India's Great Physicist and Mathematician Satyendra Nath Bose Biography

The Amazing Physicist and Mathematician Satyendra Nath Bose.

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Satyendra Nath Bose

Satyendra Nath Bose was born in India in 1894, and he was an amazing student. He went on to do his bachelor's and Master's in Applied Mathematics. After his Masters, Satyendra Nath Bose then took up a position at the university as a research scholar in mathematics and physics.

This involved a lot of teaching but also studying the scientific literature.

During his time as a research scholar, Satyendra Nath Bose gained expert knowledge in a number of areas. This included: thermodynamics and the theory of relativity. So basically all the stuff they talk about on “The Big Bang Theory”.

Now some years back, Albert Einstein (who is pretty much really famous among scientists and non-scientists as an amazing physicist) he and other physicists at the time were making amazing discoveries in physics which basically was the beginning of what we call: Quantum Physics.

It’s actually really interesting! Satyendra Nath Bose’s great discovery came while he was preparing a lecture for his students. He was trying to relate the law of radiation (such as light) to what we call the “Maxwell Boltzmann Distribution”

This distribution is a calculation that describes how atoms/molecules in a gas state behave. So this calculation states that atoms and molecules in a gas form tend to move quite freely in a container. And don’t tend to interact with each other (except for brief collisions where they would exchange energy with each other).

Now from this diagram that I’m showing you, it’s really important to note the difference in colors of these atoms and molecules. And this was the assumption made in this calculation; that the different atoms and molecules within this gas form are distinct. And this is key. Because while this holds
true for a lot of atoms and molecules, this is not necessarily the case for what we call “quantum particles”. Now you might be asking yourself “What is a quantum particle?”

Well, it’s basically the smallest physical particle that’s involved in any interaction. So if we take light for example (this is what Satyendra Nath Bose was actually working on at the time) light is an electromagnetic field. And what we call a “photon” is a tiny bundle of this electromagnetic field. And we
therefore class it as the quantum particle of light.

Now Satyendra Nath Bose was getting ready to give his lecture on the law of radiation. But he couldn’t for the life of him match how photons behave experimentally to this Maxwell Boltzmann distribution (which describes how atoms and molecules behave in a gaseous form).

Now if you remember, I said that this calculation assumes that each particle within that container of gas is different. However, Satyendra Nath Bose did his calculations and treated each particle as being exactly the same.

This formed the basis for what we call “Quantum statistics” because we now know that these particles follow Satyendra Nath Bose’s calculations (which we call Bosons; after him) they have a certain type of spin. And we characterize this spin in numbers.

Because these certain particles (which we call Bosons) have this whole number spin, it means that let’s take photons for example; Identical photons do not repulse each other and so they can
occupy the same energy state.

Now just to clarify, particles can occupy different energy states. For example, at different temperatures, let’s say at a lower temperature a particle can occupy a lower energy state. At a higher temperature, a particle can occupy a higher energy state.

An example of how Satyendra Nath Bose’s calculations (to describe Bosons and how they behave) in the real world can be seen is through the use of atom lasers. Photons in atom lasers can occupy the same energy
state because they are Bosons. And so this means that in atom lasers photons can be focussed onto an extremely small bright spot.

Satyendra Nath Bose sent his calculations (which is now known as Bose-Einstein statistics) to Einstein himself. Einstein agreed with Bose’s calculations and actually expanded these calculations from their use on photons to atoms.

Bose-Einstein Condensates

This led to the prediction of what we call “Bose-Einstein Condensates”. An example of this is Helium-4 which is the gas that makes your voice go [high pitch] really really high.

Helium-4 atoms contain 2 electrons, 2 protons, and 2 neutrons. And so it gives the whole atom an overall spin of 0.

Because Helium has a whole number spin, this means that the atoms act according to the Bose-Einstein statistics. And just to recap, this statistic states that certain particles (Bosons) can occupy the same energy state.

So in the case of helium, at room temperature, it acts as a normal gas; the atoms can occupy different energy states.

However, when Helium is cooled down to near what we call “absolute 0” so ~2 Kelvin, these helium atoms actually occupy the same lowest energy state. And what happens when they all occupy this energy state?

You get what we call a “superfluid”. Now superfluids are literally the stuff that you see in the movies. Like it’s crazy and creepy as hell. This superfluid has zero friction. It can leak through containers.

It defies gravity and so can crawl up walls. That to me is creepy as hell, it’s cool as hell, and it’s literally like some superhero type of stuff. And this phenomenon could have only been predicted and tested because of Satyendra Nath Bose’s calculations.

Now just to give a complete picture, there are quantum particles that don’t act like bosons. These are called “fermions”. Now remember how I said that boson particles have a whole number spin, well fermions have a half number spin. So this can be a ½, 1 ½, 2 ½, and so on.

And if we take electrons for example, which are fermions, they have a half spin. And can spin either upwards or downwards. And because of this half number spin, it means that the same type of electrons (these 2 blue electrons) repulse each other.

And because they repulse each other, it means that the same type of electrons cannot occupy the same energy state (or same quantum state). This can be illustrated when we look at an oxygen atom. From this diagram, you can see that the electrons that are paired together in the same energy state are different colors.

You will never get the same type of electrons paired together in the same energy state. These electrons and other fermions follow what we call the “Pauli Exclusion Principle”.

Now let’s finally talk about how Satyendra Nath Bose was recognized for his work. Well, first of all, the paper he wrote describing these calculations was rejected. Great! It turns out the journal he sent this paper to didn’t actually see the significance of this work. Hmm, interesting. So Bose sent this paper to Einstein. Einstein translated this paper to German and submitted it to another journal under Bose’s name.

And once this paper had been published, it actually opened up quite a few doors for Bose. He was able to travel to Europe where he worked with Einstein as well as Marie Curie. And these were 2 people who received Nobel Prizes that we know very well.

So naturally, you might be thinking “Well did Satyendra Nath Bose get a Nobel Prize?”  The answer is no. He didn’t. Now he was nominated for a Nobel Prize in Physics, however, someone on the Nobel committee didn’t think that his wor was worthy of a Nobel Prize. Ironically, 7 Nobel Prizes have been awarded for research related to Bose’s work.

Very Interesting. So in conclusion, I hope from this video that we’re all a little less scared of physics and quantum statistics, but also, and more importantly, I hope that we’re much more aware
of the ground-breaking work that Satyendra Nath Bose did in physics.