Often just called collimated light due to the collimator being the main procedure to obtain it.

However, you move very far away from the source, e.g. the Sun, you also get essentially parallel light.

Bibliography:

The most important type of lens is the biconvex spherical lens.

If you pass parallel light.

For a biconvex spherical lens, it is given by:where:

Ciro Santilli used to play video games when he was young. But after he reached 18 he got bored of them.

The problem is that no matter how you look at, the how to become famous in the real world game is just always more interesting and fulfilling.

Therefore adult Ciro enjoys only the following types of video game content in video form, so that other people waste their lives playing the games while you only see the highlights:

The aspect Ciro enjoys about non-PvP games is atmosphere. Not as conveyed by useless story telling, but as conveyed by music and graphics, and the context deep idea. Legend of Zelda and Metroid come to mind.

And too many games commit the sins of dependency of dexterity, no save states, how do I skip this boring part, or jump straight to the beautiful one?

Another important point is; the perfect video game is an infinitely hard one.

It also doesn't help if you are already typing on a computer all day long on your job. Hands get tired. Eyes have an infinite capacity to consume useless YouTube videos however. Medically proved.

As a result, Ciro just watches videos about video games. Notably games he played when he was a teenager and already understand the rules for.

And things got even worse as after Ciro Santilli's Open Source Enlightenment, and he started to feel bad about playing any game that is not open source.

Subsidiary of Carl Zeiss AG and also part owned by ASML, sole optics vendor of ASML as of 2020.

Can be approximated with a diaphragm.

The science and engineering of photons!

A bit more photon-specific than optics.

Funding:

As of 2025, this company was by far the most well funded in the field.

It was founded by some of the authors of the influential paper Deep learning with coherent nanophotonic circuits.

Presented e.g. at youtu.be/t0yj4hBDUsc?t=456 from Video "Silicon Photonics: The Next Silicon Revolution? by Asianometry (2022)".

Bibliography:

Funding:

This section discusses the pre-photon understanding of the polarization of light. For the photon one see: photon polarization.

polarization.com/history/history.html is a good page.

People were a bit confused when experiments started to show that light might be polarized. How could a wave that propages through a 3D homgenous material like luminiferous aether have polarization?? Light would presumably be understood to be analogous to a sound wave in 3D medium, which cannot have polarization. This was before Maxwell's equations, in the early 19th century, so there was no way to know.