Is Time Travel even possible?

Is Time Travel even possible?

Lets just assume that scientist make a device of some sorts in future that lets humans travel through time in a proper physical form and your grandson wants his ancestors to be rich and go back in time to the young you and tells to invest in BitCoin, and you do but since you get rich at young age you never met his grand mother hence his father is not born and neither is he, but since he’s never born he can’t give you the tip to get rich hence you meet his grandmother had his father and then him, this endless cycle starts which we call as The Grandfather Paradox. This paradox is the thing which makes time travel more interesting and confusing. But it is also the thing that makes the whole concept of travelling into past nearly impossible. But still we can travel to the future.

Well The Grandfather Paradox effects time travel at a significant scale, so lets start with something much lighter. Lets say you and I synchronize our watches before I go into Space and make a few trips around the Earth at 30,000 Km/hr relative to Earth and then I come back. If we check then we will have difference in time passed for me and for you, for me time would have passed a bit slow, change that is almost unnoticeable. This phenomena is known as Time Dilation, it says “Time measured along different trajectories is affected by differences in either gravity or velocity – each of which affects time in different ways.”

Let’s see how Time Dilation affects the astronauts, an astronaut who has spent 6 months on the ISS (International Space Station) would age 0.005 sec lesser than the people on Earth. This change is very small but can be significantly huge when astronauts are traveling at the speed of light. The effects of Time Dilation are very small even at 70% speed of light but once we cross the 75% mark the effect start increasing significantly . But once we reach 90% speed of light that’s where things get interesting. If you travel to a planet 10 light-years away, at traveling speed equal to speed of light you would say it would take 11 years right, no it would take only 4.4 years or it would seem like that to the astronaut, so if you travel to Earth from a planet 20 light years away at 90% speed of light would get 9 years older while everyone at home would be 22 years old. You see space and time are two faces of a coin, at 90% speed of light not only time dilates but distance in space does too. How’s that time travel we in terms of space-time it is.

There is another method my use of gravity. As we have seen in the movie Interstellar, Cooper and his team arrive at Miller’s planet which has 130% gravity of Earth and it revolves around a super massive black hole Gargantua which has mass of 100,000,000 Sun’s, this causes the time for Cooper’s team to pass 61,000 times slower that their friend on the ship, which means every hour spent on that planet is equal to 7 years of their friend in space. Which means an object or planet with immense gravity should help us slow time for us.

For those who had the patience of reading the whole article. There is a theoretical way of travelling into the past, according to some theories, ”Specific types of motion in space might allow time travel into the past and future if these geometries and motions were possible”. Well this would require something called a Closed Timelike Curve (CTC), it is a closed loop in space time which would let an object to return to its own past theoretically at least or we could use worm holes which are approved by physics, we can make one end of worm hole stationary and another travel at speed of light and bring it back to original point as we discussed before it would experience time dilation if stationary worm hole experiences 20 years the other will experience only 9 years so we enter the stationary worm hole and travel 11 years into the past or place one end near an object with huge mass and bring it back and experience the same thing.