"I believe in Spinoza's
God who reveals himself in the orderly harmony of what exists, not
in a God who concerns himself with the fates and actions of human
beings."
The general theory of relativity,
unlike quantum theory, was not rapidly developed after Einstein
showed the way. Gravity was now understood in a new way, but
the equations were difficult to work with. And the characteristics
of the theory showed up clearly only under extreme conditions,
enormous densities or vast spaces or measurements of the highest
precision. Eventually technology caught up  the modern Global
Positioning System cannot pin down a location without using
the equations of general relativity to adjust for effects
of gravity and speed. And astronomers have discovered black
holes, objects with so much mass that they cannot be understood
at all without Einstein's equations. But during Einstein's
lifetime only one such object was known: the universe taken
as a whole.
Click here to see a black hole

galaxy

Einstein with de Sitter.

In 1917 Einstein and the Dutch astronomer Willem de Sitter
showed that Einstein's equations could be used to describe a
highly simplified universe. Other scientists developed this
model, adapting it to the real universe full of stars. They
found a difficulty: the model had to show the stars either all
moving apart, as if from a giant explosion, or all collapsing
together upon each other. But Einstein had found room in his
equations for an extra mathematical term, the "cosmological
term" as he called it. He could adjust this term to give a new
model: an unchanging model universe. 
Hubble at his telescope.

In 1929 the American astronomer Edwin Hubble discovered evidence
that distant galaxies of stars are moving away from our galaxy,
and away from each other, as if the entire universe were expanding.
The original Einstein equations might give an exact description
of our universe after all. Quickly convinced by Hubble's evidence,
Einstein felt that his notion of a "cosmological term" was a
mistake. Other scientists withheld judgment, and debate over
the cosmological term still continues today. But most astronomers
agree that with or without the cosmological term, Einstein's
equations give the best available language for a description
of the overall structure of the universe. 
"I want to know how God created this world. I
am not interested in this or that phenomenon, in the spectrum
of this or that element. I want to know His thoughts; the rest
are details."

