Time travel, a concept straight out of science fiction movies, is actually already happening, but not in the form of a plutonium-powered DeLorean jumping to the past and future.
Time travel is already possible. In fact, a time machine has already been built. Scientists, however, are still working on how to make it as efficient as possible, like in the Back to the Future movies.
Traveling Through Time At The Speed Of Light
"The faster you move through space, the slower you move through time," said Ohio State University astrophysicist Paul Sutter. He added that while movies always need some sort of complicated contraption to travel through time, all that is needed is a large rocket.
Time travel is actually already happening. Astronauts living on the International Space Station are moving faster than the people on Earth. This means that astronauts age slightly slower in space than they would back home.
One example of a time traveler was cosmonaut Gennady Padalka, who arrived back on Earth in September 2015 after breaking the record for the longest stay in space at 879 days.
"When Mr. Padalka came back from his adventures, he found the Earth to be 1/44th of a second to the future of where he expected it to be," wrote Princeton physicist J. Richard Gott in his book titled Time Travel in Einstein's Universe. "He literally traveled...into the future," Gott wrote.
Meanwhile, a real time machine has also already been built. It does not look anything like a DeLorean, but it is actually rather popular in the field of science, namely the Large Hadron Collider.
The Large Hadron Collider propels proton at nearly the speed of light, which is a speed that makes the relative time of the protons move around 6,900 times slower compared to human observers. In essence, the protons are being sent into the future.
The Hurdles To Time Travel
Astronauts and subatomic particles being sent a fraction of a second into the future, however, is far from the end goal of time travel. The mission, of course, would be to transport humans through the fabrics of time.
There is still an immense gap between the concepts of time travel and making it real. The first challenge would be making a vessel that could travel at the speed of light. The Parker Solar Probe will soon become the fastest spacecraft, but it will travel only at .00067 percent the speed of light.
The required energy and safety measures for such a spacecraft would be immense, which means that a time machine for humans will likely not happen in this lifetime. Stephen Hawking, however, believed that time travel will be unlocked in the future.