Lasers emit a narrow spectrum by Ciro Santilli 37 Updated +Created
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 Updated +Created
Video 1.
Laser linewidth - measurement and explanation by Your Favourite TA
. Source.
Breakup of the Bell System by Ciro Santilli 37 Updated +Created
Video 1.
AT&T Breakup-the day after in 1984
. Source. Good documentary from the time. TODO actual title and producer.
Artificial intelligence paradigm by Ciro Santilli 37 Updated +Created
Magnetic core by Ciro Santilli 37 Updated +Created
Figure 1.
Hand drawn schematic of the magnetic field induced in a magnetic core by an electromagnetic coil
. Source.
UNSW Physics YouTube channel by Ciro Santilli 37 Updated +Created
Philosophy of education of Rousseau by Ciro Santilli 37 Updated +Created
Notion (productivity software) by Ciro Santilli 37 Updated +Created
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 Updated +Created
Lasers vs other light sources by Ciro Santilli 37 Updated +Created
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 Updated +Created
Video 1.
Spectrum of laser light by Shaoul Ezekiel
. Source. 2008, MIT.
Twisted pair by Ciro Santilli 37 Updated +Created
Education of André-Marie Ampère by Ciro Santilli 37 Updated +Created
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 Updated +Created
One more more electrical wires surrounded by an insulator.
Oliver Heaviside by Ciro Santilli 37 Updated +Created
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.
We intersect 2013 DNS Census virtual host cleanup with 2013 DNS census MX records and that leaves 460k hits. We did lose a third on the the MX records as of 260 hits since secureserver.net is only used in 1/3 of sites, but we also concentrate 9x, so it may be worth it.
Then we Wayback Machine CDX scanning. it takes about 5 days, but it is manageale.
We did a full Wayback Machine CDX scanning for JAR, SWF and cgi-bin in those, but only found a single new hit:

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