Re: Evidence for "Big Bang Theory"

Jon Thaler (jjt@lns598.lns.cornell.edu)
27 Apr 1995 16:39:26 GMT

hgibbons@hoshi.Colorado.EDU (Hugh Gibbons) writes:

> JAMES BENTHALL (st26h@jane.uh.edu) wrote:
>> When we are
>> looking at quasars millions of light-years distant receding from us, they
>> are not receding "into" space, rather *the space between us is expanding*!
>> We are stationary and the quasar is stationary, but the space between us
>> is expanding!

> This sounds like a distinction without a difference to me. How do you
> demonstrate that the redshift is due to the "expansion of space"
> rather than motion?

I think there is an observable difference. (I expect to be corrected
by GR experts). The relation between red shift and surface brightness
is not the same in an expanding universe as it would be if the red
shift is solely a result of the Doppler effect. In fact, in principle
one can distinguish between open and closed universes with this
measurement. Look at Kolb and Turner, "The Early Universe," page 44.