TIME TRAVEL

TIME TRAVEL ..

One of my favorite topic and 

always i want to explore more  about it.

During My School life,i was crazy about exploring and read 

more and more post or things about wormhole,

time machine ,four-dimension and many more things related to 

TIME TRAVEL....

We all know ,its a Cool topic .. everyone want

 to travel in past or future..

and its not possible for everyone as it is not discovered

 yet but...

One of my favorite Scientist Albert gave 

a theory called SPECIAL RELATIVITY THEORY.

Theory says "SPACE AND TIME ARE REALLY ASPECTS OF THE

SAME THING SpacE-TimE".There is a speed limit of 

300,000 kilometers per second (or 186,000 miles per second)

for anything that travels through space time..

Light Always travels the speed limit through empty space..

It also says that a surprising thing happens when you 

move through space-time and when your speed relative to other

objects is close to the speed of light.

time goes slower for you than for the people you left behind.

you won't notice this effect until you return to those

stationary people.

.

.

According to "the original string theory,

 bosonic string theory, contained a massless 

particle called the tachyon, which travels 

faster than the speed of light.

 These particles are usually a sign

 that a theory has an inherent flaw - but

 what if they actually existed? Would they

 allow a means of time travel?

The short answer is that no one knows.

 The presence of tachyons in a theory

 means that things begin to go haywire,

 which is why they're considered by physicists

 to be a sign of fundamental instabilities in 

the theory. (These instabilities in string theory

 were fixed by including supersymmetry,

 creating superstring theory.)

However, just because tachyons mess

 up the mathematics that physicists 

use doesn't necessarily mean that they

 don't exist. It may be possible that

 physicists just haven't developed the

 proper mathematical tools to address

 them in a way that makes sense.

If tachyons do exist, then in theory

 it would be possible to send messages 

that travel faster than the speed of light.

 These particles could actually travel backward

 in time and, in principle, be detected.

To avoid this problem (because, remember, time 

travel can destroy all of physics!), the physicist

 Gerald Feinberg presented the Feinberg

 reinterpretation principle in 1967, which

 says that a tachyon traveling back in time 

can be reinterpreted, under quantum field

 theory, as a tachyon moving forward in time.

Could time travel soon become a reality? Physicists simulate sending quantum light particles into the past

• *University of Queensland scientists simulate photons moving through time
• *They showed how two wormhole-travelling photons might behave
• *Time-travel in the quantum world seems to avoid famous paradoxes
• *The experiment shows bizarre behaviour of such quantum particles
• *But on larger scales time travel still remains implausible, say researchers

If a time traveller went back in time and stopped their own grandparents from meeting, would they prevent their own birth?

That’s the crux of an infamous theory known as the 'grandfather paradox', which is often said to mean time travel is impossible - but some researchers think otherwise.

A group of scientists have simulated how time-travelling photons might behave, suggesting that, at the quantum level, the grandfather paradox could be resolved.

Researchers at the University of Queensland in Australia

 have discovered that two photons travelling through 

time can interact. In the simulation a photon stuck in

 a closed timelike curve (illustrated) through a wormhole

 was found to be capable of interacting with one travelling 

through regular space-time.

WHAT IS A WORMHOLE??

Space-time can be warped and distorted. It takes an enormous amount of matter or energy to create such distortions, but theoretically, distortions are possible.

In the case of a wormhole, a shortcut is made by warping the fabric of space-time. Imagine folding a piece of paper with two pencil marks drawn on it to represent two points in space-time.

The line between them shows the distance from one point to the other in normal space-time. 

If the paper is now bent and folded over almost double - the equivalent to warping space-time -  then poking the pencil through the paper provides a much shorter way of linking the two points, in the same way a wormhole would create a shortcut. 

The problem with using wormholes to travel in space or time is that they are inherently unstable.  When a particle enters a wormhole, it also creates fluctuations that cause the structure to collapse in on it. 

A recent study suggests there are unusual-shaped wormholes than may be able to stay open longer than normal.

Wormholes are theoretical tunnels that 

create shortcuts in space-time. A study 

in May from Dr Luke Butcher at Cambridge 

University argued that if a thin wormhole 

stayed open long enough, people could send

 messages through time using pulses of light, or photons.

'The properties of quantum particles are "fuzzy" or uncertain to start with, so this gives them enough wiggle room to avoid inconsistent time travel situations,' said professor Timothy Ralph, one of the researchers on the latest study.

The results also give a better understand to how two theories in physics, on the biggest and smallest scales, are able to relate to one another.

'The question of time travel features at the interface between two of our most successful yet incompatible physical theories ' Einstein's general relativity and quantum mechanics,' said PhD student Martin Ringbauer from the University of Queensland.

'Einstein's theory describes the world at the very large scale of stars and galaxies, while quantum mechanics is an excellent description of the world at the very small scale of atoms and molecules.'

Einstein's theory suggests the possibility of travelling backwards in time by following a space-time path that returns to the starting point in space but at an earlier time - a closed timelike curve (CTC).

This possibility has puzzled physicists and philosophers alike since it was discovered by Austrian-American scientist Kurt Gödel in 1949, as it seems to cause paradoxes in the classical world.

These include the 'grandparents paradox', where a time traveller could stop their grandparents from meeting, thus preventing the time traveller's birth.

This would make it impossible for the time traveller to have set out in the first place.

But this new research suggests that such interactions might indeed be possible - albeit only on a quantum level.