Quote:there is no end for the universe, right?

Actually, nobody knows for sure.Without a demonstrably true premise,your inference (conclusion) may be logically valid,but may not be claimed to be true. Nice try though.

It's considered good manners to do an introductionary post. 15 is fairly young here. I'm delighted to have you join,and would be interested in learning a bit about you.

Welcome from Sunny Adelaide South Australia,where it's currently 0810 mid winter and a crisp 47F.

(June 6, 2012 at 5:51 pm)Hovik Wrote:

Quote:there is no end for the universe, right?

Actually, we know not only how big across the universe is, but also how much mass is in it.

Quote:our planet is pretty "lucky" in his position with the sun, some centimeters away : to cold, some cm near: to hot...

This is also untrue. The habitable zone is estimated to be some 2.28 AU wide. Furthermore, the Earth's orbit is elliptical, so its distance from the sun varies between 152 million kilometers at its aphelion and 147 million kilometers at its perihelion. That's certainly not a difference of centimeters.

quote n1, I'm going to search about that when I can, but how do we know that? what comes after the universe? it has some kind of walls? what the name of the theory? or it is definitely like that? because I see all the theories, including the existence of a god as all possible ( I see the faith ones less rational....) just no one can prove it...

quote2 interesting and good to know but that's not the point, if the position of our orbit on the sun is not the the factor for life in earth, well a factor there is, magic, superpower or simply lucky are the lasts on my list...(but still in the list...) and the fact that the earth is here tell us that there is a probability....

thanks for the reply

(June 6, 2012 at 6:42 pm)padraic Wrote: Welcome from Sunny Adelaide South Australia,where it's currently 0810 mid winter and a crisp 47F.

Winter during the summer months, driving on the wrong side of the road, living on the underside of the planet....

Is there no end to Australian insanity?

(June 6, 2012 at 6:51 pm)rafa360 Wrote:

(June 6, 2012 at 5:51 pm)Hovik Wrote: Actually, we know not only how big across the universe is, but also how much mass is in it.


This is also untrue. The habitable zone is estimated to be some 2.28 AU wide. Furthermore, the Earth's orbit is elliptical, so its distance from the sun varies between 152 million kilometers at its aphelion and 147 million kilometers at its perihelion. That's certainly not a difference of centimeters.

quote n1, I'm going to search about that when I can, but how do we know that? what comes after the universe? it has some kind of walls? what the name of the theory? or it is definitely like that? because I see all the theories, including the existence of a god as all possible ( I see the faith ones less rational....) just no one can prove it...

quote2 interesting and good to know but that's not the point, if the position of our orbit on the sun is not the the factor for life in earth, well a factor there is, magic, superpower or simply lucky are the lasts on my list...(but still in the list...) and the fact that the earth is here tell us that there is a probability....

thanks for the reply

I'm not wholly equipped to answer your questions as well as I'd like, but I can tell you that there is an "edge" to the universe in some sense. The universe is simply a space that expanded during the big bang. Outside of that space there isn't really anything, so far as we know. There could be other universes alongside ours, but we really don't know right now.

The position of our planet around the sun is indeed the factor that determines its habitability, but the range of distance from the sun in which the Earth could remain habitable is quite large (as I've previously said).

You seem to have a natural curiosity for this kind of thing, so I encourage you to perhaps read some books on elementary physics or, if you've an hour or so to kill, watch this lecture by a physicist named Lawrence Krauss. It might not give you specific answers to your questions, but you would definitely learn a lot about the modern state of our understanding of the universe, how it came to be, how big it is, and how scientists are able to figure all of this stuff out.

http://youtu.be/7ImvlS8PLIo

(June 6, 2012 at 6:53 pm)Cthulhu Dreaming Wrote:

(June 6, 2012 at 6:42 pm)padraic Wrote: Welcome from Sunny Adelaide South Australia,where it's currently 0810 mid winter and a crisp 47F.

Winter during the summer months, driving on the wrong side of the road, living on the underside of the planet....

Is there no end to Australian insanity?

-------and you live where? (this is going to be rich)

(June 6, 2012 at 6:56 pm)Hovik Wrote: I'm not wholly equipped to answer your questions as well as I'd like, but I can tell you that there is an "edge" to the universe in some sense.

Note that there are unanswered questions in this regard that make any answer to that particular question provisional. If the universe is flat, finite and otherwise geometrically compatible with having "boundaries", then reason tells you it must be bounded.

However, those questions remain unanswered to this day, though we do provisionally know that the universe is "close" to being "flat" (i.e. it's geometry is Euclidean), though it is not known to be. It is also not known to be finite (though it is suspected to be), nor can it's shape be described (particularly in terms of 3 dimensional geometry).

What lies "beyond" the boundary? Nothing. No matter, no energy, no entropy, no nothing. It simply does not exist. Anyone who thinks it's difficult to wrap thier brain around is correct.

Then again, if the universe is not flat, then it can be finite in size and still have no boundaries.

Well, the way I see if, if the universe was infinite, mass would need to be created infinitely, although I am not a physicist.

(June 6, 2012 at 6:58 pm)padraic Wrote:

(June 6, 2012 at 6:53 pm)Cthulhu Dreaming Wrote: Winter during the summer months, driving on the wrong side of the road, living on the underside of the planet....

Is there no end to Australian insanity?

-------and you live where? (this is going to be rich)

On the opposite site of the planet from you.

Say, how do you blokes keep from falling off?

---

(June 6, 2012 at 7:10 pm)Annik Wrote: Well, the way I see if, if the universe was infinite, mass would need to be created infinitely, although I am not a physicist.

That would seem reasonable, I agree. The consensus is that it is probably finite, and I would agree (not that anyone needs my agreement LOL).

There's an article on Wikipedia that describes some of the theories on the shape of the universe.

(June 6, 2012 at 7:09 pm)Cthulhu Dreaming Wrote:

(June 6, 2012 at 6:56 pm)Hovik Wrote: I'm not wholly equipped to answer your questions as well as I'd like, but I can tell you that there is an "edge" to the universe in some sense.

Note that there are unanswered questions in this regard that make any answer to that particular question provisional. If the universe is flat, finite and otherwise geometrically compatible with having "boundaries", then reason tells you it must be bounded.

However, those questions remain unanswered to this day, though we do provisionally know that the universe is "close" to being "flat" (i.e. it's geometry is Euclidean), though it is not known to be. It is also not known to be finite (though it is suspected to be), nor can it's shape be described (particularly in terms of 3 dimensional geometry).

What lies "beyond" the boundary? Nothing. No matter, no energy, no entropy, no nothing. It simply does not exist. Anyone who thinks it's difficult to wrap thier brain around is correct.

Then again, if the universe is not flat, then it can be finite in size and still have no boundaries.

In that video I linked, Lawrence Krauss briefly discusses the shape of the universe and provides cursory evidence that it is, indeed, flat. However, I'm nowhere near qualified to say anything on the matter beyond taking his word for it.

Damn it Jim, I'm a linguist, not a physicist!

(June 6, 2012 at 6:42 pm)padraic Wrote:

Quote:there is no end for the universe, right?

Actually, nobody knows for sure.Without a demonstrably true premise,your inference (conclusion) may be logically valid,but may not be claimed to be true. Nice try though.

I'm going to do one soon...

anyway, I don't think anything is true (0.o daily mindf.... again) like any theory are only a theory and there is no evidence to make them true, some "know" their own truth and some just call it their faith or myth... every one of those theories can be true till someone shows a evidence for something else....
thanks