Category Archives: Fun with Physics

A Wave of Life

We have come across this unique entity in some form or another, sometimes on a daily basis. It is the enigmatic ‘Sine Wave’. I call it enigmatic because I think it encompasses in it a lot of secrets and has well… philosophical implications:

Sine Wave - Green Reflection Removed

Does the above ring a bell? Remember the heart beat or pulse monitoring machine? This is the kind of thing they display (roughly speaking).

Some background info (skip if you have a decent understanding of waves):

A wave is a phenomena that carries information or a signal. Sound Waves are one such example. So are Light or Radio waves.
The essence of a sine wave is this: It has crests and troughs or you could call them simply as ups and downs; or to and fro motion about an axis. Mathematically ANY Wave function can be represented as a sum of some sine waves.
If you are interested in a detailed understanding you can read the following section or choose to skip it:

Let’s see how we arrive at the ups and downs. Take the heart for instance. For simplicity let’s think it’s spherical with a radius. It pumps blood so it is constantly bulging as well as compressing itself…there are cycles. There is a normal state of the heart ( in which it is just it’s proper size neither expanding nor contracting) around which the cycles happen . Let’s say I am able to catch the heart ( not literally ) at it’s normal position on an instant where it is expanding. I call this as my start time or t=0. I will now measure the radius of the heart at this instant. And I will measure the radius of the heart an instant (making a note of the instance) later and as expected the radius will be larger ( since the heart is expanding). An instant later the heart will be bigger and hence my radius will be too…and this goes on until the heart reaches the peak of the wave ( or Up). Next it begins to compress so the radius falls until it’s normal position after which it continues to fall because the heart is now shrinking even more than it’s normal until it reaches a minimum where the heart and the radius are at the smallest and this marks the lowest peak ( or Down ). After this point the heart begins to grow again and so on. If you were to plot the radius of the heart now V/S time you would get a sine wave!

Note: This is not to say that this is what hospital machines display. No one is interested in the radius. It displays the electrical activity but the concept is similar. I have taken a few liberties like assuming the heart is a sphere but yeah I am just trying to get the concept across.

Back to the topic now:
Ups and Downs, Downs and Ups. Cycles. Hmm. If in a similar way I were to plot the intensity of light at different points of the day. Then I would get say sometime where the sun’s light is brightest (i.e the Up…Mostly some time during mid day ) and sometime at night when the light is absent or it is the darkest (i.e the Down… Around midnight) and the other values would be in between. So if I plot this data I might roughly arrive at…the sine wave!
It is all around us really. The Day and Night Cycle. The Breath. The Heartbeat. The Pulse. The Tides of the sea. The Light waves. The Sound waves.
They are all the variation of some sort of sine wave or simply a wave.
And perhaps this phenomenon is internalized within us in multitude ways. Perhaps this logic could be extrapolated to ourselves? Our states of mind perhaps? The highs and lows. Happiness perhaps? Highs and Lows. So luckily it means that if we are down for a while it wont be long before a UP wave hits us and life becomes good! So keep going! ( Of course we should be vary of the other way around…and not be carried away completely when we have our highs!) . In another sense it is a law of averages. Everything evens out. As an optimist I would hope for highs everyday but the fact also is – it has not happened (yet). But of course I will keep trying!

I am likely going overboard with this (which is perhaps the point of a blog). But while we are at it let’s make a daring speculation: Do we experience the highs simply because we had the lows before and we will have the lows after. And we are experiencing a low simply because what follows will be a high…and for it to be a high this has to be a low.

I know…too general and taking too many liberties but something to think about. If everyday was the same would there be highs and lows?

Which reminds me of what Ted said to Barney, ” If every day is legendary, no day is legendary .”


Schrodinger’s Cat

               Meow. This cat has been haunting a lot of people since a while. Let’s let the cat out of the bag…um box. This is a classic conundrum which has been around since way back in 1935 and there is still no unanimous agreed upon answer. There is a lot of confusion to what this thought experiment is, leave alone the answer to it.


               How did it arise? There exists a concept in physics called quantum mechanics (fascinating but bewildering area). One of the interpretations of quantum mechanics is the Copenhagen interpretation which states that microscopic particles like electrons  exist as a ‘superposition of states’ which means we can only know the probabilities of the state in which they exist. The act of measurement or observation causes the wave function to collapse and the electron then takes one of these states. In simpler terms say we are considering the position of an electron (we could also consider momentum etc) . The electron initially exists in a superposition of states which means we don’t know where it exists. The very act of measurement causes the electron to ‘collapse’ randomly  into one of the positions which means observation or measurement affects outcome. Schrodinger who was one of the founding fathers of Quantum Mechanics argued this principle in a letter to Einstein through a thought experiment which came to be called Schrodinger’s cat:

 Conceptually the idea of this experiment is this:

‘A cat exists in a closed box which contains a radioactive substance. The substance has a 50% chance of decaying. If it does the cat dies, if it does not the cat lives.‘

              We don’t know if the cat is dead or alive until we open the box. Now according to the Copenhagen interpretation of quantum theory until the box is opened and a result confirmed, the cat lies in a superposition of states which means it is ‘both dead and alive’.

              Schrodinger did not suggest that the cat was both dead and alive, he did this experiment to illustrate the absurdity of quantum theory since a cat cannot really be both dead and alive at the same time (like yeah, what does that even mean! Way to go Schrodinger!)

             Still trying to digest this but a curious thought hit me when I was doing a popular yoga practice called observation of breath. So in this practice one needs to simply focus on his breath. When I try doing this I actually feel my breathing change…become faster or slower (not saying this is a rule…but what generally happens). The act of observation affects outcome! Now we could say that this is really a part of my body and by me observing I am somehow changing a part of my body. But in a way we are all a part of a single entity…the universe. So  observation by us (a part of the universe) of a part of the universe affects the outcome (breath). We could extrapolate this to us observing the cat and thereby affecting the outcome! Hmm.

            Love to hear your thoughts.