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Why is there a normal galaxy sitting at the edge of the Universe?

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Re: Why is there a normal galaxy sitting at the edge of the Universe?

#221

Post by kofejnik »

andy_ppp wrote: post #219
pathseeker wrote: post #211

Earlier quoted context omitted.

>This makes me sad. The entire point of Government is to be an enterprise spanning multiple generations. Not in a democracy. The point of a government in a democracy is to serve the current will of the people. The government itself might last many generations, but its goals and motivations change with every election cycle.

The point of democracy is to create AI powered propaganda to tell the people how to vote and make the rich even richer?

rich people are not a problem; if anything, they are more likely to finance this kind of project

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#222

Post by menybuvico »

outworlder wrote: post #81
depressedpanda wrote: post #64

Earlier quoted context omitted.

Strong claims, but can you back them up? How do you explain the apparent accelerating expansion of the universe, i.e. that the farther away something is, the more redshifted it gets? How do you explain the cosmic microwave background radiation enveloping us in all directions?

Of course they can't back this up. What the universe really is, is a simulation. We are trapped in it. "Lightspeed limit": this is because the simulation has a finite computing power. You can either move in time normally, or you can move in space. If you go to the max allowed speed, there's no processing left over to simulate time, therefore time stops for that entity. At intermediate speeds, slow down time according…

> See, anyone can come up with whacky stuff.

Any habitual stoner could tell you that. Once your blood THC levels are high enough, the secrets of the universe will unfold before you. And it's 100% certain, because I mean, you totally observed it, Man!

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#223

Post by ryani »

edjrage wrote: post #186
meowface wrote: post #176

Earlier quoted context omitted.

I'm absolutely terrible and uneducated when it comes to math, so I'm not sure exactly what you mean. But if you mean 1/x where x = infinity, then yes, the classical idea of a singularity (such as what's been theorized to exist within a black hole, curving to an infinitely small point) is basically like 1/infinity or dividing by zero. Rovelli hypothesizes this never actually happens and is not physically possible, and…

I'm not terribly educated either, but if you don't mind a minor possible correction, I suppose GP would have meant x = 0, which is the only point where the function would be typically undefined, and the closer x gets to 0, the more f(x) approaches infinity. Conversely, the more x approaches infinity, the more f(x) approaches 0. Also, because of the way these things are usually defined, it doesn't make sense to say x…

Although there is projective space where it does make sense to say x = infinity (and also that f(0) is defined). In projective space all of the conic sections (lines, hyperbolas, ellipses, parabolas) are connected loops.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#224

Post by mekkkkkk »

chowells wrote: post #91
mekkkkkk wrote: post #74

Earlier quoted context omitted.

Sorry for also asking a space 101 question, but since the fabric of space is expanding, does that mean that things are getting bigger as well? Naively, it would seem that way. In your balloon example, the dots would get bigger.

Not in practice. In practice, this provides a very tiny force pulling subatomic particles apart in an atom's nucleus, or pulling atoms away from each other in a molecule, or pulling a celestial body's molecules away from each other. It makes no difference at all, because that force is absolutely dwarfed by the strong nuclear force, electromagnetism, or gravity, respectively. Systems that are coupled together by those…

Great explanation! Thanks.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#225

Post by mekkkkkk »

johncolanduoni wrote: post #148
thaumasiotes wrote: post #135

Earlier quoted context omitted.

> Ultimately the molecular structure of your meter-stick is determined by various structure constants that aren’t changing Really? These structure constants never involve any units of distance? Isn't distance changing at all levels? If I have a meter stick, and then space expands by 10%, you're saying that my meter stick will end up being 0.91 new-meters long, yes? Wouldn't that require the structure constants to cha…

Structure constants are unitless by design. But obviously constants like the speed of light that do involve distance are unchanged too so that’s not a satisfying end to the story. Let’s come at this from the other direction: if everything including the space between atoms and galaxies expands by 10%, how do you tell the difference between an old-meter and new-meter? For this to be observable, something has to still s…

So just to clarify, the new-meter would be smaller if judging solely by the extent in space? But not compared to any other physical object since they are all kept together by forces that are constant regardless of space?

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#226

Post by vagrantJin »

kofejnik wrote: post #221
andy_ppp wrote: post #219

Earlier quoted context omitted.

The point of democracy is to create AI powered propaganda to tell the people how to vote and make the rich even richer?

rich people are not a problem; if anything, they are more likely to finance this kind of project

The esoteric among them.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#227

Post by meowface »

edjrage wrote: post #186
meowface wrote: post #176

Earlier quoted context omitted.

I'm absolutely terrible and uneducated when it comes to math, so I'm not sure exactly what you mean. But if you mean 1/x where x = infinity, then yes, the classical idea of a singularity (such as what's been theorized to exist within a black hole, curving to an infinitely small point) is basically like 1/infinity or dividing by zero. Rovelli hypothesizes this never actually happens and is not physically possible, and…

I'm not terribly educated either, but if you don't mind a minor possible correction, I suppose GP would have meant x = 0, which is the only point where the function would be typically undefined, and the closer x gets to 0, the more f(x) approaches infinity. Conversely, the more x approaches infinity, the more f(x) approaches 0. Also, because of the way these things are usually defined, it doesn't make sense to say x…

Thanks, I knew it had to be either zero or infinity. A singularity would indeed be like dividing by zero, which is why, if they exist, physicists would have a lot of trouble describing them mathematically.

I almost never really think or talk about physics in general. This thread just caught my eye.

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#228

Post by aasasd »

rosstex wrote: post #165
cgriswald wrote: post #105

Earlier quoted context omitted.

> On the traditional balloon model, the surface of the balloon represents space itself... For any still confused, there is also a 'raisin bread' model (which I prefer because it's 3D, unlike the surface of a balloon). The raisins are galaxies, and the bread is the space between them. As it bakes, the raisins get further apart, even though the raisins aren't moving through the dough. (Although galaxies also have movem…

Why not chocolate chip bread? I suppose raisins more closely represent galaxies.

I wanted to propose bread with sunflower seeds, because raisins are gross. But now I'm intrigued: wouldn't chocolate melt when the bread is baked? Is it effectively ‘chocolate blob’ bread?

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#229

Post by aasasd »

SloopJon wrote: post #12

I find it funny when scientific articles (esp. pop astronomy) describe something as weird, bizarre, or extremely unlikely. We're reversing the effects of gravitational lensing on a galaxy at a distance that's a significant fraction of the radius of the observable universe. Are astronomers that confident in their models that the inferred shape of this galaxy is bizarre? I'd love to have that level confidence in softwa…

> I'd love to have that level confidence in software

Well, I mean, if you spend years mathematically validating your programs...

Re: Why is there a normal galaxy sitting at the edge of the Universe?

#230

Post by aasasd »

andy_ppp wrote: post #218
biotinker wrote: post #158

Earlier quoted context omitted.

That would be tremendous. Earth is 12700 km in diameter, so such an image would be a bit more than 500px across. Here is a picture of the Earth that is about 500px in diameter: https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg

Do we only get a ring or do we get the whole thing? If we only get a ring why is that? Is the thing we are bending light around in the way?

Your question seems to be sorta answered in this thread: https://news.ycombinator.com/item?id=24425595
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