If you had the power to time travel, what would you do? Maybe you would visit the future and marvel at the advancements in technology. Maybe you would visit the dinosaurs. Maybe you would use your time travel abilities to win the lottery. Maybe you would take that chance you hadn’t taken because you were crippled with fear. Maybe you would change your life.
Picture a flat piece of fabric that is being held at the ends. If you drop a marble on it, the dip made will be barely noticeable. If you drop a big rock on the fabric, assuming the fabric doesn’t rip, the dip will be really big. This dip is what we call gravity. The whole fabric is called space-time, representing the fourth dimension — 3D objects and time.
A wormhole would be two holes in two different parts of the space-time fabric joined together. This wouldn’t be time travel, but it would definitely decrease the amount of time we spend crossing the expanse of space. Albert Einstein’s equations tell us that wormholes collapse very quickly and only work for small particles.
Einstein argued that time was relative. The passage of time (how fast or slow) depends on how close we are to the speed of light. Satellites are going at a faster speed than we observers on Earth. The clocks on satellites are 38 microseconds slower than the clocks on Earth. This effect is called time dilation. So, it seems that the faster we go, the slower our clocks are.
What if we go so fast that the clock turns backward instead? This could happen if we went faster than the speed of light (300,000,000 m/s). But according to Einstein, for something to go faster than the speed of light, it would need to have an infinite mass and a length of 0.
OK, let’s ignore the logistics. Let’s pretend we can actually time travel. What would happen then?
Let’s say your grandfather is evil, and you want to time travel because you want to stop him from being evil. So, you time travel, and you somehow succeed in making him not evil — either by helping him understand that being evil isn’t good or by killing him.
In the first scenario, it is highly likely you wouldn’t exist anymore. Our existence depends on a bunch of specific events that have occurred in the past. If the dinosaurs didn’t exist, you and I wouldn’t exist. If the asteroid that killed dinosaurs ended up not killing them, you and I wouldn’t exist. The dinosaurs had to die right at the moment they did for our existence to be real. So, with the first scenario, a bunch of things could have happened to your grandpa that would lead to you not existing.
Maybe he wouldn’t meet your grandma, or maybe he would meet your grandma later or earlier in his life. Either way, you would likely not exist.
With the second scenario, you would definitely not exist. By killing your grandfather, you are essentially ensuring that your grandparents don’t meet and produce one of your parents. Or, if you kill your grandpa after he has met your grandma, you might ensure one of your parents doesn’t meet the other parent. There is a lot that could happen by you traveling back in time that would most likely lead to you not existing. This whole scenario is called the grandfather paradox.
Imagine throwing a rock into a body of water. With just that one rock, there are many ripples. These ripples are analogous to the effects you can have if you time travel and change anything. Every small change you make will have a huge effect. This is called the butterfly effect, and it is something people warn about regarding time travel, but that is what we are doing in the present right now. Every small thing we are doing right this second is rippling out into our futures.
What ripples are you making?
Vaageesha Das is a junior at Morgantown High School.
Today’s information comes from:
- Hedquist, C. (2020, June 22). How would time travel affect life as we know it? Retrieved Jan. 31, 2021, from https://science.howstuffworks.com/science-vs-myth/everyday-myths/time-travel-affect-life.htm;
- Howell, E. (2017, November 14). Time Travel: Theories, Paradoxes & Possibilities. Retrieved Jan. 31, 2021, from https://www.space.com/21675-time-travel.html.
