df = pd.DataFrame( universe )
Warning: Specify dtype option on import or set low_memory=False.
The James Webb Space Telescope is finding too many early galaxies
181–190 of 547 posts
Re: The James Webb Space Telescope is finding too many early galaxies
#182Obligatory xkcd: https://xkcd.com/2622/
That comic just made my mind bend.
Re: The James Webb Space Telescope is finding too many early galaxies
#183Earlier quoted context omitted.
The far limit of the visible universe is the cosmic microwave background, which is the heavily red-shifted view of when all of space was filled with an opaque plasma of similar temperature to the surface of a star[0]. The galaxies we're seeing are in front of that. [0] 3000 K, https://en.wikipedia.org/wiki/Recombination_(cosmology)
This is hard to internalize. Why do we continue seeing CMB? My understanding is that the early galaxies still produced light after recombination.
The process that caused the light we see as the CMB happened everywhere in the universe roughly all at once. At the time, from any given point, you'd just have seen blinding light but as things cooled, you'd see a sphere expanding around you where this light was dimming, as less and less, and finally none was being emitted around you, but due to the finite speed of light, light from outside that sphere would still continue arriving in your eyeballs. That's the situation we're in today; that sphere's just really big now.
During recombination epoch ~400,000 years after the Big Bang, this light would have been visible. Due to expansion, over time that light has stretched to longer and longer wavelengths, and we currently see it as microwaves.
Note: It's been ~30 years since I was actually studying physics & astronomy; others may be able to offer better explanations or correct me.
Re: The James Webb Space Telescope is finding too many early galaxies
#184Is it possible that the 'edge' of universe reflects light? Have scientists been able to conclusively rule that out somehow? Does the universe even have an edge? What is our current understanding of what the boundaries of the universe might be like?
Space and time are intertwined interstingly that way. If time somehow loops back or reverses (circular time) the it is not unreasonable to suggest space also loops back. Is it possible that at a certain boundary of space and point in time you loop back and start over at 0:0:0/0:0:0 space/time coordinates. At least in this current realm of reality, is it like one big space-time movie on a loop?
Re: The James Webb Space Telescope is finding too many early galaxies
#185Can 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't see down to 0 seconds, because very soon after the big bang, the universe was filled with dense, extremely hot, opaque plasma. The closest we can get is the "recombination epoch" [0], which is roughly 370 000 years after the big bang, when, because of universal expansion, the plasma got cold enough for neutral hydrogen to start forming, at which point the universe became transparent. As protons gain electron…
What I'm going to ask you is completely dumb, but keep in mind I don't know much of physics.
If my understanding is correct, when mass gets dense enough inside, a star you have a black hole, that would be like a hole in the fabric of space time. Ok, we have black holes in the contemporary universe. So how was the primordial universe a ball of dense, extremely hot, opaque plasma without becoming a huge black hole?
Re: The James Webb Space Telescope is finding too many early galaxies
#186Earlier quoted context omitted.
At that point why not call it “witchcraft;” a sciencey word for something is not an explanation.
Clearly you've never recalibrated the thermal interferometery scanner so you can reverse the polarity of the neutron flow in the isoneutronic pulse wave carrier.
A good retroencabulator helps a lot here.
Re: The James Webb Space Telescope is finding too many early galaxies
#187Earlier quoted context omitted.
The far limit of the visible universe is the cosmic microwave background, which is the heavily red-shifted view of when all of space was filled with an opaque plasma of similar temperature to the surface of a star[0]. The galaxies we're seeing are in front of that. [0] 3000 K, https://en.wikipedia.org/wiki/Recombination_(cosmology)
This is hard to internalize. Why do we continue seeing CMB? My understanding is that the early galaxies still produced light after recombination.
The CMB happened everywhere in the universe at the same time[0], so what we're seeing is the light which took 13-point-whatever billion years to get here[1] from some part of the universe in that direction at that younger age.
> My understanding is that the early galaxies still produced light after recombination.
I'm not sure what you're imagining about recombination, because I've not heard any suggestion of any galaxies existing before it, so they only produced light after recombination.
[0] for some definition of the concept, even though relativity is formulated with the assumption that there isn't any good concept of simultaneousness.
[1] from our point of view. From light's point of view, time isn't defined.
Re: The James Webb Space Telescope is finding too many early galaxies
#188I don't know if this instance qualifies as one, but I think its fair to say that cosmology is the one domain of "fundamental" physics where "discrepancies" or question marks keep piling up and not really resolving. It the pattern of previous science revolutions repeats, there could come a point where reinterpreting the large existing body of knowledge using a different paradigm would explain an number of "oddities" i…
Fields of science should always be willing to change based upon empirical evidence. I think there are several other scientific areas where we know less than we ought. 1. The sub-atomic level 2. The cellular level 3. Ocean biology 4. Geology, particularly effects of earthquakes and volcanic activity 5. Weather patterns over time
I feel for the Weather pattern folk. All of the one I have spoken to over the years are pretty cool. They are trying to model an insanely complex system - oh but thanks to global warming they are struggling to make models that work for longer than a few years because it all keeps changing!
Re: The James Webb Space Telescope is finding too many early galaxies
#189So there could've been civilizations that are literally BILLIONS of years ahead of us? Imagine what these people know about the universe!
This reminds me of the Star Wars lead-in: "A long long time ago in a galaxy far far away." It really could've happened you know!
Re: The James Webb Space Telescope is finding too many early galaxies
#190Earlier quoted context omitted.
So if we can see CMB in all directions, why do we really even say "the observable universe" as though there could be more matter and more galaxies beyond what we can see? If the maximum of what we can see is implied to be before all galaxies, then shouldn't it be implied that all galaxies that exist can be seen?
Here’s the important point I think you are missing. You are looking in TIME, not in space. When you look very far away, you are looking back to the beginning of time, back to a singularity where all matter and energy existed at a single point. In every “direction” you end up looking back to the same time and the same place, the beginning of everything. There’s nothing “beyond” that, it is the beginning. If you ask, w…
But if we're looking in the direction of a galaxy far far away (i.e. 14bn ly away) (which we don't know it's there, but let's assume it is, because likely some galaxies must be there), how come we see the CMB, which is 13.7bn years old, and not the galaxy itself, which is (by definition) less than 13.7bn years old?