Ciro Santilli @cirosantilli 37

The period does depend on the initial height/angle, except for the very small angle approximation:

In 2019, a paper proved that MTG is Turing complete with a legacy legal deck. Live demo with some hand waving: Video "I Built a COMPUTER in Magic: The Gathering by Because Science (2019)". As Ciro Santilli comments at: github.com/cirosantilli/cirosantilli.github.io/issues/42 this was an interest addition to the previous "indefinite infinite loop" e.g. as found in a Four Horsemen combo deck

On github.com/cirosantilli/china-dictatorship:

Given a linear operator $A$ over a space $S$ that has a inner product defined, we define the adjoint operator $A^{†}$ (the $†$ symbol is called "dagger") as the unique operator that satisfies:

Most commonly refers to: exponential map.

You could put an LED in a cavity with a thin long hole but then, most rays, which are not aligned with the hole, will just bounce inside forever producing heat.

So you would have a very hot device, and very little efficiency on the light output. This heat might also behave like a black-body radiation source, so you would not have a single frequency.

The beauty of lasers is the laser cavity (two parallel mirrors around the medium) selects parallel motion preferentially, see e.g.: youtu.be/_JOchLyNO_w?t=832 from Video "How Lasers Work by Scientized (2017)"