What is actually happening when a superconductor refuses to fall.

A superconductor is a material that, below a certain temperature, conducts electricity with exactly zero resistance. Not “very little” — zero. A current started in a superconducting loop will circulate indefinitely without a power source.

That temperature is called the critical temperature, or Tc. For the YBCO used in our kits it is 92 K (−181 °C), which is why liquid nitrogen at 77 K is enough to get there. Conventional superconductors need liquid helium at 4 K, which is expensive and needs a cryostat — that difference is the entire reason a tabletop demonstration is possible.

The Meissner effect

When a material becomes superconducting it expels magnetic field from its interior. Surface currents arise that exactly cancel the applied field inside the material, so a magnet brought close is pushed away. This is the classic “floating magnet” demonstration, and it is genuinely different from ordinary magnetic repulsion — it is a consequence of the superconducting state itself.

Flux pinning — the interesting one

Real high-temperature superconductors like YBCO are not perfect. Magnetic field penetrates them in discrete tubes called flux vortices, and defects in the crystal structure pin those vortices in place. The result is that the superconductor doesn’t merely repel the magnet — it remembers exactly where the field was when it cooled.

That is why a levitator holds a magnet at any angle, upside down, at a fixed separation, and glides along a track without friction. Repulsion alone would be unstable and the magnet would slide off. Pinning is what makes it lock.

Why it matters beyond the demo

Frictionless magnetic bearings, maglev transport, MRI magnets, lossless power transmission and quantum computing hardware all rest on the same physics. The kit on the table is the same effect, at a scale you can hold.