Unbelievable how much we can work out from just the odd photon hitting us from somewhere in the great unknown.
"The odd photon hitting us" is also a pretty good description of eyesight, radio, and fiber optics.
Webb and Hubble confirm Universe's expansion rate
31–40 of 380 posts
Re: Webb and Hubble confirm Universe's expansion rate
#32Earlier 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?
Philosophical indeed, as it's impossible to define the idea of a rate of time, when the idea of rate is defined in terms on time itself.
Re: Webb and Hubble confirm Universe's expansion rate
#33The scale of the universe sometimes feels terrifying to me
Re: Webb and Hubble confirm Universe's expansion rate
#34Earlier 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?
I’d assume that we have some notion of how the laws of physics have changed, if at all, since the Big Bang.
We measure time in vibrations of a cesium isotope IIRC
Re: Webb and Hubble confirm Universe's expansion rate
#35Re: Webb and Hubble confirm Universe's expansion rate
#36Earlier 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…
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.
Re: Webb and Hubble confirm Universe's expansion rate
#37What are the implications?
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.
Re: Webb and Hubble confirm Universe's expansion rate
#38Earlier 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?
Time in this context is just an arbitrary measurement. Like extrapolating the calendar back to the Big Bang which is when space/time began, another way to think about time.
Re: Webb and Hubble confirm Universe's expansion rate
#39The thing that strikes me, is the detailed image description. That looks like good fodder for an ML visitor.
Re: Webb and Hubble confirm Universe's expansion rate
#40[deleted]