[Still off-top] Physics [was Requests author discusses MentalHealthError exception]

[Dan Sommers]

On Fri, 04 Mar 2016 12:38:28 +0200, Marko Rauhamaa wrote:

> As for the existence of a negative mass, it is interesting to note
> that the (rest) mass of an alpha particle is less than the sum of the
> (rest) masses of its constituents. About 1% of the mass is "missing."

https://en.wikipedia.org/wiki/Binding_energy