Transcript Time Travel - Santee Education Complex

Time Travel
Science Fiction or Reality?
Is It Possible?
• Whenever we think of science fiction, we think of
outer space, black holes, other dimensions and
time travel. But is it proper to classify time travel
as science fiction? Many people would say yes
because they think it is not possible. As a matter
of fact it isn’t possible to time travel yet.
Scientists always look for a way to prove that
something exists or it doesn’t. Time travel
actually cannot be proved or debunked but we
are beginning to see that time travel actually isn’t
as imaginary as we thought it was.
Origins of the Concept of
Time Travel
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There is no way of knowing what are the earliest concepts of time travel but there are many old
stories about traveling forwards in time:
700’s BCE to 300’s CE –Mahabharatha
King Revaita travels to heaven to meet the creator
Brahama, but when he travels back to Earth, he finds out many years have passed.
720 CE- Urashima Taro – A young fisherman named Urashima Taro travels to an undersea
palace for three days and finds out three hundred years have passed on the surface.
1819 Rip Van Winkle – A man named Rip Van Winkle takes a nap at the top of a mountain and
wakes up twenty years in the future.
1771 – L’An 2440, reve s’il en fut jamais – The main character falls asleep and wakes up in Paris
during the year 2440.
1838 – Missing One’s Coach: An Anachronism – A man takes a nap under a tree and wakes up
one thousand years in the past.
1843 – A Christmas Carol – Ebenezer Scrooge is transported to the past, present and future by
ghosts.
1861 – Paris avant les hommes – The main character is transported back thousands of years and
meets dinosaurs and humankinds earliest ancestors.
1889 – A Connecticut Yankee in King Arthur’s Court- The main character is transported back in
time to King Arthur’s palace after he was hit with a sledge hammer in a fight.
1895 – The Time Machine – This is the first story that uses the phrase time machine.
Time Travel in Theory
• There are theories that actually would allow us
to travel in time if these geometries are possible.
Physicist don’t talk about traveling thought time,
they talk about moving through curves in space
that bend time as well which would allow
whatever travels through them to return to their
own past. In reality, it is possible to travel
forwards in time in space because time travels
faster on earth than in space so if someone were
to travel to Neptune for example, the trip would
probably take 20 year but 30 years would have
passed on Earth.
Tourism in Time
Stephen Hawking once said that the absence of
tourists from the future constitutes an argument
the existence of time travel. This doesn’t prove
that time travel is impossible, just that it hasn’t
been developed yet or never used. Hawking
notes that time travel might only be possible in a
region of space-time that is warped the right way
that we cannot create until the future. There is
also a theory that states that you can only travel
back until the point the time machine you’re
using was invented, which would explain why we
haven’t run in into any travelers from the future.
Time Travel to the Past in Physics
• Time travel to the past is theoretically
possible using the following methods:
• Space traveling faster than the speed of light
• The use of cosmic strings and black holes
• Wormholes and Alcubierre ‘warp' drive
Time Travel via Faster-Than-Light
Travel
• If you could move information or matter
faster than the speed of light, then
according to special relativity, there would
be an inertial frame of reference in which
the signal or matter would be moving
backwards in time. To accelerate an object
to the speed of light, it would take an
infinite amount of energy to accelerate an
object to the speed of light.
Wormholes
• Wormholes are hypothetical warped spacetime
permitted by Einstein’s field equation of general
relativity, although it would be impossible to
travel through a wormhole unless you knew it
was a traversable wormhole.
• The way to travel in time is to accelerate one
end to the speed of light and leave on end
stationary. Anyone traveling through the
stationary end to the spinning end would travel
forwards in time and backwards in the other way.
Black Holes
• Black holes are the end result of suppermasive stars
after they go supernova. When these stars are about to
die, they implode into a single point, called a singularity
and explode. The singularity is small at first but soon it
turn into a giant hole in space which is known as a black
hole. Many people believe that black holes are portals to
other universes and worlds but some believe they may
be time machines. Every one knows that nothing can
escape a black hole, not even light. It is because of this
law that many believe we can travel back in time. Some
physicists believe that time is a dimension that intersects
with ours. If light can’t escape from a black hole, then
maybe time can’t either so going through a black hole or
just residing near it’s event horizon would allow an object
to travel back in time.
Alcubierre’s Warp Drive
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In 1994, the Mexican physicist Miguel Alcubierre proposed a method of
stretching space in a wave which would in theory cause the fabric of space
ahead of a spacecraft to contract and the space behind it to expand. The
ship would ride this wave inside a region known as a warp bubble of flat
space. Since the ship is not moving within this bubble, but carried along as
the region itself moves, conventional relativistic effects such as time dilation
do not apply in the way they would in the case of a ship moving at high
velocity through flat spacetime. Also, this method of travel does not actually
involve moving faster than light in a local sense, since a light beam within
the bubble would still always move faster than the ship; it is only "faster than
light" in the sense that, thanks to the contraction of the space in front of it,
the ship could reach its destination faster than a light beam restricted to
traveling outside the warp bubble. Thus, the Alcubierre drive does not
contradict the conventional claim that relativity forbids a slower-than-light
object to accelerate to faster-than-light speeds. However, there are no
known methods to create such a warp bubble in a region that does not
already contain one, or to leave the bubble once inside it, so the Alcubierre
drive remains a hypothetical concept at this time.
Tipler Cylinders
• Tipler cylinders are a concept put forward
one hundred and fifty years ago. The basic
formula to make one is to get matter
strong and flexible enough to stretch into
infinity and then it must be spun.
Clockwise for future and anti-clockwise for
past. Then you get a spaceship to travel
through it and if it makes it through, the
ship will end up in a different time.
Time Travel to the Future
• There are more ways to travel to the future
than to the past. Some of theses methods
are
• Time Dilation Theory of Special Relativity
• Time Dilation Theory of General Relativity
Theory of Special Relativity
• Time dilation is permitted in both of Einstein's Theories
of Relativity. The theories state that time passes slower
for moving objects than those that are stationary. For
example a clock that is moving will appear to go tick
slower than a stationary one. As the clock approaches
the speed of light, the clock will seem to stop. Using the
twin paradox we can assume that if one twin travels to
Alpha Centauri at the speed of light and one twin stays
on Earth. For the traveling twin about 8 years would
have gone by but maybe a thousand years would have
gone by on Earth for the Earth twin.
Theory of General Relativity
• Another way to travel back in time is to
reside within a hollow sphere with a great
mass. Let’s say that this object has the
mass of Jupiter. If you stay in it for one
hour you would exit it and four hours
would have gone by.
Time Perception
• Two other ways of that people travel
through time at a faster pace are
Hibernation and Suspended Animation.
They are however not recognized as time
travel because they would still go at
normal pace instead of an accelerated
way of travel.
Paradoxes
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Paradox-something absurd or contradictory: a statement, proposition, or situation that
seems to be absurd or contradictory, b…
- self-contradictory statement: a statement or proposition that contradicts itself
- person of opposites: a person with seemingly self-contradictory qualities
If we were to travel back in time, what would we do? How many laws of
physics and nature would we break? What would happen if someone tried
to go back in time to kill their grandfather before he married his
grandmother? Is there a way of changing the past without endangering the
future? These are some of the questions that physicist and everyday people
ask themselves if we were to travel back in time. Paradoxes are what
people fear in the world of physics and many wonder there a way around
them”
Paradoxes (cont.)
• There are some theories that allow us to evade
paradoxes. A theory says that anyone traveling through a
wormhole can never engender paradoxes because they
would only be allowed to travel through time but not be
able to interact with it. Another way to evade paradoxes
is through the theory of parallel universes that would
allow a traveler to be transported to a universe that
favors the outcome of his change. Another more somber
theory states that the universe is conscious and will stop
anyone who tries to change it by making them disappear
on their way to travel through time. Finally, there is a
theory that states that any changes to the time stream
would disintegrate the universe itself.
Grandfather Paradox
• The most famous paradox when it comes to time
travel goes like this. Tim hates his grandfather
and would like nothing more than to kill him. The
only problem for Tim is that his grandfather died
years ago. Tim wants so badly to kill his
grandfather himself that he constructs a time
machine to travel back to 1955 when his
grandfather was young and kill him then.
Assuming that Tim can travel to a time when his
grandfather is still alive, the question must then
be raised; Can Tim kill his grandfather?
The Solution
• Consider now the fact that Tim’s grandfather died in 1993 and not in
1955. This new fact about Tim’s situation reveals that him killing his
grandfather is not compassable with the current set of facts. Tim
cannot kill his grandfather because his grandfather died in 1993 and
not when he was young. Thus, Lewis concludes, the statements
"Tim doesn’t but can, because he has what it takes," and, "Tim
doesn’t, and can’t, because it is logically impossible to change the
past," are not contradictions, they are both true given the relevant
set of facts. The usage of the word "can" is equivocal: he "can" and
"can not" under different relevant facts. So what must happen to Tim
as he takes aim? Lewis believes that his gun will jam, a bird will fly
in the way, or Tim simply slips on a banana peel. Either way, there
will be some logical force of the universe that will prevent Tim every
time from killing his grandfather
So Should We Time Travel?
• Maybe we can travel in time but should
we. Many theories out there state that
even if we could go back in time, we
couldn’t change it because time is
prewritten, maybe by God or destiny or
who knows so there might not be any point
in time traveling. Right now we don’t have
the technology to travel through time but
one day we will and only then we can see
what really will happen.
Claims of Time Travel
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Philadelphia Experiment
Chronovisor
Billy Meier
Darren Daulton
John Titor
Moberly-Jourdain Incident
Montauk Project
Time Slip
Religion And Time Travel
• Many people believe hat God exist but
where would he exist if he doesn’t age?
For him to exist he has to pass through
time but the Bible says that he never ages
but it is said that God can change time as
well. God is believed to exist outside our
dimension but can travel to ours if it
wishes as well.