IS TIME TRAVEL POSSIBLE? I ISABELLE
- hederahelixscience
- Jun 27, 2020
- 3 min read
The simple answer to this question is YES! Everyone travels in time. Today itself, you have travelled 24 hours in time. The real question then is, can you travel in time by greater or less than 1 hour per hour?
Albert Einstein is the scientist responsible for most of the theory which tells us that time travel might be possible. He developed his theory of Special Relativity. This is based on the fact that the speed of light is constant (which we know thanks to the earlier work of Michelson and Morley). Einstein stated that space was linked to time. Time serves as the fourth dimension. He called this system space-time and it is the model of the universe that we use today.
Light travels at 300,000 kilometers per second (or 186,000 miles per second) through empty space. Einstein’s theory of Special Relativity says that if you move through space-time at a speed, closer to the speed of light than other people, then time will go slower for you than for those you have left behind.
Now, we have proof that this is true…
In 1971, a group of scientists took 4 super-accurate atomic clocks (synchronized with other clocks left on the ground), aboard a plane. After the plane had flown around the world, the clocks on-board showed a different time to those left on the ground. This is known as time dilation.
We have another example from Sergei Krikaleve, a Russian cosmonaut. He is known as the greatest time traveller in human history. In 2005, he spent 803 days, 9 hours and 39 minutes orbiting the earth. During this period, he was travelling at 17,500 miles per hour. That is closer to the speed of light compared to people on earth. By the time he returned to earth he had time-travelled into his own future by 0.02 seconds. He experienced the effect of time dilation.
Now these might not sound like a very significant piece of time travel, but we do know that the faster you can go… the more time dilates. We know this thanks to Einstein’s theory of Special Relativity. If we could travel closer to the speed of light then the possibilities for time travel become more impressive...
One example states that, “if you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage, when you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Time will have passed more slowly for you: you will have experienced only five years of life, while your classmates will have experienced a full 50 years”.
The amount of time dilation that we can achieve today might seem small but it is significant enough to cause problems...
Satellites in the global positioning system (GPS) are hurtling around the earth at thousands of miles per hour. They travel closer to the speed of light that we on earth are travelling. This causes the effect of time dilation. The speed that they are travelling at, causes the atomic clocks on board to disagree with the clocks on the ground by seven millionths of a second each day. If this was left uncorrected this would cause GPS to lose accuracy by a few kilometres each day. GPS is so important to people on earth and so if it was losing accuracy each day, it wouldn’t be long before people were getting lost all over the world!
The main barrier to time travel will be trying to get heavy objects, like humans, and spaceships, to travel up to the speed of light. The amount of energy required to achieve this would be ridiculous! It already takes enormous particle accelerators like the large Hadron Collider to accelerate tiny subatomic particles so close to the speed of light.
One day we might be able to develop the technology to accelerate ourselves to similar speeds as subatomic particles in the Hadron Collider, and then we may regularly send time travelers into the future. Now the question of whether we will ever be able to go back in time remains more of a challenge to answer… and who really wants to go into the future, if we can’t then travel back to the present?
Sources used:
Is time travel possible? with Colin Stuart (Youtube)
Is Time Travel Possible?
Can we build a real time machine?
Isabelle
Comments