Monday, August 31, 2009
Sunday, August 30, 2009
Friday, August 28, 2009
Thursday, August 27, 2009
Wednesday, August 26, 2009
BlindSearch is a search engine taste test:
Type in a search query, hit "search", then vote for the column which you believe best matches your query. The columns are randomised with every query.(Via BBspot.)
The goal of this site is simple, we want to see what happens when you remove the branding from search engines. How differently will you perceive the results?
Tuesday, August 25, 2009
Coin flipping is less random than commonly believed:
1. If the coin is tossed and caught, it has about a 51% chance of landing on the same face it was launched. (If it starts out as heads, there's a 51% chance it will end as heads).Here are the strategy implications:
2. If the coin is spun, rather than tossed, it can have a much-larger-than-50% chance of ending with the heavier side down. Spun coins can exhibit "huge bias" (some spun coins will fall tails-up 80% of the time).
3. If the coin is tossed and allowed to clatter to the floor, this probably adds randomness.
4. If the coin is tossed and allowed to clatter to the floor where it spins, as will sometimes happen, the above spinning bias probably comes into play.
5. A coin will land on its edge around 1 in 6000 throws, creating a flipistic singularity.
6. The same initial coin-flipping conditions produce the same coin flip result. That is, there's a certain amount of determinism to the coin flip.
7. A more robust coin toss (more revolutions) decreases the bias.
1. Always be the chooser, if possible. This allows you to leverage Premise 1 or Premise 2 for those extra percentage points.Here's the academic paper. (Via Bruce Schneier.)
2. Always be the tosser, if you can. This protects you from virtuoso coin-flippers who are able to leverage Premise 6 to produce a desired outcome. It also protects you against the added randomness (read: fairness) introduced by flippers who will occasionally, without rhyme or reason, invert the coin in their palm before revealing. Tricksy Hobbitses.
3. Don't allow the same person to both toss and choose. Unless, of course, that person is you.
4. If the coin is being tossed, and you're the chooser, always choose the side that's initially face down. According to Premise 1, you'd always choose the side that's initially face up, but most people, upon flipping a coin, will invert it into their other palm before revealing. Hence, you choose the opposite side, but you get the same 1% advantage. Of course, if you happen to know that a particular flipper doesn't do this, use your better judgment.
5. If you are the tosser but not the chooser, sometimes invert the coin into your other palm after catching, and sometimes don't. This protects you against people who follow Rule 4 blindly by assuming you'll either invert the coin or you won't.
6. If the coin is being spun rather than tossed, always choose whichever side is lightest. On a typical coin, the "Heads" side of the coin will have more "stuff" engraved on it, causing Tails to show up more frequently than it should. Choosing Tails in this situation is usually the power play.
7. Never under any circumstances agree to a coin spin if you're not the chooser. This opens you up to a devastating attack if your opponent is aware of Premise 2.
"Scientists are only months away from creating artificial life...":
Dr Craig Venter – one of the world’s most famous and controversial biologists – said his U.S. researchers have overcome one of the last big hurdles to making a synthetic organism.
The first artificial lifeform is likely to be a simple man-made bacterium that proves that the technology can work.
But it will be followed by more complex bacteria that turn coal into cleaner natural gas, or algae that can soak up carbon dioxide and convert it into fuels.
Monday, August 24, 2009
Sunday, August 23, 2009
Friday, August 21, 2009
Thursday, August 20, 2009
Wednesday, August 19, 2009
Interesting revelation principle:
At Legoland, admission is discounted for two-year-olds. But a child must be at least three for most of the fun attractions.(Via MR.)
At the ticket window the parents are asked how old the child is. But at the ride entrance the attendants ask the children directly.
The parents lie. The children tell the truth.
Tuesday, August 18, 2009
"DNA evidence can be fabricated":
Scientists in Israel have demonstrated that it is possible to fabricate DNA evidence, undermining the credibility of what has been considered the gold standard of proof in criminal cases.
The scientists fabricated blood and saliva samples containing DNA from a person other than the donor of the blood and saliva. They also showed that if they had access to a DNA profile in a database, they could construct a sample of DNA to match that profile without obtaining any tissue from that person.
"You can just engineer a crime scene," said Dan Frumkin, lead author of the paper, which has been published online by the journal Forensic Science International: Genetics. "Any biology undergraduate could perform this."
Monday, August 17, 2009
Nice overview of the mathematics of gambling.
Includes this following good discussion of the "marriage problem":
Includes this following good discussion of the "marriage problem":
Suppose you are told you must marry, and that you must choose your spouse out of 100 applicants. You may interview each applicant once. After each interview you must decide whether to marry that person. If you decline, you lose the opportunity forever. If you work your way through 99 applicants without choosing one, you must marry the 100th. You may think you have 1 in 100 chance of marrying your ideal partner, but the truth is that you can do a lot better than that.(Via Kottke.)
If you interview half the potential partners then stop at the next best one - that is, the first one better than the best person you've already interviewed - you will marry the very best candidate about 25 per cent of the time. Once again, probability explains why. A quarter of the time, the second best partner will be in the first 50 people and the very best in the second. So 25 per cent of the time, the rule "stop at the next best one" will see you marrying the best candidate. Much of the rest of the time, you will end up marrying the 100th person, who has a 1 in 100 chance of being the worst, but hey, this is probability, not certainty.
You can do even better than 25 per cent, however. John Gilbert and Frederick Mosteller of Harvard University proved that you could raise your odds to 37 per cent by interviewing 37 people then stopping at the next best. The number 37 comes from dividing 100 by e, the base of the natural logarithms, which is roughly equal to 2.72. Gilbert and Mosteller's law works no matter how many candidates there are - you simply divide the number of options by e.
Friday, August 14, 2009
Thursday, August 13, 2009
Wednesday, August 12, 2009
Tuesday, August 11, 2009
Monday, August 10, 2009
Sunday, August 09, 2009
"Accused Florida man says his cat downloaded child porn, not him":
Florida law enforcement agents have charged 48-year-old Keith R. Griffin ...with 10 counts of possession of child pornography after a detective found over a thousand such images on his computer.
In his defense, Mr. Griffin told detectives "he would leave his computer on and his cat would jump on the keyboard. And when he returned there will be strange material downloaded."
He is jail, with bail set at a quarter million dollars. His cat roams free.
Saturday, August 08, 2009
Friday, August 07, 2009
Thursday, August 06, 2009
Wednesday, August 05, 2009
Tuesday, August 04, 2009
Hackers fooled by fake ATM:
...A malicious ATM kiosk was positioned in the conference center of the Riviera Hotel Casino capturing data from an unknown number of hackers attending the DefCon hacker conference before someone noticed something suspicious about the kiosk.
...[CEO of Aries Security, Brian] Markus said it was clear to him the ATM was fake when he looked at the smoked glass on the front of the machine and noticed something funny about it. When he beamed a flashlight through the glass, instead of seeing a camera behind it, he saw the PC that was set up to siphon card data.
The ATM had been placed right outside the hotel’s security office.
Monday, August 03, 2009
"Mosquitoes deliver malaria 'vaccine' through bites":
In a daring experiment in Europe, scientists used mosquitoes as flying needles to deliver a "vaccine" of live malaria parasites through their bites.(Via Howard Roerig.)
The results were astounding: Everyone in the vaccine group acquired immunity to malaria; everyone in a non-vaccinated comparison group did not, and developed malaria when exposed to the parasites later.