What is time travel? Is time travel possible
Time travel is the concept of movement between certain points in time, analogous to moving between different points in space by an object or a person.
Time travel is a widely-recognized concept in philosophy and fiction. The idea of the time machine was popularized by H. G. Wells in 1895 novel “The Time Machine”.
While most of the people think that time as a constant, the physicist Albert Einstein showed that “time is an illusion; it is relative, it can vary for different observers depending on your speed through space”.
The great scientist Albert Einstein developed a theory called Special Relativity (the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels). The ideas of Special Relativity are very hard to imagine, but scientists have confirmed them.
This theory says that space and time are really aspects of the same thing as space-time. Special Relativity also says that, when you move through space-time, Time goes slower for you than for the people you left behind in the earth. So, if your journey began in 2018, it would have taken you only 5 years to travel to the year 2068. In a sense, this means you have been time traveling. This is a way of going to the future at a rate faster than 1 hour per hour.
Einstein had another remarkable theory called General Relativity, which predicts that time passes more slowly for objects in gravitational fields (earth) than for objects far from such fields.
Both the general and special relativity theories have been proven with GPS satellite technology that has very accurate timepieces. The effects of gravity, as well as the satellites, increased speed above the Earth relative to observers on the ground, make the unadjusted clocks gain 38 microseconds a day.
It is called a time dilation, means astronauts are time travelers, as they return to the Earth they were very slightly younger than their identical twins that remain on the earth. And one of the scientists said “we all constantly time travel but it is in only one direction. We re inevitably moving 1 second at a time into the future, and we could go faster if we wanted”.
While Einstein theories are difficult to make time travel, so some scientists have proposed alternate solutions for time travel. These are Tipler cylinder, Black holes, Cosmic strings.
I am confident in time travel into the future is may be possible, but we would need to develop some very advanced technology. But, Time travel to the past is more difficult.