Forgot your password?
typodupeerror
Math

+ - The biggest number of all: the Holderness number-> 2

Submitted by
CosmoCurio
CosmoCurio writes "If you guessed it's the number of atoms in the observable universe (i.e., 10^80 atoms), that's not it.

And we are not talking about hypothetical large numbers that do not represent anything. So googol [10^100], googolplex [10^googol], Graham's number, and Moser's number don't count.

The biggest number that actually represents something can be found right inside our brains, literally. Which brain contains about 10^27 atoms incidentally. In John D. Barrow's The Constants of Nature (2002), we find the following discussion [pp. 116-118]:

"... astronomy is not the place to look. The big numbers of astronomy are additive. They arise because we are counting stars, planets, atoms and photons in a huge volume. If you want really huge numbers you need to find a place where the possibilities multiply rather than add. For this you need complexity. And for complexity you need biology.


"In the seventeenth century the English physicist Robert Hooke [1635-1703] made a calculation 'of the number of separate ideas the mind is capable of entertaining' [1]. The answer he got was 3,155,760,000. Large as this number might appear to be (you would not live long enough to count up to it!) it would now be seen as a staggering underestimation. Our brains contains about 10 billion neurons, each of which sends out feelers, or axons, to link it to about one thousand others. These connections play some role in creating our thoughts and memories. How this is done is still one of Nature's closely guarded secrets. Mike Holderness suggests that one way of estimating [2] the number of possible thoughts that a brain could conceive is to count all those connections. The brain can do many things at once so we could view it as some number, say a thousand, little groups of neurons. If each neuron makes a thousand different links to the ten million others in the same [neuron] group then the number of different ways in which it could make connections in the same neuron group is 10^7 x 10^7 x 10^7 x ... one thousand times. This gives 10^7000 possible patterns of connections. But this is just the number for one neuron group. The total number for 10^7 neurons is 10^7000 multiplied together by 10^7 times. This is 10^70,000,000,000. If the 1000 or so groups of neurons can operate independently of each other then each of them contributes 10^70,000,000,000 possible wirings, increasing the total to the Holderness number, 10^70,000,000,000,000.


"This is the modern estimate of the number of different electrical patterns that the brain could hold. In some sense it is the number of different possible thoughts or ideas that a human brain could."


Hence for now, it looks like the Holderness number is it. There's still no Wikipedia entry on the Holderness number incidentally.

For more on large numbers, please see also Scott Aaronson's "Who Can Name the Bigger Number?"

Footnotes:

[1] The estimate was reported in Albrecht von Haller's Elementa Physiologiae, vol. 5, London, 1786, p. 547.

[2] The estimates were made by Mike Holderness, in 'Think of a Number', New Scientist, 16 June 2001, p. 45."

Link to Original Source
Security

+ - Zero-knowledge web application: dream or reality?->

Submitted by
Marco Barulli
Marco Barulli writes "A zero-knowledge web application knows nothing about its users and their data. This blog post describes the 4 rules that web developers should follow to build zero-knowledge web apps. We got the "social web", are we ready for the "private web"? We got used to trust online services with our data (text documents, spreadsheets, ...), but is it necessary? Many useful web applications can (and should) be developed applying a zero-knowledge methodology."
Link to Original Source
PC Games (Games)

+ - Gamers Have Friends, Girls Like Grand Theft Auto->

Submitted by
Jeremy Dean
Jeremy Dean writes "New research dispels the well-worn stereotypes that computer gamers having no social skills and girls avoid violent games like Grand Theft Auto. Results showed children playing violent M-rated games were more likely to play in groups. Friendship groups amongst boys, in particular, were often based around violent computer games. Also, children used games to help manage their emotions. When angry or stressed they liked to use games to get these emotions out."
Link to Original Source
Space

+ - Scares in space->

Submitted by Soft
Soft (266615) writes "`Did you hear the one about (...) the astronaut who became so despondent after his orbital experiment failed that his colleagues feared he would blow the hatch on the space shuttle?' Jon Clark, a former NASA flight surgeon, tells Alan Boyle's cosmic log about a number of horror stories which happened in space over the course of the space program. (To ward off predictable jokes, there are none with diapers; that didn't happen in space, anyway.)"
Link to Original Source
Google

+ - Inside Google's Black Box

Submitted by
Pcol
Pcol writes "Google's "ranking algorithm" — the formulas that decide which Web pages best answer each user's question is crucial part of Google's inner sanctum, a department called "search quality" that the company treats like a state secret. Google recently allowed a reporter from the New York Times to spend a day with Google Fellow Amit Singhal and his search-quality team who explained how every week they make about a half-dozen major and minor changes to the vast nest of mathematical formulas that power the search engine. Mr. Singhal has developed a far more elaborate system for ranking pages than PageRank. The system, involving more than 200 types of information, are what Google calls "signals." Some signals are on Web pages — like words, links, images and so on. Some are drawn from the history of how pages have changed over time. Some signals are data patterns uncovered in the trillions of searches that Google has handled over the years. Increasingly, Google is using signals that come from its history of what individual users have searched for in the past, in order to offer results that reflect each person's interests. "People still think that Google is the gold standard of search," says John Battelle, author of "The Search," a book about Google. "Their secret sauce is how these guys are doing it all in aggregate. There are 1,000 little tunings they do.""
The Internet

+ - Technology and Terrorism: Are we being too naive?->

Submitted by
ReadWriteWeb
ReadWriteWeb writes "Are web tools like Google Earth, social networks like LinkedIn, and photo-sharing sites like Flickr being used against us by terrorists? Today we learned of a terrorist plot targeting the JFK international airport in New York. Luckily this attack was prevented and three out of the four terrorists are already in custody. But during a CNN report, a curious fact was revealed — terrorists have used Google Earth to get access to aerial views of airport facilities. Obviously it would be ridiculous to argue that tools like Google Earth should not be built because terrorists might use them. Yet, after hearing this on CNN one cannot help but wonder: what other seemingly innocent software technologies are we building that can be used to harm us?"
Link to Original Source

1 Mole = 25 Cagey Bees

Working...