THE colour of the light which is emitted from the capillary of a vacuum tube containing pure hydrogen is the familiar vivid, deep pink, the prevailing tint being due to the predominating ...

Astronomers have identified a bright hydrogen emission from a galaxy in the very early universe. The surprise finding is ...

Evans found that the 4686 series and the Pickering series can be obtained in a helium spectrum showing no trace of the ordinary hydrogen lines. These series were observed a few years ago by Prof.

When a gas is very hot, it doesn’t emit all wavelengths of light. Hot gases don’t produce a continuous emission spectrum. Black hydrogen absorption lines are at the same wavelength as the ...