The James Webb Space Telescope is finding too many early galaxies
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The James Webb Space Telescope is finding too many early galaxies
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Re: The James Webb Space Telescope is finding too many early galaxies
#2Ethan Siegel isn't so certain: https://bigthink.com/starts-with-a-bang/most-distant-galaxie...
The tl;dr is that we're finding quite a few red galaxies and red can mean distant (and therefore old) but you need to follow-up and do further direct measurements of each galaxy to be really certain that it's old and not red looking for some other reason.
Some of these unexpectedly red galaxies have been followed up on, and some are indeed old, but it's not enough data points yet to be certain of anything.
The fun part of science is that either way it's pretty exciting!
Re: The James Webb Space Telescope is finding too many early galaxies
#3Ethan Siegel isn't so certain: https://bigthink.com/starts-with-a-bang/most-distant-galaxie... The tl;dr is that we're finding quite a few red galaxies and red can mean distant (and therefore old) but you need to follow-up and do further direct measurements of each galaxy to be really certain that it's old and not red looking for some other reason. Some of these unexpectedly red galaxies have been followed up on, and…
Yes! Beautiful pictures and scientists scratching their heads? This telescope is awesome!
Re: The James Webb Space Telescope is finding too many early galaxies
#4Can someone explain to me what would be behind the galaxies if we could see it, to the point of 0 seconds after the big bang? Black, white, is it even possible?
Re: The James Webb Space Telescope is finding too many early galaxies
#5Worth noting: For a very long time MOND has been predicting earlier galaxies than LCDM.
Re: The James Webb Space Telescope is finding too many early galaxies
#6Worth noting: For a very long time MOND has been predicting earlier galaxies than LCDM.
This is not unusual. There's many predictions made by MOND ahead of the fact that are borne out by reality. But don't worry - dark matter will be "retrofitted" so that it fits the facts and everybody will suffer collective memory loss again.
Edit: see for example table 1 on page 12 here: https://arxiv.org/pdf/2110.06936.pdf from a review of prior expectations by both MOND and dark matter vs how they turned out against reality for a large variety of astrophysical scenarios.
Re: The James Webb Space Telescope is finding too many early galaxies
#7[flagged]
Re: The James Webb Space Telescope is finding too many early galaxies
#8Can someone explain to me what would be behind the galaxies if we could see it, to the point of 0 seconds after the big bang? Black, white, is it even possible?
The very early universe can't be observed with visible light. It was filled with ionized hydrogen and thus opaque over long distances. The oldest light is from the era of "recombination", when things had cooled enough (c. 370k years after the big bang by consensus models) to permit light to travel. This is just the thermal glow of the universe, redshifted (way, way) down into the radio spectrum. And we can see it just fine; it's the cosmic background radiation and has been very well studied.
It's the region between recombination and the currently-visible-to-telescopes galaxies that Webb is particularly well-suited to study.
Re: The James Webb Space Telescope is finding too many early galaxies
#9Can someone explain to me what would be behind the galaxies if we could see it, to the point of 0 seconds after the big bang? Black, white, is it even possible?
Visible light was scattering off densely packed electrons up to about 300k years after the Big Bang - so I guess - white.
Re: The James Webb Space Telescope is finding too many early galaxies
#10Can someone explain to me what would be behind the galaxies if we could see it, to the point of 0 seconds after the big bang? Black, white, is it even possible?
We can see it and it’s called the Cosmic Microwave Background https://en.m.wikipedia.org/wiki/Cosmic_microwave_background. It’s not t=0.0000001 though as the time before the cosmic microwave background the universe was opaque to photons, you wouldn’t be able to see anything.