A Huge Cosmology Problem Might Just Have Disappeared

The rate at which the universe is currently expanding is known as the Hubble Rate. In recent years, different measurements have given different results for the Hubble rate, a discrepancy between theory and observation that's been called the “Hubble tension”. Now, a team of astrophysicists claims the Hubble tension is gone and it's the fault of supernovae data. Let’s have a look.

🔗 Join this channel to get access to perks ➜

#science #sciencenews #cosmology

[Llortnerof]

I hope after refinement we end up with 3 distinct outcomes, making everything even worse.

[mcarston]

Thank you for this, I can definitely relate to the issue. In my household there is a tension between the amount of energy my kids state that they expend on chores, versus what I observe in my measurements.

Research into the issue is ongoing, but no resolution is in sight.

[drbuckley]

Thanks for taking the time to respond to so many commentators. So few of your colleagues offer the same consideration. You're the tops, Sabine.

[marktaylor]

“nobody wants to wait that long for a YouTube video.”

perfectly drill delivery of that line. So funny!

[tedbomba]

Hossi, [ if I may ] your sense of humor is just one reason why I follow your channel and it makes the dryer information much easier to follow. Thanks to you and your colleagues for such great videos.

[CaseyW]

Hey, Sabine, you're a WONDERFUL science communicator, thank you for all your hard work.

[tb]

I remember readding some time ago that the super nova work that won the Nobel had been shown to have been bad science from start to finish. Too few super novas. All in the same direction. And some other issues that aren't coming to mind. My English major mind has only a few slots of physics nerd data.

[JK_Vermont]

I’m confused by the diagram at 4:45 which shows JWST uncertainty overlapping with both CMB and SN data. Assuming the visual is correct, why would the JWST data favor the CMB value over the SN value?

[PhysicsNative]

Freedman et al. have been pushing for an Ho parity with LCDM for years, nothing new. They don’t pinpoint what might be a problem with the SNe/local distance ladder methods in their recent paper. Sarkar et al. were pushing for no accelerated expansion a few years ago, through a statistical re-analysis of SNe data, wiping out any tension. Clarifications.

[rigeus]

Dr Becky also did recently a slightly more detailed video on this ("Has JWST SOLVED the crisis in cosmology?!").

[Lucius_Chiaraviglio]

The Venn diagram of Hubble Constant measurement methods makes it look like the newest one overlaps almost equally with the CMB Hubble Constant and the supernova Hubble Constant, and has a wider margin of error than either of them.

[SickPrid]

4:58 got me distracted with those images, had to rewind 😂

[seditt]

Anyone ever tried a patchwork approach to check if we are just getting these errors due to the expansion being uneven and not constant? Use 1 measuring method but group various parts of the sky to see if we can get results that are outside of each others error bars or at least close to it? The universes structure seems to suggest such a thing at this point and since the big bang was likely a super luminal expansion of a point in what is likely a much larger universe it seems reasonable that Dark energy is not constant over all points in space.

[MCsCreations]

Fascinating. Looking forward to hear what they did differently from other studies about this same data.
Thanks, Sabine! 😊
Stay safe there with your family! 🖖😊

[mkrichey]

At 4:44 I got confused by the graphic as it looks like JWST overlaps both of the other 2 measurements, but the audio says it agrees with only CMB. Otherwise, as always, I love the presentation of the science :)

[bjornfeuerbacher]

Sabine misrepresents the study. Actually, the error does _not_ lie directly with the SN data, but with the _Cepheid_ data - which was used to _calibrate_ the SN data! Dr. Becky explained that in much more detail.

[tomduke]

one of the most common things i notice, is that scientists routinely severely overestimate the precision of their data/calculations/model.

[thomasherbig]

Any problems with supernova measurements are unlikely to negate the Nobel prize work of Riess et al. Their results are based entirely on supernovae, so most systematic errors are likely to be common. The issue with the "Hubble tension" is that you are comparing results based on completely different physics. Their respective systematic errors are not common. I don't think that the Nobel Committee has much to worry about.

[ainru]

In 2015 I was on a summer practice in SAO observatory where a world-class CMBR expert Professor Oleg Verkhodanov (now, sadly, deceased) taught us postgrads to analyze CMBR data. I don't remember the exact details of how the Hubble tension was brought up, but he convinced everyone in the group that there can just be no way how the CMBR data could be out of the error bar while there's a myriad of ways how the cosmic distance latter could be broken, even discounting possible supernovae-specific problems. We haven't considered any new physics then, but in the last 9 years (in which I have long left physics) I have never had any doubt that an error in the alternative figure must be found eventually

[HustlinHugh]

The first thing that came to mind when you mentioned that the Supernovae data is more than likely at odds, is that, if that is true, then distances might be all wrong also... Like you said "a lot of other studies would have to be redone too"
Love your videos Sabine :) thank you for keeping those of us without the time to dig in, a chance to keep up with science 😊