On Thu, May 26, 2011 at 3:09 PM, Jacob Albretsen <[email protected]> wrote:
> On Thursday 26 May 2011, Levi Pearson wrote:
>> On Thu, May 26, 2011 at 2:40 PM, Jason Van Patten <[email protected]>
> wrote:
>> > However it is theoretically possible to establish a context from the
>> > center of existence if you assume that such a point exists.
>>
>> You might think so, but by calculating the doppler shift in the light
>> coming from stars in any direction from the Earth, we know that they
>> are all red-shifted roughly the same amount.
>
> No, this is not true.
>
> The further away astronomers look into space (time), the more red-shifted
> objects appear to be. However, in the local area, you can have objects which
> appear blue-shifted (example: Andromeda Galaxy). This is because in the
> local area, Doppler shifts of light due to relative motion are dominate over
> the cosmological redshift due to the expansion of the universe. However once
> you get much further away, there is a larger cosmological redshift and Doppler
> shifts of light due to relative motion are negligible.
Thanks for the clarification. I think my overall point was still
correct, though: there's no "center point" to the universe that
everything moves away from. The entirety of space once *was* the
center point, and the universe itself is expanding. I realize the
universe is probably also not a spherical geometry, that was just an
illustration of the idea of an expanding geometry rather than a
conventional explosion. When one gets far enough into physics, any
discussion in lay English about it becomes hopelessly vague and
inaccurate, unfortunately. As the Doctor says, "It's not like that at
all, but if it helps...."
--Levi
/*
PLUG: http://plug.org, #utah on irc.freenode.net
Unsubscribe: http://plug.org/mailman/options/plug
Don't fear the penguin.
*/
