bernardZ wrote:
> General relativity was published by Albert Einstein in 1915/16. Albert
> Einstein only adopted the big bang theory long after trying several
> other alternatives first.
This is incorrect on several levels.
Hubble first discovered the red****ft of galaxies in 1918, and the Hubble
law relating red****ft to distance in 1929. Those resulted in the
development of the Big Bang theory, so there was no such thing at the
time that Einstein was developing general relativity.
Indeed, at the time, the conventional wisdom was that the Universe was
finite in size and static and had been around forever. However, when
applying general relativity to cosmology, Einstein discovered that his
new theory predicted dynamic cosmologies: expanding or contracting
ones, but not static ones. Instead of going with what his theory
predicted, Einstein added a fudge factor, the cosmological constant, so
that his theory could result in static universes. Not paying attention
to what his theory was telling him and introducing the fudge factor was
what he called the greatest "blunder" of his life. (Though now we think
the cosmological constant is still relevant for other reasons, due to
dark energy.)
> Clearly Einstein never saw that concept of an expanding spacetime is
> necessary for GR to be correct.
No one said it did. But it is certainly true that general relativity
predicts dynamic cosmologies, and Einstein tried to shoe-horn it into a
static version, instead of being able to triumphantly declare Hubble
expansion as the first and foremost prediction of his new theory.
--
Erik Max Francis && max@[EMAIL PROTECTED]
&& http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM, Y!M erikmaxfrancis
God will forgive me. It's his job.
-- Heinrich Heine
|
