Einstein
put forward his theory of general
relativity 100 years ago. His prime insight
concerned the reciprocal relationship between mass and spacetime.
Mass (matter and energy) warps spacetime (our three observed
physical dimensions plus time) and warped spacetime determines how
objects move around mass. Mass in motion always moves in straight
lines. However, in the presence of massive objects, those straight
lines follow the curves of warped spacetime. Thus things fall.
Einstein
also contributed to the elaboration of quantum
mechanics. But quantum
physics and relativity
seem to be fundamentally different ways of understanding reality.
The former reduces all we observe to a realm of particles and waves
that remain intrinsically probabilistic. The latter places reality
into a universal geometrical framework of space and time. Einstein
was uncomfortable with quantum physics because of its probabilistic
nature – “God does not play dice with the universe” – and
because until observed, particles also exist as waves. A further
issue for Einstein was the apparent implication of quantum physics
known as entanglement.
Quantum
entanglement occurs when two or more particles
are generated or interact in such a way that they share the same wave
function (quantum state). When that happens,
no matter how far apart those particles may move away from each other
– even to opposite ends of the universe – they remain entangled:
measurement of one – collapsing its wave function – also
determines the measurement of the other. This bothered Einstein –
he termed it “spooky action at a distance” – because the two
particles seem to communicate through space instantaneously and –
more to the point – faster than the speed of light. For Einstein,
the speed of light is a fundamental constant and nothing can go any
faster. But experiment has consistently verified the phenomenon of
quantum entanglement. Most recently a group of Dutch
physicists gave what is widely seen as
definitive proof that entanglement across distance is real and
reveals that reality is in some way non-local.
Non-locality
implies that entangled things exist in a relationship that is not
determined by the local conditions that impinge upon those things.
In other words, when one of the things is measured, the qualities of
the far distant formerly entangled thing are not determined by where
that thing is but by some deeper reality that is not local to the
thing itself. Non-locality implies that there is some more
fundamental level of reality that exists outside space and time.
We
live in a universe in which time and space do exist. We travel
through space (in any direction of three directions) and time (only
forward). Things with mass travel travel no faster than the speed of
light. At the speed of light, everything
happens at the same instant because time does
not pass. If we could be that massless surfer riding a photon
created at the moment of the Big Bang, we would experience everything
and everywhere that photon would ever be at the same instant.
We
experience time as passing because we live in a world of matter and
energy, which seems to give rise to spacetime. Our consciousness
exists in time as our body exists in space.
But non-locality points to a reality in which the universe exists
without time or space as one object in which all time and space exist
at once. We appear not to experience this deeper reality outside the
realm of quantum experimentation (though it may make it possible
someday to have quantum
computing). But non-locality – as St. Thomas
Aquinas might argue – points to consideration of First Cause and
Ultimate Reality. That is spooky.