Descriptive Presentation on Mysterious topic "Time travel"

1. TIME TRAVEL
A SCIENCE FICTION OR A FACT

2. NOTICE ANYTHING
C.
1941

3. ISTIMETRAVEL
POSSIBLE??

4. 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”

5. DEFINITION OFTIME
TRAVELTime 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.

6. 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

7. .
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.

8. TIME TRAVEL TO THE PAST
If 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!

9. TIME TRAVEL TO THE PAST
If 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.

10. `TIME TRAVEL TO THE PAST
If 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

11. 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.

12. TIME TRAVEL INTO THE
FUTUREIf 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

13. TIME TRAVEL INTO THE
FUTUREIf 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

14. 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.

15. INTIME 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.

16. ....oh yes, and then there are the time paradoxes
!!
We’ll Never go Back in time

17. GRANDFATHER PARADOX
Going back in
time
Time traveler
kills his
grandfather
His parents
are not born
Even time
traveler is not
born
So he didn’t
kill his
grandfather!!
?????

18. 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.

19. 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!!

20. 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.

21. CONFUSED YET….THESE ARE
CONCLUSIONS
According to Albert Einstein,
▫ To travel into the future
we must approach the speed of light.
▫ To travel into the past
we 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.

22. THANK YOU
ANY QUESTIONS…???

23. 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
was moving backward in time. This is consequence of the relativity of simultaneity in special
says the concept that distant simultaneity – whether two spatially separated events occur at the
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

24. 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
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.

25. 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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26. 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

27. 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.

28. 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.