Time Travel: A Paradox ??
The
ability to travel through time, whether it is to fix a mistake in the past or
gain insight into the future, has long been embraced by science fiction and
debated by theoretical physicists. While the debate continues over whether
travelling into the past is possible, physicists have determined that
travelling to the future most certainly is. And you don’t need a wormhole or a
DeLorean to do it.
Real-life
time travel occurs through time dilation, a property of Einstein’s special relativity.
Einstein was the first to realize that time is not constant, as previously
believed, but instead slows down as you move faster through space.
So
why hasn’t humanity succeeded in making such drastic leaps forward in time? The
answer to this question comes down to velocity… In order for humanity to send a traveller years into the future, we
would either have to take advantage of the intense gravitational acceleration
caused by black holes or send the traveller rocketing into space at close to the speed of light (about
1 billion km/h). With our current technology, jumping a
few microseconds into the future is all humans can manage…
But
if technology one day allows us to send a human into the future by travelling
close to the speed of light, would there be any way for the traveller to use
time dilation to return to the past and report her findings? “Interstellar
travel reaching close to the speed of light might be possible,” says Dr. Jaymie Matthews, professor of astrophysics at the University
of British Columbia, “[but] this voyage is one way – into the future, not back
to the past.”
If we can’t use time dilation to return to the past, does this mean that
the past is forever inaccessible? Perhaps not. Einstein proposed that time travel into the past could be achieved
through an Einstein-Rosen bridge, a type of wormhole. Wormholes are theoretical
areas of spacetime that are warped in a way that connects two distant points in
space.
While
it would be fascinating to travel back in time to see the dinosaurs or to meet
Albert Einstein and show him the reality of time travel, perhaps it is best if
the past remains untouched. Travelling to the past invites the possibility of
making an alteration that could destroy the future. For example, in “Back to the Future”,
Marty McFly travels to the past and
inadvertently prevents his parents from meeting each other, nearly preventing
his own existence. But if he had undone his own existence, how could he have
travelled back in time in the first place?
A recent study at the
University of Queensland may have the answer to this baffling paradox. In this
study, the researchers prove mathematically that paradox-free time travel is
possible, showing that the universe will self-correct to avoid inconsistencies.
If this is true, then even if we could
travel back in time, we would never be able to alter events to create a
different future.
While
these new findings are enlightening, there appears to be more evidence that,
although time dilation can allow us to glimpse the future, we will never be
able to visit the past. As the late Stephen Hawking said
in his book Black Holes and Baby Universes, “The best evidence we have that time travel
[into the past] is not possible, and never will be, is that we have not been
invaded by hordes of tourists from the future.”
So
with all these knowledge I would just like you all to imagin, what is the one thing you would like to
change in case…. you could peep in to
your past or could fly into the future….
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