Time travel is possible or not | Can we actually travel in time
Time travel is one of my favorite topics! I have continued to study this fascinating concept as the years have gone by. Let’s talk about our question.
The simplest answer is — Time travel to the past is not possible.
Time travel to the future is easy.
Let’s understand this with few examples, Consider these situation.
Grandfather paradox
You travel back to the past and kill your grandfather. So now, your father won’t be born and neither will you.
So if you are not even born, who killed your grandfather?
Hitler paradox
You travel back to the past and kill Hitler. So history changes and now, there is no Hitler.
Now, if Hitler doesn’t exist, why would you travel back in the first place to kill him?
Infinite loop paradox
A man travel backs to the past and marries a woman. After that, he returns to the present. But the woman gets pregnant and has a son.
Many years later, that son becomes the time traveler who goes to the past and marries the woman.
So who is the son and who is the father?
This is a type of paradox in which an object, person, or piece of information sent back in time results in an infinite loop where the object has no discernible origin, and exists without ever being created.
Multiple universes hypothesis
You have an enemy, you pop back in time, walk up to him, and point a revolver at his head.
You pull the trigger and Boom! The deed is done. You return to the “present” but you never existed here.
Everything about you has been erased, including your family, friends, home, possessions, bank account, and history.
You’ve entered a timeline where you never existed.
Scientists entertain the possibility that you have now created an alternate timeline or entered a parallel universe.
An alternate parallel universe or timeline is created each time an event is altered in the past.
One More Example
You want to go back to 2019 and stop COVID-19 before it makes the leap from animals to humans.
You isolate the very first patient and boom now corona doesn’t exist.
Simple as that, huh? But if corona didn’t exist, you wouldn’t come back in time to stop it, would you?
But if you didn’t stop it then the corona still happens, and it goes on as a viciously stupid cycle.
What you fail to notice is that you are ‘in the present’ all the time. You just ‘skipped’ some time (days or years) by traveling at relativistic speeds, that’s all.
You meet the people whom you left behind and depending on the time you have skipped, they may or may not recognize you, and for all practical purposes, they may have given you up for dead.
How can we call this ‘time travel’?
Why time travel is not possible
Time is the 4th dimension. Time is also the only dimension that has one direction. It only can move forward, not backwards.
There are four basic dimensions. Three of them are spatial.
There are often called height, width, and depth. You can travel in two directions in any one of these dimensions.
You can have an almost infinite number of positions inside of all three dimensions.
The fourth dimension is time. But, we are much more limited in how we travel through this fourth dimension.
We cannot travel backward. It’s the only dimension where we can only travel forward.
Many dreamers have wondered what it would be like to be able to travel backward through time but based on our current understanding of the laws of physics; such a journey is only possible in dreams and our wildest fiction.
According to quantum physics, time does not exist in a quantum level.
Time is affected by gravity. Gravity bends the very fabric of spacetime and time runs slower where gravity is strongest.
There is so much more to time travel that we don’t know yet.
However, one thing is certain: it most definitely will not be like how it’s shown in TV shows and movies.
Also, it is highly unlikely that we will ever be able to ‘time travel’ due to technological problems as we do not have the ability to travel nearly the speed of light yet, which is something that is needed in order to travel forward in time.
Time travel is seriously spooky. The deeper you dive to understand Time travel, the more you will be MIND BLOWN.
The universe may not allow change when you time travel
It’s no surprise that Hawking once believed time travel to be impossible; there are simply too many paradoxes involved in the whole procedure.
The most famous of these is the grandfather paradox — proposes the following conundrum:
If you were to travel back in time and kill your grandfather, would you not then cease to exist, never having had the chance to be born?
Since its mind-boggling inception, the grandfather paradox has seen many attempts to satisfy its confusion.
Perhaps the most successful came from American physicist Hugh Everett III, who first proposed the many-worlds interpretation (MWI) of time travel.
Though it has gone through several revisions, the MWI essentially states that many universes may exist, one for every possible outcome to every possible event.
Therefore, if you were to travel back in time and kill your grandfather, the universe from which you traveled would remain unaffected and you would live on(albeit as a parricidal sadist) because the universe would shift to keep you alive, however possible.
Time Doesn’t Pass the Same Way for Everywhere
Time may seem to be going slower when you’re in a boring meeting or the days before Christmas, but that’s just an illusion, right?
It turns out that time passes differently at different altitudes. Even a small altitude difference can be detected with sensitive enough equipment.
A height difference of just 12 inches can make a difference in the speed that time passes.
If you live in the Mile-High City, time is going faster for you than if you live in Death Valley.
Why time travel is possible
Time travel is always one of many controversial topic among Intellectual people of our society,
but if we analyses theories, it always comes out to be Yes, it is possible.There are mainly three ways for time travel
Through the Wormhole
Wormhole is one the many fascinating topic among our scientist. It is theoretically possible to time travel through wormhole.
Wormhole can take us in one minute past. It is not much but still it is time travel and the fact is it is the only way to travel in past.
Though there are many problem associated with worm hole.
1) Its small size, even word small is too big. Wormhole is found (in theory) at the center of nucleus.
2) Even if somehow we manage to magnify the wormhole, even then it will not be possible to pass through it due to its very very high resistance.
3) And What if we travel back in one minute past and shot ourselves. Then what ? We are dead one minute before. But then who killed us ? It creates a paradox.
And this paradox is the best reason which state that nature will never allow us to travel in past.
Black hole
We have heard that Gravitational force attract object but the fact is even attract time. Like time near our Earth is dense.
What does dense time means ? It means time moves slow near Earth and yes it is proved by a experiment conducted by International Space station.
In the experiment two quantum watch were taken with same time. (Quantum watch are Highly accurate watch ) One watch was sent to Space station away from gravity while other stayed on earth.
After a year , it was found that Space’s quantum Watch was 1 Nanosecond ahead of Earth’s watch which proved that Yes, Time really moves slow near Gravitational Field.
Now what if we Revolve around Black hole which has infinite Gravitational force.
Yes, it will really work if somehow we can manage to revolve around Black hole. Time near the orbit of black hole move half of that on earth i.e.
If we revolve around it for 20 years, 40 years will pass on Earth.
Though it will be impossible since to revolve around black hole we will need speed greater than speed of light since even light cannot escape the gravitational pull of black hole and so it is impossible.
Another Black hole theory could be like that
Black holes generate intensely strong gravitational fields, so strong that they could actually bend space-time itself.
Time travel may be possible if you could enter a black hole and exit through a white hole on the other side.
While a black hole pulls everything toward it, a white hole would essentially push everything away from it, using you guessed it matter with negative energy density.
Though it sounds like a peachy theory, unfortunately, all known forms of matter have positive density.
However, exotic matter is predicted by quantum field theorists to exist, only it has yet to be produced and seems available in quantities far too small for actual time travel.
Don’t fret just yet; new research now proposes that time travel may be possible — without using exotic matter.
Speed of Light
One of the many interesting topic in physics is Speed of Light. Speed of light is topic of discussion since the era of Newton and it is still a controversial topic in Modern science.
Let’s get back to the point. Theoretically, if an Object travel at speed of light , time for it will stop completely.
To understand it more perfectly let us take an example.
We say that Light of stars take around millions of years to reach us. It is our perspective.
But for photon (Light particle), it take zero second to travel millions of light years i.e. for photon, it is emitted by the star and next moment it reaches to earth.
Why? Because it is traveling at speed of light and time for it becomes zero.
Now if somehow our train or spaceships are able to travel at speed of light, time for the person sitting inside that Train or spaceship will be zero.
But it is not possible to travel at speed of light since it is universal speed limit.
But the beautiful point in this theory is even if we are able to travel at 99% of speed of light we can still time travel at rate of 1 second on Train equal to 1 year on Earth.
So currently it is only possible way to travel in future.
Main problem in this theory is energy and work is going on in this field and latest discovery in the field is of Anti-Matter.
Mixture of Antimatter and matter creates tremendous amount of energy.
It has a drawback though. Once we travel in future we can never return back to present.
Conclusion
400 years back no one had thought that we can talk to a person 3000s of miles away with just a box in our hand but today smart phone are normal.
Similarly, implementation of this theory in practical may seems impossible at present but this does not mean it is impossible.
👇👇👇
