The possibility of time travel have fascinated mankind for ages. We are all familiar with the concept of the time machine, from H.G. Wells
to current sci-fi writers, and there are physicists who say we cannot rule out time travel.
Even though time travel is generally associated with science fiction, physicists know that time travel is a serious prediction of Einstein's
general relativity equations
One way to visit the pas or the future is to use wormholes which serve as a time portals between past present and future.
Your world has four dimensions. Three dimensions are space; time is the fourth.
The Time Traveller in Wells' classic 1895 novel The Time Machine explains it simply enough, "There is no difference between Time and any of
the three dimensions of Space, except that our consciousness moves along it".
According to Stephen Hawking, "time travel movies often feature a vast, energy-hungry machine.
The machine creates a path through the fourth dimension, a tunnel through time.
A time traveler, a brave, perhaps foolhardy individual, prepared for who knows what, steps into the time tunnel and emerges who knows when.
The concept may be far-fetched, and the reality may be very different from this, but the idea itself is not so crazy."
The laws of physics actually accommodate the notion of time travel, through portals known as wormholes.
According to Stephen Hawking "wormholes are all around us, only they're too small to see. They occur in nooks and crannies in space and time.
Nothing is flat or solid. If you look closely enough at anything you'll find holes and wrinkles in it. It's a basic physical principle,
and it even applies to time. Even something as smooth as a pool ball has tiny crevices, wrinkles and voids."
"A wormhole is a subway trip trough space and time. It was Einstein himself who in 1935 that first proposed the possibility of wormholes
and we find that Einsteins equations are littered with wormholes. Wormholes to the future, wormholes to the past", Dr, Michio Kaku
The idea of a wormhole is that you come into the wormhole from within our Universe and temporarily exit our space-time continuum and return
again to our space-time continuum at some other space location at some other time location, astrophysicist Charles Liu explained.
Time is a dimension, but it's so unsual in that sense that we can only move forward in it as long as we are in our Universe.
Traveling to the future is possible, but going back in time violates a number of known physical laws.
We try to find ways to travel back in time, but by doing that we are affecting a very important part of our physical Universe, called
causality. If we want to travel back in time, we must find a way to prevent causality from being violated, Charles Liu said.
Maybe if there were a theory of everything, one could solve all of Einstein's equations through a wormhole, and see whether time travel
is really possible, Kaku says.
"But that would require a technology far more advanced than anything we can muster," he said. "Don't expect any young inventor to
announce tomorrow in a press release that he or she has invented a time machine in their basement."
For now, the only definitive part of travel in the fourth dimension is that we're stepping further into the future with
each passing moment. So for those hoping to see Earth a million years from now, scientists have good news.
"If you want to know what the Earth is like one million years from now, I'll tell you how to do that," said Brian Greene,
a consultant for "Déjà Vu," a recent movie that dealt with time travel.
"Build a spaceship. Go near the speed of light for a length of time-that I could calculate. Come back to Earth, and when
you step out of your ship you will have aged perhaps one year while the Earth would have aged one million years. You would have traveled to Earth's future."
So, how does Dr. Who time travel, we wonder...
The Doctor's TARDIS is an obsolete "Type 40 TT capsule" that he unofficially "borrowed" when he departed his home planet of Gallifrey.
"Dr. Who has a technology centuries maybe millennium more advanced than ours. In which case going right up at the speeds of light is child's play.
When that happens time slows down inside your rocket ship. So if you want to go to a nearby star for example,
it takes four years for a light beam to reach that star, but in his TARDIS it may take four seconds," Dr. Kaku says.
"In the opening sequence of Dr. Who, you see the TARDIS tumbling through a tunnel. To my mind that tunnel could represent a wormhole,"
Jim Al Khalili, theoretical physicist says.
Space-Time Crystal Computer That Can Outlive Even The Universe Itself!
It may seem strange to think something can survive even the death of the Universe,
but that could actually be possible as a result of the laws of quantum physics.
Scientists are now suggesting a new blueprint for a device, known as a time crystal, that can
theoretically continue to function as a computer even after the universe cools to absolute zero.
Physicists Challenge Validity Of Big Bang Theory
We all know that the Big Bang theory is an effort to explain what happened at the very beginning of our universe.
However, Australian team of theoretical physicists at the University of Melbourne and RMIT University say that it's time to change our understanding of this process.
Ground-Breaking Discovery Suggests
Gravity May Not Be A Fundamental Force Of Nature
Can information really escape from a black hole? According to new research it seems to be possible for something to actually escape from a black hole.
If correct, the results are ground-breaking suggesting that gravity may not be a fundamental force of Nature after all!
Black holes are objects in space that are so massive and compact they were described by Einstein as “bending” space.