At a UCLA workshop attended by
yours truly and an assortment of future-thinkers, the late physicist Dr. Robert
Forward told the group that further understanding of general relativity and
quantum mechanics would one day enable humans to travel backwards and forwards
through time. "Given the money and the mandate," Forward said, "a time machine
will be built."
This workshop convened in 1983, and today, 24 years later, scientists are
bringing this bold concept closer to reality. Professor Amos Ori at
Technion-Israel Institute of Technology recently created a theoretical model of
a time machine based on Einstein’s theory of relativity, which would allow
people to travel back in time.
Ori’s theory, published in the prestigious science journal Physical Review,
describes how a future time machine could be built by forming "closed time-like
curves" in a donut-shaped area of space-time. A person traveling around this
donut loop would go further back in time with each lap.
Although the laws of physics permit time travel, the concept is laden with
uncomfortable contradictions. Say we travel back in time and stop our parents
from getting together. This would prevent us from being born; we would not exist
and our journey in time could never happen. Scientists call this a paradox; we
created a past different from the one that already exists.
Clearly, mischievous time travelers cannot change the present. People are not
suddenly disappearing because a rerun of events has prevented their birth.
Therefore, something is stopping time travelers from changing our present, and
Stephen Hawking, Michio Kaku, and other visionaries believe they know what it is
– parallel universes.
If we travel to the past and prevent our parents from meeting, we are
immediately thrust into a parallel universe, similar to our old universe, but
one where we never existed. In this universe, we appear as a visiting
time-traveler from another universe; however returning home could pose a
problem. If roundtrip procedures have been developed, we’re OK; if not, we may
be stuck forever in a strange world.
Though construction of Ori's time machine is beyond today’s science, many
believe that exponentially-advancing technologies could turn this dream into
reality by the end of the century.
Advantages to time travel are mind-boggling. A glimpse into the future would
reveal what our lives will be like in the 22nd century and beyond. Will we find
extra-terrestrial intelligent life? And visiting the past could allow us to scan
the minds of lost loved ones before they died and bring them into our time to
continue their lives.
Four billion years ago, life was only a biochemical machine capable of
self-reproduction. Today, we venture into space and study ideas ranging from
general relativity to quantum cosmology. We're already thinking about
teleporting people instantly from one location to another; and some bold
scientists believe that humanity will one day achieve an indefinite lifespan,
eliminating the causes of most deaths.
Who knows how far we can evolve. Will we merge with intelligent machines by
mid-century as futurist Ray Kurzweil and others predict? If so, these creations
could survive virtually forever with human ideas, hopes, and dreams carried with
them. Welcome to our incredible "magical future."