Landscape Architecture

Readers of Lee Smolin's The Trouble With Physics will recall that the whole string theory landscape problem depends on flux compactification. I probably can't be trusted to explain it correctly, but the trouble starts with the fact that you need to curl up six of the space dimensions of ten dimensional spacetime. Once one has done this with Calabi-Yau manifolds, you have two more problems: They don't naturally lend themselves to a positive cosmological constant (which we observe) and they seem likely to spontaneously self-destruct.

A way was found to stabilize them with tape and baling wire, or, more technically, electric and magnetic flux bound to branes. A lot of ways. Say 10^350. Kachru and Douglas, the inventors, have a new Reviews of Modern Physics article: hep-th/0610102 on the subject, and Peter Woit has some commentary. The article has at least some elementary parts, and Peter's commentary is interesting. So are the responses in his comment section.

Opinions remain divided as to whether a)the landscape really exists and b)whether anything can be deduced from it if it does.

Epicycles! We need more epicycles!

Comments

Post a Comment

Popular posts from this blog

Anti-Libertarian: re-post

The most pointed critique of social security and liberalism in general is the libertarian critique. The problem with libertarians, for a liberal, is that we have too much in common. We both believe in individual rights, tolerance of individual differences, and dislike government prescription of religion. The basic difference, it seems to me, is the different answers we give to Cain's (with thanks to the Captain - my original version had the corpse asking the question!) famous question: "Am I my brother's keeper?" That's not really my basic bitch against the libertarians though. My real complaint is the same as my complaint against most religion - its premise is a fraud. For those who can't stand to wait for the punchline, I believe that trying to implement libertarian principles leads to tyranny or social disintegration. Demonstrating that takes some historical (and pre-historical) context. For all but the last 15,000 or so of the 100,000 years the human spec...
Read more

Uneasy Lies The Head

Uneasy lies the head that wears a crown ........... Shakespeare Henry IV, Part II. So it is with us and our slightly distant primate cousins , so it seems. A 9-year study of wild baboons in Kenya by Princeton University and the Institute of Primate Research may turn conventional assumptions of alphas males upside down. The study found that alpha males have high testosterone levels, which allows them to dominate other baboons, get access to more food, and attract better mates. This is expected. Surprisingly, though, the alpha males also have high levels of stress hormone glucocorticoid, which scientists measured from their feces samples. In fact, the stress of alpha baboons was on par with low-ranking baboons. The convention wisdom is that access to food and females provides life security and thus less stress for dominant males. Conversely, weak males who are constantly threatened by starvation and physical violence from stronger males are thought to be more stressed. The st...
Read more

We Call it Soccer

The US played its best, and maybe only good game of World Cup, but lost thanks to brilliant goalkeeping by the Swedish keeper and the bizarre method soccer uses to settle ties when three US stars could not put the ball on frame from the 12 yard spot.  At the end it came down to a blocked shot that spun in by maybe a couple of centimeters. Well, that's football - too much like life.   Which brings me to a modest proposal.  Replace the thirty minute overtimes with as many 7-player 15 minute periods as needed to settle it.  Scoring should be much easier with fewer players.
Read more