In March 2003, the FBI arrested a man named Andrew Carlssin. The newspapers reported that this man was extraordinarily lucky in the history of Stock Markets. He invested $800 and it turned out to be $350 million within two weeks. The FBI suspected him to be a scammer when Andrew was questioned he claimed that he was a time traveler who had come from the future. On the day of Andrew's bail hearing day he had disappeared and was never to be found. So this raised a question for many people about whether time travel is possible or not. According to science, it is possible to do time travel.
In 1885, a well-known writer H.G wells wrote the novel The Time Machine. It was after that the phrase "time machine" became popular. Although the novel was science fiction several philosophers and physicists were inspired by it. Time travel is of two types one is to travel in the future and the other is to go back into the past. The scientific theories behind traveling to the future, are derived from Albert Einstein's theory of special relativity. The concept of time dilation was introduced by Einstein. Before the theory of special relativity was introduced by Einstein it was believed that time is constant. Whether you are on earth or mars or near a black hole time was believed to be constant. According to Einstein time can be sped up and slowed down if the speed and gravitational force could be changed this is known as time dilation.
As of now, we can't travel into the past, but we can get a glimpse of the past. Because it takes time for light to travel, from one place to another, even with how fast light travels, if we talk about the distance of light-years, it takes years for light to travel to some places. So if we could reach somewhere before the light reaches there, and then look back at the approaching light, the light would be from the past. This is how we can see the past. On 28th June 2009 world-famous physicist, Stephen Hawking organized a party for time travelers this experiment was conducted to prove that it is not possible to travel to the past.