1.4. I want you to remember that number long after you've finished this series. It's rare for the universe to just hand us a number that matters this much, one so central to how everything hangs together. We have a few of them. Pi. The number 4. The fine-structure constant, that mysterious 1 in 137. And today we're going to meet another: one point four.

But more important than the number is the person behind it. The man who worked out this number, or rather worked out why this number matters so much, was the Indian physicist Subrahmanyan Chandrasekhar. And since we went and named an X-ray telescope after him, then shortened it to Chandra, I feel fully entitled to hand him a nickname of my own, one that captures his enormous and sometimes overlooked contribution to physics and astronomy. Ladies and gentlemen, today we're telling the story of Big Chandra.

And there are three words for the arc of Big Chandra's career: triumph, humiliation, and vindication.

Let's start with triumph.

Big Chandra was born in 1910 in Lahore, though at the time he was still only a Little Chandra. Chandra, by the way, means "moon," or "luminous," in Sanskrit, which is lovely. His uncle was C.V. Raman, who would go on to win the 1930 Nobel Prize in Physics for the Raman effect, so there was no pressure at home to amount to anything (although the story goes that while working in his uncle's lab the young Chandra once broke a critical piece of equipment and decided on the spot that the experimental life was not for him).

His father wanted him in the Indian Civil Service: safe, prestigious, sensible. Chandra wanted physics. His mother took his side, with the warm and simple observation that a person does best the thing he most loves to do. He "compromised" on an honors degree in physics, and his father came around largely because Uncle Raman's fame had made a scientific career look respectable. So, thanks, Uncle.

Chandra had a big brain and worked years ahead of everyone around him. While he was at Presidency College, the great Arnold Sommerfeld, one of the literal architects of quantum theory, passed through on a lecture tour. Most students attended and grasped a fraction of it. Chandra had already read and mastered Sommerfeld's textbook, "Atomic Structure and Spectral Lines." And what did Sommerfeld tell him during that 1928 visit? That the textbook he'd mastered was now out of date. It was built on the old Bohr model of the atom, not the new quantum mechanics of Schrödinger, Heisenberg, and Dirac. Then, rather than just leaving him gut-punched, Sommerfeld handed him the galley proof of a brand new paper applying a fancy new mathematical tool, Fermi-Dirac statistics, to the behavior of electrons inside metals.

So now an undergraduate in India was holding advanced physics that most of Europe hadn't caught up with yet. He read it, understood it, and months later wrote his own paper building on the math.

Here's the piece Chandra had to get his head around, and it's worth getting yours around too. Electrons are antisocial. They obey a rule called the Pauli exclusion principle, which says that no two of them can ever occupy the exact same quantum state. Fermi-Dirac statistics is just the careful bookkeeping for a whole crowd of these antisocial particles. Squeeze a gas of electrons hard enough and they can't all pile into the lowest energy levels, because those seats are already taken. They get forced up into higher and higher energy states whether they like it or not. And that resistance to being crammed together produces a pressure, a stubborn outward push that has nothing to do with heat. It's called degeneracy pressure, and it persists even in cold, dead matter.

Which brings us to white dwarf stars, the puzzle Chandra couldn't stop chewing on. A white dwarf is something like the mass of the Sun crushed into the volume of the Earth. It's blazing hot, radiating away its energy, cooling off, and by every ordinary expectation it should be collapsing under its own gravity. But it isn't. In 1926 a Cambridge physicist named Ralph Fowler had cracked why: a white dwarf is held up not by heat but by exactly that degeneracy pressure. Its electrons are jammed so tightly that the exclusion principle itself props the star open. Fowler had shown that "dead" stars aren't so much dead as degenerate. A cooling ember of a star, held up by a purely quantum effect.

When Chandra needed an eminent name to submit his own paper to the Proceedings of the Royal Society, he sent it to Fowler, because Fowler was the one man who would instantly understand it. Fowler was duly impressed and got it published. Two years later Chandra won a scholarship to Trinity College, Cambridge, with Fowler quietly pulling strings behind the scenes.

Then came the boat. Chandra boarded a ship for a two-and-a-half week voyage to England with three things rattling around in his head: the mystery of white dwarfs, Fowler's paper on the subject, and Fermi-Dirac statistics. And somewhere out on the water, he spotted the opening everyone else had missed. Relativity.

Here's the picture. Think of the electrons in a white dwarf as bees trapped in a box. Shrink the box and the bees get angrier, buzzing faster, shoving harder against the walls. That shove is the degeneracy pressure. But there's a catch nobody had properly accounted for: as the box gets very small, the bees start moving at close to the speed of light, and once that happens the old rules break down. You need relativity. And relativity puts a speed limit on those bees. They can't push back any harder than a certain amount, because they can't move faster than light. Gravity, meanwhile, has no such limit. It can just keep squeezing.

Do the fully relativistic calculation, marrying quantum mechanics to special relativity in a way almost no one at the time could manage, and a number falls out. A maximum mass. Below about 1.4 times the mass of the Sun, a white dwarf can hold itself up with degeneracy pressure essentially forever. Above it, the bees lose. Gravity wins. And the star has nowhere left to go but down.

So here's a nineteen-year-old who has just made a genuinely major discovery and yet feels like he belongs nowhere. He arrives in England, his paperwork gets bungled, and he's nearly sent home before Fowler intervenes, aggressively (I picture a great deal of shouting and creative profanity). He'd wanted to do pure mathematics, got funneled into physics as the only viable path, and then solved a problem in astrophysics, a field he barely knew. He would later say he never really felt at home in it.

And he was a kid. A brilliant kid, which delighted the establishment when he worked on problems they liked and got answers they agreed with. It went over rather less well when he started suggesting that stars could die and never come back.

Enter the second act of his career: humiliation.

In Part 2, the most eminent astronomer in the world stands up in front of a packed room and sets out to demolish Chandra's discovery in public.