Re: accelerating universe and Leslie constraints

Damien Broderick (
Sat, 27 Mar 1999 13:36:40 +0000

At 10:16 AM 3/26/99 -0500, Mike Lorrey wrote (amid a blizzard of inane drivel and some interesting but not quite relevant reminders from Billy):

>> The farthest galaxies will
>> start to be carried away faster than light some 15 billion years hence.
>So the Guardian thinks matter can travel faster than light? Whoever wrote
>is mistaken.

Stay with me here, Michael. *Space* can obviously expand faster than light, and can carry along with it any matter and energy embedded locally in it (so to speak) How do you think the Big Bang could have happened so fast otherwise?

>> Indeed, I wonder if it has any salience to the traditional explanation for
>> Olber's paradox.

>If the universe were eternal, we would have infinitely bright starscapes. We
>do not, so it is not.

Grrr. Olber's paradox is exactly that we don't see the whole sky as being as bright as the sun (*not* infinitely bright, due to inverse square diminishment), since every bit of it would be filled in by stars between stars beyond stars out to infinity.

The point of this fresh new and challenging perspective is that if the cosmos is *accelerating*, the sky goes darker much faster than you'd expect if only red shift were at work in a gravitationally decelerating cosmos. What's more, the assumption is (as I made clear) that this effect is not expected to become notable for as long into the future as the (local?) universe has already existed since the Bang: some 15 billion years.

Find the paper itself at,gr-qc,hep-ex,hep-ph,hep-th/1/lawrence;krau ss/0/1/0/96,97,98,99/1/0

Damien Broderick