Tapasya and Sanatan Dharma: How a Biologist Perceives Them Through Thermodynamics.

Tapasya.

An integral part of Sanatan Dharma, it is translated as penance, austerity, devotion, or meditation, depending on context.

Tapasya is deep spiritual austerity. It is sustained, disciplined effort, held for long stretches of time. It endures heat and cold, hunger and stillness. It masters the body and the mind.

Sages sat in it for years.

Devas withdrew into it.

Kings left their thrones for it.

They did it to purify themselves.

To earn a boon.

To make the divine turn and look at them.

Tapasya runs through the whole of Sanatan Dharma like a hidden current, and almost every great figure, at some point, sits down and begins it.

I am a biologist. And I am surrendered to Krishna. I look at Sanatana Dharma through the lens of biology. Not to shrink it, but because I believe a truth this old will show itself in more than one language.

And when I look at tapasya, I perceive it through thermodynamics, the science of energy. I want to be careful and honest here. I see the slow, patient storing of energy, moment by moment, over years. And once you see tapasya that way, an old and sobering story begins to mean something new.

It is the story of a sage named Kapil, and sixty thousand princes who did not stop to think.

King Sagar sent a horse to wander the earth. Wherever it walked unchallenged, that land became his. His sixty thousand sons rode behind it, guarding it.
But Indra, the Vedic God of weather and the king of the devas, grew watchful of how vast a mortal king's power was becoming. He is the lord of storm and rain and the heavens. To guard the balance of his own realm, he took the horse and carried it deep beneath the world, to a place called Patala. There he left it beside the sage Kapil, who had been sitting in tapasya for so long that time itself had stopped counting the years around him.

The sixty thousand came searching. They dug down through the earth. And at the very bottom of the world they found the horse, standing quietly beside the silent, motionless sage. They did not stop to ask. They saw the horse, they saw the man, and they decided he had stolen it. They raised their weapons and rushed him.

Kapil opened his eyes.

And in that single moment, the sixty thousand were gone. Not killed the way men are killed in war. Turned to ash. Sixty thousand princes became sixty thousand small grey heaps on the floor of the world. And it was finished before a single one of them could complete the step he had begun.

Now I want to tell you what I see in that sage.

For uncountable years, Kapil sat in tapasya. And to a biologist, that long discipline has a shape I recognise. It is the shape of storing energy against the natural direction of things.

Think of charging a battery. Energy does not flow into it on its own. You have to connect it to a source and push the energy in, slowly, against the way it wants to go. Left alone, a battery never fills itself. It gains its store only because effort keeps being fed into it, moment after moment.

Biology has a name for this. We call it an endergonic process. The word means one thing: uphill. Energy stored slowly, against the current. And only for as long as effort keeps being poured in. There is no other way to fill the store. You cannot rush it, and you cannot skip it.

That is what Kapil was doing, all those years. He was storing energy within himself. Pouring discipline in, moment by moment. Storing something that would never have gathered on its own. A slow, uphill, endergonic climb. And by the end, he held an enormous store of energy inside him.

But a store like this is never truly still. Leave a charged battery alone and it slowly leaks away on its own. And the same is true of everything we build.

A voice left unpractised loses its edge.

A discipline left unkept begins to loosen.

A trained mind, untended, softens.

This is why tapasya is not a summit you climb once and then own forever.

It is a climb you are always making, because the ground is always sliding back beneath you. The store holds only for as long as the effort keeps being fed into it. Stop feeding it, and it begins, quietly, to return to where it came from.

Then the princes rushed him. And in that moment, Kapil felt anger. And with that anger, he let everything he had stored so slowly come out at once.

Return to that battery. Filling it takes hours of patient charging. But damage it, let its two ends touch, and it short-circuits. Every bit of stored energy pours out in a single second. As heat. Violently. And the battery destroys itself.

Biology has a name for a release like this. We call it an quick exergonic process. It means the opposite of the first word: downhill. Energy flowing out on its own, freely, needing no effort to make it happen. Not the slow climb, but the quick fall.

Kapil's release was exergonic. Years of stored energy, let go. But I have to be very careful here, because this is the heart of the whole thing. Being exergonic, being downhill, is not what made it destroy.

Here is what I did not understand at first, and what I most want you to understand.

Downhill does not have to mean destruction. Energy can flow downhill slowly, or all at once. It can be let out under control, or in an uncontrolled flash. And that difference, not the direction, is everything.

Think of the same battery again. When it powers your phone through a whole day, that is also exergonic. Also downhill. Also the store flowing out. But it flows out slowly, under control, tied to useful work. And so it serves you.

When it short-circuits, the very same energy floods out all at once, uncontrolled, tied to nothing. And so it destroys. Same battery. Same direction. Opposite outcomes. The difference is control.

And your own body is the proof. Right now, inside you, there is enormous energy locked in the food you have eaten. If your cells released it all at once, it would be Kapil's gaze. You would burn from the inside. But they do not. Your cells let that energy out slowly, in small controlled steps. Each step is tied to useful work. And so much of it is captured and put to use, instead of lost.

That is what metabolism is. It is the art of releasing a stored fortune slowly enough, and carefully enough, that it powers a life instead of ending one.

Even this careful release is not free. Even when your cells do everything right, they still lose a real part of every fortune as plain heat. They hold the energy back. They let it out in small steps. They tie each step to useful work. And still, some is always lost. Perfection was never on the table. Control does not mean nothing is wasted. It means enough is kept to go on living. That is the most that careful release can buy.

Not a perfect saving, but a survivable one. And it turns out that is enough. It is, in fact, the whole of what keeps you alive.

There is a word for that carefulness. Reversible. A release so slow and so controlled that little is lost, and it could almost be run backward. And there is a word for its opposite.

Irreversible. A release so fast and so violent that it can never be undone, and everything is lost. Your living cells stay close to the careful side.

Kapil, in his anger, crossed all the way to the other. He chose the flash. And the flash cannot be taken back.

So the sixty thousand were not destroyed because energy came out of Kapil. They were destroyed because it came out all at once, uncontrolled, tied to nothing, in a single irreversible flash of anger. Released slowly, the very same store could have sustained. Released the way he released it, it could only turn princes to ash.

And now I want to step back, because this is not only one story.
When I look across Sanatan Dharma, I see this same shape returning, again and again. A person spends years in discipline, slowly building something rare within themselves. And then, in a single moment, they surrender to a fast reaction. Anger. Pride. Desire. And all that was gathered over years floods out at once, uncontrolled, tied to nothing, and is lost.

I do not believe the sages were teaching thermodynamics. They were teaching restraint. They were warning us about the moment of surrender, the instant that undoes a lifetime.

But as a biologist who has given himself to this tradition, I cannot help perceiving something. Their warning and the physics of energy fall into the same shape. What you gather slowly, you can lose in a single uncontrolled instant. They saw it in the language of sages and gods. I perceive it in the language of energy. And the two do not argue. They agree.

This is not only a story about ancient people in an ancient world. Because Sanatan Dharma never taught tapasya as something only sages in forests could do. It taught tapasya as a way of living. And a way of living does not belong to one age. It belongs to every age, including yours and mine, today.

Everything worth having is still built the slow way.

A voice trained to sing.

A skill practised for years.

A discipline held morning after morning.

A steady and quiet mind.

None of these fill on their own.

You have to pour the effort in, slowly, uphill, against the current. Every one of them is a tapasya. These are not merely like tapasya. They are tapasya. Each one is the same slow, uphill, endergonic climb the sages sat down to make, only in the form your own life takes.

You are meant to spend what you store. The singer is meant to sing. The trained mind is meant to be used. Storing is not the whole of it. The question is how you spend it. You can release what you gathered slowly, under control, tied to something worthy. Then it will create and sustain, the way your own cells turn a stored fortune into a living day.

Or you can lose it all in a single uncontrolled moment, tied to nothing. And it will destroy in seconds what took years to build. That is the flash sitting inside the ash.

So this is what the story leaves me with. Store slowly. And when the time comes to spend, spend with control, tied to something worthy. Never let yourself short-circuit.

This is not an old rule for old people.

It is what Sanatan Dharma has been teaching all along, as the way to live, in any age. And underneath it, it is also, exactly, physics.