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A-Z of thought: Relativity
John Polkinghorne

'To God's elect…who have been chosen according to the
foreknowledge of God the Father…' (1 Peter 2:2)
This is but one of several references in the Bible to God's
foreknowledge. Yet many believers, including many theologians,
regard knowledge of the future as an impossibility - even for God.
Personally I have no problems with it. That is because of
Einstein's Theory of Relativity.
The theory, which revolutionised physics in the 20th century
superceding Newton's theories, demonstrates that there is a much
closer relationship between time and space than one would suspect
from the very different ways we perceive and measure them. Indeed,
the relationship is so close that physicists now regard time as a
fourth dimension - one to be added to the three dimensions of
space.
To get an idea of what this is about, hold out the thumb and
three fingers of one of your hands (keeping the little finger
tucked out of sight). The extended fingers represent the three
dimensions of space; the thumb the extra dimension of time. They
are welded seamlessly together. As Einstein himself once put it,
'Henceforth we deal in a four-dimensional reality, not a
three-dimensional reality evolving in time'.
This four-dimensional reality is called spacetime. It
encompasses all of space - and all of time. Just as all of your
thumb is there, so too is each point in time, whether past,
present, or future - all on an equal footing. In some sense, the
past continues to exist, and the future already exists - just like
the present.
What do we find in this spacetime? Whatever it is will be
characterised by being at a certain position in space at a
particular point in time. We are talking about events. For
instance, one event will be you sitting where you are located at
present reading this sentence, at the point in time indicated by
your watch. A second event might be you in the bathroom at a later
time searching for a headache pill.
These events, etched into the fabric of spacetime, are but two
of the events that make up your life from birth to death. All of
these events, taken together, make up your worldline. (An odd name,
I know, but that's what it is called!). And the whole of your
worldline is there in spacetime - together with the worldlines of
all other existent objects.
I reckon that the fingers/thumb analogy is a good way of
understanding how God (God beyond spacetime) can possess
foreknowledge. Just as you, from your privileged position looking
down upon your hand from outside, can take it all in, so a
transcendent God can look down on spacetime and take it all in at a
glance - including the future.
Russell Stannard