Time travel is a popular subject in science fiction. In the first, it popularized in 1895 when H.G. Wells wrote a novel The Time Machine which moved as concept of time travel by public imagination. After that many physicists give theories and concept to understand time travel.
Time travel is a concept which helps us to move between certain points in time. Time Machine also uses in time travel. It is a hypothetical device which helps to time travel.
Time travel may be in the past or in the future.
We all are travelling in future with 1 minute/ minute means that we travelling in future one minute in one minute. If we can do less or more it then we can travel in the past or in the future. Imagine you can less it like you are moving at 0.001 minute/ minute then you will go in past and if you are moving at 1 hour or 1 month or 1 year/ minute than you can go in future. But there is a big problem that how we can less it or more it.
There are three possible method to travel in time.
- According to Special Theory of Relativity
- According to General Theory of Relativity
- Via Warmholes
1. According to Special Theory of Relativity
We can go in future using The Special Theory of Relativity. Einstein tell about time dilation in his theory. If you move at near the speed of light (300,000 km/s) then you can go in future. At this speed, time would go slow for you than other people who is on the earth and time would go fast for people than you.
Imagine that you are going to a space mission at the speed of light. When you started it then you was 20 years old and your girlfriend was too 20 years old. After then you went to mission. On this mission, the time will be go slow for you than her and the time will go faster for her than you. Imagine after 2 years, you came again on the earth. So, when you will meet with her then she would 60 years old (may be more) and you only would 22 years old. So you will be in the future.
So why scientists are not going in the future? Because we haven’t got a space vehicle which travel at near the speed of light.
Before go in future, we have to build a space vehicle that move at the speed of light.
Scientists cannot know that how much time takes for traveler and other people who is on the earth. We don’t know the actual relativistic time.
2. According to General Theory of Relativity
Einstein give a theory on gravity which called General Theory. The theory predicts that time passes more slowly for objects in gravitational field than other objects which are far from the earth. There are many space and time distortions near black holes where is gravity very intense. This space and time distortions called space-time. So we can travel in time to travel in space and living near the black holes.
3. Via Warmholes
We can travel in time using warmholes (a kind of tunnel through space-time connecting otherwise very distant parts of the universe). But the warmholes are hypothetical. A natural warmhole is not possible. It may be shortcuts through space-time.
Many scientists say that if any warmholes formed after big-bang then it might have collapsed. So there are no possibility to form a natural warmhole.
Travel in past is very hard then future.
We can go in past using above theories. But there is an interesting fact that if we can go in past then we cannot come in future. Imagine that you are going to travel in past. You go in past and then you kill your girlfriend’s grandfather (just imagine) before her father’s birth. Then what will be existence of your girlfriend? If you kill then it will be two events at same time and same place. So, how is this possible? So, this is not solved yet. In that time, if we can go in past then we cannot come again in future.
So the simple answer is that time travel is not possible yet but it will be possible in the future. When scientists will make a space vehicle which travel at the speed of light then it will possible. But it is too hard to make such type space vehicle because it required infinitive energy. But it will be possible in future with advance technology.
In my view, we can solve this past time travel problem. It is an interesting way. If we can made space vehicle which can travel at the speed of light then we can solve this problem. We will send someone in past which understand how to make such type space vehicle. And when he reached in past then he will make this space vehicle and he will able to come in future again.
It is only my view. What are you think? Can he do this? or will he face problems? Give your opinion on this in comments.
Updated: Grandfather Paradox Resolved