Sambit Roychowdhury‘s essay: Stardust

Prthivyapastejovayuriti tattvani

Tatsamudaye sarirendriyavisayasamjnah

Tebhyaschaitanyam … 
 … Chaitanyavisitha kayah purusah 

Sarirad eva”
Earth, water, fire and air are the principles, nothing else

Their combination is called the “body”, “sense” and “object”
 Consciousness arises/is manifested out of these …

… The “self” is nothing but the body endowed with consciousness

from the body itself 1

The above lines are from the first aphorism of Charvaka’s Sutra which survive thanks to Madhavacharya and his 14th century CE comparison of sixteen philosophical systems, the Sarvadarsanasamgraha. Madhavacharya believed in Advaita philosophy, believed in a God, but was also a scholar and therefore also believed in the fairness of acknowledging the competitors and defeating them through arguments. Unfortunately though, as the present times prove once again, most believers in India tend to be rather more zealous regarding their beliefs, with little patience for contradictory views. It is not surprising then that the original Charvaksutra is long lost.

What is evident from the quoted text though is that there was/is a few thousand year old materialistic tradition in India, which had the courage to see the world for what it is without resorting to guesswork (anumana) or invoking any divinity. Charvaka’s view matches our present empirical understanding of the human body perfectly. As to how consciousness emerges from the mass of neural connections in our brains, Charvaka’s analogy is as good as any explanation we have yet managed to come up with. So ‘we’ are basically what we are made up of, but truly become ‘us’ when the magical thing called consciousness kicks in – possibly few months after conception. But what we are made of have been in existence for much much longer, in principle from the moment this Universe we know and can observe came into existence.

The Universe came into existence with the Big Bang about one thousand three hundred and eighty crore years ago. At Big Bang we have a Universe of infinite energy while all of space – which might be infinitely large – is infinitesimally small! I realize that the above statement is not something we are even remotely capable of visualizing as we are beings used to finite things, and so I will not even try to simplify it. So let us move a little ahead in time, which also starts at Big Bang and has a definite direction of increase. The Universe starts expanding and also starts to cool. Within this expanding Universe energetic photons collide to form proton & antiproton pairs, which promptly annihilate themselves and change back into photons. Ten-thousandths of a second after the Big Bang the Universe’s temperature has dropped below ten lakh crore degree Kelvin – water boils just below four hundred degree Kelvin – and the photons are not any more energetic enough to produce proton & antiproton pairs. Due to a subtle bias in the laws of physics though, for about every hundred crore proton & antiproton pairs produced and annihilated, one proton survives. These protons will form the basis of the nuclei of all elements that will ever exist in the Universe, including those that make up the cells in our body.

Of the other sub-atomic particles, neutrons freeze out – no more are created – about the same time as protons, whereas the much lighter electrons freeze out when the Universe is four seconds old. After about three minutes the Universe has cooled down enough (below hundred crore degree Kelvin!) to have also formed a spattering of heavier nuclei – a proton and a neutron, and two protons and two neutrons (nucleus of helium). But it will be three lakh eighty thousand years more before the photons that abound and surround these sub-atomic particles will stop interacting with them and allow protons and electrons to come together to form the first hydrogen atoms. Hydrogen atoms in our body are 10% of our body weight 2, and all of those atoms have been in existence for almost the entire lifetime of the Universe!

At this point the Universe is filled with a gas cloud consisting almost entirely of hydrogen other than a bit of Helium and traces of Lithium, and will remain so for at least the next fifteen crore years till the first stars start forming in the first galaxies. The first stars are almost pure hydrogen, and burn by converting hydrogen to helium through nuclear fusion. As the stars run out of hydrogen they become cooler and redder on the outside and their outer shells begin to expand, while simultaneously their cores begin to compress. The cores finally reach densities and temperatures at which the helium nuclei themselves begin to fuse, creating the nuclei of carbon, nitrogen, and oxygen, which constitute roughly 18%, 3%, and a whopping 65% (mostly as part of water) of our body weights respectively. These massive early stars end their lives within at most a few tens of crore years, exploding in massive energetic explosions called supernovae which spew out the newly created atoms into interstellar and sometime even intergalactic space. The next generation of stars would form from hydrogen mixed with these more heavy elements. They would be of varying masses, not all massive enough to end their lives with a bang as a supernova, but with a whimper instead. For example, our own Sun will end up as a cold and dense object called a white dwarf. But sometimes even white dwarfs can increase their mass above a critical limit, potentially by feeding off a companion star, and become a different type of supernova. From the calcium in our bones to the iron in our blood, all the atoms that make up the remaining 4% of our body weight are also made either in the cores of stars and dispersed into space when massive stars and white dwarfs explode, or created during the explosions themselves as is the case for iron 3. All these elements now enriching space also combine and form stable molecules that float around in space as solid particles, and we call these particles interstellar dust.

About four fifty crore years ago a run-of-the-mill star starts to form in an outer spiral arm of a normal galaxy we call the Milky Way or Akashganga. As the hydrogen cloud collapses under gravity into a spherical ball of fire, a rotating disk made out of interstellar dust also forms around it.  This disk will later fragment and form multiple planets, one of which is Earth. And about three fifty crore years ago by some as yet unknown process the first unicellular organisms start to thrive on Earth, created out of those same elements that we have been following throughout our little story. The jump to multicellular life will take a long time and happens sometime about sixty crore years ago. But once that happens, evolution takes over creating billions of species leading to the first Homo Sapiens appearing only about three lakh years ago. So here we are at the end of this fascinating journey, all made out of stardust, nothing more, but nothing less. 

1 from “Carvaka Fragments: A New Collection”, Ramkrishna Bhattacharya, 2002, Journal of Indian Philosophy 30, 597-640



Sambit is an Astronomer by profession. Passionate about (subaltern) history, art (including movies), and cricket, he likes to read, roam, and satiate the senses.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s