Physics students often ask how it is that a massless photon can have momentum. In this video, Fermilab’s Dr. Don Lincoln shows that the question arises from a misuse of equations and also shows that, when you think about it, it’s not surprising at all.

Why E = mc2 is wrong:

The origins of mass:

Further reading:

http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/releng.html

Fermilab physics 101:

Fermilab home page: