IN 1896 Prof. E. C. Pickering discovered a series of lines in the spectrum of the star ζ Puppis which has been attributed to hydrogen in consequence of numerical relationship to the Balmer series ...

THE SPECTRUM OF HYDROGEN IN NEBULÆ.—If hydrogen gas in a Geissler tube be examined spectroscopically, the brightest line observed is Hα. If, on the other hand, the lines of hydrogen in nebulæ be ...

Antimatter is matter that we don’t encounter very much in everyday life. This form of matter is different to the stuff we see around us. In simple terms, antimatter is matter that carries an opposite ...