frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Dexterous robotic hands: 2009 – 2014 – 2025

https://old.reddit.com/r/robotics/comments/1qp7z15/dexterous_robotic_hands_2009_2014_2025/
1•gmays•2m ago•0 comments

Interop 2025: A Year of Convergence

https://webkit.org/blog/17808/interop-2025-review/
1•ksec•11m ago•1 comments

JobArena – Human Intuition vs. Artificial Intelligence

https://www.jobarena.ai/
1•84634E1A607A•15m ago•0 comments

Concept Artists Say Generative AI References Only Make Their Jobs Harder

https://thisweekinvideogames.com/feature/concept-artists-in-games-say-generative-ai-references-on...
1•KittenInABox•19m ago•0 comments

Show HN: PaySentry – Open-source control plane for AI agent payments

https://github.com/mkmkkkkk/paysentry
1•mkyang•21m ago•0 comments

Show HN: Moli P2P – An ephemeral, serverless image gallery (Rust and WebRTC)

https://moli-green.is/
1•ShinyaKoyano•30m ago•0 comments

The Crumbling Workflow Moat: Aggregation Theory's Final Chapter

https://twitter.com/nicbstme/status/2019149771706102022
1•SubiculumCode•34m ago•0 comments

Pax Historia – User and AI powered gaming platform

https://www.ycombinator.com/launches/PMu-pax-historia-user-ai-powered-gaming-platform
2•Osiris30•35m ago•0 comments

Show HN: I built a RAG engine to search Singaporean laws

https://github.com/adityaprasad-sudo/Explore-Singapore
1•ambitious_potat•41m ago•0 comments

Scams, Fraud, and Fake Apps: How to Protect Your Money in a Mobile-First Economy

https://blog.afrowallet.co/en_GB/tiers-app/scams-fraud-and-fake-apps-in-africa
1•jonatask•41m ago•0 comments

Porting Doom to My WebAssembly VM

https://irreducible.io/blog/porting-doom-to-wasm/
1•irreducible•42m ago•0 comments

Cognitive Style and Visual Attention in Multimodal Museum Exhibitions

https://www.mdpi.com/2075-5309/15/16/2968
1•rbanffy•43m ago•0 comments

Full-Blown Cross-Assembler in a Bash Script

https://hackaday.com/2026/02/06/full-blown-cross-assembler-in-a-bash-script/
1•grajmanu•48m ago•0 comments

Logic Puzzles: Why the Liar Is the Helpful One

https://blog.szczepan.org/blog/knights-and-knaves/
1•wasabi991011•1h ago•0 comments

Optical Combs Help Radio Telescopes Work Together

https://hackaday.com/2026/02/03/optical-combs-help-radio-telescopes-work-together/
2•toomuchtodo•1h ago•1 comments

Show HN: Myanon – fast, deterministic MySQL dump anonymizer

https://github.com/ppomes/myanon
1•pierrepomes•1h ago•0 comments

The Tao of Programming

http://www.canonical.org/~kragen/tao-of-programming.html
2•alexjplant•1h ago•0 comments

Forcing Rust: How Big Tech Lobbied the Government into a Language Mandate

https://medium.com/@ognian.milanov/forcing-rust-how-big-tech-lobbied-the-government-into-a-langua...
3•akagusu•1h ago•0 comments

PanelBench: We evaluated Cursor's Visual Editor on 89 test cases. 43 fail

https://www.tryinspector.com/blog/code-first-design-tools
2•quentinrl•1h ago•2 comments

Can You Draw Every Flag in PowerPoint? (Part 2) [video]

https://www.youtube.com/watch?v=BztF7MODsKI
1•fgclue•1h ago•0 comments

Show HN: MCP-baepsae – MCP server for iOS Simulator automation

https://github.com/oozoofrog/mcp-baepsae
1•oozoofrog•1h ago•0 comments

Make Trust Irrelevant: A Gamer's Take on Agentic AI Safety

https://github.com/Deso-PK/make-trust-irrelevant
7•DesoPK•1h ago•4 comments

Show HN: Sem – Semantic diffs and patches for Git

https://ataraxy-labs.github.io/sem/
1•rs545837•1h ago•1 comments

Hello world does not compile

https://github.com/anthropics/claudes-c-compiler/issues/1
35•mfiguiere•1h ago•20 comments

Show HN: ZigZag – A Bubble Tea-Inspired TUI Framework for Zig

https://github.com/meszmate/zigzag
3•meszmate•1h ago•0 comments

Metaphor+Metonymy: "To love that well which thou must leave ere long"(Sonnet73)

https://www.huckgutman.com/blog-1/shakespeare-sonnet-73
1•gsf_emergency_6•1h ago•0 comments

Show HN: Django N+1 Queries Checker

https://github.com/richardhapb/django-check
1•richardhapb•1h ago•1 comments

Emacs-tramp-RPC: High-performance TRAMP back end using JSON-RPC instead of shell

https://github.com/ArthurHeymans/emacs-tramp-rpc
1•todsacerdoti•1h ago•0 comments

Protocol Validation with Affine MPST in Rust

https://hibanaworks.dev
1•o8vm•2h ago•1 comments

Female Asian Elephant Calf Born at the Smithsonian National Zoo

https://www.si.edu/newsdesk/releases/female-asian-elephant-calf-born-smithsonians-national-zoo-an...
5•gmays•2h ago•1 comments
Open in hackernews

How Lewis Carroll computed determinants (2023)

https://www.johndcook.com/blog/2023/07/10/lewis-carroll-determinants/
209•tzury•1mo ago

Comments

messe•1mo ago
HN title filter cut off the initial "How".

You can manually edit it back in.

marcusestes•1mo ago
“Drop the ‘how.’ It’s cleaner.”
vharuck•1mo ago
It gives it a different implication. As I read it, an article titled "Lewis Carroll Computed Determinates" has three possible subjects:

1. Literally, Carroll would do matrix math. I know, like many on HN, that he was a mathematician. So this would be a dull and therefore unlikely subject.

2. Carroll invented determinates. This doesn't really fit the timeline of math history, so I doubt it.

3. Carroll computed determinates, and this was surprising. Maybe because we thought he was a bad mathematician, or the method had recently been invented and we don't know how he learned of it. This is slightly plausible.

4. (The actual subject). Carroll invented a method for computing determinates. A mathematician inventing a math technique makes sense, but the title doesn't. It'd be like saying "Newton and Leibnitz Used Calculus." Really burying the lede.

Of course, this could've been avoided had the article not gone with a click-bait style title. A clearer one might've been "Lewis Carroll's Method for Calculating Determinates Is Probably How You First Learned to Do It." It's long, but I'm not a pithy writer. I'm sure somebody could do better.

miltonlost•1mo ago
"How Lewis Carroll Computed Determinates" is fine and not clickbait because it provides all the pertinent information and is an accurate summary of its contents. Clickbait would be "you would never guess how this author/mathematician computed determinants" since it requires a clickthrough to know who the person is. How is perfectly fine IMO to have in the title because I personally would expect the How to be long enough to warrant a necessary clickthrough due to the otherwise required title length.
867-5309•1mo ago
it's not quite McKean's Law so I'll settle for contagious
SAI_Peregrinus•1mo ago
"Lewis Carroll's Method for Computing Determinates" is headlinese and avoids the "how".
esafak•1mo ago
> Arrange the given block, if necessary, so that no ciphers [zeros] occur in its interior.

I forgot that cipher used to have a different meaning: zero, via Arabic. In some languages it means digit.

pinkmuffinere•1mo ago
lol I never made that connection — in Turkish, zero is sıfır, which does sound a lot like cipher. Also, password is şifre, which again sounds similar. Looking online, apparently the path is sifr (Arabic, meaning zero) -> cifre (French, first meaning zero, then any numeral, then coded message) -> şifre (Turkish, code/cipher)
celaleddin•1mo ago
Nice! Imagine the second meaning going back to Arabic and now it's a full loop! It can even override the original meaning given enough time and popularity (not especially for "zero", but possibly for another full-loop word).
lupire•1mo ago
0 is a full loop!
cgio•1mo ago
The Turkish password word may be the same used for signature? I suspect so, because in Greek we have the Greek word for signature but also a Turkish loan word τζίφρα (djifra).
pinkmuffinere•1mo ago
Hmm i don’t think that one is related in Turkish — i only know of “imza” as signature, but there could also be other variants.
esafak•1mo ago
imza is signature while şifre is password. I imagine the conflation occurred because signatures are used like passwords for authentication...
NextHendrix•1mo ago
Likewise, the monogram of the sitting english monarch (as seen on postboxes and so forth) is the "Royal Cypher".

https://en.wikipedia.org/wiki/Royal_cypher

elbear•1mo ago
In Romanian:

- cifru -> cipher

- cifră -> digit

cryptonector•1mo ago
In Spanish:

- cifrar -> to encipher

- cifra -> digit

elbear•1mo ago
I wasn't sure how encipher is in Romanian (it's not common), it's "a cifra". The infinitive in Romanian puts "a" in front of the verb, so it's very close to Spanish.
jacquesm•1mo ago
Dutch too: "Cijfer", German, "Ziffer", French: "Chifre", Spanish: "Cifra".
estomagordo•1mo ago
Swedish: "Siffra"
sundarurfriend•1mo ago
In Tamil, it still means a zero. It's usually pronounced like 'cyber' though, because Tamil doesn't have the 'f'/'ph' sound natively.
aiuu•1mo ago
When someone says "it still means zero" about Tamil when responding to comments about Arabic, two languages which have no shared root and little similarity, what does that mean?

I think it means HN is full of misleading ideas.

Razengan•1mo ago
Buddy English has no "shared root" with Japanese but we still say sushi.

What does it mean when someone creates a new account for posting contradictory comments?

stackghost•1mo ago
English's superpower is readily absorbing new words from other languages.

Sushi is now an English word. So is hummus, etc.

_0ffh•1mo ago
If that's a superpower, it's a staggeringly common superpower.
kergonath•1mo ago
> Sushi is now an English word.

Eyeballing the Wikipedia page, and out of the only scripts I could read, I counted 72 languages that used a direct transcription of "sushi". It isn’t as much a superpower as a thing languages do in general.

Isamu•1mo ago
Isn’t the implication that cipher is a loanword? So language relatedness is irrelevant?

We use “arabic” numerals around the world. So use of an Arabic loan word is unsurprising.

vee-kay•1mo ago
Cipher and "Arabic" numerals are not just loan words, they are loan concepts - from India. They originated from ancient India, because the Arabs adopted and translated those ideas and texts from the original texts written by ancient Indians/Hindus.

Fact - Origin of Numerals and Mathematical Zero: Mathematical zero and numerals were not discovered/invented by the Arabs. There is no such thing as "Arabic" numerals because the Arabs did NOT invent numerals or cipher (to represent emptiness and/or mathematical zero).

The Arabs learnt the concept & use of mathematical zero, numerals, decimal system, complex mathematical calculations (including the subjects we call today as Algebra, Calculus, Trignometry), etc. from the ancient Hindus/Indians. And from the Arabs, the Europeans learnt it all.

https://en.wikipedia.org/wiki/Hindu-Arabic_numeral_system

Persian scholar Al Khwarizmi translated and used the Hindu/Indian numerals (including concept of mathematical zero) and "Sulba Sutras" (Hindu/Indian methods of mathematical problem solving) into the text Al-Jabr, which the Europeans translated as "Algebra" (yup, that branch of mathematics that all schoolkids worldwide learn from kindergarten).

Origin trivia: Originating from the Sanskrit word for zero शून्य (śuṇya), via the Arabic word صفر (ṣifr), the word "cipher" spread to Europe as part of the Arabic numeral system during the Middle Ages. https://www.etymonline.com/word/cipher

https://en.wikipedia.org/wiki/Cipher#Etymology

Fun fact: The Sanskrit word for mathematical zero and emptiness/voidness is the same: Shunya (शून्य). In fact, mathematicians are of the opinion that ancient Indians were among the first to understand the concept of mathematical zero because they understood the meaning of empty/void (Shunyata). Dhyana (meditation by focusing on voidness/stillness, away from random intrusive thoughts) is an aspect of Yoga (world's oldest active fitness discipline).

Another fun fact: The world's oldest recorded cipher (as an example of cryptography/ encryption) is the ancient Indian epic Ramayana by Maharshi Valmiki. It has 24000 verses (Sanskrit shlokas), and the first syllable (akshara) of each 1000th verse/shloka forms a series of 24 syllables that form the sacred Sri Gayatri Mantra.

Proofs of oldest records mathematical zero being of Indian origin, are available..

https://thebetterindia.com/270912/chaturbhuj-temple-in-gwali...

World's oldest known evidence of Mathematical Zero and numerals - ancient inscription on wall of Chaturbhuj temple in Gwalior, India.

https://www.glam.ox.ac.uk/article/carbon-dating-finds-bakhsh...

Bakhshali manuscript (stored in Oxford) from ancient India/Bharat - is the world's oldest text having Mathematical Zero and equations.

World should know the vital mathematical concepts & representations of numerals, decimal system, binary system, algebra, calculus, trigonometry, etc. we know and use today are originated from Indian/Hindu texts and scholars.

Both Isaac Newton and Gottfried Leibniz claimed to be The Father of Calculus, but reality is that they likely learnt it from maths-savvy Jesuit missionaries who themselves simply carried the knowledge of Calculus to Europe from its source: The Kerala School of Mathematics from Malabar, India.

https://www.manchester.ac.uk/about/news/indians-predated-new...

Wikipedia used to mention that the "Arabic" numerals are originated from "Hindu" numerals, but I see that origin has been removed from Wikipedia. It is sad when historical truths are hidden from the world, and mistruths are propagated instead.

By the way, Tamil and Sanskrit are the oldest extant (active) languages in the world.

adrian_b•1mo ago
While the use of zero and of the positional writing system for numbers have become widespread in Europe after taking them from the Arabs, which had previously taken them from India, these were already known in the Ancient World, both in Ancient Greece and even earlier in Assyria and Babylonia.

However, in the Ancient World the use of zero and positional numbers was restricted to some special applications, e.g. in astronomical tables, and it was unknown for most of the people.

The most novel feature of the Indian system was the application of the positional principle to decimal numbers, instead of sexagesimal numbers, and not the use of zero, which did not differ much from how it was used earlier.

vee-kay•1mo ago
The most novel feature of the Indian numerals is the use of the rounded zero symbol for the mathematical zero, so we all know it so well.

The Indian numerals also covered all the basic numeral digits and fit perfectly into the decimal system (which was also invented by the ancient Indians - they primarily used it for measuring weights, especially for currency/trade). The word meter/metre (from Sanskrit "miti") is also of Indian origin. The mathematical zero also fits in perfectly with binary system, also an ancient Indian invention.

The ancient Babylonians did use a dot/period as symbol of zero, but there is no information on whether they also associated zero with voidness/emptiness which the ancient Indians certainly did.

It can be argued that the ancient Babylonians and Indians independently discovered the concept of mathematical zero, and rest of the world learnt such basic concepts from them gradually, Interestingly, while even modern science+mathematics only uses big numbers to a certain extent, the ancient Indian Jain's & Hindus were doing computations of up to 10^32! Hindu cosmology even calculates time up to 10^15, and knows about multiverse, whereas modern science calculates Time only upto billions of years (10^9) and only recently started acknowledging the possibility of multiverse (as it is only explanation of what existed before the Big Bang), I i.e. Time is cyclical, and universes are birthed (Big Bang), grow (expand), decay (collapse) and shrink back to the Infinitesimal Dot again).

So it is a shame that ancient India's contributions to mathematics and other fields (e.g., geography, surgeries, medical tools, metallurgy, etc.) are unknown and ignored by most of the world, and the credits for such knowledge were stolen.

Did you know?.. India built and managed the world's first universities, in Takshashila and Nalanda, which has lots of diverse subjects/disciplines being taught and researched. The Arabs/Turks later invaded, looted and destroyed these amazing universities and their priceless treasure trove of books (the libraries were so huge that the arson fires burnt for months). The ruins of these ancient pioneering repositories of knowledge still stand as mute witnesses to their glorious knowledge-sharing past.

gsf_emergency_6•1mo ago
So is Gemini. but from it I gather there might be something interesting about a word that "loops back" (geographically) but evolutionarily speaking it was a reworking of _independent_ discoveries of "emptiness"

Arabic -> Tamil <- Arabic - Sanskrit

https://en.wikipedia.org/wiki/0#Etymology

sundarurfriend•1mo ago
The original comment was about one language that borrowed cipher from Arabic (i.e. English) where the word no longer means zero. So my comment was about a different language that also borrowed the word cipher (i.e. Tamil) where it still retains that meaning.
vee-kay•1mo ago
Fun fact: zero and numerals were not invented by the Arabs. The Arabs learnt the concept & use of mathematical zero, numerals, decimal system, mathematical calculations, etc. from the ancient Hindus/Indians. And from the Arabs, the Europeans learnt it.

https://en.wikipedia.org/wiki/Hindu-Arabic_numeral_system

Persian scholar Al Khwarizmi translated and used the Hindu/Indian numerals (including concept of mathematical zero) and "Sulba Sutras" (Hindu/Indian methods of mathematical problem solving) into the text Al-Jabr, which the Europeans translated as "Algebra" (yup, that branch of mathematics that all schoolkids worldwide learn from kindergarten).

gsf_emergency_6•1mo ago
The word used to mean "empty" (and not algebraic zero) in both Arabic and Sanskrit.

https://www.open.ac.uk/blogs/MathEd/index.php/2022/08/25/the...

vee-kay•1mo ago
Origin trivia: Originating from the Sanskrit word for zero शून्य (śuṇya), via the Arabic word صفر (ṣifr), the word "cipher" spread to Europe as part of the Arabic numeral system during the Middle Ages.

https://www.etymonline.com/word/cipher

https://en.wikipedia.org/wiki/Cipher#Etymology

Fun fact: The Sanskrit word for mathematical zero and emptiness/voidness is the same: Shunya (शून्य). In fact, mathematicians are of the opinion that ancient Indians were among the first to understand the concept of mathematical zero because they understood the meaning of empty/void (Shunyata). Dhyana (meditation by focusing on voidness/stillness, away from random intrusive thoughts) is an aspect of Yoga (world's oldest active fitness discipline).

Another fun fact: The world's oldest recorded cipher (as an example of cryptography/ encryption) is the ancient Indian epic Ramayana by Maharshi Valmiki. It has 24000 verses (Sanskrit shlokas), and the first syllable (akshara) of each 1000th verse/shloka forms a series of 24 syllables that form the sacred Sri Gayatri Mantra.

Proofs of oldest records mathematical zero being of Indian origin, are available..

https://thebetterindia.com/270912/chaturbhuj-temple-in-gwali...

World's oldest known evidence of Mathematical Zero and numerals - ancient inscription on wall of Chaturbhuj temple in Gwalior, India.

https://www.glam.ox.ac.uk/article/carbon-dating-finds-bakhsh...

Bakhshali manuscript (stored in Oxford) from ancient India/Bharat - is the world's oldest text having Mathematical Zero and equations.

aebtebeten•1mo ago
may be all for naught, but here's "the last word in combinators": https://www.dcs.ed.ac.uk/home/pgh/amen.html
gsf_emergency_6•1mo ago
>if one is a little charitable
lappet•1mo ago
Yeah I believe modern trigonometry and the terms sine and cos also trace their origins to Sanskrit through Arabic. It's a shame that ancient/medieval India contributed so much to science and math but hasn't been able to innovate in centuries past :(
wwweston•1mo ago
Start with love of the domain and a culture of respect working in it, then move to a love of the status and respect, then a focus on those instead of the domain…
vee-kay•1mo ago
The word "Trigonometry" itself is of Sanskrit origin: Tri (three) + kona (corner/angle) + niti (measure). The word "meter" or "metre" is from Sanskrit "Miti" (मिती) (meaning: measure/measurement). The decimal system of weights and counting we all know so well is of Indian origin too.

India was enslaved and exploited for centuries. By the people who stole its ideas and claimed them as their own.

But greatness can only be suppressed for a while, sooner or later, it will show itself.

The world will heal from its wounds, and the truths shall surface again.

India is #5 world economy now, by the way, and will become #3 before the end of this decade. Not bad for a nation that was still a slave just a few decades ago.

Did you know.. Ancient India (subcontinent) was world #1 economy for thousands of years? Guess who made it poor?

xphos•1mo ago
I mean i would never dispute that India was enslaved, but I think characterizing it as they were enslaved and all there ideas were stolen is a stretch. If they were so innovative and advanced how were they enslaved? Western institutions were a major advancement, things like the caste system held back India and did not come from the west. Those systems were certainty perpetuated by the west but also be Indian leadership as well the same way slavery held the US back but still was spurred on by southern leadership.

Adopting western institutions is a large reason Japan become the dominant Asian force leading up to ww2.

I think your probably correct they will become the 3rd largest economy but they also have the second largest economy that makes a huge difference. What makes Americas economy insane is they have been about 25-50% of world GDP for the last 100 years despite being less than 5% of the population. In terms of an efficient economy they are a large way to go still but I think they will become very wealth because I agree the country is full of smart people

vee-kay•1mo ago
Q.> I mean i would never dispute that India was enslaved, but I think characterizing it as they were enslaved and all there ideas were stolen is a stretch. If they were so innovative and advanced how were they enslaved?

A.: It's because the ancient Indians focused mostly on scientific and cultural progress, while their enemies focused on warfare and destruction.

That's why ancient India built and shared the world's first universities, but the Turkish/Arabic invaders (led by Khilji) from the desert raided, destroyed and looted those priceless vast knowledge repositories.

It is always easier to destroy, it is much harder to build. It is easier to shoot a gun to kill, it is harder to build a library or a home.

Ancient Indians shared so much information to the world, but instead of thanks, the world took so much. Because it is easier to hate when you are jealous of someone's achievements and prosperity (ancient India was world's #1 economy for thousands of years, and had the most fertile lands and biggest rivers).

Q.>What makes Americas economy insane is they have been about 25-50% of world GDP for the last 100 years despite being less than 5% of the population.

A.>The super economies of America, Europe and UK were not built upon their own merits, it was all done by invading, looting and enslaving half the world, especially India, Asia and Africa. Read up on colonial history first.

It is easy to build a skyscraper or a beige in USA or UK or Europe, if you have tons of money that was looted by selling the tons of food & goods stolen from the mouths & hands of millions of Indians that starved and died on the streets of the most fertile land in the world, due to artificial famines deliberately caused by evil governance during colonial enslavement.

Churchill killed more Hindus, than Hitler killed Jews.

The colonial powers have blood on their hands.

Search Google Images for "Great Bengal Famines", "Great Madras Famines", "Great Decdan Famines". You will not get sleep after seeing those horrific images from history that has been suppressed at most schools of the world.

And before you argue about smartness, you should first find out why Wikipedia has suppressed that fact that Arabs never invented any numerals or decimal system or algebra or trigonometry or calculus -- it was all copied and translated from the ancient Indians. But Wikipedia doesn't credit the numerals to be of Indian/Hindu origin and invention.

Once you understand why and how even in modern era, the powers that be, are still suppressing India because they are afraid of India rising to be great again, then all your arguments will fall by the wayside.

blacksmith_tb•1mo ago
And the English word 'algorithm' comes from Al Khwarizmi's name[1].

1: https://en.wikipedia.org/wiki/Al-Khwarizmi#:~:text=His%20nam...

vee-kay•1mo ago
Ah, but you need to dig deeper, my friend.

"Algorithm" is derived from Al-Khwarizmi, but only because he translated the ancient Indian/Hindu "Sulba Sutras" texts into Persian, especially in his "Al Jabr" text.

"Sulba Sutra" literally means "method of problem solving". So the Sukna Sutras were all basically Algorithms - different ways to solve mathematical and scientific problems.

In fact, Al Khwarizmi himself borrowed the title of the original Indian/Hindu texts for his translations and he even acknowledged their Indian/Hindu origin. That's why the meaning of the full title of the Al Jabr book is "The Concise Book of Calculation by Restoration and Balancing" (because that's how algebraic equations are understood and solved).

This Al Jabr book (based on Hindu methods of problem solving and algebraic equations) got translated and understood by British and Europeans, so they simply named this new (new to them) branch of Mathematics as Algebra (derived from "Al Jabr").

SOURCE: the British scholar "Robert of Chester" who translated the Al Jabr book to Latin (during 1876-2956, published in 1915, under book title "Algebra of al-Khowarizmi") documented that the ancient Indians knew the algebraic equations BEFORE Al Khwarizmi. Not only that, Robert also confirmed the ancient Indians knew and used the Pythagorean triangle theorem before the time of Pythagoras.

You can check and read these evidences for yourself please. Sources are linked below.

https://web.archive.org/web/20181118154937/http://library.al...

https://en.wikipedia.org/wiki/Robert_of_Chester

https://archive.org/details/robertofchesters00khuw

Trivia: in 1974, IBM released an advertisement, in which it gave the credit of Algebra to most ancient Indian mathematicians. In the advertisement, IBM had explained 'How India gave the world the logic of indeterminate equations' by naming three prominent historic mathematicians: Aryabhata, Bhaskara and Brahmagupta, who developed the concept of Algebra and gave meaning to something (Zero) which was termed to be meaningless before.

The IBm ad proclaimed: "History owes a debt to three Indian mathematicians of 1500 years ago who developed Algebra to give meaning to the meaningless. Bhaskara, who originated the radical signs. Brahmagupta, who created the symbols. Aryabhata, who worked out the first equations. A search that continues today in new directions with newer tools, among them, a machine that helps man in more ways than any other inventions in history: the computer. We are proud that IBM introduced the manufacturing of computers and other data processing equipment in India, which are helping the nation meet the challenge of building a new tomorrow," reads the IBM advertisement.

IBM's advertisement also features an excerpt 'The Poetry of Algebra' from the book Indian Wisdom by Sir Monier Monier-Williams.

* Among the several contributions made by Aryabhata, he discovered the nine planets and found out the correct number of days in a year i.e. 365. * Brahmagupta made one of the most significant contributions to mathematics when he introduced zero(0), which once stood for “nothing”. * Bhāskara declared that any number divided by zero is infinity and that the sum of any number and infinity is also infinity. * 2000 years before Fibinacci, the Indian scholar Pingala discovered and documented by 200 BC the series we today call as Fibonacci series. Pingala wrote the Chandahśāstra, a treatise on prosody — poetic meter. To study Sanskrit meters, he analyzed long and short syllables, generating combinations using what we would now call binary patterns and recursive enumeration. And in doing so, he uncovered (and documented) the interesting series we today call as Fibonacci series.

blarg1•1mo ago
That explains Major Zero and his organisation Cipher in the metal gear series
kazinator•1mo ago
> Dodgson’s original paper from 1867 is quite readable, surprisingly so given that math notation and terminology changes over time.

Given that Jabberwocky is also quite readable, we shouldn't be too astonished.

saghm•1mo ago
I think in this case "readable" means "comprehensive", which maybe doesn't apply quite as much to Jabberwocky (albeit by design).
JadeNB•1mo ago
> Given that Jabberwocky is also quite readable, we shouldn't be too astonished.

The conventions of literature have changed a lot less than math notation and terminology have since 1867.

01jonny01•1mo ago
When I'm not cognitively depleted from over working and kids I'd really like to sit down and read this properly.
howling•1mo ago
Terrence Tao blogged about this.

https://terrytao.wordpress.com/2017/08/28/dodgson-condensati...

BobbyTables2•1mo ago
Wow, I never realized the cofactor method wasn’t the only one.

I loathed it and it put me off wanting to get into advanced matrix topics.

RossBencina•1mo ago
I don't think determinants play a central role in modern advanced matrix topics.

Luckily for me I read Axler's "Linear Algebra Done Right" (which uses determinant-free proofs) during my first linear algebra course, and didn't concern myself with determinants for a very long time.

Edit: Beyond cofactor expansion everyone should know of at least one quick method to write down determinants of 3x3 matrices. There is a nice survey in this paper:

Dardan Hajriza, "New Method to Compute the Determinant of a 3x3 Matrix," International Journal of Algebra, Vol. 3, 2009, no. 5, 211 - 219. https://www.m-hikari.com/ija/ija-password-2009/ija-password5...

srean•1mo ago
> I don't think determinants play a central role in modern advanced matrix topics.

Not true at all. It's integral to determinantal stochastic point processes, commute distances in graphs, conductance in resistor networks, computing correlation via linear response theory, enumerating subgraphs, representation theory of groups, spectral graph theory... I am sure many more

omnicognate•1mo ago
The 4th edition of Linear Algebra Done Right has a much improved approach to determinants themselves (still relegated to the end, where it should be). From the list of improvements:

> New Chapter 9 on multilinear algebra, including bilinear forms, quadratic forms, multilinear forms, and tensor products. Determinants now are defned using a basis-free approach via alternating multilinear forms.

The basis-free definition is really rather lovely.

barbazoo•1mo ago
And just like back in university I know how how calculate Determinants but have no clue what one would actually use it for.
Razengan•1mo ago
3blue1brown is your friend
ComplexSystems•1mo ago
Suppose you have (let's say) a 3x3 matrix. This is a linear transformation that maps real vectors to real vectors. Now let's say you have a cube as input with volume 1, and you send it into this transformation. The absolute value of the determinant of the matrix tells you what volume the transformed cube will be. The sign tells you if there is a parity reversal or not.
RossBencina•1mo ago
Form a quadratic equation to solve for the eigenvalues x of a 2x2 matrix (|A - xI| = 0). The inverse of a matrix can be calculated as the classical adjugate multiplied by the reciprocal of the determinant. Use Cramer's Rule to solve a system of linear equations by computing determinants. Reason that if x is an eigenvalue of A then A - xI has a non-trivial nullspace (using the mnemonic |A - xI| = 0).
adrian_b•1mo ago
As another poster has also said, the determinant of a matrix provides 2 very important pieces of information about the associated linear transformation of the space.

The sign of the determinant tells you whether the linear transformation includes a mirror reflection of the space, or not.

The absolute value of the determinant tells you whether the linear transformation preserves the (multi-dimensional) volume (i.e. it is an isochoric transformation, which changes the shape without changing the volume), or it is an expansion of the space or a compression of the space, depending on whether the absolute value of the determinant is 1, greater than 1 or less than 1.

To understand what a certain linear transformation does, one usually decomposes it in several kinds of simpler transformations (by some factorization of the matrix), i.e. rotations and reflections that preserve both size and shape (i.e. they are isometric transformations), isochoric transformations that preserve volume but not shape, and similitude transformations (with the scale factor computed from the absolute value of the determinant), which preserve shape, but not volume. The determinant provides 2 of these simpler partial transformations, the reflection and the similitude transformation.

programjames•1mo ago
Here are three reasons you want to be able to calculate the volume change for arbitrary parallelpipeds:

- If det M = 0, then M is not invertible. Knowing this is useful for all kinds of reasons. It means you cannot solve an equation like Mx = b by taking the inverse ("dividing") on both sides, x = M \ b. It means you can find the eigenvalues of a matrix by rearranging Mx = λx <--> (M-λI)x = 0 <--> det M-λI = 0, which is a polynomial equation.

- Rotations are volume-preserving, so the rotation group can be expressed as the matrices where det M = 1 (well, the component connected to the identity). This is useful for theoretical physics, where they're playing around with such groups and need representations they can do things with.

- In information theory, the differential entropy (or average amount of bits it takes to describe a particular point in a continuous probability distribution) increases if you spread out the distribution, and decreases if you squeeze it together by exactly log |det M| for a linear transformation. A nonlinear transformation can be linearized with its gradient. This is useful for image compression (and thus generation) with normalizing flow neural networks.

doetoe•1mo ago
Rotations have determinant 1, but not all matrices of determinant 1 in the connected component of the identity are rotations
gsf_emergency_6•1mo ago
http://www.gutenberg.org/files/37354/37354-pdf.pdf