes like Feynman, Euler, Socrates and Emo Philips.
Please keep doing your thing. I appreciate you without limit. For me your sarcastic and compassionate humour is pitch perfect. You go girl!

[densonsmith]

The multiverse theory is important because some of the best episodes of star trek are based upon it.

[kostuek]

We are only doing this for a few hundred years, would be surprising if we already got everything right. In fact - we may be not even close yet.

[crawkn]

"Various tensions" is a very polite way of saying we know for a fact we have many things very wrong.

[brendanwood]

I love that this channel exists to question everything we think we know. This is the critical step in evolving our understanding.

[ronmasters]

Deeply appreciate your insight and reliable reporting in a field swamped with clickbait! What an age we live in, when so much good observational science has become available. 🙏🏻

[WonkyWiIl]

Thanks for another good discussion about our universe and our understanding of it.
We should never be disturbed by gaps between observations and theory. These gaps tell that there interesting stuff to discover

[EternalStarVoyager]

Cosmology is in its infancy. Why would we expect the first generally accepted model would be correct? We have many paradigm shifts left to go.

[jwv]

I think it's amazing that we can even do this type of testing in the first place. But, after all the testing and hypothesizing, it looks to me that we have barley scratched the surface of figuring out what is really going. So, we will need more people like Sabine for a long time.

[francoislacombe]

The universe has not been clumping enough, yet the early universe apparently has bigger galaxies and black holes than expected. Interesting mix of contradictory observations there. 🤔

[hdufort]

Can we have a video covering the modified gravity models or theories as of now? Too many readers seem to assume there is a single theory or model of modified gravity (MOND) but it's more complicated than that. Fudging the equations until they fit observations, then testing the fudged equations against results at different scales or measuring different phenomena... it's a good start. Then if we identify an equation that seems to be a good approximation of multiple phenomena we've measured, we have to go from "what" to "why".

[sinecure]

Another highly engaging review of the follies of Big Bang cosmology. Unfortunately, it remains taboo to question the basic premise, namely, that the Hubble constant measures the rate of expansion of the Universe, rather than some distance and/or density based interaction between light and matter which could be investigated without resorting to preposterous notions like creation ex nihilo or a primordial singularity.

[chrisolmsted]

In other branches of science every time they got stuck for a long time, it was evidence from a lower more foundational level that resolved the issue. Spacetime physicists can't do that. But, they can learn a different lesson. The earliest flaw in the model always was followed by other flaws required to make the theory work.
Today there are probably multiple flaws that support each other in the best models of physics. Correcting a singular flaw may not fit the data any better.
This seems like it makes the problem more difficult. But that's an illusion because physics itself is unchanged by theory.

[nickrich]

Theories about anything can be dissected and reasoned to be flawed. Your videos assist this layman tremendously Sabine ... thank you.

[AArata]

So, even before the JWST, every inch of the Standard Model had been patched over multiple times to make every part of it's theory to work.

The big bang, the gravitational lensing, black holes, Cosmic Microwave Background Radiation (CMBR), Neutron stars, Red shift, Dark matter/energy, how solar systems are created, how stars function, ....

Once JWST discovered those far way galaxies, my first thought was they will double the age of the universe to save the Standard Model. Lol, that was exactly the first thing they started saying :)

[creatorsremose]

Your glee when saying "physics just got a new problem" got me rolling... that was awesome!

[brothermine]

I recommend to Sabine that each new video she makes that involves dark matter or MOND include a summary (at the end of the video) that lists both the falsifications of dark matter and the falsifications of MOND. When both have been falsified, it's silly to think that an additional falsification of one suggests a champagne celebration of the correctness of the other might be anticipated.
A recent Caltech newsletter mentions a Caltech grad student studying observations of galactic clusters that, due to collisions, have had spatial separation of their normal matter and their dark matter. (Like the famous Bullet Cluster.) Since MOND chokes on those observations, the champagne should be reserved for some other celebration.

[dougjones]

Sabine, I think of Halton Arp every time I see something like this. I'm so glad Germany was open-minded enough to let him continue his research there.