Two dimensional string theory

Promotion has sapped the output of my favorite physics bloggers, so I'm grateful to FMH for my physics fix:

Shadow World: Science News Online, Nov. 17, 2007

....Since 1997, physicists have proposed countless variations on Maldacena's theme, all of which interpret a string as a swarm of particles living in a small number of dimensions. Perhaps the easiest case to visualize is when that number is two. In such a scenario, anything that takes place in your many-dimensional, stringy universe has a sort of shadow representation in terms of particles moving on that universe's 'sphere at infinity.' This esoteric-sounding concept is actually similar to the familiar celestial sphere of the night sky as seen from Earth: It's the two-dimensional surface spanning all possible directions one can point to infinitely far in space...

So this re-representation of string theory has been popular for 10 years -- but I don't recall reading about it.

Annoying.

Sciam did cover this in Nov 2005 ("The Illusion of Gravity"), but I wasn't a subscriber then. (SciAm is the only periodical I subscribe to does not give archival access to current print subscribers. It's their right, but I do hold it against them.)

Wikipedia presents the theory more technically:

Juan Martín Maldacena (born September 10, 1968) is a theoretical physicist born in Buenos Aires, Argentina. Among his many discoveries, the most famous one is the most reliable realization of the holographic principle - namely the AdS/CFT correspondence, the successfully tested conjecture about the equivalence of string theory or supergravity on Anti de Sitter (AdS) space, and a conformal field theory defined on the boundary of the AdS space.

and on AdS/CFT correspondence:

In physics, the AdS/CFT correspondence (anti-de-Sitter space/conformal field theory correspondence), sometimes called the Maldacena duality, is the conjectured equivalence between a string theory defined on one space, and a quantum field theory without gravity defined on the conformal boundary of this space, whose dimension is lower by one or more...

Now, as we all know one of the primary challenges of the last 80 or so years of physics has been quantizing gravity. So, as a hobbyist reading this, I'm thinking the mathematical trick is to make the problem more tractable (and perhaps more constrained?) by taking gravity out of the picture. Hence the SciAm title - the "illusion of gravity".

This might be a bit like the old polar vs. cartesian coordinate transformation in Physics 101. Neither is "truer" than the other, but in some problems solutions are much easier. Or maybe the the Maldacena view will turn out to be the "better" model of "reality" (whatever that slippery beast might be).

I'll have to look around for some other popular summaries ...

Ravel on Bolero

Maurice Ravel

I have written only one masterpiece. That is Boléro. Unfortunately, it contains no music.

Guess what phone isn't promoted on the A&T site

Yep. No sign. No sign of the iPhone. It's beginning to look like AT&T's margins are every bit as thin, and Apple's every bit as fat, as rumor suggests.

AT&T is promoting phones where they at least make money on the plans.

I wonder if AT&T will eventually beg Apple to let them out of the contract early ...

Update: At least one commentator sees an iPhone, though it doesn't appear on the screen I get.

The best Trek: Slashdot chooses

Slashdot Polls are generally silly, but this time they asked a question that both matched the readership and was taken seriously.

They asked which Trek was the best. Voyager was not an option.

The rankings as of 61,594 votes (talk about a significant sample size) were:

• Star Trek: 14%
• Next Generation: 46%
• Deep Space 9: 16%
• Enterprise 5%
• Joke responses: 12%

I've never watched Enterprise, but that's the way I'd rank the rest. NG wins by a landslide and DS 9 and the original are roughly equal.

Of course NG was better before Picard was transiently assimilated. The Borg were great theater, but they sucked the oxygen out of the rest of the series.

One of my most memorable episodes, oddly, featured the often annoying "Q". Picard disdains his youthful recklessness, and Q decides to, you know, "teach him". Q causes Picard to live his life more circumspectly, leading Picard to a dead end job in the science division.

Any relationship to my current employment is purely coincidental :-).

Five by Dyer: two on Oil

Five from Gwynne Dyer

Oct 29 The Indo-US Alliance: The Wheels Fall Off
Nov 2 Telling the Truth about Oil
Nov 8 After Peak Oil
Nov 13 Pakistan Scenarios
Nov 18 Australia's Climate Change Election

All interesting, as usual.

Particle vs. Field: which is truer

Today it seems that particles are merely secondary ....

Nonlocality of a Single Particle Demonstrated Without Objections

... The scientists note an interesting comparison of their result to a principle of Leibniz’s metaphysics, the identity of indiscernibles. According to the principle, a pair of entangled quantum particles must be indiscernible from a single particle, since both objects have in common all the same properties—this is the only stipulation of the principle, number being irrelevant. The single-state nonlocality demonstrated here reinforces the equivalence of a single state and an entangled state—giving more credence to the position that quantum field theory, where fields are fundamental and particles secondary, is a close representation of reality...

In knowledge modeling the debate is between the nodes (statements) and the arcs (relationships). The arcs are pulling ahead.

Galois: killer unknown

My IOT podcast of the moment is on Symmetry. That story begins its modern history with Evariste Galois, who died in a duel aged 20.

Wikipedia tells the story, it's a bit less dramatic than the IOT version:

Évariste Galois - Wikipedia, the free encyclopedia

.... As to his opponent in the duel, Alexandre Dumas names Pescheux d'Herbinville, one of the nineteen artillery officers on whose acquittal the banquet that occasioned Galois' first arrest was celebrated. However, Dumas is alone in this assertion, and extant newspaper clippings from only a few days after the duel give a description of his opponent which is inconsistent with d'Herbinville, and more accurately describes one of Galois' Republican friends, most probably Ernest Duchatelet, who was also imprisoned with Galois on the same charges...

Whatever the reasons behind the duel, Galois was so convinced of his impending death that he stayed up all night writing letters to his Republican friends and composing what would become his mathematical testament, the famous letter to Auguste Chevalier outlining his ideas... However, the legend of Galois pouring his mathematical thoughts onto paper the night before he died seems to have been exaggerated. In these final papers he outlined the rough edges of some work he had been doing in analysis and annotated a copy of the manuscript submitted to the academy and other papers. On 30 May 1832, early in the morning, he was shot in the abdomen and died the following day at ten in the Cochin hospital (probably of peritonitis) after refusing the offices of a priest. He was 20 years old. His last words to his brother Alfred were...

If Galois had lived, there's little doubt the history of mathematics would be rather different.

Galois story is invariably described as romantic, but "stupid" seems more appropriate. Even a genius can be a fool - especially at age 20.

I was curious about the history of his opponent. The man played a major role in history after all. It's disappointing that he turns out be anonymous.

I could find nothing on the web about the subsequent life of Mr. Duchatelet, though I did find a number of spam sites that copied the wikipedia article. I suppose to track this down one would have to look for descendants, and see if there were some kind of oral family history.

Profiling: the astrology of criminology

Schneier sent me to this New Yorker article on the pseudo-science of FBI "profiling". It turns out to be about as scientific as lie detectors -- meaning not at all.

Dept. of Criminology: Dangerous Minds: Reporting & Essays: The New Yorker:

They had been at it for almost six hours. The best minds in the F.B.I. had given the Wichita detectives a blueprint for their investigation. Look for an American male with a possible connection to the military. His I.Q. will be above 105. He will like to masturbate, and will be aloof and selfish in bed. He will drive a decent car. He will be a “now” person. He won’t be comfortable with women. But he may have women friends. He will be a lone wolf. But he will be able to function in social settings. He won’t be unmemorable. But he will be unknowable. He will be either never married, divorced, or married, and if he was or is married his wife will be younger or older. He may or may not live in a rental, and might be lower class, upper lower class, lower middle class or middle class. And he will be crazy like a fox, as opposed to being mental. If you’re keeping score, that’s a Jacques Statement, two Barnum Statements, four Rainbow Ruses, a Good Chance Guess, two predictions that aren’t really predictions because they could never be verified—and nothing even close to the salient fact that BTK was a pillar of his community, the president of his church and the married father of two.

The Jacques, Barnum, Rainbow Ruse, etc are techniques used by professional "psychics" on their marks.

Second Life: 2.5 billion lines of code

I believe this is more code than runs in Vista (emphases mine) ...

OOPSLA 2007 « Dan Weinreb’s Weblog

... Jim Purbrick and Mark Lentczner of Linden Labs, the creators of Second Life, explained a great deal about what Second Life is and how it works. The most interesting thing is that 15% of the residents actually do coding, in a language that lets you make active objects. There are 30,000,000 running scripts, 2.5 billion lines of code. Generally there are 15,000 scripts actively running on each “region” (processor), updating at 45 frames per second, and there are 4,000 processors. There are 30,000,000 concurrent threads. The language itself they described as “terrible”; they are working on bringing up the Mono implementation of the CLR so they can provide good languages. There are some complicated issues in which threads must be migrated from one CPU to another as an object moves around within regions of the Second Life world. The most impressive thing is how many people with little or no technical training are doing programming. They also talked about how the Linden Labs developers, eight of them at five physical locations, use Second Life itself as a collaborative development environment; they say it works really well, particularly due to having stereo audio that’s good enough that you can tell where sounds are coming from. During the talk they showed Second Life on the big screen and moved around and interacted with people, so that you could see what it’s like...

One of the common themes of modern science fiction is that the human world fissions into mutually incomprehensible domains.

Babel 2.0, in other words.

I can see that happening.

How to demo software

Joel Spolksy, geek god, tells us what he learned about demoing software -- after a world wide software demo.

How to demo software - Joel on Software:

...It’s already all a blur. 26 cities. 6 weeks. 2913 attendees. $160,000. 23 hotels, one Cambridge college, one British library, and a “Sociëteit Het Meisjeshuis.” (“Gesundheit!”)...

Stuff like this is like finding diamonds scattered on the front lawn.

It's hard to remember there was a time this sort of thing wasn't freely available.

America, the richest third world nation

Twenty six years ago I watched a long line of children and teens waiting for dental care. This was in the north of Thailand.

The dentists pulled bad teeth, one after the other. I don't recall any anesthesia, there wasn't time for much.

I think one of the children cried, and I recall a sense of disapproval from his peers.

It was a long time ago.

Things have changed since then. Now we have those lines in America ...

Health and Medicine - Insurance - Health and Managed Care - Doctors - New York Times

... The group, most often referred to as RAM, has sent health expeditions to countries like Guyana, India, Tanzania and Haiti, but increasingly its work is in the United States, where 47 million people — more than 15 percent of the population — live without health insurance. Residents of remote rural areas are less likely than their urban and suburban counterparts to have health insurance and more likely to be in fair or poor health...

And so each summer, shortly after the Virginia-Kentucky District Fair and Horse Show wraps up at the fairgrounds, members of Virginia Lions Clubs start bleaching the premises, readying them for RAM’s volunteers, who, working in animal stalls and beneath makeshift tents, provide everything from teeth cleaning and free eyeglasses to radiology and minor surgery. The problem, says RAM’s founder, Stan Brock, is always in the numbers, with the patients’ needs far outstripping what his team can supply. In Wise County, when the sun rose and the fairground gates opened at 5:30 on Friday morning, more than 800 people already were waiting in line. Over the next three days, some 2,500 patients would receive care, but at least several hundred, Brock estimates, would be turned away. He adds: “There comes a point where the doctors say: ‘Hey, I gotta go. It’s Sunday evening, and I have to go to work tomorrow.’...

Dental care is particularly in demand.

Comet Holmes - it's quite simple

This isn't unusual.

Comet Holmes and the case of the Disappearing Tail | The Register

"Amateur astronomers the world over have been stunned and amazed by the weirdest new object to appear in the sky in memory," wrote Sky and Telescope .

"The comet shocked skywatchers as it went from a dim 17th magnitude then suddenly to 3 magnitude" wrote Theo from the Pacific Northwest.*

Zorgonian battle cruisers always do that on approach to the target system.

Consumers Union Toy Safety campaign: sign up now

Via TMW I've learned that Consumers Union has an advocacy campaign for toy safety. They want inspections funded and they want a real inspection program.

Of course I signed up immediately. They generate email to senators and file names.

Kmart's lead jewelry was the most recent episode I've commented on. It's only one of many such.

Highly recommended, though of course what we really need is to get the GOP out of the government.

Be sure to use your spam email (for me that's a Yahoo account). I don't trust CU not to spam me.

Next they can tackle generic drug quality. Our son uses a medication which recently came to use with an unusual scent and a somewhat different appearance. It's produced by a Spanish chemical/pharmaceutical vendor that obtains products from "Asia" (meaning China).

We're not giving him any more until we check this out.

I remember a time when it would never have occurred to us to worry.

Sign the toy petition. Mostly, though, don't forget we need a different government.

The hidden insurance problem: they can play the game better than we can

Last week I wrote that it is impossible for a sane human to truly judge the value of employment benefits, particularly health care benefits.

That complexity is not accidental. Complexity facilitates deception. The consumer can't really price the product, but the vendor can. A product that seems to offer good consumer value may be a trap.

It's a huge competitive advantage. Companies that don't leverage it will disappear, until finally it's the only way to play the game.

Bob Herbert provides a great example of the game in action:

It’s Not Just the Uninsured - Bob Herbert - New York Times:

...The next round of bad news came in a double dose. One night, after coming home from school, Brittney suddenly found that she couldn’t walk. The cancer had attacked her spinal cord. As the doctors geared up to treat this new disaster, Ms. Hightower received word that her insurance policy had maxed out. The company would not pay for any further treatment.

Ms. Hightower was aghast: “I said, ‘What do you mean? It was supposed to be a $3 million policy.’ ”

She hadn’t understood that there was an annual limit of $75,000 on benefits. “It was just devastating when they told me that,” she said.

Most of the debate about access to health care has centered on people without insurance. But there are cases like this one all over the country in which individuals are working and paying for coverage that, perversely, kicks out when a devastating illness kicks in...

Few consumers would knowingly purchase an insurance policy with a $75K yearly cap, but that cap can make the coverage very profitable.

The best way out of this trap is to create offerings that apply across a state or region, and make the available to all persons in the region. This allows newspapers, consumer organizations, and government to analyze plans and expose deception. The next best option is to create standard care scenarios and require insurers to describe how their plans would operate under the scenarios.

Lastly, we could make insurance companies liable when a "reasonable person" would be unable to understand the true costs and benefits ofa given plan.

There are lots of ways we could make things better - even without reforming the health care system.

A year from now, we might even hope that some of them might become law.

The best pro-Hillary argument

The best argument for Hilary:

Hillary Fries the Waffle - Gail Collins - New York Times:

...All these people believe pretty much the same thing, and when it’s time to take on the Republicans, I would prefer the candidate who knows how to change the subject and stack the deck."...

The best argument against: Bush-Clinton-Bush-Clinton.