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Hacker's Delight
Hacker's Delight is a software algorithm book by Henry S. Warren, Jr. and published by Addison-Wesley Professional. The first edition was released in 2002,[1] and the second in 2013.[2] It discusses a variety of programming algorithms for common tasks involving integer types, often with the aim of performing the minimum number of operations or replacing slow operations by faster ones (e.g., converting a divide by a constant into a multiply by another constant that gives the same result).[3]
hacking  integer 
yesterday
Observable HQ - Data Science Notebooks
Observable is the javascript version of data science notebooks written by Mike Bostock, of d3.js fame.
d3  datascience  bostock  javascript 
2 days ago
How to become a GOOD Theoretical Physicist
This is a web site (under construction) for young students - and anyone else - who are (like me) thrilled by the challenges posed by real science, and who are - like me - determined to use their brains to discover new things about the physical world that we are living in. In short, it is for all those who decided to study theoretical physics, in their own time.
hooft  physics  theoretical 
4 days ago
Focus Issue: Entanglement and Quantum Gravity – Hover Brothers
Recent years have seen a flourishing of interest in the role that entanglement entropy plays in the physics of spacetime. New insights have been obtained into the role of entanglement for the entropy for black hole thermodynamics, and new ideas have been explored connecting entanglement to holography, wormholes, the structure of semiclassical spacetime itself and others. In this special issue, we collect a number of articles on this topic, offering a partial overview of these new developments. The issue includes review articles as well as speculative works on specific ideas.

Eduardo Martín-Martínez and Nicolas Menicucci open the special issue with a review on entanglement in quantum fields, which includes a discussion of flat spacetime phenomena such as the Unruh effect, as well as cosmological spacetimes. They also discuss novel ideas such as echoes of the early universe, entanglement harvesting, and a nascent proposal for quantum seismology.

Robert Myers and Eugenio Bianchi observe the similarity of the role played by entanglement entropy in the context of various approaches to quantum gravity, and propose entanglement entropy as an ingredient of the very semiclassical structure of spacetime in quantum gravity.
rovelli  quantum  gravity 
5 days ago
The Map of Mathematics | Quanta Magazine
Here is a map of mathematics as it stands today, mathematics as it is practiced by mathematicians.

From simple starting points — Numbers, Shapes, Change — the map branches out into interwoven tendrils of thought. Follow it, and you’ll understand how prime numbers connect to geometry, how symmetries give a handle on questions of infinity.

And although the map is necessarily incomplete — mathematics is too grand to fit into any single map — we hope to give you a flavor for the major questions and controversies that animate the field, as well as the conceptual tools needed to dive in.
map  mathematics  quantamag 
6 days ago
How to Implement a Killer GTD System in Google Sheets
Recently, I stumbled into a most unlikely piece of software to implement my kind of GTD system: Google Sheets. And you know what? I really, really like it. Who would have thought a simple web-based spreadsheet program could run a totally rad implementation of GTD?
gtd  sheets  google  cloud  spreadsheet 
6 days ago
The Technium: The Shirky Principle
Institutions will try to preserve the problem to which they are the solution.” — Clay Shirky
shirky  cooltools  kk 
6 days ago
Yuval Noah Harari Gives the Really Big Picture | The New Yorker
In 2008, Yuval Noah Harari, a young historian at the Hebrew University of Jerusalem, began to write a book derived from an undergraduate world-history class that he was teaching. Twenty lectures became twenty chapters. Harari, who had previously written about aspects of medieval and early-modern warfare—but whose intellectual appetite, since childhood, had been for all-encompassing accounts of the world—wrote in plain, short sentences that displayed no anxiety about the academic decorum of a study spanning hundreds of thousands of years. It was a history of everyone, ever. The book, published in Hebrew as “A Brief History of Humankind,” became an Israeli best-seller; then, as “Sapiens,” it became an international one. Readers were offered the vertiginous pleasure of acquiring apparent mastery of all human affairs—evolution, agriculture, economics—while watching their personal narratives, even their national narratives, shrink to a point of invisibility. President Barack Obama, speaking to CNN in 2016, compared the book to a visit he’d made to the pyramids of Giza.
harari  pocket  newyorker  history  bighistory 
7 days ago
Artificial atoms create stable qubits for quantum computing
Professor Andrew Dzurak explains that unlike a real atom, an artificial atom has no nucleus, but it still has shells of electrons whizzing around the centre of the device, rather than around the atom's nucleus.

"The idea of creating artificial atoms using electrons is not new, in fact it was first proposed theoretically in the 1930s and then experimentally demonstrated in the 1990s—although not in silicon. We first made a rudimentary version of it in silicon back in 2013," says Professor Dzurak, who is an ARC Laureate Fellow and is also director of the Australian National Fabrication Facility at UNSW, where the quantum dot device was manufactured.
unsw  dzurak  cqct  qis  qisnews  quantum 
8 days ago
How the CIA used Crypto AG encryption devices to spy on countries for decades - Washington Post
For more than half a century, governments all over the world trusted a single company to keep the communications of their spies, soldiers and diplomats secret.

The company, Crypto AG, got its first break with a contract to build code-making machines for U.S. troops during World War II. Flush with cash, it became a dominant maker of encryption devices for decades, navigating waves of technology from mechanical gears to electronic circuits and, finally, silicon chips and software.

The Swiss firm made millions of dollars selling equipment to more than 120 countries well into the 21st century. Its clients included Iran, military juntas in Latin America, nuclear rivals India and Pakistan, and even the Vatican.

But what none of its customers ever knew was that Crypto AG was secretly owned by the CIA in a highly classified partnership with West German intelligence. These spy agencies rigged the company’s devices so they could easily break the codes that countries used to send encrypted messages.
crypto  cia  encryption 
9 days ago
Something in Deep Space Is Sending Signals to Earth in Steady 16-Day Cycles - VICE
A mysterious radio source located in a galaxy 500 million light years from Earth is pulsing on a 16-day cycle, like clockwork, according to a new study. This marks the first time that scientists have ever detected periodicity in these signals, which are known as fast radio bursts (FRBs), and is a major step toward unmasking their sources.
galaxy  astronomy  frb  radio  cosmos 
11 days ago
Debt is Coming – alexdanco.com
Debt is going to finally come to the tech industry. 

We can hate it, we can criticize it, we can raise the alarm about how dangerous debt is to the VC model we’ve honed to perfection over decades. Or we can see this moment for what it is: a turning point into a new deployment period for software and the internet. Debt is coming, whether we like it or not. And I’m actually pretty excited for it. 
technology  finance  debt  vc 
11 days ago
My productivity app is a single .txt file
I gave up and started just tracking in a single text file and have been using it as my main productivity system for 12 years now. It is so essential to my work now, and has surprisingly scaled with a growing set of responsibilities, that I wanted to share this system. It's been my secret weapon.
todo  text  productivity 
12 days ago
Tarkovsky’s Advice to the Young: Learn to Enjoy Your Own Company – Brain Pickings
I don’t know… I think I’d like to say only that they should learn to be alone and try to spend as much time as possible by themselves. I think one of the faults of young people today is that they try to come together around events that are noisy, almost aggressive at times. This desire to be together in order to not feel alone is an unfortunate symptom, in my opinion. Every person needs to learn from childhood how to be spend time with oneself. That doesn’t mean he should be lonely, but that he shouldn’t grow bored with himself because people who grow bored in their own company seem to me in danger, from a self-esteem point of view.
tarkovsky  solitude 
20 days ago
Andrei Tarkovsky's Message to Young People: "Learn to Be Alone," Enjoy Solitude | Open Culture
Andrei Tarkovsky’s Message to Young People: “Learn to Be Alone,” Enjoy Solitude
tarkovsky  film  solitude 
20 days ago
Tarkovsky Films Now Free Online | Open Culture
Watch Andrei Tarkovsky’s Films Free Online: Stalker, Solaris, The Mirror & Andrei Rublev
tarkovsky  film  art  online  free 
20 days ago
Error-mitigated quantum gates exceeding physical fidelities in a trapped-ion system | Nature Communications
Demonstration that GST can provide the basis for error-mitigated gates. Reduced 2Q errors from 1e-2 to 1-e3.
gst  quantum  error  mitigation 
21 days ago
Latacora - The PGP Problem
Cryptography engineers have been tearing their hair out over PGP’s deficiencies for (literally) decades. When other kinds of engineers get wind of this, they’re shocked. PGP is bad? Why do people keep telling me to use PGP? The answer is that they shouldn’t be telling you that, because PGP is bad and needs to go away.
pgp  encryption  age 
21 days ago
Jeffrey Paul: Starlink is a Big Deal
SpaceX has a subsidiary, known as Starlink, which is presently endeavoring to blanket the majority of the inhabited latitudes of Earth with orbiting satellites to provide wireless internet access and private-line communications services. This is a Big Deal, the consequences of which I will explain momentarily. But first, some background.
satellite  geosynchronous  starlink  internet 
21 days ago
Thinking Forth
This is the homepage of the Thinking Forth project.

Thinking Forth captures the philosophy of the language to show users how to write more readable, better maintainable applications. This project makes the book available in electronic form (LaTeX and PDF).

The project has two milestones: the reprint and the 21st century version. The reprint is done, scroll down for the ongoing project.
books  language  programming  forth  free 
22 days ago
How To Fight The Enemy That Lives Between Your Own Two Ears
There’s a war going on inside your head. And you’re not even aware of it.

Here are 10 war strategies that will help you to win your inner battles.
mindfulness  mind 
22 days ago
Up Close, There’s More to the Ghent Altarpiece Than the Lamb - The New York Times
After causing a stir on social media, the unveiling of a restored panel kicks off a year celebrating the late-medieval master Jan van Eyck.
ghent  altarpiece  vaneyck 
23 days ago
Sunrise and sunset times in Albuquerque
Chart of sunrise and sunset times in albuquerque.
sunset  sunrise  annual 
23 days ago
An Interview with William Gibson
When everyone is talking about the features of the latest Silicon Valley gadget, he might peer at the physical thing itself — from what materials is it constructed? How does it feel cupped in the palm of a hand? What do the awkward lines of its design call to mind? Who might have access to the data it collects? When Wired asked him to write an essay about Tokyo in 2001, he spent a sleepless night wandering the interzone of Roppongi, noting how a particular sex worker looked like she might have stepped straight out of a neon-saturated, hustler-filled, pre-Bubble version of the city. By exploring the ragged edges of things, Gibson consistently manages to shed new light on the strange world we inhabit, coining terms like “cyberspace” and making oft-repeated observations like, “The future is already here — it’s just not evenly distributed.”
gibson  cyberpunk  reading  future 
23 days ago
Glial Brain Cells, Long in Neurons’ Shadow, Reveal Hidden Powers | Quanta Magazine
The glial cells of the nervous system have been eclipsed in importance by neurons for decades. But glia are turning out to be central to many neurological functions, including pain perception.
glia  neurons  brain 
23 days ago
[1910.12277] The Quantum Illumination Story
Superposition and entanglement, the quintessential characteristics of quantum physics, have been shown to provide communication, computation, and sensing capabilities that go beyond what classical physics will permit. It is natural, therefore, to explore their application to radar, despite the fact that decoherence---caused by the loss and noise encountered in radar sensing---destroys these fragile quantum properties. This paper tells the story of "quantum illumination", an entanglement-based approach to quantum radar, from its inception to its current understanding. Remarkably, despite loss and noise that destroy its initial entanglement, quantum illumination does offer a target-detection performance improvement over a classical radar of the same transmitted energy. A realistic assessment of that improvement's utility, however, shows that its value is severely limited. Nevertheless, the fact that entanglement can be of value on an entanglement-breaking channel---the meta-lesson of the quantum illumination story---should spur continued research on quantum radar.
quantum  radar  illumination 
24 days ago
‘The Righteous Mind,’ by Jonathan Haidt - The New York Times
To the question many people ask about politics — Why doesn’t the other side listen to reason? — Haidt replies: We were never designed to listen to reason. When you ask people moral questions, time their responses and scan their brains, their answers and brain activation patterns indicate that they reach conclusions quickly and produce reasons later only to justify what they’ve decided. The funniest and most painful illustrations are Haidt’s transcripts of interviews about bizarre scenarios. Is it wrong to have sex with a dead chicken? How about with your sister? Is it O.K. to defecate in a urinal? If your dog dies, why not eat it? Under interrogation, most subjects in psychology experiments agree these things are wrong. But none can explain why.
politics  listening 
24 days ago
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