I thought it was something like ~90 billion ly across.

I still can't understand how can people think the universe can be infinite. What do they mean by that? Is it already infinite? Then how come it's expanding? That's illogical. Is it potentially infinite in that it will expand forever? Not so, we already know it's going to end one day(though I really hope scientists are wrong about that last part).

(February 23, 2016 at 6:47 am)Alex K Wrote: It does not appear very sensible to me to describe the observable universe as having 13.8 billion lightyears radius. The furthest things we now see are now what, 50 billion lightyears away? I don't understand where the 13.8 would even come into play as a distance, but I am happy to be told

That is why I put the google search in, and why I put the NASA link in. It still amounts to going with the experts. I'm seeing articles claiming varying distances, which is confusing to a layperson. I'd say get your info from NASA or Neil for that matter.

(February 23, 2016 at 8:35 am)Excited Penguin Wrote: I thought it was something like ~90 billion ly across.

I still can't understand how can people think the universe can be infinite. What do they mean by that? Is it already infinite? Then how come it's expanding? That's illogical. Is it potentially infinite in that it will expand forever? Not so, we already know it's going to end one day(though I really hope scientists are wrong about that last part).

I hate the infinite vs finite argument. Still doesn't require a magic man with a magic wand, and as far as our species and this planet and our sun, there is no dispute that in the scope of time and the universe we are FINITE and totally unimportant in that scale. 5 billion years from now there will be no record of what you or I, or famous or poor have done ever. 

We still right now have a damned good measurement of scale of what is in the universe, and sure, with changing data our views will change, as they should. But that does not mean we know nothing at all, nor does it mean anything goes, nor does it mean fictional sky wizard claims born in antiquity and believed out of ignorance fill in those gaps. Only time, and more observation and testing will improve our understanding of the universe.

(February 23, 2016 at 8:35 am)Excited Penguin Wrote: I thought it was something like ~90 billion ly across.

It's not important, since all of these calculations are based on what we know - as of yet. Give it another few decades and it might turn out to be even larger. Give it another few decades and what is now only considered a possibility, might turn into a theory. The multiverse.

It's huge, that's all that counts. And we're not even a dot making up it's entirety. Just the same way, as humanity is just a bad and shortlived joke compared to earth's history and preexisting life forms.

(February 23, 2016 at 9:40 am)abaris Wrote:

(February 23, 2016 at 8:35 am)Excited Penguin Wrote: I thought it was something like ~90 billion ly across.

It's not important, since all of these calculations are based on what we know - as of yet. Give it another few decades and it might turn out to be even larger. Give it another few decades and what is now only considered a possibility, might turn into a theory. The multiverse.

It's huge, that's all that counts. And we're not even a dot making up it's entirety. Just the same way, as humanity is just a bad and shortlived joke compared to earth's history and preexisting life forms.

To be clear though, the 90 billion lightyears is not the estimate for the size of the entire universe, but a measurement for the observable universe - that's not very likely to change dramatically. Most cosmologists would probably guess that the universe as a whole if finite at all, is much much much larger. If inflation happened as people suspect it did, numbers suggest it was an increase by a factor of like 10^30 in size, and in that scenario it seems very unlikely that it would just have accidentally stopped at or anywhere near the size of our observable universe as we see it now.

(February 23, 2016 at 9:07 am)Brian37 Wrote:

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(February 23, 2016 at 8:35 am)Excited Penguin Wrote: I thought it was something like ~90 billion ly across.

I still can't understand how can people think the universe can be infinite. What do they mean by that? Is it already infinite? Then how come it's expanding? That's illogical. Is it potentially infinite in that it will expand forever? Not so, we already know it's going to end one day(though I really hope scientists are wrong about that last part).

---

I hate the infinite vs finite argument. Still doesn't require a magic man with a magic wand, and as far as our species and this planet and our sun, there is no dispute that in the scope of time and the universe we are FINITE and totally unimportant in that scale. 5 billion years from now there will be no record of what you or I, or famous or poor have done ever. 

---

We still right now have a damned good measurement of scale of what is in the universe, and sure, with changing data our views will change, as they should. But that does not mean we know nothing at all, nor does it mean anything goes, nor does it mean fictional sky wizard claims born in antiquity and believed out of ignorance fill in those gaps. Only time, and more observation and testing will improve our understanding of the universe.

---

Don't be so quick to make that last statement. As I understand it, information is indestructible and who knows how good we'll get at retrieving it in the future. Unless you're arguing life itself won't exist 5 billion years from now, which I would be curious to know why. (That is, if I understood correctly what I read about the topic.)

(February 23, 2016 at 9:40 am)abaris Wrote:

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(February 23, 2016 at 8:35 am)Excited Penguin Wrote: I thought it was something like ~90 billion ly across.

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It's not important, since all of these calculations are based on what we know - as of yet. Give it another few decades and it might turn out to be even larger. Give it another few decades and what is now only considered a possibility, might turn into a theory. The multiverse.

It's huge, that's all that counts. And we're not even a dot making up it's entirety.

---

Just the same way, as humanity is just a bad and shortlived joke compared to earth's history and preexisting life forms.

Humanity is only a joke in that manner if you somehow value something else above it, which is irrational in itself.

(February 23, 2016 at 12:09 pm)Alex K Wrote:

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(February 23, 2016 at 9:40 am)abaris Wrote: It's not important, since all of these calculations are based on what we know - as of yet. Give it another few decades and it might turn out to be even larger. Give it another few decades and what is now only considered a possibility, might turn into a theory. The multiverse.

It's huge, that's all that counts. And we're not even a dot making up it's entirety. Just the same way, as humanity is just a bad and shortlived joke compared to earth's history and preexisting life forms.

---

To be clear though, the 90 billion lightyears is not the estimate for the size of the entire universe, but a measurement for the observable universe - that's not very likely to change dramatically. Most cosmologists would probably guess that the universe as a whole if finite at all, is much much much larger. If inflation happened as people suspect it did, numbers suggest it was an increase by a factor of like 10^30 in size, and in that scenario it seems very unlikely that it would just have accidentally stopped at or anywhere near the size of our observable universe as we see it now.

Again, how could it possibly be anything but finite? I am genuinely curious here, not saying it couldn't be, just that I don't understand how infinity fits in with anything real when talking about the size of the universe.

It being infinite is sure hard to comprehend, but I don't see any concrete reasons why it can't ?

(February 23, 2016 at 12:28 pm)Excited Penguin Wrote:

(February 23, 2016 at 9:07 am)Brian37 Wrote:

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I hate the infinite vs finite argument. Still doesn't require a magic man with a magic wand, and as far as our species and this planet and our sun, there is no dispute that in the scope of time and the universe we are FINITE and totally unimportant in that scale. 5 billion years from now there will be no record of what you or I, or famous or poor have done ever. 

---

We still right now have a damned good measurement of scale of what is in the universe, and sure, with changing data our views will change, as they should. But that does not mean we know nothing at all, nor does it mean anything goes, nor does it mean fictional sky wizard claims born in antiquity and believed out of ignorance fill in those gaps. Only time, and more observation and testing will improve our understanding of the universe.

---

Don't be so quick to make that last statement. As I understand it, information is indestructible and who knows how good we'll get at retrieving it in the future. Unless you're arguing life itself won't exist 5 billion years from now, which I would be curious to know why. (That is, if I understood correctly what I read about the topic.)

(February 23, 2016 at 9:40 am)abaris Wrote:

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---

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It's not important, since all of these calculations are based on what we know - as of yet. Give it another few decades and it might turn out to be even larger. Give it another few decades and what is now only considered a possibility, might turn into a theory. The multiverse.

It's huge, that's all that counts. And we're not even a dot making up it's entirety.

---

Just the same way, as humanity is just a bad and shortlived joke compared to earth's history and preexisting life forms.

Humanity is only a joke in that manner if you somehow value something else above it, which is irrational in itself.

(February 23, 2016 at 12:09 pm)Alex K Wrote:

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To be clear though, the 90 billion lightyears is not the estimate for the size of the entire universe, but a measurement for the observable universe - that's not very likely to change dramatically. Most cosmologists would probably guess that the universe as a whole if finite at all, is much much much larger. If inflation happened as people suspect it did, numbers suggest it was an increase by a factor of like 10^30 in size, and in that scenario it seems very unlikely that it would just have accidentally stopped at or anywhere near the size of our observable universe as we see it now.

Again, how could it possibly be anything but finite? I am genuinely curious here, not saying it couldn't be, just that I don't understand how infinity fits in with anything real when talking about the size of the universe.

If we go by Krauss's statement that "nothing is something", and "nothing is unstable", then the way I am picturing "all this" is now currently on, but will flicker out and the wave function will collapse back to nothing. Then that unstable nothing will at the quantum level lead to another big bang. 

I could be wrong of course, but the way I'm picturing this is a ongoing fluctuation where on is a finite state, and off is a finite state, but the cycle could be going off to on to off to on to off ect ect...... I don't think that suffers infinite regress because you aren't trying to  explain either finite state with something even bigger, you are just going from one to the other. Just like winter goes to spring to summer then to fall, back to winter. Off to On  back to Off.

Fuck I feel small now. Thanks.

(February 23, 2016 at 7:30 pm)KUSA Wrote: Fuck I feel small now. Thanks.

Small in what context? I hope you are just kidding. If humans didn't evolve with self esteem we would have evolved, it is the arrogance and narcissism our species needs to ditch. We most certainly are important to ourselves and to our fellow humans, but we are not important long term to the universe. Just like I was not important to anyone before I was born. The universe will go on fine after I am gone.