31–40 of 67 posts
Um. What? Is this the new "the earth is flat"? Space is infinite. I believe it goes on forever in every direction. Whether you can see whatever is out there from here in no way proves that it isn't...
Noob physics question: I assume this talks about stars close enough that we can receive their light. Can we say anything about the number of stars & galaxies that are further away than that?
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
I can see having a dislike of my opinion and beliefs ( which is not a valid reason to downvote by the way according to what Hackers News itself says... ), but downvoting me when I am attempting to communicate useful information. Come on now.
Specifically, from the article: > New measurements of that weak background glow show that the unseen galaxies are less plentiful than some theoretical studies suggested, numbering only in the hundreds of billions rather than the previously reported two trillion galaxies. We used to think that we couldn't see 90% of the galaxies/stars, this study proposes that we can't say about ½ of the galaxies/stars.
Earlier quoted context omitted.
This depends on your definition of visible. If you think of visible as some form of light reaching a man-made object, then GPs statement is still true.
Well, stars whose light has never even reached us are likely out of our light hypercone, so they might not exist in the scientific sense (i.e. Their existence or non-existence is completely unprovable and has no consequences, even in principle).
Important to note, that this number refers to the “observable universe”. The number might be much higher, especially given inflation theory, but those galaxies currently lay outside our observable universe due to speed of light constraints. Another interesting possibility is a finite but unbounded universe which means we might see duplicate galaxies from light circumnavigating (think of an old video game where you le…
Would this mean the universe would be spherical?
Noob physics question: I assume this talks about stars close enough that we can receive their light. Can we say anything about the number of stars & galaxies that are further away than that?
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
Earlier quoted context omitted.
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
Why in the fuck is sharing some knowledge of what I know about science that leads to people believing there is nothing outside the observable universe downvoted? I can see having a dislike of my opinion and beliefs ( which is not a valid reason to downvote by the way according to what Hackers News itself says... ), but downvoting me when I am attempting to communicate useful information. Come on now.
Earlier quoted context omitted.
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
Why in the fuck is sharing some knowledge of what I know about science that leads to people believing there is nothing outside the observable universe downvoted? I can see having a dislike of my opinion and beliefs ( which is not a valid reason to downvote by the way according to what Hackers News itself says... ), but downvoting me when I am attempting to communicate useful information. Come on now.
Earlier quoted context omitted.
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
Why in the fuck is sharing some knowledge of what I know about science that leads to people believing there is nothing outside the observable universe downvoted? I can see having a dislike of my opinion and beliefs ( which is not a valid reason to downvote by the way according to what Hackers News itself says... ), but downvoting me when I am attempting to communicate useful information. Come on now.
The last consensus I remember is a Big Bang, rapid expansion, and then slower expansion. There are some other theories but not as popular. It’s a fun topic to dive into. The horizon problem, variable speeds of light, and of course string theory.
Earlier quoted context omitted.
My main response to this article is essentially the same question. I think the article is presuming some things to come to this conclusion. The main thing that is being presumed is the "big bang". If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter. It is still a valid theory but I myself don't understand the physics of what is…
Why in the fuck is sharing some knowledge of what I know about science that leads to people believing there is nothing outside the observable universe downvoted? I can see having a dislike of my opinion and beliefs ( which is not a valid reason to downvote by the way according to what Hackers News itself says... ), but downvoting me when I am attempting to communicate useful information. Come on now.
No mainstream scientific source says this. The observable universe is purely a limit on the distance we can see - a horizon - due to the speed of light and the age of the universe.
> The main evidence used as "proof" of the big bang is the observed data seeming to show that the everything in the universe is "dispersing" slowly. That is at least what I've heard claimed.
There is much, much more evidence than this. Wikipedia lists observational evidence in 7 categories: https://en.wikipedia.org/wiki/Big_Bang#Observational_evidenc...
> If you proscribe to believing in the big bang, then the entirety of everything we see is an expansion from a single dense explosion of matter.
This is misleading. The Big Bang is not an "explosion" of the kind we see on Earth, where some matter is pushed apart from a central point by an explosive force. If that were the case, then what we observe would be different.
Instead, what we observe has so far only been well explained by the idea that space itself is expanding. In this model, there is no center - there's no location you can point to as where the explosion happened, the expansion happened everywhere equally, it didn't radiate outward from a central point.
We have evidence of this omnidirectional expansion, in the form of the cosmic microwave background (CMB) radiation, which is radiation from the early universe that comes from all directions in the sky, because the Big Bang similarly occurred in all directions. Again, this is not what we would observe if it was similar to a traditional explosion.
> I believe that they are seeing something similar enough that it could be perhaps a "localized bang" or something like that.
If you're thinking of something more like a traditional explosion, no, that is ruled out by the observational evidence.