time travel - a science fiction or a fact

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TIME TRAVEL A SCIENCE FICTION OR A FACT

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Page 1: Time travel - A science Fiction or A Fact

TIME TRAVELA SCIENCE FICTION OR A FACT

Page 2: Time travel - A science Fiction or A Fact

NOTICE ANYTHING STRANGE??

C. 1941

Page 3: Time travel - A science Fiction or A Fact

IS TIME TRAVEL POSSIBLE??

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INTRODUCTION▫ At its most basic level, time is defined as the “rate of change in the universe” --- like it or not, we are constantly undergoing change . We age, the planets move around the sun etc.▫ We measure the passage of time in sec, min, hours and years, but this doesn’t mean time flows at a constant rate. Just as the water in a river rushes or slows depending on the size of the channel, time flows at different rates in different places. In other words, ‘time is relative’.

Human beings frolic about in three spatial dimensions of length, width and

depth

Time joins the party as that most crucial fourth dimension

Time can’t exist without space, and space can’t exist without time. The two exist as one : “ space-time continuum”

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DEFINITION OF TIME TRAVEL Time Travel is the concept of movement between certain points in time,

analogous to movement between different points in space, typically using a hypothetical machine known as “Time Machine “, in the form of a vehicle or of a portal connecting distant points in time.

Time travel is a recognized concept in philosophy and fiction, but travelling to an arbitrary point in time has a very limited support in theoretical physics.

The physics of time travel works usually only in conjunction with quantum mechanics or Einstein-Rosen bridges.

In a more narrow sense, one-way time travel into the future via time dilation is a proven phenomenon in relativistic physics, but travelling any significant ‘distance’ requires motion at speeds close to speed of light which is not feasible for human travel with current technology.

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The Mahabharata mentions the story of king Kakudmi, who travels to heaven to meet Brahma and is shocked to learn

that many ages are passed when he returns

to Earth.

In Payasi Sutta, one of the Buddha’s chief disciples,

Kumara Kassapa, explains to the skeptic Payasi that “In heaven of the thirty

three devas, time passes at a different pace

Earliest known stories to involve time travelling

forward time is Japanese tale of “Urashima Taro”

Washington Irving’s 1819 story “Rip Van Winkle” tells a man named Rip Van Winkle who takes a nap on a mountain and wakes up at 20 years in

the future.

A more recent story involving travel to future

is Louis- Sebastian Mercier’s L’An 2440, a utopian novel in which

main character is transported to year 2440

Another old example of this type of story can be found in year 1771 with story of Honi HaM’agel,

who went to sleep for 70 years and woke up to the

world where his grand children were grandparents.

HISTORY OF FORWARD TIME TRAVEL

Page 7: Time travel - A science Fiction or A Fact

.

One of the backward time travel story is

Memoirs of the Twentieth Century (1733) by Samuel Madden

In 1836 Alexander Veltman wrote a Russian science fiction novel and the first novel to use time travel. In it, he rides to ancient Greece on a hippogriff meets Aristotle and goes on a voyage with Alexander the Great.

HISTORY OF BACKWARD TIME TRAVEL

In the science fiction anthology Far Boundaries , the editor identifies the short story "Missing One's Coach: An Anachronism", written for the Dublin Literary Magazine by an anonymous author , as a very early time travel story

Charles Dickens’ book A Christmas Carol is considered by some[ to be one of the first depictions of time travel in both directions, as the main character is transported to Christmases past, present and yet to come

In 1881, Edward Everett Hale published "Hands Off", about an unnamed being free to travel through time and space, who interferes with Earth history in Ancient Egypt.

H. G. Wells’ 1895 story, The Time Machine,

popularized the concept of time travel by

mechanical means.

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TIME TRAVEL TO THE PASTIf we can travel to the Past, we can……

Go back to age of dinosaurs and clarify this world that how they look!

See Evolution of Man from apes...Have chance to meet our great ancestor!

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TIME TRAVEL TO THE PASTIf we can travel to the Past, we can……

Watch Mahabharata war and can be a part of that epic saga…if you have guts?

Witness World war-1 & 2…see guns, guts and love of those people.

Page 10: Time travel - A science Fiction or A Fact

`TIME TRAVEL TO THE PASTIf we can travel to the Past, we can……

But is this travel to the past possible ???

A glance into night sky should supply an answer

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TIME TRAVEL TO THE PAST IN PHYSICS

Time Travel to the past is theoretically allowed using the following methods:

▫ Travelling faster than the speed of the light.

▫ The use of Cosmic strings and Black holes.

▫ Worm holes and Alcubierre drive.

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TIME TRAVEL INTO THE FUTURE

If we can advance through years faster than the next person, we can…

See ultra modern cities with advanced optical communication…

Robot armies with advanced AI weapons and machines

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TIME TRAVEL INTO THE FUTURE

If we can advance through years faster than the next person, we can…

Possibly go back to world war III….where even beautiful cities look like barren lands

Bio-weapons replacing nuclear weapons…countries pool their resources to build them

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TIME TRAVEL INTO THE FUTUREIf we can advance through years faster than the next

person, we can…But is this travel into future is possible…???

We need to exploit space-time.

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IN TIME TRAVEL INTO THE FUTURE IN PHYSICS▫ There are various ways in which a person could “travel into the future” in a

limited sense: the person could set up things so that small amount of his own subjective time, a large amount of subjective time has been passed for other people on Earth.▫ For example, an observer might take a trip away from the Earth and back at relativistic velocities, with the trip only lasting a few years according to the observer's own clocks, and return to find that thousands of years had passed on Earth

▫Time Travel to the future is theoretically allowed using the following methods:

▫ Time-Dilation.

▫ Hibernation.

▫ Time perception.

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....oh yes, and then there are the time paradoxes !!

We’ll Never go Back in time

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GRANDFATHER PARADOXGoing back

in timeTime

traveler kills his

grandfather

His parents are not born

Even time traveler is not born

So he didn’t kill his

grandfather!!

?????

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REPLIES TO THE “GRANDFATHER

PARADOX”▫ Novikov’s Self-Consistency loop.

It is a principle developed by Russian physicist Igor Dmitriyevich Novikov in the mid-1980 to solve problem of paradoxes in time travel, which states Contradictory casual loops cannot form, but those consistent ones can.

▫ Parallel universes.But there is another possibility: the future or past we travel into

might just be in a parallel universe. Think of it as a separate sandbox: We can build or destroy all the castles we want in it, but it doesn't affect our home sandbox in the slightest.

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HAWKING’S PARADOX▫ Why don’t we observe tourists, souvenir hunters, historians, archaeologists, criminals visiting us from future?

A Reply to this paradox is

▫ Global warming, Nuclear war, Super virus or the Robotic Uprising killed all human!!

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THE TWIN PARADOX▫ This paradox deals more properly with travel into the future. It involves two newborn, identical twins, one who stays on Earth, and one who travels to Proxima Centauri, the nearest star, 4 light years away. If the spacecraft travels at 80% the speed of light, which amusingly seems more realistic, the round trip will take 10 years. That means the twin on Earth will be 10 years old when his brother returns.

▫ But on the spacecraft, the crew observes Proxima Centauri and Earth also moving with relation to the craft, and this causes Points A and B to shorten to a distance of 2.4 light years, not 4. Each leg of the journey will take 2.4 light years divided by the speed, 80% of the speed of light, for a duration of 3 years one way, 6 round trip. Thus, the twin onboard will have aged 6 years in the same relative span of time. This much is not logically impossible.

▫ What is impossible is the effect of one twin traveling 101% or more of the speed of light. This would, at least according to this scenario as we understand it, cause him to travel into the past and cease to exist, i.e. disappear from onboard, and not return to his brother on Earth.

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CONFUSED YET….THESE ARE CONCLUSIONSAccording to Albert Einstein,

▫ To travel into the futurewe must approach the speed of light.

▫ To travel into the pastwe must surpass the speed of light.

▫ The current record holder for time-traveling is Sergei Krikalev.▫ He has traveled about 337 million miles in orbit at some 17,450 mph – reaching a grand total of 0.02 seconds into the future.▫ This means that from now on, he takes a step two hundredths of a second before you see him take it.

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THANK YOU

ANY QUESTIONS…???

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VIA FASTER-THAN-LIGHT TRAVEL▫ If one were able to move information or matter from one point to another faster than light, then according to the theory of relativity, there would be some inertial frame of reference in which the signal or object was moving backward in time. This is consequence of the relativity of simultaneity in special relativity, which says the concept that distant simultaneity – whether two spatially separated events occur at the same time – is not absolute, but depends on the observer's reference frame.

▫ Technically, these disagreements occur when the space-time interval between the events is ‘space-like’, meaning that neither event lies in the future light cone of the other.▫ If one of the two events represents the sending of a signal from one location and the second event represents the reception of the same signal at another location, then as long as the signal is moving at the speed of light or slower, the mathematics of simultaneity ensures that all reference frames agree that the transmission-event happened before the reception-event

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THE USE OF COSMIC STRINGS AND BLACK HOLES▫ Cosmic Strings are a hypothetical 1-dimensional (spatially) topological defect in the

fabric of space-time left over from the formation of the universe. Interaction could create fields of closed time-like curves permitting backwards time travel. 

▫ Some scientists have suggested using "cosmic strings" to construct a time machine. By manoeuvring two cosmic strings close together – or possibly just one string plus a black hole – it is theoretically possible to create a whole array of "closed time-like curves." we can fire two infinitely long cosmic strings past each other at very high speeds, then fly our ship around them in a carefully calculated figure eight. In theory, we would be able to emerge anywhere, anytime.

▫ At the moment, these are purely theoretical objects that might possibly be left over from the creation of the universe in the Big Bang. A cosmic string, if such a thing existed, would be a two-dimensional infinitely thin line that has even stranger effects space-time. Although no one has actually found a cosmic string, astronomers have suggested that they may explain strange effects seen in distant galaxies. 

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WORMHOLES AND ALCUBIERRE DRIVE▫ A wormhole or Einstein–Rosen bridge is a hypothetical topological feature that would fundamentally be a shortcut connecting two separate points in space-time. A wormhole, in theory, might be able to connect extremely far distances such as a billion light years or more, short distances such as a few feet, different universes, and different points in time. A wormhole is much like a tunnel with two ends, each at separate points in space-time.▫ Wormholes have never been proven to exist, and if they are ever found, they are likely to be tiny that a person couldn’t fit into inside, never mind a space ship. ▫ The theory of general relativity predicts that if traversable wormholes exist, can also alter the speed of time. They could allow time travel and this could be accomplished by accelerating one end of the wormhole to a high velocity relative to the other, and then sometime later bringing it back, relativistic time dilation would result in the accelerated wormhole mouth aging less than the stationary one as seen by an external observer

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TIME DILATION ▫ In the theory of relativity, time dilation is a difference of elapsed time between two events as measured by observers either moving relative to each other or differently situated from a gravitational mass or masses. These theories state that, relative to a given observer, time passes more slowly for bodies moving quickly relative to that observer, or bodies that are deeper within a gravity well.

▫ It has been calculated that, under general relativity, a person could travel forward in time at a rate four times that of distant observers by residing inside a spherical shell with a diameter of 5 meters and the mass of Jupiter. For such a person, every one second of their "personal" time would correspond to four seconds for distant observers

ISS astronauts return from missions having aged slightly less than they would have been if they had remained on Earth

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TIME-PERCEPTION▫ Time perception is a field of study within psychology and neuroscience that refers to the subjective experience of time, which is measured by someone's own perception of the duration of the indefinite and continuous unfolding of events.

▫ Time perception is a construction of the brain that is manipulable and distortable under certain circumstances. These temporal illusions help to expose the underlying neural mechanisms of time perception.

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HIBERNATION▫ Space trips to the other planets would require months of travel through the vacuum of space. Maintaining the crew’s health is a vital concern. If the crew could be induced to hibernate, the problems of survival become easier to solve.

▫ Hibernation is a type of torpor, or reduced metabolism caused by hypothermia. Unlike in cryogenics, the body does not actually freeze. A 10 degree drop in body temperature reduces metabolic rate by 50 to 70 percent.