A MOST significant feature of the success of the quantum theory in explaining the sequence of radiation-frequencies forming the Balmer type of series in the spectra of hydrogen and ionised helium ...

The droplets are made of superfluid helium, which holds some unique properties ... the transparency over the spectral range from UV to the far infrared, and the almost non-existent interaction ...

It’s time to introduce our hero, (Joseph) Norman Lockyer (1836-1920). Lockyer was a respected though minor civil servant, working as a secretary for the War Office in Whitehall. He had a comfortable ...

The droplets are made of superfluid helium, which holds some unique properties compared to normal fluids. Some of those ...