The scale of the universe sometimes feels terrifying to me
It's not if you consider we can only move at less than the speed of light or that we go on forever.
Webb and Hubble confirm Universe's expansion rate
41–50 of 380 posts
Re: Webb and Hubble confirm Universe's expansion rate
#42Dr.Becky goes over this in a video [0] from a year ago about the divergent results obtained by the two main ways we measure the rate of expansion.
Cosmic Microwave Background Vs. Supernovae. As the accuracy of each method has improved, the end results have diverged.
[0] 'theJWST just made the "Crisis in Cosmology" WORSE' https://www.youtube.com/watch?v=hps-HfpL1vc&t=858s
Re: Webb and Hubble confirm Universe's expansion rate
#43those are some pretty old energy waves
Re: Webb and Hubble confirm Universe's expansion rate
#44Earlier quoted context omitted.
Basically it means that we can't regard the Hubble result as a mismeasurement and the age of the universe seems to be different depending on how you measure it. From the article: "The bottom line is that the so-called Hubble Tension between what happens in the nearby Universe compared to the early Universe’s expansion remains a nagging puzzle for cosmologists. There may be something woven into the fabric of space tha…
I just think it means the expansion rate is not a constant, but a variable.
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Re: Webb and Hubble confirm Universe's expansion rate
#45Earlier quoted context omitted.
Sounds like they don't want to spoil everyone's research grants!
Outside of the tinfoil, it just sounds like the universe is complex and not always predictable.
I meant it as a comment on the phrasing. Potentially jeopardizing a field's cash flow is a legitimate worry, and I see a few have felt that, as well.
Re: Webb and Hubble confirm Universe's expansion rate
#46I've asked this question before, but I don't think I received a good answer, so figured I'd try asking again.
How do we know that galaxies are accelerating away from us and not moving at constant speed? People often point to the observation that the further away a galaxy is, the faster it appears to be moving away from us, implying acceleration.
However, wouldn't we expect to see the same observation even without any acceleration? Imagine there are some objects in space all moving in random directions and speeds, relative to Earth. After long enough time, all objects will appear to be moving away from Earth, even if they were moving towards it initially. And after long enough time, the objects that move fastest should be farthest away, by the simple definition of speed!
In short, even if galaxies weren't accelerating, we would still see that the further away a galaxy is, the faster it recedes.
Re: Webb and Hubble confirm Universe's expansion rate
#47If we can travel faster than light does it blow up the theory that the universe expands? Because if we can travel faster than light the universe is theoretically be infinite if I can go to a point pas the furthest reaches of stars/matter.
Re: Webb and Hubble confirm Universe's expansion rate
#48Earlier quoted context omitted.
Outside of the tinfoil, it just sounds like the universe is complex and not always predictable.
I meant it as a comment on the phrasing. Potentially jeopardizing a field's cash flow is a legitimate worry, and I see a few have felt that, as well.
There's a whole lot of open problems in cosmology, nobody's going to be out of work if they solve this one.
Re: Webb and Hubble confirm Universe's expansion rate
#49Earlier quoted context omitted.
> we’ve been using the 13.8 billion cosmological age estimate ever since I started brushing up my layman's understanding of the subject. I remembered the age of the universe as as 13.7 billion years, but I wasn't sure why that was. Well, the initial WMAP results in 2003 supported an age of 13.7 billion years. Later results nudged this upwards to 13.8 billion years. Of course, all the results have error bars.
> Of course, all the results have error bars. Not to mention the underlying philosophical assumptions, such that the "rate of time" has been constant across all of... time. Aka: How do we know a "year" 13 Billion "years" ago bears any resemblance to one now? What would it mean for it not to?
How do we know ? Observations we can make plus models that relate those to the things we can't observe directly.
Re: Webb and Hubble confirm Universe's expansion rate
#50Earlier quoted context omitted.
Sounds like they don't want to spoil everyone's research grants!
Outside of the tinfoil, it just sounds like the universe is complex and not always predictable.
It's amazing that barely a 100 years ago The Great Debate in astronomy was weather the Milky Way was the extent of the universe or things like Andromeda were their own 'island universes'. In the 1920s, Edwin Hubble showed that Andromeda was far outside the Milky Way by measuring Cepheid variable stars. These are the same stars that we are measuring today in this debate.
https://en.wikipedia.org/wiki/Great_Debate_(astronomy)