The Prony equation is a mathematical model used to represent the behavior of complex systems, particularly in the fields of signal processing, control systems, and engineering. It is commonly employed in the analysis of time-series data and can be used to characterize the dynamic response of systems.
Linear map of two variables.
More formally, given 3 vector spaces X, Y, Z over a single field, a bilinear map is a function from:that is linear on the first two arguments from X and Y, i.e.:Note that the definition only makes sense if all three vector spaces are over the same field, because linearity can mix up each of them.
The most important example by far is the dot product from , which is more specifically also a symmetric bilinear form.
A **regular constraint**, often encountered in the context of constraint programming and formal languages, is a type of constraint that can be expressed using regular languages or finite automata. This means that a regular constraint can be represented by a regular expression or recognized by a finite state machine. In general, regular constraints allow for the expression of patterns and conditions that must be satisfied by a sequence of values (often strings or sequences of characters).
A self-concordant function is a specific type of convex function that has properties which make it particularly useful in optimization, especially in the context of interior-point methods.
Predictability refers to the extent to which a future event or outcome can be anticipated based on existing information or patterns. In various contexts, predictability can take on different meanings: 1. **Mathematics and Science**: In these fields, predictability often involves using mathematical models or scientific principles to forecast outcomes. For example, the laws of physics can predict the motion of objects under certain conditions.
The atmospheric carbon cycle refers to the continuous movement of carbon among the atmosphere, land, oceans, and living organisms. It plays a crucial role in regulating the Earth's climate and supporting life. Here are the main components and processes involved in the atmospheric carbon cycle: 1. **Carbon Sources**: Carbon enters the atmosphere through various processes, including: - **Respiration**: Animals and plants release carbon dioxide (CO2) when they break down organic material for energy.
Atmospheric optics is the study of how light interacts with the Earth's atmosphere, leading to various optical phenomena. This field encompasses the understanding of how atmospheric conditions—such as the presence of particles, water vapor, and gases—affect the propagation and perception of light. Some key phenomena studied in atmospheric optics include: 1. **Refraction**: The bending of light rays as they pass through layers of air with different temperatures and densities, leading to phenomena like superior and inferior mirages.
An atmospheric river is a narrow, elongated corridor of concentrated moisture in the atmosphere. These phenomena can transport large amounts of water vapor from tropical regions toward higher latitudes, particularly affecting coastal areas. The water vapor can then condense and fall as precipitation, leading to significant rainfall or snowfall when the moist air is lifted over mountains or cooler regions. Atmospheric rivers can vary in intensity and duration and are categorized into different levels based on their impact.
Atmospheric scientists study the Earth's atmosphere, focusing on its composition, structure, dynamics, and processes. This field encompasses a variety of topics, including weather patterns, climate change, air quality, and atmospheric phenomena. Atmospheric scientists typically work in several areas, including: 1. **Meteorology**: They analyze weather data to forecast short-term atmospheric conditions, such as storms, temperature changes, and precipitation.
Cool data embedded in the Bitcoin blockchain Early AtomSea & EMBII uploads by 
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01These are of course likely all made by AtomSea & EMBII themselves while developing/testing their upload system.
They are also artsy peoeple themselves, and as pointed at twitter.com/AllenVandever/status/1563964396656812034 what they were doing was basicaly non-fungible token art, which became much much more popular a few years later around 2021.
The first upload that we could find at github.com/cirosantilli/bitcoin-inscription-indexer/tree/3f53e152ec9bb0d070dbcb8f9249d92f89effa70#atomsea-index was tx 44e80475dc363de2c7ee17b286f8cd49eb146165a79968a62c1c2c4cf80772c9 on block 272573 (2013-12-01) but it does not show on Bitfossil: bitfossil.org/44e80475dc363de2c7ee17b286f8cd49eb146165a79968a62c1c2c4cf80772c9/. This is was due to an upload bug explained by the following entry. By looking at the ASCII data at github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0272.txt#L449 that this is meant to contain the same content as the following message: a quote from the Bhagavad Gita, so this is definitely a bugged version of the following one.
The next one is tx c9d1363ea517cd463950f83168ce8242ef917d99cd6518995bd1af927d335828 block 272577 (2013-12-02). It actually shows on bifossil and it reads:followed by:The bug message is definitely a reference to the previous non-visible bugged upload bitfossil.org/4b72a223007eab8a951d43edc171befeabc7b5dca4213770c88e09ba5b936e17/, TODO understand exactly how they fucked up. This illustrates the beauty of the blockchain very well: unlike with version control, you don't just see selected snapshots: you see actual debug logs!!!
He who regards
With an eye that is equal
Friends and comrades,
The foe and the kinsman,
The vile, the wicked,
The men who judge him,
And those who belong
To neither faction:
He is the greatest.
WeAreStarStuff.jpgThe filename is of course a reference to the quote/idea: We Are Made of Star-Stuff that was much popularized by Carl Sagan.
bitfossil.org/fac0b9a4f90414710b806fd286e020aea2404498946845ef3783f305dd4cd3a7 (2024-01-13) contains a cropped version with only AtomSea persent.
HugPuddle.jpgThe fourth AtomSea & EMBII upload, and the second image. Message:
HugPuddle Testing Apertus Disk Drive
And then finally we meet Chiharu, EMBII's partner, with her hair painted blond (she's Japanese): ILoveYouMore.jpg.
Then there are two undecoded ones TODO investigate:
Then Nelson-Mandela.jpg.
Then there's an approximation of pi as ASCII decimal fraction on tx 70fd289901bae0409f27237506c330588d917716944c6359a8711b0ad6b4ce76 from block 273522 (2013-12-07):
3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989
tx b8b9f50a354166c46b69ecd47a0fbd20ee78c3471d2557bf275aff1b4cf4752d (2013-12-07) on bitfossil.org) contains Where the Sidewalk Ends by Shel Silverstein:
There is a place where the sidewalk ends
And before the street begins,
And there the grass grows soft and white,
And there the sun burns crimson bright,
And there the moon-bird rests from his flight
To cool in the peppermint wind.
tx 56768b30dec33bd284223d85c23087975e2360b3391d20d505aa59a5675e5379 (2013-12-13, on bitfossil.org):
Dear Aliens,Hey.Sincerely,
EMBII & AtomSea
tx 415c702759893c63b3a57a7d196b014e51b2a33d2396c74b8e71acfaff6b9360 (2013-12-14) contains a poem by 13th century Persian poet Rumi (TODO find bitfossil.org toplevel), starting with:Reproduced e.g. at: www.abuddhistlibrary.com/Buddhism/H%20-%20World%20Religions%20and%20Poetry/World%20Religions/Islam/Teachers/Rumi/My%20dear%20friend/Rumi%20-%20my%20dear%20friend.htm
My dear friend
never lose hope
when the Beloved
sends you away.
bitfossil.org/73ca50321147bac9010bec43d63f7f76857fe9ede240cc89710e28723fdb242f/ (2013-12-14) has message:and links to 3 .txt files
MULTIFILE SUPPORT TEST
1.txt, 2.txt, 3.txt containing single characters 1, 2, and 3.
CompressedLogo.png
. Source. 2013-12-20. Message:Possibly www.linkedin.com/in/colby-nelson-59b538207/.
Colby Nelson and myself burnt the midnight oils designing the APERTUS imagery last night....Thanks Colby for all your help.
Contains an Apertus logo which is used on bitfossil.org/ itself, presumably they were designing that logo.
Atomic engineering, often referred to in the context of nuclear engineering, is the branch of engineering that focuses on the design, construction, operation, and maintenance of systems and equipment that utilize nuclear energy and radiation. This field encompasses a wide range of activities, including: 1. **Nuclear Reactor Design**: Developing and optimizing nuclear reactors for generating electricity, medical applications, and research purposes.
A steerable filter is a type of image processing filter that can be rotated or "steered" to different orientations to enhance or detect features in an image, such as edges or textures. This concept is useful in various applications, including computer vision, image analysis, and pattern recognition. ### Key Characteristics of Steerable Filters: 1. **Orientation Selectivity**: Steerable filters can adapt their response based on the orientation of the features in the image.
A strictly determined game is a type of two-player zero-sum game in which each player has a clear and linear strategy that leads to a specific outcome based on the strategies chosen by both players. In such games, there is a unique equilibrium strategy for both players, meaning that there is one optimal strategy that each player can follow that guarantees the best possible outcome for themselves, regardless of what the other player does.
A tachytrope is a term used to describe a type of optical illusion or a visual device that creates the appearance of motion through sequential frames or images. The term can sometimes be associated with devices similar to a zoetrope, which is a device that produces the illusion of motion by displaying a rapid sequence of static images. The concept of a tachytrope can be explored through various art forms, animations, and media that engage with the dynamic representation of movement.
"Charmides" is one of Plato's dialogues, featuring a conversation between the philosopher Socrates and several Athenian youths, including Charmides, a young nobleman. The dialogue primarily explores the nature of temperance or moderation (sophrosyne in Greek) and relates to broader themes of self-knowledge, wisdom, and the ethical conduct of individuals. In the dialogue, Socrates engages Charmides in an examination of what it means to be temperate.
Transfinite interpolation is a mathematical technique used to create a continuous surface or function that passes through a given set of points, typically in a multidimensional space. It extends the concept of interpolation beyond finite-dimensional spaces to infinite-dimensional or higher-dimensional contexts. The technique is particularly useful in the context of geometric modeling, computer graphics, and numerical analysis. The key idea is to define a function that satisfies certain properties at specified boundary points (or control points) while allowing for continuity and smoothness in the interpolation.
Ciro Santilli's hardware Tefal rice cooker (2017) by Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-07-01 +Created 1970-01-01Bought around: 2017-09.
TEFAL Multicook 8in1 RK302E15 MultiCooker - 4 Portions / 5L.
Likely bought from: www.johnlewis.com/tefal-rk302e15-8-in-1-multi-cooker/p231378165
How to open videos: can't find any, but the hard part (remove top lid) was the same as the video for joyoung rice cooker (2014), can be done by inserting a thin metal and going around it.
Bottom opens by taking off a single screw on the bottom and pulling it out (not obvious, a little bit of force).
2021-01: while making congee it overflowed without us noticing it, and next time we were going to cook something, it started to burn bits of congee that stuck to the heat plate. Opened it up and tried to clean everything.
2020-03: E01 error, looked up on manual and it is a top wire broken, opened up and confirmed one of the three wires going up broken, exactly like the previous one joyoung rice cooker (2014). Managed to fix easily with heat gun and Solder Seal Heat Shrink, no soldering iron, that thing is amazing: www.amazon.co.uk/dp/B085415G8N Let's see how long it lasts.
Pinned article: ourbigbook/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!
Intro to OurBigBook
. Source. We have two killer features:
- 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-calculusArticles 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/derivativeVideo 2. OurBigBook Web topics demo. Source. - 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.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 5. . 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. 
- Infinitely deep tables of contents:
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