Infinity

[valleyhornman]

There's not much argument that the Big Bang was 13.7 B/years ago. However, some think that the universe is infinate. How can this be? I think I understand that expansion accounts for a huge universe, but infinate is impossible, isn't it?. Please help!

Edited September 28, 2012 by valleyhornman

[timo]

Imagine the set you obtain by multiplying each real number with a number t. Let's call this set s(t). For all t>0, s(t) is a set with an infinite number of elements that is infinite in size in the sense that any finite interval on the reals is fully contained in it (or just "infinite in size" if you don't understand the "in the sense ..." part). In fact, the set is equal to the real numbers. For t=0, however, s(t=0) contains only a single element: zero (because every real number multiplied by zero is zero).

 

That's pretty much how the whole big bang scenario works, except that many people add statements about "unification of forces", "quantum fluctuations", ... .

 

PS.: Note that "infinity" has only been used in form of the adjective "infinite" in above, not as a noun.

Edited September 28, 2012 by timo

[JohnStu]

There's not much argument that the Big Bang was 13.7 B/years ago. However, some think that the universe is infinate. How can this be? I think I understand that expansion accounts for a huge universe, but infinate is impossible, isn't it?. Please help!

 

the cup is a cup, but some call it a tool, others may call it a creation

 

so this argument about 13.7billion years ago or it was there forever is really a battle of preference than actual reasoning

 

My personal stance on this is the universe is infinite, even if Big Bang did happen. I could simply include the period before the Big Bang as part of the infinite age of the universe and viola

[between3and26characterslon]

There's not much argument that the Big Bang was 13.7 B/years ago. However, some think that the universe is infinate. How can this be? I think I understand that expansion accounts for a huge universe, but infinate is impossible, isn't it?. Please help!

 

Hence the term visable universe

 

the cup is a cup, but some call it a tool, others may call it a creation

 

so this argument about 13.7billion years ago or it was there forever is really a battle of preference than actual reasoning

 

Or you have a set of laws that describe how things behave and a set of theories which give rules to describe a mechanism that causes the behaviour. By knowing these laws and theories you can predict future events and past events. Looking at past events you reach a point, about 13.7bn years ago beyond which you can not know anything. So this is really a battle of reasoning and not preference.

 

 

My personal stance on this is the universe is infinite, even if Big Bang did happen. I could simply include the period before the Big Bang as part of the infinite age of the universe and viola

 

...and viola, you have just ascribed a property to something of which you could not possibly have any knowledge. Time before the big bang is meaningless.

[IM Egdall]

 

so this argument about 13.7billion years ago or it was there forever is really a battle of preference than actual reasoning

 

 

Good science is not based on preference but reasoning and independent confirmation of a theory through empirical evidence. The big bang theory is one such theory. It is the best scientific theory we have on the creation and evolution of the universe due to all the evidence which supports its predictions. See for example: http://en.wikipedia.org/wiki/Big_Bang#Observational_evidence.

 

You can also google "age of universe" to see the scientific reasoning, calculations, and evidence for the 13.7 billion-year age of the universe. For example, see: http://www.astro.ucla.edu/~wright/age.html

[michel123456]

There's not much argument that the Big Bang was 13.7 B/years ago. However, some think that the universe is infinate. How can this be? I think I understand that expansion accounts for a huge universe, but infinate is impossible, isn't it?. Please help!

 

No help. I have trouble understanding even simpler things.

For example

Take a line: it extends to the left till infinite, and to the right till infinite.

Now cut the line in 2 parts: you get 2 segments. One of these 2 segments extends to the right till infinite.

The segment is thus infinite.

But you have one end of the infinite in your hand (that's the point where you have cut the line).

 

So you have an infinite segment that has a beginning. Or an end.

I just try to explain something I cannot understand.

[DarkStar8]

I imagine infinity not so much a very large number but rather an accelerating number series. Can I do this? On this basis there can be many infinities depending on the rate of acceleration of the number series.