Thali by Ciro Santilli 40 Updated 2025-07-16
Indian vegetarian thali is the best thing ever! The Southern version in particular. Also do watch a video on how to eat it.
A good place to have it abroad is Saravana Bhavan. The founder killed a dude to marry his wife, but failed and was sentenced to life prison. But he died in 2019 so we're all fine eating there now.
Figure 1. Source. This Wikipedia image of Thali is fundamentally wrong: you have to have a banana leaf on the bottom of the tray!
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.
Indian classical music by Ciro Santilli 40 Updated 2025-07-16
This was Ciro Santilli's main study/work music for several years around 2020. Tabla rules.
Johannes Martin Bijvoet (1894-1971) was a Dutch chemist known for his significant contributions to the field of crystallography, particularly in the development of methods to determine the structure of complex organic molecules. He is perhaps best known for his work in X-ray crystallography and for his contributions to the study of stereochemistry, including the Bijvoet polymorph, which is a type of crystalline form related to the study of molecular chirality.
Fan Haifu (范海福) is a Chinese composer and musician known for his contributions to film and television scores, as well as traditional Chinese music. He has gained recognition for his ability to blend modern musical techniques with classical Chinese elements, creating a unique sound.
Hartmut Bärnighausen is a prominent figure known for his work in public health and global health research. He is affiliated with institutions such as the Harvard T.H. Chan School of Public Health, where he focuses on areas like health systems, health policy, and the evaluation of health interventions, particularly in low- and middle-income countries. His research often emphasizes the importance of health equity and the social determinants of health.
Helen Megaw is an accomplished scientist known for her contributions to materials science and crystallography. She has been involved in research related to the properties and structures of various materials, particularly in the context of mineralogy and the study of crystalline substances. Megaw's work has significantly contributed to our understanding of the relationships between crystal structures and their physical properties. In addition to her research, she is also recognized for her role in academia, particularly in mentoring students and contributing to scientific education.
Jacques Mering is likely a reference to a French mathematician known for his work in the field of mathematics, particularly in the areas of analysis and number theory.
Johann Reinhard Blum was a notable German painter and graphic artist, born in 1803 and active in the 19th century. He is primarily known for his landscapes and historical scenes, typical of the Romantic style prevalent during that time. Blum's works often reflect a deep appreciation for nature, emotional depth, and an interest in depicting the sublime aspects of the environment.
Paul Niggli (1888–1953) was a prominent Swiss chemist known for his work in the field of crystallography and the study of molecular structures. He made significant contributions to the understanding of crystal lattices and the arrangement of atoms within crystals. His research played a critical role in the development of X-ray crystallography as a technique to determine the structure of complex molecules, which has had a profound impact on fields such as chemistry, materials science, and biology.
Stephen Neidle is a prominent chemist known for his work in the field of molecular and structural biology, particularly in the study of DNA and its potential applications in medicine. He has made significant contributions to the understanding of DNA topology and the development of small molecules that can target and interact with DNA structures, such as G-quadruplexes, which are four-stranded configurations of DNA that play important roles in gene regulation and cellular processes.
The British Crystallographic Association (BCA) is a professional organization dedicated to promoting the study and application of crystallography, a branch of science that deals with the arrangement of atoms in crystalline solids. Established in 1948, the BCA serves as a forum for researchers, educators, and practitioners in the field of crystallography, supporting collaboration and communication among its members. The association organizes conferences, workshops, and training programs to facilitate sharing of knowledge and advancements in crystallographic techniques and applications.

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