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Re: Question about inflation theory

Subject: Re: Question about inflation theory
From: "George Dishman"
Date: Sun, 19 Mar 2006 21:10:36 -0000
Newsgroups: sci.astro
"jacob navia" <jacob@xxxxxxxxxxxxxxxx> wrote in message 
news:441dbd42$0$21282$8fcfb975@xxxxxxxxxxxxxxxxxx
> George Dishman a écrit :
>>
>> Releativity says an object cannot travel through
>> space faster than the speed of light in vacuo,
>> but that doesn't stop the sapce between objects
>> expanding at a rate such that the distance between
>> them increases faster than that speed.
>>
>>
> SPACE itself expands ?????

That is the common way of expressing it.

> Sorry but INTO WHAT would space "expand" ????

It is not embedded in some more fundamental
manifold, space isn't "in" anything.

> I would bet that it would expand into... more space isn't it?
> This is just nonsense.

It is indeed.

> But imagine for a moment that space is "expanding" faster than light, as 
> proposed by this wonderful "inflation" theory.
> Since no object can go faster than light, NOTHING MOVES and all objects in 
> the universe have negative speed:

Don't confuse SR and GR, the limit is local.
Consider a galaxy we can see perhaps 10 billion
light years away. Space between us and it is
expanding so the distance is increasing at a
significant proportion of the speed of light.
However, light within that galaxy is moving
past its stars at the speed of light relative
to those stars in all directions.


>
>     point a                                point b
>     object x   -->
>
> Object "X" starts moving at some speed smaller than "c" to point b, say, 
> at 50 Km/sec. In one second object x has traveled 50 Km, but the distance 
> between a and b has increased by more than 300 000 Km since space is 
> "expanding".
>
>
> This reasoning is valid FOR ANY POINT A AND B.

The reasoning is valid only for objects sufficiently
far apart, the speed is proportional to the distance.

> Then, object X will NEVER reach point b, ...

Correct, it is called a "horizon".

> ... nothing in the universe can move at all,

No, object x is still moving relative to a.

> the temperature of the universe is below absolute zero.
>
> Why?
>
> At absolute zero objects do not move at all. But since space is expanding, 
> the speed of every object in this universe is negative (the object is 
> flying AWAY from all other objects in the universe)
>
> All this is quite comic.

Indeed, your ideas are bizarre.

> Space is "expanding". Yeah.
>
> And I am getting younger every day.

Perhaps that's true, your infantile response
appears to confirm it.

George



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