The Strange History of Zero Resistance

A 113-Year Journey from Frozen Mercury to Room-Temperature Dreams

How We Learned That Electricity Can Flow Forever — and Why We Still Can’t Do It at Room Temperature (Yet)

Stephen Horton | Independent Researcher | February 2026

The Wave Coherence Blog Series — Part 1 of 2 Part 2: Wave Coherence Demystified — The PART Framework

The Day Electricity Stopped Resisting

On April 8, 1911, in a basement laboratory in Leiden, the Netherlands, a Dutch physicist watched his instruments do something impossible. The electrical resistance of mercury didn’t just drop. It vanished.

Heike Kamerlingh Onnes wasn’t looking for superconductivity. He was looking for what happened to metals when you made them really cold. Two years earlier, he’d become the first person to liquefy helium — reaching 4.2 Kelvin, or about –269°C — and now he was methodically dipping various metals into the stuff to measure their resistance.

The prevailing theories of the day made three different predictions about what should happen to electrical resistance at absolute zero. Some physicists thought resistance would gradually approach zero as atoms stopped vibrating. Others thought it would plateau at some minimum value determined by impurities. A third camp, led by Lord Kelvin himself, predicted that electrons would freeze in place and resistance would shoot to infinity.

Onnes picked mercury because it could be purified to extreme levels — you need clean data when you’re settling a three-way bet between theorists. What he got instead was a result none of them predicted.

At 4.19 K, the resistance of mercury didn’t gradually decrease, didn’t plateau, and didn’t increase. It dropped off a cliff. One moment it was measurable. The next, his instruments read zero. Not approximately zero. Not very small. Zero.

Onnes initially suspected his equipment was broken. He repeated the measurement. Same result. He wrote in his notebook, with the understatement characteristic of the era: “Mercury has passed into a new state, which on account of its extraordinary electrical properties may be called the superconductive state.”

He had just discovered a phenomenon that would consume physics for the next 113 years — and counting.

Quick Physics Primer: What Is Resistance, Anyway?

Before we go further, let’s make sure we’re all on the same page about what “electrical resistance” actually means, because it’s the thing superconductivity eliminates.

Atoms, Electrons, and Current

Everything is made of atoms. Atoms have a nucleus (protons and neutrons) surrounded by electrons. In metals, the outermost electrons aren’t bound tightly to any single atom — they form a “sea” of free electrons that can drift through the material. When you apply a voltage (like plugging something into a wall socket), you push those free electrons in one direction. That flow of electrons is electrical current.

But here’s the problem: those electrons don’t flow smoothly. They slam into things.

Resistance: Electrons Pinballing Through a Crowd

Imagine rolling a marble through a room full of people who are all swaying and shuffling in place. The marble bounces off legs, gets deflected, loses energy with every collision. Some of that kinetic energy turns into heat (the people’s legs get warm from being hit). The marble does eventually make it across the room, but it’s lost most of its energy along the way.

That’s electrical resistance. The “people” are atoms in the metal lattice, vibrating because of their thermal energy. The “marble” is an electron. Every collision transfers some of the electron’s kinetic energy to the lattice as heat. This is why wires get warm when you run current through them. This is why power lines lose 5–7% of all generated electricity between the power plant and your house. This is why your phone charger gets hot.

Resistance is waste. It’s the tax you pay on every electron you move.

THE NUMBERS ARE STAGGERING: The U.S. power grid loses roughly 5% of all electricity to resistance in transmission lines alone. That’s about 200 billion kilowatt-hours per year — enough to power every home in California, Texas, and New York combined. Globally, transmission losses waste more energy than most countries generate. If you could eliminate resistance from the grid — even partially — the implications for energy, computing, transportation, and medicine would be civilization-altering.

Temperature and Vibration

Here’s the critical connection: temperature is atomic vibration. When we say something is “hot,” we mean its atoms are vibrating violently. When something is “cold,” its atoms are barely moving. At absolute zero (0 Kelvin, –273.15°C), atoms would theoretically stop vibrating entirely.

So Onnes’s logic was sound: cool a metal down, its atoms vibrate less, electrons bounce off fewer things, resistance drops. Every physicist expected this. What nobody expected was that the resistance wouldn’t just decrease — it would disappear completely, all at once, at a specific temperature.

That abrupt transition — not gradual, but a sharp phase change like water freezing into ice — meant something fundamentally new was happening. Something that would take 46 years to explain.

The Fermion Problem: Why Electrons Shouldn’t Be Able to Do This

To understand why superconductivity was so baffling, you need to know one thing about quantum mechanics: the universe has two kinds of particles, and they follow completely different rules.

Fermions: The Loners

Electrons, protons, and neutrons are fermions. Fermions obey the Pauli Exclusion Principle, which says: no two identical fermions can be in the same quantum state at the same time. This is why electrons in an atom arrange themselves in shells — each electron must have a unique set of quantum numbers. It’s why matter is solid, why you don’t fall through your chair, why chemistry works.

Think of fermions as extreme individualists. They cannot occupy the same spot, ever. Two electrons in a wire will always maintain their own distinct states and trajectories. They are fundamentally incapable of acting in unison.

Bosons: The Herd

Photons (light), phonons (sound/vibration), and certain atoms are bosons. Bosons follow the opposite rule: any number of identical bosons can occupy the same quantum state simultaneously. This is why lasers work — trillions of photons all in the same state, same frequency, same direction, perfectly synchronized. Bosons are natural conformists. They actually prefer to pile into the same state.

Here’s the paradox: superconductivity requires electrons to move in perfect lockstep — all in the same state, all flowing together with zero resistance. But electrons are fermions. They are physically forbidden from doing this. So how does superconductivity exist at all?

THE FERMION-BOSON CHEAT SHEET:

Fermions (half-integer spin: 1/2, 3/4, …): electrons, protons, neutrons, quarks. Only one per state. Makes matter solid and chemistry possible.
Bosons (integer spin: 0, 1, 2, …): photons, phonons, gluons, Higgs boson. Unlimited per state. Makes lasers, superfluidity, and superconductivity possible.
The key trick: two fermions can bind together to form a composite boson. 1/2 + 1/2 = 1 (integer spin). The pair now follows boson rules. This is the entire basis of BCS theory.

46 Years of Confusion: 1911–1957

For nearly half a century after Onnes’s discovery, superconductivity resisted all attempts at theoretical explanation. Some of the greatest minds in physics took their shots and missed.

Albert Einstein tried in 1922. He proposed that supercurrents flowed along chains of molecules, but the model didn’t hold up. Werner Heisenberg, Felix Bloch, Niels Bohr, Richard Feynman, and Lev Landau all attempted explanations at various points. None succeeded completely.

The problem wasn’t that these physicists weren’t smart enough. The problem was that the answer required a fundamentally new idea — one that seemed to violate a basic law of quantum mechanics. How do you make fermions act like bosons?

Meanwhile, experimentalists kept finding new superconductors. Lead (Tc = 7.2 K), niobium (Tc = 9.3 K), niobium-tin alloys (Tc = 18 K). Each one superconducted only at temperatures near absolute zero. Each one exhibited the same sharp phase transition. And in 1933, Walther Meissner and Robert Ochsenfeld discovered something even stranger: superconductors don’t just conduct without resistance — they actively expel magnetic fields from their interior. This “Meissner effect” proved that superconductivity wasn’t just perfect conductivity; it was an entirely new state of matter.

The Breakthrough: BCS Theory (1957)

The answer, when it finally came, was elegant, counterintuitive, and worth a Nobel Prize.

In 1956, Leon Cooper — a young postdoc at the University of Illinois — showed mathematically that something surprising happens when you add just two electrons to a filled Fermi sea (the quantum mechanical description of all the electrons in a metal) at low temperature. Even an arbitrarily weak attractive interaction between them causes them to form a bound state. These bound pairs of electrons are now called Cooper pairs.

How Enemies Become Partners

This is deeply weird. Electrons are negatively charged. They repel each other. How can they form a “bound pair”? The mechanism is indirect, and it involves the very lattice vibrations (phonons) that cause resistance in normal metals.

Picture it like this: an electron zooms through the crystal lattice. As it passes, its negative charge pulls the nearby positive atomic nuclei slightly toward it — the lattice distorts, just a tiny bit, creating a fleeting region of slightly positive charge density in the electron’s wake. A second electron, some distance behind, feels this positively-charged wake and is drawn toward it. The two electrons never interact directly — in fact, in a typical superconductor, the two electrons in a Cooper pair are separated by hundreds of nanometers, with millions of other electrons in between.

The lattice vibration — the phonon — is the matchmaker. The first electron creates a disturbance; the second electron surfs on it. The attractive force is unbelievably weak, which is why it only works at very low temperatures where thermal vibrations are small enough not to shake the pairs apart.

An electron distorts the lattice. A second electron rides the disturbance. The lattice — the very thing that causes resistance in normal metals — becomes the glue that eliminates it. The enemy becomes the ally.

The Fermion Loophole

Here’s where Cooper’s insight solves the fermion paradox. A single electron has spin 1/2 — it’s a fermion. But a Cooper pair consists of two electrons with opposite spins: +1/2 and -1/2. The total spin is 1/2 + (-1/2) = 0. Zero is an integer. A Cooper pair is a boson.

And bosons can all pile into the same quantum state.

When enough Cooper pairs form, they undergo Bose-Einstein condensation — they all collapse into a single, macroscopic quantum state. Every pair moves in lockstep. Every pair has the same momentum. The condensate behaves as a single quantum object spanning the entire material. One wave function describes the whole thing.

In this state, there is simply no mechanism for resistance. Scattering an electron out of the condensate requires breaking a Cooper pair, which costs energy (the “superconducting gap”). At low temperatures, the thermal environment doesn’t have enough energy to pay that cost. The current flows forever.

THE BCS SUMMARY:

Electrons repel each other directly, but lattice vibrations (phonons) can mediate a weak attraction.

At low temperature, this weak attraction binds electrons into Cooper pairs.

Cooper pairs have integer spin (0), making them bosons.

Bosons can all occupy the same quantum state simultaneously.

The condensate of Cooper pairs is a single macroscopic quantum state with no resistance.

Breaking a pair costs energy (the gap). Below Tc, the thermal bath can’t pay the price.

John Bardeen, Leon Cooper, and Robert Schrieffer published their theory in 1957. It became known as BCS theory after their initials. They received the Nobel Prize in Physics in 1972. It remains one of the most successful theories in all of condensed matter physics.

The Temperature Ceiling: Why BCS Had a Speed Limit

BCS theory was beautiful. It was also discouraging.

The math was clear: the critical temperature Tc depends on the phonon frequency and the strength of the electron-phonon interaction. Both are fundamentally limited by the materials involved. Run the numbers for conventional metals, and BCS theory predicts a hard ceiling somewhere around 30–40 K (–233°C). That’s warmer than liquid helium, but still brutally cold — achievable only with expensive, specialized cryogenic equipment.

For decades, this seemed like the end of the story. Superconductivity was confined to laboratory curiosities. Useful applications (MRI machines, particle accelerators, sensitive magnetic sensors) existed, but they all required liquid helium cooling. Room-temperature superconductivity — the holy grail — seemed physically impossible.

Then in 1986, everything changed.

The Cuprate Revolution: Rules Were Made to Be Broken

Georg Bednorz and Alex Muller, working at IBM’s Zurich Research Laboratory, discovered superconductivity at 35 K in a lanthanum barium copper oxide ceramic. Within a year, other groups had pushed the temperature above 77 K — the boiling point of liquid nitrogen, which costs about the same as milk per liter.

This was a revolution. Liquid nitrogen cooling is cheap, safe, and practical. Suddenly, superconductor applications that had been science fiction were engineering problems.

But there was a theoretical crisis lurking beneath the excitement. These “cuprate” superconductors (named for their copper-oxide layers) blew past the BCS ceiling. YBa2Cu3O7 superconducted at 93 K. Thallium-based cuprates hit 125 K. Mercury-based cuprates reached 133 K, and under pressure, 164 K.

BCS theory said this shouldn’t be possible. The electron-phonon coupling in these materials was too weak to explain such high critical temperatures. Clearly, something else was going on — but nobody could agree on what. Hundreds of theories were proposed. Magnetic fluctuations, spin resonances, exotic pairing symmetries. Nearly four decades later, the mechanism of cuprate superconductivity remains unsettled. It is arguably the biggest open question in condensed matter physics.

The Hydride Era: Crushing Atoms Into Submission

While the cuprate mystery simmered, a parallel track was developing based on an idea from 1968. Neil Ashcroft at Cornell predicted that metallic hydrogen — hydrogen compressed to such extreme pressures that it behaves like a metal — should be a high-temperature or even room-temperature superconductor. The reasoning was pure BCS: hydrogen is the lightest element, so it vibrates at the highest frequencies, which should translate to the highest Tc.

The problem was that metallic hydrogen requires pressures above 400 GPa (about 4 million atmospheres). Nobody could achieve that reliably. But a workaround existed: hydrogen-rich compounds, where a heavier element provides “chemical precompression” — essentially pre-squeezing the hydrogen into a metallic-like arrangement at lower (but still extreme) pressures.

In 2015, the dam broke. Mikhail Eremets and colleagues at the Max Planck Institute compressed hydrogen sulfide (H3S) to 150 GPa inside a diamond anvil cell and measured superconductivity at 203 K (–70°C). This was the highest Tc ever measured — by a massive margin — and it was a conventional, BCS-type superconductor. The phonons were doing the heavy lifting, exactly as Ashcroft predicted.

The floodgates opened:

Year	Who	What Happened
2015	Drozdov, Eremets et al.	H3S at 203 K (150 GPa) — first hydride superconductor
2019	Drozdov et al.	LaH10 at 250–260 K (170 GPa) — near room temperature
2023	Multiple groups	Confirmed magnetic flux trapping in hydrides, proving bulk superconductivity
2025	Ma et al.	La-Sc-H ternary system reported at 298 K — above room temperature (high pressure)

The temperatures were astonishing. 250 K is –23°C — a cool autumn day. 298 K is 25°C — actual room temperature. But there was a catch, and it was an enormous one: the pressures required were between 150 and 250 GPa. That’s the pressure at the center of the Earth. You can create it in a laboratory with diamond anvil cells, but only for tiny samples (microns across) under conditions that are completely impractical for any real-world application.

We had proven that room-temperature superconductivity is physically possible. Now we needed to figure out how to do it without recreating the conditions at the center of the planet.

Where We Stand: The Trillion-Dollar Question

As of early 2026, the state of superconductivity research looks like this:

The good news: we know room-temperature superconductivity exists. BCS theory and its extensions (Migdal-Eliashberg theory) can predict which materials will superconduct and at roughly what temperature. Computational screening has identified hundreds of promising candidate materials. The physics works.

The bad news: every room-temperature superconductor discovered so far requires crushing pressure. Attempts to “quench” the pressure — synthesizing the material at high pressure and then releasing it while maintaining the superconducting phase — have shown some promise but no breakthrough. Nobody has achieved ambient-pressure, room-temperature superconductivity in a bulk material.

The frustrating news: BCS theory tells you that a material will superconduct and approximately where (at what temperature), but it doesn’t give you much intuition about why certain structural motifs produce anomalously high critical temperatures, why some materials show weirdly strong flux pinning, or how to systematically reduce the pressure requirements. It’s a calculation engine, not a design tool.

And that gap — between computation and physical intuition — is exactly where the PART framework enters the picture.

What Comes Next: A New Way of Listening

Everything you’ve just read — the discovery, the 46-year mystery, Cooper pairs, the fermion loophole, the cuprate revolution, the hydride breakthroughs — rests on one theoretical framework developed in 1957. BCS theory is extraordinary. It earned a Nobel Prize. It predicted hydride superconductivity fifty years before it was observed.

But it has a blind spot.

BCS theory describes superconductivity as an electronic phenomenon: electrons pairing, condensing, flowing without resistance. The lattice — the crystal structure, the vibrations, the sound — is treated as a background player. A matchmaker that introduces the Cooper pairs and then steps offstage.

What if the lattice isn’t the matchmaker?

What if it’s the main act?

In Part 2, we introduce the Parametric Acoustic Resonance Theory (PART) — a framework that reinterprets superconductivity not as electron pairing, but as acoustic cavity resonance. The lattice doesn’t just introduce the Cooper pairs. It builds them a stage, tunes the instrument, and plays the music. And the thermal environment doesn’t fight the superconductor — it powers it.

But first, you needed to understand the history. You needed to know what BCS theory gets right, where the gaps are, and why 113 years of brilliant physics still hasn’t solved the ambient-pressure problem. Because PART doesn’t discard any of this. It adds a physical layer — an acoustic engineering interpretation — that reveals design parameters BCS theory can’t see.

Phonons are quantized sound. Everyone knows this. What PART asks is: what if we took that seriously?

Appendix: The Complete Superconductivity Timeline

Year	Who	What Happened
1911	Kamerlingh Onnes	Discovers superconductivity in mercury at 4.19 K
1933	Meissner & Ochsenfeld	Discover the Meissner effect — superconductors expel magnetic fields
1935	London brothers	Phenomenological equations describing Meissner effect and penetration depth
1950	Ginzburg & Landau	Phenomenological theory using order parameter (Nobel 2003)
1950	Froehlich; Reynolds et al.	Isotope effect proves phonons are involved; phonon frequency matters
1956	Cooper	Shows that even weak attraction binds electron pairs in a Fermi sea
1957	Bardeen, Cooper, Schrieffer	BCS theory published — complete microscopic explanation (Nobel 1972)
1957	Abrikosov	Predicts Type II superconductors with vortex lattices (Nobel 2003)
1960	Eliashberg	Strong-coupling extension of BCS — Migdal-Eliashberg theory
1962	Josephson	Predicts quantum tunneling between superconductors (Nobel 1973)
1968	Ashcroft	Predicts metallic hydrogen would be a room-temperature superconductor
1986	Bednorz & Muller	Discover cuprate superconductivity at 35 K in LaBaCuO (Nobel 1987)
1987	Wu, Chu et al.	YBa2Cu3O7 at 93 K — above liquid nitrogen temperature
1993	Hg-Ba-Ca-Cu-O	Cuprate record: 133 K (164 K under pressure)
2001	Nagamatsu et al.	MgB2 at 39 K — a conventional BCS superconductor above the “ceiling”
2006	Kamihara et al.	Iron-based superconductors discovered — new family, new mystery
2015	Drozdov, Eremets et al.	H3S at 203 K under 150 GPa — hydride era begins
2019	Drozdov et al.	LaH10 at 250–260 K under 170 GPa
2023	Multiple groups	Flux trapping confirmed in hydrides; strong pinning anomaly observed
2025	Ma et al.	La-Sc-H ternary reported at 298 K (room temperature, high pressure)
2025	Errea, Chen et al.	Ambient-pressure high-Tc predictions: RbPH3, KB3C3, Mg2XH6
2026	Horton	Parametric Acoustic Resonance Theory (PART) proposed

The Wave Coherence Blog Series Part 1: The Strange History of Zero Resistance Part 2: Wave Coherence Demystified — The PART Framework Stephen Horton — Independent Researcher — February 2026