Devboard battery power by Ciro Santilli 40 Updated 2025-07-16
Many devborads require a 5V power supply.
This is common on wall transformers and USB, but not in batteries.
For battery power you need a transformer.
Many/most microcontroller boards have analog-to-digital converters built into them, it is very convenient. E.g. it is the case for the Raspberry Pi Pico.
Brownian motion by Ciro Santilli 40 Updated 2025-07-16
Small microscopic visible particles move randomly around in water.
If water were continuous, this shouldn't happen. Therefore this serves as one important evidence of atomic theory.
The amount it moves also quantitatively matches with the expected properties of water and the floating particles, was was settled in 1905 by Einstein at: investigations on the theory of the Brownian movement by Einstein (1905).
This suggestion that Brownian motion comes from the movement of atoms had been made much before Einstein however, and passed tortuous discussions. Subtle is the Lord by Abraham Pais (1982) page 93 explains it well. There had already been infinite discussion on possible causes of those movements besides atomic theory, and many ideas were rejected as incompatible with observations:
Further investigations eliminated such causes as temperature gradients, mechanical disturbances, capillary actions, irradiation of the liquid (as long as the resulting temperature increase can be neglected), and the presence of convection currents within the liquid.
The first suggestions of atomic theory were from the 1860s.
Tiny uniform plastic beads called "microbeads" are the preferred 2019 modern method of doing this: en.wikipedia.org/wiki/Microbead
Original well known observation in 1827 by Brown, with further experiments and interpretation in 1908 by Jean Baptiste Perrin. Possible precursor observation in 1785 by Jan Ingenhousz, not sure why he wasn't credited better.
Video 1.
Observing Brownian motion of micro beads by Forrest Charnock (2016)
Source.
The conventional starting point is not at the E. Coli K-12 MG1655 origin of replication.
biocyc.org/ECOLI/NEW-IMAGE?type=EXTRAGENIC-SITE&object=G0-10506 explains:
This site is the origin of replication of the E. coli chromosome. It contains the binding sites for DnaA, which is critical for initiation of replication. Replication proceeds bidirectionally. For historical reasons, the numbering of E. coli's circular chromosome does not start at the origin of replication, but at the origin of transfer during conjugation.
If it is a bit hard to understand what they mean by "origin of transfer" though, as that term is usually associated with the origin of transfer of bacterial conjugation.
Marc Verdiell by Ciro Santilli 40 Updated 2025-09-11
Marc Verdiell is a French electrical engineer born in 1963 or 1964[ref] and best known for being the creator and host of the CuriousMarc YouTube channel where he does mind blowing repairs and reverse engineering of vintage computers and other electronic equipment.
Marc sold his company LightLogic, an optoelectronics company he founded, to Intel in April 2001. This was just after the dot-com crash, but Intel apparently still correctly believed that the networking and the Internet would continue to grow and was investing in the area. His associate Frank Shum sued claiming he should be credited for some of the inventions sold but lost and Marc got it all.[ref][ref][ref]. Marc was then almost immediately appointed an Intel fellow at the extremelly early age of 37, and then stayed for a few years at Intel until 2006 according to his LinkedIn.[ref][ref]
Figure 1. . Source. Location inferred from Marc's videos, but likely, he often frequents the place, and it looks a bit like that.
Marc's full name is actualy Jean-Marc Verdiell, but Ciro Santilli remembers there was one YouTube video where he mentions he gave up on "Jean" partly because anglophones would murder its pronounciation all the time.
Marc's PhD thesis is listed at: theses.fr/1990PA112048 and it is entitled:
Mise en phase de reseaux de lasers a semi-conducteur
which is translated into English as:
Phase locking of semiconductor laser arrays
but the full text is not available online.
Video 1.
Profile of Marc Verdiell by Gizmodo (2018)
Source.
youtu.be/ZgAreiFXhJk?t=253 lists some famous people who live there. It's like a micro heaven.
And a person who makes open educational content like Marc, truly deserves it.
Atherton managed to keep the entire place green and every house has a pool. Wikipedia comments web.archive.org/web/20220906010554/https://www.forbes.com/home-improvement/features/most-expensive-zip-codes-us/:
Atherton is known for its wealth; in 1990 and 2019, Atherton was ranked as having the highest per capita income among U.S. towns with a population between 2,500 and 9,999, and it is regularly ranked as the most expensive ZIP Code in the United States [(94027)]. The town has very restricting zoning, only permitting one single-family home per acre and no sidewalks. The inhabitants have strongly opposed proposals to permit more housing construction and Forbes confirms it for 2022: web.archive.org/web/20220906010554/https://www.forbes.com/home-improvement/features/most-expensive-zip-codes-us/, by far on top.
Marc has reached out to us and requested that some personal information be removed from this article, to which we complied.
NGC 1893 is an open cluster of stars located in the constellation Cassiopeia. It is situated near the more well-known nebula known as the LBN 762, also referred to as the “Cederblad 126” nebula. NGC 1893 is notable for being a relatively young cluster, with an age of around 3 to 5 million years, and it contains a mix of stars in various stages of development.
The Gamma distribution is a continuous probability distribution defined by two parameters: shape (often denoted as \( k \) or \( \alpha \)) and scale (denoted as \( \theta \) or \( \beta \)). It is widely used in various fields, including statistics, finance, and engineering, due to its ability to model waiting times and processes that are characterized by events that occur independently at a constant average rate.
Bradymetabolism refers to a slower than normal metabolic rate. It is characterized by a reduced rate of metabolic processes, which can impact how the body processes and uses energy, nutrients, and oxygen. This term is often used in medical contexts to describe conditions that may lead to lower energy expenditure, such as hypothyroidism, where there is an underproduction of thyroid hormones that regulate metabolism.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact