James Webb Telescope Confirms That the Universe Is Expanding at Different Speeds

Previous discussion (363 comments) linking to a better article: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39673087">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39673087</a>

This is a poorly written article, it almost appears whole paragraphs are missing. For instance the phrase &quot;an impossibly high value when compared to Planck’s measurements&quot; is not explained at all. (Planck was a physicist, but I suspect they&#x27;re referring to <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Planck_(spacecraft)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Planck_(spacecraft)</a><p>I think what it&#x27;s actually saying is that we&#x27;ve confirmed that the Hubble tension is real. Whether or not that means different parts of the universe are accelerating at different speeds is still not clear. If the meaning of the results is deeper than that, it seems to have completely eluded the author who nonetheless wrote a breathless exaggeration of the findings.<p>EDIT: In 2024 actually I have to wonder if any humans were involved in the making of this article. It certainly doesn&#x27;t appear to have passed an editor&#x27;s eyes.

This result has 8.3-sigma confidence, so it&#x27;s as good as it can get statistically. Even greater confidence than that of the Hubble tension itself.<p>The Hubble Tension is real. The expansion of universe is accelerating.

Garbage article, clickbait tile; they&#x27;re talking about the Hubble tension, not any kind of anisotropy in the Hubble constant. The latter would be actual news.

Can someone more familiar with the science help me out?<p>- On the one hand, the universe can be expanding at different rates.<p>- On the other hand, is it possible our approach to measuring the expansion (e.g., using Cepheid variable stars) might be the problem?

Interesting, could a physical system exploit differences in the rate of expansion?<p>What happens to an object as it moves from a high rate-of-expansion region to a low rate-of-expansion region?

Doesn&#x27;t this article talk about the same problems and results? <a href="https:&#x2F;&#x2F;science.nasa.gov&#x2F;missions&#x2F;webb&#x2F;nasas-webb-hubble-telescopes-affirm-universes-expansion-rate-puzzle-persists&#x2F;" rel="nofollow">https:&#x2F;&#x2F;science.nasa.gov&#x2F;missions&#x2F;webb&#x2F;nasas-webb-hubble-tel...</a>

The &quot;cosmic ladder&quot; supposition&#x27;s underpinnings are a bit shaky anyway. Calculating distance and age by examining ever distant Cepheid variable stars is prone to cumulative error. But it&#x27;s the best estimate we&#x27;ve got.

If the universe expands at different speeds, is it even possible to determine expansion relative to earth since you don’t have something fixed (since everything is at different speeds) to measure earths local expansion against?

Confused, are they saying that different parts of the universe are expanding at different rates? Or are they saying two methods give different results for the same parts?

given everything we already know about the fabric of spacetime, this makes sense. Every time we expect there to be an even distribution, we find more structure. So if something like dark energy is the driver of the expansion, and there is an unequal distribution of that, then this would be an expected outcome. But of course, without this new data it would be difficult to believe!

But what is it expanding into? If the universe is expanding like a balloon then there&#x27;s some sort of &quot;edge&quot;. What is that edge expanding into? Imagine we had a craft that could take us to the edge and you could stand on it, the way you place your finger on the outside of a balloon. If you could stand on the outside&#x2F;edge of the expanding universe, what would you see, that we&#x27;re expanding into?<p>It can&#x27;t be nothing. Something can&#x27;t expand into nothing.

So it means it isn’t expanding like a sphere but like an irregular explosion?

I get that the universe can be expanding, and that there might be different methods to calculate&#x2F;measure this that have discrepancies. But that the rate of expansion is <i>accelerating</i>, how in the world is that possible?

I thought universe is infinitely large, how is it expanding

The [Study] has a better framing in its title &quot;JWST Observations Reject Unrecognized Crowding of Cepheid Photometry as an Explanation for the Hubble Tension at 8σ Confidence&quot;.<p>It rejects the hypothesis that there was a systematic observational problem in observing Cepheid variables (CVs), which are in turn used to estimate distances to Type Ia Supernova (SNs), towards a long-term goal the Study concludes with of &quot;Tying all of these together by observing large samples in common can lead to the calibration of ∼100 [SNs] and a &lt;1% local measurement of [The Hubble Constant, H0], a landmark in our quest to understand the expansion of the Universe.&quot;<p>Notably the paper doesn&#x27;t provide a new estimate of H0, but it does strengthen the case for CV&#x2F;SN being at odds with other methods of estimating H0, a problem called the Hubble Tension.<p>JWST was built primarily to extend the sensitivity range for infrared observations, so we can see fainter sources from further away, or near sources with greater resolution. This study is about the latter.. the study of CVs and SNs in nearby galaxies.<p>&quot;the significantly greater resolution of JWST over [Hubble Space Telescope] has greatly reduced—in practical terms, almost eliminated—the main source of noise in [Near-Infrared] photometry of [CVs] observed in the hosts of nearby [SNs]. The resolution of JWST provides the ability to cleanly separate these vital standard candles from surrounding photometric &quot;chaff.&quot;<p>CVs and SNs are &quot;standard candles&quot;, rungs on the Cosmic Distance Ladder[CDL], the framework we use to compare and contrast different astronomical distance measurements. The term &quot;standard candle&quot; is used for a physical process we think we understand well enough to use its appearance at astronomical distance to infer other properties of its observation, e.g. the candle&#x27;s color shift towards red the further away it appears to be. (&quot;appears&quot; since we can&#x27;t directly measure actual distances, but observe that galaxies get smaller&#x2F;fainter&#x2F;redder together)<p>Cepheids are a relatively common kind of star that pulsates regularly during its lifetime, while SuperNovas are much rarer one-time very bright events. SNs are really useful to see them far away bc how bright they are, but since there&#x27;s so few of them, we calibrate nearby SN distances based on the many CVs in the host galaxy of the SN.<p>In all, this study starts by looking at CVs in NGC 4258 at 23 Million lightyears away, and then looks for photometric crowding of CVs at successively further steps away in NGC 5643 (41 Mly), NGC 1559 (48 Mly), NGC (1448 56 Mly) and NGC 5468 (140 Mly), but don&#x27;t find evidence of crowding to account for apparent brightness&#x2F;closeness of the CVs, so rejects that idea with a high confidence. Those galaxies are actually as far away as they appear to be if CVs are good standard candles.<p>These are at the nearer end of the CDL.. 140 Mly vs the observable Universe is thought to be at least 13 billion light years radius. But if it in turn makes us more confident about SNs, those go out to a current max of 16Bly[FarthestSN].<p>[Study] <a href="https:&#x2F;&#x2F;iopscience.iop.org&#x2F;article&#x2F;10.3847&#x2F;2041-8213&#x2F;ad1ddd" rel="nofollow">https:&#x2F;&#x2F;iopscience.iop.org&#x2F;article&#x2F;10.3847&#x2F;2041-8213&#x2F;ad1ddd</a><p>[CDL] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cosmic_distance_ladder" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cosmic_distance_ladder</a><p>[HT] <a href="https:&#x2F;&#x2F;xkcd.com&#x2F;2516&#x2F;" rel="nofollow">https:&#x2F;&#x2F;xkcd.com&#x2F;2516&#x2F;</a><p>[FarthestSN] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;SN_UDS10Wil" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;SN_UDS10Wil</a>

Cosmology feels a lot like quackery these days.<p>Does it even bother to rely on physics? Physical experiments show explosions do not propel all matter at the same rate.<p>James Webb telescope recently found galaxies that were “too old”, would have formed right after the Big Bang. The prevailing wisdom was all matter spread out evenly due to the Big Bang, then coalesced into galaxies (I emailed various researchers to confirm I understood this was indeed the consensus).<p>But again, other physics shows that clusters of matter ejected from explosions are never uniformly distributed.<p>Just more evidence the well educated (I assume if it’s concensus driven even the best educated agree) are just typical people and their expertise should be challenged constantly rather than sit back and assume things are figured out.<p>As Asimov illustrated in the Foundation, if you aren’t measuring for yourself you’re serving someone else’s interpretation.<p>Hyper-normalized social society just leads to normalization of outputs, which helps preserve and propagate poor science.

Just as the Three Body Problem releases on Netflix and science starts to break down? ;)

This does not seem strange to me, since time does not flow the same everywhere - and phenomena occur at different subjective speeds.