- What were alpha and beta particles later shown to actually be?
Cryogenics and Low-Temperature Physics
The physics and technology of extremely cold conditions.
- How did Ramsay use fractional distillation of liquid air to isolate neon, krypton, and xenon?
- What temperature did Kamerlingh Onnes reach when he successfully liquefied helium in 1908?
- What later discovery did Kamerlingh Onnes make using the same cryogenic apparatus that liquefied helium?
- Why did liquefying helium open up a new experimental regime that room-temperature physics could not predict?
- How did Kamerlingh Onnes manage to liquefy helium when no one had achieved it before?
- What modern technologies depend on materials cooled near absolute zero?
- What modern technologies rely on the third law of thermodynamics today?
- How did evaporating liquid hydrogen repeatedly allow Urey to concentrate the heavier isotope enough to detect it?
- How does adiabatic demagnetization actually cool a sample to near absolute zero?
- Why did reaching temperatures within thousandths of a degree of absolute zero matter scientifically?
- Why was the Ivy Mike device impractical to deploy as an actual weapon?
- What happens to liquid helium below 2.17 kelvin that makes it a superfluid?
- How did Landau's two-fluid model explain superfluid helium's phonons and rotons?
- Why can superfluid helium climb up and over the walls of its container?
- Why does liquid helium lose all viscosity below 2.17 Kelvin, and what does 'superfluidity' actually mean?
- What other areas of physics did Feynman contribute to beyond quantum electrodynamics?
- What anomalous signal in the Cornell pressure readings led Lee, Osheroff, and Richardson to discover helium-3 superfluidity?
- How does helium-3 achieve superfluidity differently from helium-4?
- How did George Goble use liquid oxygen to light a charcoal barbecue in three seconds?
- How much faster was Goble's method compared to a conventional charcoal lighting approach?
- What happens to a cloud of atoms when it is cooled to within nanokelvins of absolute zero?
- What makes superfluid helium-3 behave so differently from an ordinary liquid?
- Why does cooling near absolute zero matter for keeping quantum behaviour from being washed out by thermal noise?