Page 52 - INSPERIA-School Magazine TIGPSKON 2021.indd

ENTROPY AND TIME
ENTROPY AND TIME

ver dropped an egg on the floor just after you bought them outside and returned home? It would’ve been
some serious sort of mess, but there is something really cool in the process. Well, the egg slipping off
Eyour sweaty palm, falling on the floor and shattering into pieces does not quite amaze you. But what
if the pieces of the egg scattered on the floor, gathered themselves up, reformed as an egg as it lifts off the
ground and arrived gently on your palms. The latter simply doesn’t happen in this world and it’s obviously the
former process in a reversed way, just like playing a video clip backward. But the movement of every atom in
this time-reversed egg is perfectly consistent with the laws of physics. And yet this never happens!

The Second Law of Thermodynamics says, as one moves “forward” through time, the entropy of an isolated
system can increase. Now, what the heck is Entropy? Well, to put it short and clear, it is a quantity in physical
sciences that requires a fixed direction for time. To get its meaning more sorted out, practically it’s the count
of the number of different ways you can arrange the atoms and molecules of the matter microscopically,
keeping in mind that the macroscopic structure remains the same.
Despite being an abstract concept, people tend to have individual intuitive notions about Entropy. It is often
easy to tell a video if it’s moving forward or backward. Unlike the egg-dropping technique we discussed earlier,
if there’s a video showing a wood fire melting an ice block. Now play it in reverse, a puddle of water turned
into smoke into unburnt wood and froze itself in the process. Surprisingly, in both cases the laws of physics
remain intact. When a law of physics applies equally when time is reversed, it is said to be in “T-symmetry”.
So it is entropy that’s helping us distinguish a forward playing video-clip from playing backward. Hence,
Entropy measurement is a way of distinguishing the past from the future.

Now, can entropy of a system be decreased theoretically? Well, the Second Law of Thermodynamics just
stands as a barrier, due to which macroscopic objects are prevented from showing T-symmetry. And we
don’t know much enough in microscopic levels. But it is also fascinating that decreasing entropy is observed
in nature, such as in biological systems. It is quite possible that systems are open and the energy exchanges
create a large number of arrangements and the net factor remains the same- Increasing Entropy.
There are still a lot of questions unanswered in this domain of study, such as why the hell did the universe have
such low entropy in the past that resulted in a past-future distinction and The Second Law of Thermodynamics.
The answers we seek are scrambled out there and all we need to do is to play a jigsaw-puzzle game.

Rangan Chakraborty
Class XI

Section : Medical

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