Ciro Santilli @cirosantilli 37

You select a generating set of a group, and then you name every node with them, and you specify:

Not unique: different generating sets lead to different graphs, see e.g. two possible en.wikipedia.org/w/index.php?title=Cayley_graph&oldid=1028775401#Examples for the

For specific species:

Related:

The first time Ciro Santilli Googled this was when trying to repair his cell phone.

2019 cell phones are glued together with adhesive, which makes them impossible to repair them unless you have a heat gun, spend hours and hours learning and planning, and accept the risk of breaking the screen

Repairability scores: www.ifixit.com/smartphone-repairability

If you take a phone less than 300 dollars to a repair shop in the first world, they will say: I've never repaired this crap, and likely for the price of the repair you should just buy a new one, and so to the trash goes the old one, polluting the planet, and in comes a new one, enriching the manufacturer further.

European Union, I need you now.

Oh, there is some 2017 EU action actually: (archive) www.europarl.europa.eu/news/en/press-room/20170629IPR78633/making-consumer-products-more-durable-and-easier-to-repair

Good article: www.androidauthority.com/device-repairability-807585/ (archive).

About 50k subscribers on 2021, which feels way too little for the video quality and quantity.

Ciro Santilli believes that this channel will go very far, certainly achieving 1M subscribers in they keep it for one or two more years. Update: it didn't, as of 2024, shame.

They are Utah-based, and they do many many amazing weekend trips. They mostly drive from home to some trailhead, and then climb up and down it the entire day.

No technical rock climbing, only bouldering, but they still manage to reach many amazing places, and there is a level of danger in many of their ascents.

They also often ski down the mountains when there is snow.

The cool thing about this channel is that as the name suggests, they are not professionals, and what they do can be done by anyone without working full time on it, as long as you have adequate preparation.

The fundamental intuition about capacitors is that they never let electrons through.

They can only absorb electrons up to a certain point, but then the pushback becomes too strong, and current stops.

Therefore, they cannot conduct direct current long term.

For alternating current however, things are different, because in alternating current, electrons are just jiggling back and forward a little bit around a center point. So you can send alternating current power across a capacitor.

The key equation that relates Voltage to electric current in the capacitor is:So if a voltage Heavyside step function is applied what happens is:More realistically, one may consider the behavior or the series RC circuit to see what happens without infinities when a capacitor is involved as in the step response of the series RC circuit.

It resists to change in electric current. Well seen at: Video "LC circuit by Eugene Khutoryansky (2016)".

When Ciro Santilli was studying electronics at the University of São Paulo, the courses, which were heavily inspired from the USA 50's were obsessed by this one! Thinking about it, it is kind of a cool thing though.

That Wikipedia page is the epitome of Wikipedia failure to explain things in a way that is of any interest to any learner. Video 1. "Tutorial on LC resonant circuits by w2aew (2012)" is the opposite.

Example from École Polytechnique: Figure "A typical small classroom at École Polytechnique".