Most of us experience time in a linear fashion running along
a line in a sequence. Just as you read this article you think it as of your
current moment(present) and as you go through the article every second before
the current moment it becomes your past and we believe we are on cutting edge
of time, it’s now. And then after some time it’s now again and that now is
gone. In a nutshell we experience time in a continuous flow, it’s all unfolding
of a moment after moment and we all agree what’s happening now. And in the fore
coming seconds this now will be our past and we will be having a new now
moment. All this is what we understand time as.
But is this the way how time works? Is this is what time is
about? Is this the reality of time? Answer is No. Time works a way too
different than what we assume it to be.
Consider various things happening right at this moment of
time like you picked a pen from table, some bird flies off, some star is
collapsed and some galaxy is formed. We will picture all these moments
happening at different parts of universe but at same moment in time are lying
on a single slice of space time. Let’s call it now slice. Our common sense say
that I and everyone else will agree on what’s happening and what exists right
now. Well this is true if all the events happening in different parts of
universe are still and not moving relative to each other. But if they move
relative to each other.
Einstein realized that when we take motion into account this
common sense picture of time goes out the window. To understand this think of “space
time” as a “hot-dog”. He realized that just as there are different ways to cut
a hot-dog into individual slices, there are different ways to cut space time
into individual now slices i.e. because motion effects the passage of time. Just as we know time moves differently for a
moving object than for a steady object. So someone moving have a different
conception on what’s right now so they will cut space time into a different now
slice. These slices will be at a different angle.
To get the feel of bizarre effect, imagine an alien 10
billion light years from earth and here is a guy on earth in his home. Now
if they are still i.e. if they are not
moving in relation to one another then their clock will tick of at same rate, so they share same now slice
which cuts straight across the hot dog. But what if the alien is moving cycling
directly away from earth. Since motion slows the passage of time their clicks
will no longer tick off the time at same rate. And if their clocks don’t agree
their now slices will no longer agree either, the aliens now slice cuts the
pace time differently. It’s angled towards the past. Since alien is cycling at
very low pace his slices angle to the past by merely a minuscule amount but across such a vast
distance that tiny angle result in huge difference in time.
So what alien would find on his angled now slice, what he
considers is happening right now on earth from his perspective no longer
include a guy sitting in his home. Rather it could be from some of the past
events like when he was a kid 40 years earlier which we consider as the events
of distant past on earth.
That’s not strange enough, the direction you move makes a
difference too. Now what would happen if alien cycles towards the Earth. The
alien new now slice is angled towards the future and so it includes events that
haven’t happened on earth yet and will happen after 200 years perhaps that
guy’s great great great grand daughter teleporting from Paris to India.
And here’s the leap, once we know that your now can be what
I consider to be the past or your now can be what I consider to be the future
and your now is every bit as valid as my now then we learnt that the past must
be real, the future must be real and it could be your now. That means past
present future all are equally real as they all co-exist.
Remember past is not gone and future is not in non-existence.
Just as we think of all space as being out there, we should also think of all
time as being out there too. Everything that has ever happened or will happen
it all exists. With this bold insight Einstein shattered one of the most basic
concepts of how we experience time.
A big thanks to Sir Albert Einstein in recognizing never
heard picture of time.
References: Books- The Fabric of Cosmos, The Elegant Universe; Google images.
