Surely many of us would want to travel back in time for voting another politician, marrying another person, or choosing a different job. Just like we’re starting things over once again in a video game, why wouldn’t it be possible in real life as well? The laws of physics are there to shatter our dreams, as we’ve all been educated that time doesn’t forgive anybody and you can’t change the past. But still, things could be a bit different.
When we speak about time travel, it doesn’t necessarily mean to jump into an energy portal and then meet our inner self when we were a lot younger, as we’ve seen in sci-fi movies and cartoons. There’s not even one hundred percent guarantee that any sort of time travel will work. It would be more like “fooling” time, and we’ll get into detail right away.
Flying at the speed of light
Considering Einstein’s principles regarding relativity, we know that time depends on speed and gravity. The famous physicist has mathematically proven that time will flow a lot slower if you would jump into a spaceship that travels close to the speed of light. This means that if you travel through space at the speed of light for a few minutes, you could find your friends a few decades older compared to how you left them. This means that you would practically be able to travel into the future. Furthermore, you wouldn’t even feel time running slower.
If the spaceship will somehow surpass the speed of light, which is impossible for any object according to Einstein, time would run backward. In other words, all you have to do to repair your past mistakes is to build a spaceship that flies faster than the speed of light.
Of course, no spaceship is able to reach anywhere near the speed of light, not to mention to surpass it. But technology always reaches new heights and ways to bypass nature’s laws, and hoping doesn’t cost anything. Furthermore, Einstein wasn’t perfect. He also made mistakes. And maybe you’ll prove him wrong someday!
Jumping in a black hole
It’s certainly not worth the risk, as jumping into a black hole will almost surely kill you. But there’s a slight theoretical chance that black holes are portals to other dimensions of spacetime. And who knows, maybe a super spacesuit of the future will make astronauts able to withstand the tremendous gravity of a black hole and go beyond the event horizon without getting themselves killed.
The “Interstellar” movie released in 2014 was pure science fiction, indeed, and the famous astrophysicist Neil deGrasse Tyson confirmed for us that the scene where Matthew McConaughey’s character falls into a black hole to travel back in time is highly unfeasible in real life. But still, the movie speculates that slight theoretical possibility of traveling back in time using a black hole.
Last but not least, no scientist knows for sure what happens with all the matter absorbed by a black hole. That’s another reason to believe that great-great-great-great-grandmother could be waiting on the other side.
Spending time on another planet
Remember what we said earlier that time is dependent on gravity? Spending time on another planet that has a much different gravity than Earth would also cause your time to run differently than it does on our planet. Once you return home after plenty of time spent, you would find your friends, family, and even foes older than expected, judging by how time flows on Earth.
The method is also resulting from the famous Theory of General Relativity of Albert Einstein. Until now, humanity had never been to another planet, but that will soon change in the following decades. Unfortunately, we can’t count on Mars to solve our space travel fantasies.
Of course, nobody denies that humanity won’t be able to easily travel back into the past someday. Ironically, only time will tell for sure.