How would you like to return to the future in a DeLorean car? Or traveling with the USS Enterprise crew to rescue the whales? These two examples (from "Back to the Future" and "Star Trek IV: The Journey Home") show a very common trope in science fiction time travel.
We all have things that we regret in life, so turning back the concept of Time (or reversing Earth's rotation in the case of a "Superman" movie) is inviting. Who would not want to repair the past or erase a regrettable historical event that has had a negative impact on humanity? Or for people who are more focused on the future, how about the time to see a beautiful event ̵
Time travel is at the heart of episode 6 of "AMC Visionaries: James Cameron's History of Science Fiction," which airs during a two-hour finale tonight (May 25) at 9 pm EDT / PDT (8 pm CDT) as part of the 2-hour relay finale of the show. [How Time Travel Works in Science Fiction (Infographic)]
A scientist points out that we're all traveling all the time – but it's all about one direction. We'll inevitably move a second into the future and we could go faster if we wanted to.
"In fact, we can jump as far as we want, it's all about going really fast," said Paul Sutter, astrophysicist at Ohio State University, Space.com in an email. He began by citing evidence from Albert Einstein's Theory of Special Theory of Relativity, which shows that time is relative, depending on how fast you move.
"The faster you move through space, the slower you move through time To measure this with ultra-precision atomic clocks in jet aircraft, the accuracy of the GPS system must take this into account. Sci-Fi always seems to require complicated equipment To jump in time when all you need is very big rocket, "wrote Sutter.
This means that astronauts, for example, are already time travelers. Because they go into space and live on the International Space Station, sometimes for months. At a speed of about 8 kilometers per second, astronauts on the space station are moving faster than we are on Earth. This means that astronauts only age a little bit slower on the station than on the planet's surface. (And when astronaut Scott Kelly returned to space after a year, the gap in age widened a bit with his slightly older identical twin Mark.)
Jumping into the past
But many sci-fi franchises focus on time travel in the past. Such trips raise neat questions, such as whether you can go back in time and kill your own grandfather (a puzzle sometimes referred to as "the grandfather paradox").
Sutter pointed out that the physics of our universe seems to ban this situation, at least as far as we can see. But surprisingly, some of Einstein's equations from general relativity can enable time travel into the past. (This theory basically discusses how huge objects distort space-time, which we perceive as gravity.)
So how could Einstein's theory allow for time travel? Well, one way would be to break the cosmic speed limit and go faster than the speed of light – but that probably would not work because an object traveling at that speed would have infinite mass. Another possibility would be to make "wormholes" between points in space-time, although this would probably only work for small particles. There are even more exotic possibilities, such as the use of black holes, huge cylinders, or cosmic strands to play with the fabric of space-time.
"When It Comes to the Past," said Sutter, "The Mathematics of General The theory of relativity allows for some strange scenarios in which you can land in your own past, but all of these scenarios violate other known physics, such as The Need for a Negative Mass or Infinitely Long Rotating Cylinders Why does general relativity allow for time travel in the past? Physics always jumps in to spoil the fun? We honestly do not know it. "
But that does not mean that scientists give up. In 2015, Ali Övgün of Eastern Mediterranean University in Cyprus said that wormholes in dark matter zones are possible. (This is a theoretical form of matter that can not be seen or otherwise perceived by telescopes, but is shown in its gravitational effects on other bodies.) While his equations show that wormholes can occur in these regions, Övgün said he always still looking for evidence. "It's just a mathematical proof," he said. "I hope one day it will also be possible to find direct experimental evidence."
Even the world-famous physicist Stephen Hawking was fascinated by the idea of the journey through time before his death this year, when he spoke in the Daily Mail about how a black hole could make it possible. "Around them, they would only experience half the time, far away from the black hole, the ship and its crew would travel through time," he wrote in 2010. The physicist Amos Iron of the Technion-Israel The Institute of Technology in Haifa , Israel, said that a machine orbiting a black hole would probably decay before moving quickly.
A Review of This Series:
This story was inspired by episode 6 of "AMC Visionaries: James Cameron's Story of Science Fiction," aired during a two-hour finale at 10 pm tonight EDT / PDT (9 o'clock CDT) .A companion book is available on Amazon.com.
Follow us @SpaceTotcom Facebook and Google+ .Original article on Space.com.