Monday's Google Doodle marks World Quantum Day, April 14. The occasion promotes "public awareness and understanding of ...

That’s pretty much all you need for instruments to determine Planck’s constant to a decent degree of precision, the way that [poblocki1982]’s did. There’s a little more to it, of course ...

Quantum superposition is a phenomenon in which a tiny particle can be in two states at the same time — but only if it is not being directly observed.

The wavelength emitted is a function of the energy times a constant (h), now known as Planck's constant. Though Planck's idea was not immediately believed by most physicists, it is now accepted as ...