Is Time Travel possible in reality?
Category – Fun facts
Time travel is often considered to be a part of science fiction but time travel is indeed a real thing! It's not
quite what we usually see in movies where people use time machines. In fact, in reality time travel is
possible without any machine! Under certain conditions, it is possible to experience time passing at a
different rate than 1 second per second. And there are very important reasons why we need to understand
this real-world form of time travel.
There are four basic dimensions, namely height, width, and depth. We can have an almost infinite number
of positions inside of all three dimensions. The fourth dimension is time. But we are much more limited
in how we travel through this fourth dimension.
Well, we humans can't hop into a time machine and go back in time, but clocks on airplanes and satellites
travel at a different speed than those on Earth which leads to a change in how time travels!
At different altitudes, time passes differently. Even a small altitude difference can be detected with
sensitive enough equipment. A height difference of just 12 inches can make a difference in the speed that
time passes!
Two people can feel time at different rates. Time passes differently for someone who is moving fast,
compared to someone who is staying still. This is a very complicated idea called “time dilation. Even if
you flew all the way around the world, the time would only feel about a billionth of a second different to
someone who stayed home.
Albert Einstein had come up with an idea about how time works. He called it 'The Theory of Relativity’
which says that time and space are linked together. Einstein also said our universe has a speed limit:
nothing can travel faster than the speed of light (186,000 miles per second).
According to this theory, the faster you travel, the slower you experience time.
Hawking’s theory says that if we discover how to travel really fast, up to even half the speed of light in a
specially made train around the world for a period of time, the passengers after a week of really fast travel
would end up 100 years into the future from when the train first took off. It may just happen one day
when technology allows us to move so fast in time.
Also, time travel is possible if you have an object with infinite mass. Time travel is a one-way ticket. If
we go into the future, it is said we won’t be able to come back in the past!
Light has a fixed speed. It’s really, really fast, but things in the universe are so far apart that it still takes a
long time for light to reach us from faraway stars and planets.
When light arrives from the Sun, the light we see actually left the Sun eight minutes and twenty seconds
ago. This means we see the Sun as it was eight minutes and twenty seconds in the past.
So, we can easily see into the past, every night. The nearest galaxy to our Milky Way is 25,000 light years
away which means it takes the light 25,000 years to get here!
So, when we look at this galaxy through a telescope, we’re actually seeing it as it was more than 25,000
years ago. So, although we can’t time-travel ourselves, we can look up to the sky and see the past every
night!
