Ciro Santilli @cirosantilli 35

A function that maps two sets to a third set.

Theses places give out free food all the time.

The first time Ciro Santilli went to one was when an Indian friend of his took him to the one in the North of Paris when they were living there in the first half of the 2010's, the Gurdwara Singh Sabha France.

Much like Islam's Ramadan, Ciro Santilli appreciates this a lot due to due to Ciro Santilli's self perceived compassionate personality and Ciro Santilli's cheapness.

Instead of just talking, those people really go out, and put food on the plate for anyone who needs it (or even for those that don't really need it! Although who would be so souless to eat for free and not donate a few bucks if they can afford to???). There's a beauty to that.

Writing this also remembered Ciro of non-religious groups that would give out free food to the poor at

Once Ciro joked in a twenty questions-like game that humans are animals.

But counting humans a fish would have been a stroke of genius.

A fundamental component of three-level lasers.

As mentioned at youtu.be/_JOchLyNO_w?t=581 from Video "How Lasers Work by Scientized (2017)", they stay in that state for a long time compared to non spontaneous emission of metastable states!

phys.libretexts.org/Courses/University_of_California_Davis/UCD%3A_Physics_9HE_-_Modern_Physics/06%3A_Emission_and_Absorption_of_Photons/6.3%3A_Lasers mentions that they are kept in that excited state due to selection rules.

This is also one of mechanisms behind phosphorescence with triplet states.

This mostly faceless German dude is awesome!