Ciro Santilli @cirosantilli 37

Weight: medium.

Can import from: MIDI.

Can export to:

Cannot hear any sound from it on Ubuntu 20.04: askubuntu.com/questions/510052/how-do-you-get-rosegarden-to-play-sound-when-playing-a-midi-in-it

Part of the motivation letter required by some American universities explaining how amazing of a teacher you are, e.g.: wstein.org/job/Teaching/index.html

Predicted by the Dirac equation.

We've likely known since forever that photons are created: just turn on a light and see gazillion of them come out!

Photon creation is easy because photons are massless, so there is not minimum energy to create them.

The creation of other particles is much rarer however, and took longer to be discovered, one notable milestone being the discovery of the positron.

In the case of the electron, we need to start with at least enough energy for the mass of the electron positron pair. This requires a photon with wavelength in the picometer range, which is not common in the thermal radiation of daily life.