Lasers emit a narrow spectrum by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
It emits a very narrow range of frequencies (small linewidth), which for many purposes can be considered a single frequency.
It does however have a small range of frequencies. The smaller the range, the better the laser quality.
Laser linewidth by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Video 1.
Laser linewidth - measurement and explanation by Your Favourite TA
. Source.
Breakup of the Bell System by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Video 1.
AT&T Breakup-the day after in 1984
. Source. Good documentary from the time. TODO actual title and producer.
Magnetic core by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Figure 1.
Hand drawn schematic of the magnetic field induced in a magnetic core by an electromagnetic coil
. Source.
Notion (productivity software) by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Video 1.
9-Year Hustle to Achieve a Single Goal by EO
. Source. Interview with Akshay Kothari and Ivan Zhao.
Video 2.
How Notion Handles 200 BILLION Notes by Coding with Lewis
. Source.
Type of laser by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Lasers vs other light sources by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
The key advantages of lasers over other light sources are:
One cool thing about lasers is that they rely on one specific atomic energy level transition to produce light. This is why they are able to to be so monchromatic. Compare this to:
As such, lasers manage to largely overcome "temperature distribution-like" effects that create wider wave spectrum
Video 1.
Crazy difference between 5W laser and 5W LED by Brainiac75
. Source. Baseic but good. Uses a laser photometer.
Laser spectrum by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
Video 1.
Spectrum of laser light by Shaoul Ezekiel
. Source. 2008, MIT.
Education of André-Marie Ampère by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
en.wikipedia.org/w/index.php?title=Andr%C3%A9-Marie_Amp%C3%A8re&oldid=1211946256:
Jean-Jacques Ampère, a successful merchant, was an admirer of the philosophy of Jean-Jacques Rousseau, whose theories of education (as outlined in his treatise Émile) were the basis of Ampère's education. Rousseau believed that young boys should avoid formal schooling and pursue instead a "direct education from nature." Ampère's father actualized this ideal by allowing his son to educate himself within the walls of his well-stocked library.
TODO find the source for this.
Electrical cable by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
One more more electrical wires surrounded by an insulator.
Oliver Heaviside by Ciro Santilli 37 Created 2024-06-26 Updated 2025-07-16
He participated in the development of the electrical telegraph, and he did some good modeling work that improved the foundations of the field, notably creating the telegrapher's equations.
He was one of those idealists who just want to do some cool work even if they have to starve for it, people had to get a state pension for him for his contributions. Nice guy. en.wikipedia.org/w/index.php?title=Oliver_Heaviside&oldid=1230097796#Later_years_and_views:
In 1896, FitzGerald and John Perry obtained a civil list pension of £120 per year for Heaviside, who was now living in Devon, and persuaded him to accept it, after he had rejected other charitable offers from the Royal Society.
He also never married: www.nndb.com/people/627/000204015/
Figure 1.
Oliver Heaviside c. 1900
. Source.

There are unlisted articles, also show them or only show them.