Can you see the past by time travel?
In the past, some paradoxes about time travel have caused a lot of trouble. Now what is the paradox ? Let’s start with the paradox.
Paragraphs of the paradox
The word paradox means ‘deception’ or ‘seemingly contradictory’. This eliminates the possibility of anything. This paradox is used to mean something that is interrelated but contradictory.
In physics, the time-travel paradox is divided into two major parts : one is the Consistency Paradox , which is explained by the example of the Grandfather Paradox. The other is the casual paradox, that is, the unconventional cycle. It is also called casual loop. This means turning around and seeing the change in the previous position. This is a game of loop. Let’s try to figure out what the paradoxes are before time travel.
Casual loop or unconventional cycle
When the past is changed by a future event, then the future event also naturally changes due to a change in that past event (i.e. the first mentioned future becomes another future), this event is called casual loop.
In that case, the two events then coexist in space-time but their past cannot be found precisely. The casual loop may be due to an event, person or object, or information. In the case of story-novel, the term casual loop is used instead of boot-strap paradox, predestination paradox or ontological paradox.
Hitler’s paradox
Coming to the real place, this paradox is quite funny. Suppose for some reason time travel was possible in the past. I made you a time machine, you went to the past using this time machine. You went to the time machine in 189. Hitler was born on April 20, 189. As soon as he was born, you shot and killed him.
Will this poor have any more history? For example, he has become known as a villain all over the world by killing Jews. For which we know him today. If he had lived as an ordinary citizen of Austria at the time and died of natural causes, we would certainly not remember him today, would we? And since, according to this paradox, you killed him right after he was born in the past, a murder case will be filed in your name in Austria for the murder of a child named Hitler. Nothing more is happening? That means no one will remember him from generation to generation. Neither you nor I. So why would you go back to the past and kill Hitler?
Bootstrap paradox
In the case of the Bootstrap Paradox , the word Bootstrap here means “pull oneself over a fence by one’s bootstraps”. I’m explaining.
This paradox refers to any discovery that, if taken in the past, would lead to the question of ‘who invented it or where did it come from or where did it originate’. Do you feel dizzy? Let’s explain in simple examples .Like the previous paradoxes, this time you will travel to the past by time travel. However, in this paradox, you have to take some things with you. Getting into one end of the time machine and exiting through the other end, let’s go to the past, say, to 5-year-old poet Rabindranath Tagore. Going there, you handed over the Gitanjali book of poetry to Ravi Tagore. He was pleasantly surprised! ‘What’s this again?’ You said ‘this is your writing’.
Notice, you have already given the poet his book of poetry, which the poet himself did not write. So who wrote it? Ravi Tagore published a book of poems exactly like the Gitanjali that you have given, which is similar to the Gitanjali that you have brought, matching every word. The point is that Ravi Tagore composes that book of poetry by photocopying the knowledge you have given, so who wrote the book of poetry that you brought in the past? Where is the origin of the book of poetry?
Answer: Unresolvable. That means there can be no such thing as an object or knowledge without existence or ownership. Does this mean that it is possible to travel to the past according to this paradox? Of course not.
The paradox of the firm
If time travel is possible then where are the time travelers? Why haven’t you come yet? ” — The paradox of time travel can be summed up as follows. This is known as the paradox of Fermi.
The answer to the paradox, however, is that “time travel is not possible” or “future travelers will not be able to attend any event / place where conflict occurs” or “they wander around in disguise so that no one can recognize them.” However, Carl Sagan himself spoke of the possibility that they could turn around in disguise and be around us.
That means this can be answered in such a way that if you go past, your presence will be such that you can’t do anything from there or no one will find you there.
Grandfather Paradox
What is Dadajan’s fault here? There is nothing wrong. I will do a theoretical experiment with a little grandfather! How’s that again?
The paradox of grandparents about grandparents can be called the king of all the paradoxes of time travel. The possibility of full time travel is ruled out for this paradox. Suppose a person wants to travel to the past by time travel. Okay, time machine went into the past. Going to the past, he killed his grandfather right after birth. Then his grandfather died as a child. Since the grandfather died as a child, it is impossible for the father of that person to be born, because the grandfather did not give birth to any children. And if the father was not born, where did that person come from? Busy! This one question is enough to prevent time travel to the past.
That means if you go to the past and do all the activities that question the identity of the present, then how do you travel to the past?
There are two common theories about the paradox of time travel. Assuming that after the above paradox we became upset that time travel might not be possible, the possible solution to all these paradoxes. However, let’s go to the solution of the paradox.
Let’s talk about Novikov’s theory of self-defense .
Novikov’s self-consistency theory
This theory was discovered by the Russian physicist Igor Dimitrievich Novikov. According to this theory, even if one travels back in time to the past, one will not be able to engage in any activity (meaning the world will not allow that to happen according to the laws of the world) that will affect its actual present. Suppose a person goes to the past and tries to kill himself as a child, he will not be able to do so. Because according to the rules, if he kills his childhood, his existence becomes impossible. Maybe he goes to where he used to live as a child and tries to find himself in childhood then he will see that they are not there. No other family is living there. The world has changed their position. According to this theory, no matter how hard one tries, one cannot do anything that will change the real present.
This means that according to this theory, it is possible to create a possible solution to the grandfather’s paradox, bootstrap paradox, etc.
Seth Lloyed of the Massachusetts University of Technology and his research team describe Novikov’s theory in some detail: “The chances of escaping the paradox will always change as needed. That means you can travel to the past but you will not be given any power to kill grandpa.
You have to work in the midst of limitations so that the past does not erode the point of your current existence. Do you want to kill Hitler as a child? It turns out you can’t find him. This means that everything that exists now will remain unchanged. There is no chance to start a new life by correcting one’s mistakes in the past.
Let’s end this by telling a short story :
Stephen Hawking hosted a dinner party on June 26, 2009 at a place near Cambridge. However, he invited people to the end of the party, the time was June 29. At the end of the party, he made an ‘invitation letter’ to attend the June 26 party. He believed that someone from the future would travel to the party with this invitation letter to attend the party. How strange! However, this possibility can not be blown away.
Written by : Md. Wasif Bin Hafiz
