"math" entries

Four short links: 10 August 2012

Four short links: 10 August 2012

Coffee Rings, Scaling Laws, Autonomous Aircraft, and Dreaming Computers

  1. The Coffee-Ring Effect (YouTube) — beautiful video of what happens in liquids as they evaporate, explaining why coffee stains are rings, and how to create liquids with even evaporative coating.
  2. The Importance of Quantitative Thinking Medicine (PDF) — scaling laws underly aging, metabolism, drug delivery, BMI, and more. Full of wow moments, like Fractals are a common feature of many complex systems ranging from river networks, earthquakes, and the internet to stock markets and cities. […] Geometrically, the nested levels of continuous branching and crenulations inherent in fractal­like structures optimise the transport of information, energy, and resources by maximising the surface areas across which these essential features of life flow within any volume. Because of their fractal nature, these effective surface areas are much larger than their apparent physical size. For example, even though the volume of our lungs is about 5–6 L, the total surface area of all the alveoli is almost the size of a tennis court and the total length of airways is about 2500 km. Even more striking is that if all the arteries, veins, and capillaries of an individual’s circulatory system were laid end to end, its total length would be about 100000 km, or nearly two and a half times around the earth.
  3. Autonomous Robotic Plane at MIT (YouTube) — hypnotic to watch it discover the room. A product of the Robust Robotics Group at MIT.
  4. Electric Sheep — hypnotic screensaver, where the sleeping computers collaborate on animations. You can vote up or down the animation on your screen, changing the global gene pool. Popular animations survive and propagate.
Four short links: 1 August 2012

Four short links: 1 August 2012

Chinese Hackers, Edible Sensors, Quantum Physics

  1. China Hackers Hit EU Point Man and DC (Bloomberg) — wow. The extent to which EU and US government and business computer systems have been penetrated is astonishing. Stolen information is flowing out of the networks of law firms, investment banks, oil companies, drug makers, and high technology manufacturers in such significant quantities that intelligence officials now say it could cause long-term harm to U.S. and European economies. (via Gady Epstein)
  2. Digestible Microchips (Nature) — The sand-particle sized sensor consists of a minute silicon chip containing trace amounts of magnesium and copper. When swallowed, it generates a slight voltage in response to digestive juices, which conveys a signal to the surface of a person’s skin where a patch then relays the information to a mobile phone belonging to a healthcare-provider. (via Sara Winge)
  3. Quantum Mechanics Make Simple(r) — clever way to avoid the brain pain of quantum mechanics and leap straight to the “oh!”. [N]ature is described not by probabilities (which are always nonnegative), but by numbers called amplitudes that can be positive, negative, or even complex. […] In the usual “hierarchy of sciences”—with biology at the top, then chemistry, then physics, then math—quantum mechanics sits at a level between math and physics that I don’t know a good name for. Basically, quantum mechanics is the operating system that other physical theories run on as application software (with the exception of general relativity, which hasn’t yet been successfully ported to this particular OS). (via Hacker News)
  4. Selectively De-Animating Video — SIGGRAPH talk showing how to keep some things still in a video. Check out the teaser video with samples: ZOMG. I note that Maneesh Agrawala was involved: I’m a fan of his from Line Drive maps and 3D exploded views, but his entire paper list is worth reading. Wow. (via Greg Borenstein)
Four short links: 21 June 2012

Four short links: 21 June 2012

Randomized Trials for Policy, Crowdfunding Equity, Safe DIYBio, and Easy Unique Experiences

  1. Test, Learn, Adapt (PDF) — UK Cabinet Office paper on randomised trials for public policy. Ben Goldacre cowrote.
  2. UK EscapeTheCity Raises GBP600k in Crowd Equity — took just eight days, using the Crowdcube platform for equity-based crowd investment.
  3. DIY Bio SOPs — CC-licensed set of standard operating procedures for a bio lab. These are the SOPs that I provided to the Irish EPA as part of my “Consent Conditions” for “Contained Use of Class 1 Genetically Modified Microorganisms”. (via Alison Marigold)
  4. Shuffling Cards — shuffle a deck of cards until it’s randomised. That order of cards probably hasn’t ever been seen before in the history of mankind.
Four short links: 18 June 2012

Four short links: 18 June 2012

Facebook Sociology, Microbiome Mapping, Attention Surplus Disorder, and Makematics

  1. What Facebook Knows (MIT Tech Review) — Analyzing the 69 billion friend connections among those 721 million people showed that the world is smaller than we thought: four intermediary friends are usually enough to introduce anyone to a random stranger. and our close friends strongly sway which information we share, but overall their impact is dwarfed by the collective influence of numerous more distant contacts—what sociologists call “weak ties.” It is our diverse collection of weak ties that most powerfully determines what information we’re exposed to.
  2. Human Microbiome Mapped (The Scientist) — the Human Microbiome Project sequenced DNA of bacterial samples collected from 242 healthy volunteers. 3.5 terabytes of data, all accessible through public databases. One fascinating finding: Although each body part is characterised by some signature microbial groups, no species was universally present across every volunteer. “One of the HMP’s original mandates was to define the core microbiome, or the bugs that everyone shares,” said Huttenhower. “It looks like there really aren’t any.”
  3. Kids Today Not Inattentive (Neuroskeptic) — There’s no evidence that children today are less attentive or more distractible than kids in the past, according to research just published by a team of Pennsylvania psychologists. (via Ed Yong)
  4. Teaching Makematics at ITP (Greg Borenstein) — Computer vision algorithms, machine learning techniques, and 3D topology are becoming vital prerequisites to doing daily work in creative fields from interactive art to generative graphics, data visualization, and digital fabrication. If they don’t grapple with these subjects themselves, artists are forced to wait for others to digest this new knowledge before they can work with it.
Four short links: 11 May 2012

Four short links: 11 May 2012

Flipping the Medical Classroom, Inclusion Haters, Information Leveling, and Ars Longa Vita Brevis

  1. Stanford Med School Contemplates Flipped Classroom — the real challenge isn’t sending kids home with videos to watch, it’s using tools like OceanBrowser to keep on top of what they’re doing. Few profs at universities have cared whether students learned or not.
  2. Inclusive Tech Companies Win The Talent War (Gina Trapani) — she speaks the truth, and gently. The original CNN story flushed out an incredible number of vitriolic commenters apparently lacking the gene for irony.
  3. Buyers and Sellers Guide to Web Design and Development Firms (Lance Wiggs) — great idea, particularly “how to be a good client”. There are plenty of dodgy web shops, but more projects fail because of the clients than many would like to admit.
  4. What Does It Mean to Say That Something Causes 16% of Cancers? (Discover Magazine) — hey, all you infographic jockeys with your aspirations to add Data Scientist to your business card: read this and realize how hard it is to make sense of a lot of numbers and then communicate that sense. Data Science isn’t about Hadoop any more than Accounting is about columns. Both try to tell a story (the original meaning of your company’s “accounts”) and what counts is the informed, disciplined, honest effort of knowing that your story is honest.
Four short links: 10 May 2012

Four short links: 10 May 2012

Illuminated Mario, Touchstone Facts, Calculating Spamicity, and Abstract Quantified Self

  1. Gravity in the Margins (Got Medieval) — illuminating illuminated manuscripts with Mario. (via BoingBoing)
  2. Hours Days, Who’s Counting? (Jon Udell) — What prompted me to check? My friend Mike Caulfield, who’s been teaching and writing about quantitative literacy, says it’s because in this case I did have some touchstone facts parked in my head, including the number 10 million (roughly) for barrels of oil imported daily to the US. The reason I’ve been working through a bunch of WolframAlpha exercises lately is that I know I don’t have those touchstones in other areas, and want to develop them. The idea of “touchstone facts” resonates with me.
  3. Spotting Fake Reviewer Groups in Consumer Reviews (PDF) — gotta love any paper that says We calculated the “spamicity” (degree of spam) of each group by assigning 1 point for each spam judgment, 0.5 point for each borderline judgment and 0 point for each non-spam judgment a group received and took the average of all 8 labelers. (via Google Research Blog)
  4. Visualizing Physical Activity Using Abstract Ambient Art (Quantified Self) — kinda like the iTunes visualizer but for your Fitbit Tracker.
Four short links: 2 May 2012

Four short links: 2 May 2012

Elective Dickery, Probabilistic Data Analysis, Data Cleaning, and SSL Security

  1. Punting on SxSW (Brad Feld) — I came across this old post and thought: if you can make money by being a dick, or make money by being a caring family person, why would you choose to be a dick? As far as I can tell, being a dick is optional. Brogrammers, take note. Be more like Brad Feld, who prioritises his family and acts accordingly.
  2. Probabilistic Structures for Data Mining — readable introduction to useful algorithms and datastructures showing their performance, reliability, and resources trade-off. (via Hacker News)
  3. Dataset — a Javascript library for transforming, querying, manipulating data from different sources.
  4. Many HTTPS Servers are Insecure — 75% still vulnerable to the BEAST attack.
Four short links: 26 April 2012

Four short links: 26 April 2012

Historic Software, Flickr Javascript, Twitter Commandline, and Math Mental Habits

  1. Apollo Software — amazing collection of source code to the software behind the Apollo mission. And memos, and quick references, and operations plans, and …. Just another reminder that the software itself is generally dwarfed by its operation.
  2. flickrapi.js (Github) — Aaron Straup Cope’s Javascript library for Flickr.
  3. t (Github) — command-line power-tool for Twitter.
  4. Habits of Mind (PDF) — Much more important than specific mathematical results are the habits
    of mind used by the people who create those results,and we envision a curriculum
    that elevates the methods by which mathematics is created,the techniques used
    by researchers,to a status equal to that enjoyed by the results of that research.
    Loved it: talks about the habits and mindsets of mathematicians, rather than the set of algorithms and postulates students must be able to recall. (via Dan Meyer)
Four short links: 12 April 2012

Four short links: 12 April 2012

Financial Data, 21C Learning for Parents, IQ Battles, and Etsy Hacker Grants

  1. Big Data in Finance (PDF, 9M) — Algo trading systems have begun to resemble an arms race. Competition, data, and the race for real-time.
  2. A Parent’s Guide to 21st Century Learning (Edutopia, free registration required to download) — What should collaboration, creativity, communication, and critical thinking look like in a modern classroom? How can parents help educators accomplish their goals? We hope this guide helps bring more parents into the conversation about improving education. (via Derek Wenmoth)
  3. Chess Intelligence and Winning — survey of IQ gaps between contestants needed to win competitions. We could view cops and killers as being involved in a grim contest. In the USA around 65% of all murders are solved. That converts to an average “murder” ELO rating difference between police and murderers of 108 ELO points. It is also known that the mean IQs of murderers and policemen are 87 and 102, respectively. So successfully solving murders is a puzzle then the “a” coefficient is 0.041, and each IQ point difference is worth 7.2 ELO points. I suspect this is masturbatory math extrapolation rather than anything significant or predictive, but the cops-vs-robbers IQ contest was an interesting angle. (via Dr Data’s Blog)
  4. Etsy Hacker Grants: Supporting Women in TechnologyToday, in conjunction with Hacker School, Etsy is announcing a new scholarship and sponsorship program for women in technology: we’ll be hosting the summer 2012 session of Hacker School in the Etsy headquarters, and we’re providing ten Etsy Hacker Grants of $5,000 each — a total of $50,000 — to women who want to join but need financial support to do so. Our goal is to bring 20 women to New York to participate, and we hope this will be the first of many steps to encourage more women into engineering at Etsy and across the industry.
Four short links: 4 April 2012

Four short links: 4 April 2012

Touch-Typing Instruction, HTTP Header Attacks, Sorting Ratings, and Risks of Inspecting Applicants' Facebook Pages

  1. Typing Club — lessons to improve your touch-typing, building you up letter by letter to speed and mastery. Like how I learned, only without the typewriters and the bibs and the roomful of girls. It wasn’t easy being the only boy in typing class, but somehow I managed. (via EdTech ideas)
  2. SQL Injection via HTTP Headers — excellent introduction to how some surprising HTTP headers can be attack vectors.
  3. How Not to Sort by Average Rating (Evan Miller) — so easy to get it wrong, so eye-wateringly complex a formula to do it right. (via Hacker News)
  4. I Hereby Resign (Reg Braithwaite) — not an actual resignation letter, but it highlights exactly why asking to see applicants’ Facebook pages is a bad idea. “If you are surfing my Facebook, you could reasonably be expected to discover that I am a Lesbian. Since discrimination against me on this basis is illegal in Ontario, I am just preparing myself for the possibility that you might refuse to hire me and instead hire someone who is a heterosexual but less qualified in any way. Likewise, if you do hire me, I might need to have your employment contracts disclosed to ensure you aren’t paying me less than any male and/or heterosexual colleagues with equivalent responsibilities and experience.” Ditto “spouse is pregnant so I’m about to take maternity leave just after you hire me”, etc. Those things you spend days thumping into HR that they aren’t supposed to ask about? All on the applicants’ Facebook pages.