A joint Fermilab/SLAC publication
Logbook of February 2005
The Israel Museum, Jerusalem

Special relativity

02/01/05

Einstein had promised but later refused to publish this 1912 expository treatise, his earliest known manuscript on special relativity. No original manuscripts survive for the articles of Einstein’s 1905 annus mirabilis.

This page is from a section entitled “Equations of Motion of the Material Point.” Einstein shows how the most basic freshman-physics equations must change to fit the new world.

In the bottom paragraph, m is an object’s mass q; its speed, and is the speed of light in the vacuum. The text, continuing on the next page, reads: “The expression within the brackets on the right plays the role of the energy of the moving mass point. This expression: [formula 28] grows to infinity when approaches the value c; thus, it would require an infinite expenditure of energy to impart the velocity to the body.”

That is why even today’s highest-energy particle accelerators can only push particles to approach—but never equal or surpass—the speed of light.

The old Newtonian formula, gives zero if is zero. Here, for q=0 the formula reduces to a special case, called rest energy:E=mc2.

Logbook of February 2005
The Israel Museum, Jerusalem