Saturday, January 29, 2011

WikiLeaks Draws FBI Ire

40 Search Warrants Executed as FBI Goes After 'Anonymous'

Police agencies worldwide are turning up the heat on a loosely organized group of WikiLeaks activists. On Thursday U.K. police arrested five people, and U.S. authorities said they'd executed more than 40 search warrants in the U.S. in connection with last month's Web-based attacks against companies that had severed ties with WikiLeaks.

Investigations are also ongoing in the Netherlands, Germany and France, the U.S. Federal Bureau of Investigation said Thursday.

Acting on information from German authorities, the FBI raided Dallas ISP Tailor Made Services last month, looking for evidence relating to one of the chat servers used by Anonymous. Another server was traced to Fremont, California's Hurricane Electric.

The actions come after Anonymous knocked websites for MasterCard, Visa and others offline briefly by recruiting volunteers to target them with a network stress-testing tool called LOIC (Low Orbit Ion Cannon). LOIC flooded the sites with data, making them unable to serve legitimate visitors. This type of attack is called a distributed denial of service (DDoS) attack.

Anonymous has also targeted PayPal, Amazon and the websites of Sarah Palin and the Swedish Prosecutor's Office with these attacks.
"[F]acilitating or conducting a DDoS attack is illegal, punishable by up to 10 years in prison, as well as exposing participants to significant civil liability," the FBI said in a press release.

Anonymous members say they want to send a message to companies that dropping WikiLeaks over its decision to publish classified documents is an attack on free speech.

These types of political DDoS attacks have become commonplace. Pro-Russia computer users used them to shut down much of Estonia's Internet infrastructure in 2007, and two years later, supporters of Iran's pro-democracy movement attacked a number of state-sponsored websites.

Anonymous has launched similar DDoS attacks in the past, too, knocking the websites of the Recording Industry Association of America and Scientology offline in recent years.

On Thursday, a Web page used to coordinate this latest round of DDoS attacks was offline, and the group's Twitter and Blogspot pages were silent.

The U.K.'s Metropolitan Police arrested five men aged 15 to 26 on Thursday. No arrests have been announced in the U.S. Last month, Dutch authorities arrested two teenagers in connection with the attacks.


Saturday, January 15, 2011

Strange Number 6174

6174 is known as Kaprekar's constant[1][2][3] after the Indian mathematician D. R. Kaprekar. This number is notable for the following property:
  1. Take any four-digit number, using at least two different digits. (Leading zeros are allowed.)
  2. Arrange the digits in ascending and then in descending order to get two four-digit numbers, adding leading zeros if necessary.
  3. Subtract the smaller number from the bigger number.
  4. Go back to step 2.
The above process, known as Kaprekar's routine, will always reach 6174 in at most 7 iterations.[4] Once 6174 is reached, the process will continue yielding 7641 – 1467 = 6174. For example, choose 3524:
5432 – 2345 = 3087
8730 – 0378 = 8352
8532 – 2358 = 6174
The only four-digit numbers for which Kaprekar's routine does not reach 6174 are repdigits such as 1111, which give the result 0 after a single iteration. All other four-digit numbers eventually reach 6174 if leading zeros are used to keep the number of digits at 4:
2111 – 1112 = 0999
9990 – 0999 = 8991 (rather than 999 – 999 = 0)
9981 – 1899 = 8082
8820 – 0288 = 8532
8532 – 2358 = 6174
9831 reaches 6174 after 7 iterations:
9831 – 1389 = 8442
8442 – 2448 = 5994
9954 – 4599 = 5355
5553 – 3555 = 1998
9981 – 1899 = 8082
8820 – 0288 = 8532 (rather than 882 – 288 = 594)
8532 – 2358 = 6174
Note that in each iteration of Kaprekar's routine, the two numbers being subtracted one from the other have the same digit sum and hence the same remainder modulo 9. Therefore the result of each iteration of Kaprekar's routine is a multiple of 9.
495 is the equivalent constant for three-digit numbers. For five-digit numbers and above, there is no single equivalent constant; for each digit length the routine may terminate at one of several fixed values or may enter one of several loops instead.[4]

See also


  1. ^ Mysterious number 6174
  2. ^ Kaprekar DR (1955). "An Interesting Property of the Number 6174". Scripta Mathematica 15: 244–245. 
  3. ^ Kaprekar DR (1980). "On Kaprekar Numbers". Journal of Recreational Mathematics 13 (2): 81–82. 
  4. ^ a b Weisstein, Eric W., "Kaprekar Routine" from MathWorld.

External links

Thursday, January 13, 2011

College Humor for John Ellis

Hey, I don't do this stuff! One of my college-aged kids showed it to me. It's from a site called


The story behind this seems to be that particle theorist John Ellis and experimentalist Melissa Franklin were playing darts one evening at CERN in 1977, and a bet was made that would require Ellis to insert the word "penguin" somehow into his next research paper if he lost. He did lose, and was having a lot of trouble working out how he would do this. Finally, 'the answer came to him when one evening, leaving CERN, he dropped by to visit some friends where he smoked an illegal substance'. While working on his paper later that night 'in a moment of revelation he saw that the diagrams looked like penguins'.

Saturday, January 1, 2011

Cranks, Quacks, and Crackpots

I feel bad for you PhDs. in Physics to have to waste your time reading crackpottery. Well, no job is perfect, everything has a downside, what can you do about it? Nothing really. Hopefully the "amusing" aspect counteracts the "annoyance" factor.

While John Baez' The Crackpot Index is amazing in its own right, are you aware of another AMAZING one by Dr. Warren Siegel of SUNY's dept. of Physics?

It's called "Are you a Quack?" and can be accessed by clicking on this sentence. Good stuff. :-)