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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

#41

Post by pc86 »

boppo1 wrote: post #36
SkyMarshal wrote: post #30

Earlier quoted context omitted.

> because the light from it won't reach us. This is one of the most interesting aspects to the universe. It's not, "because the light from it hasn't reached us yet but is on the way and will get here eventually." Rather it's that the rate of expansion of the universe is accelerating, so that we're moving away from parts of it faster than its light can cover the distance to us. It will never reach us. That's mindboggl…

What do I have to study to understand all this in mathematical terms? Is an undergrad text good enough?

Depends what you mean by "in mathematical terms." There are YouTube videos that cover the concept with real numbers.

Re: The James Webb Space Telescope is finding too many early galaxies

#43

Post by 0xbadcafebee »

twawaaay wrote: post #23
cwkoss wrote: post #14

Is 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?

The edge of visible universe is Big Bang. Or more concretely, the time couple hundred thousand years after Big Bang when the universe became translucent to light. Things cannot "reflect off of the edge of visible universe" because that would require that the light travel back in time which is nonsense. As of this moment we cannot exclude possibility of discontinuities in the universe which would be cause for example…

if time is a dimension, and we can only see the past and the present, could it not be that, if one's gaze were shifted, one could see the future? effectively looking at the "other side" of the dimension of time? looking straight at one "side" of time, you can only see the past and present. but if you had a galactic set of mirrors set up around "time", couldn't you "see" the other side where the future lies? effectively you'd be looking at a reflection of the future.

or, time being malleable (relative to things like mass and movement), wouldn't it be possible to refract or bend time the way light is, such that you could see things (that already happened in the past) sooner, even if they are really far away? maybe like how bending a race track can allow a vehicle to exert more force or go faster, but with light?

Re: The James Webb Space Telescope is finding too many early galaxies

#44

Post by drexlspivey »

soiler wrote: post #13
cevn wrote: post #4

Can 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 actually already see that time period, in its present form. It's called the Cosmic Microwave Background. It is the (now extremely cold) energy which permeated the entire universe in that very early time period. The entire universe was opaque and extremely hot... then as it expanded, it began to cool enough for particles and then atoms to form. Only then were stars possible, and later galaxies. How/why can we s…

Kinda relevant xkcd that was published today https://xkcd.com/2723/

Re: The James Webb Space Telescope is finding too many early galaxies

#45

Post by Twisol »

SkyMarshal wrote: post #30
pwatsonwailes wrote: post #18

Earlier quoted context omitted.

Without getting into lots of detail, this is basically correct. It's why we talk about the observable universe. There's lots of stuff we can't see because the light from it won't reach us.

> because the light from it won't reach us. This is one of the most interesting aspects to the universe. It's not, "because the light from it hasn't reached us yet but is on the way and will get here eventually." Rather it's that the rate of expansion of the universe is accelerating, so that we're moving away from parts of it faster than its light can cover the distance to us. It will never reach us. That's mindboggl…

> Rather it's that the rate of expansion of the universe is accelerating, so that we're moving away from parts of it faster than its light can cover the distance to us.

From my understanding, it's not that we're moving away from parts of the universe, but that the distance between us is growing so fast that light sent from one part will find that after traveling toward us for some amount of time, the remaining distance to travel is actually more than than when it started.

One way for the distance between two objects to increase is indeed for those objects to literally be moving in opposite directions through space. But the expansion of the universe itself causes the distance between two otherwise-stationary points to nonetheless increase. Put differently, it's the cosmic yardstick that's shrinking, not the entities that must necessarily be moving.

(This is also why two points can be "moving apart" faster than light speed, the cosmic speed limit.)

Re: The James Webb Space Telescope is finding too many early galaxies

#46

Post by jayzalowitz »

I may be stupid, but considering that the models of galaxy stability are based on a universe where we are made from star stuff and not energy stuff, is it not possible that they formed way quicker with less complication because it was basically only hydrogen and empty space?

Re: The James Webb Space Telescope is finding too many early galaxies

#47

Post by dave333 »

Tuna-Fish wrote: post #25
dave333 wrote: post #7

[flagged]

This doesn't work. The universe was opaque for the first few hundred thousand years, even if there is a cycle, we cannot possibly see it.

We are not looking back into the past cycle, but we see mature galaxies that date from the previous cycle.

Re: The James Webb Space Telescope is finding too many early galaxies

#48

Post by Beltalowda »

dave333 wrote: post #7

[flagged]

That entire site reads like "what if Elizabeth Holmes set up a power generation company?"

Reading up on the company on Wikipedia, it seems to be pretty much exactly that.

https://en.wikipedia.org/wiki/Brilliant_Light_Power

Re: The James Webb Space Telescope is finding too many early galaxies

#49

Post by micromacrofoot »

oblio wrote: post #26
pwatsonwailes wrote: post #18

Earlier quoted context omitted.

Without getting into lots of detail, this is basically correct. It's why we talk about the observable universe. There's lots of stuff we can't see because the light from it won't reach us.

I was thinking about something weird right now. We don't (can't?) even know if there weren't multiple Big Bangs, right? I.e we're just in a specific "universe" we can observe, but maybe several of these are just side by side, not necessarily parallel as in parallel realities.

assuming light from a big bang travels in all directions, then another big bang's light could be heading in our direction and potentially observable — the reason we can't observe the entirety of our universe is that spacetime is expanding in a way where light at the beginning isn't traveling fast enough to outpace expansion

Re: The James Webb Space Telescope is finding too many early galaxies

#50

Post by micromacrofoot »

make3 wrote: post #34
pwatsonwailes wrote: post #18

Earlier quoted context omitted.

Without getting into lots of detail, this is basically correct. It's why we talk about the observable universe. There's lots of stuff we can't see because the light from it won't reach us.

how can that work if nothing is faster than light in the referential of the objects being compared? is it that space expands faster than light moves?

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