Matryoshka World

Friday, April 20, 2012

The Multiverse Interpretation of Quantum Mechanics

Raphael Bousso and Leonard Susskind argue that the many-worlds of quantum mechanics and the many worlds of the multiverse are the same thing.
We argue that the global multiverse is a representation of the many-worlds (all possible decoherent causal diamond histories) in a single geometry. We propose that it must be possible in principle to verify quantum-mechanical predictionsexactly. This requires not only the existence of exact observables but two additional postulates: a single observer within the universe can access in nitely many identical experiments; and the outcome of each experiment must be completely de nite. In causal diamonds with nite surface area, holographic entropy bounds imply that no exact observables exist, and both postulates fail: experiments cannot be repeated in- nitely many times; and decoherence is not completely irreversible, so outcomes are not de nite. We argue that our postulates can be satis ed in \hats" (supersymmetric multiverse regions with vanishing cosmological constant). We propose a complementarity principle that relates the approximate observables associated with nite causal diamonds to exact observables in the hat.
 The Multiverse Interpretation of Quantum Mechanics

Thursday, April 19, 2012

Lack of evidence of dark matter in solar neighborhood may indicate dark matter theories are wrong

A new study of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun.

This is's article on the findings:

Serious Blow to Dark Matter Theories?

Tuesday, April 17, 2012

Monday, April 16, 2012

A disappearing physicist, and a discovery that may lead to understanding dark matter and a real quantum computer has an article on the possible recent discovery of “Majorana fermions” — particles that "would be right on the border between matter and antimatter."

Some theories even suggest that these particles may ultimately provide the explanation for Dark Matter. Also, the article suggests that "Majorana fermions could be fundamental building blocks for a future quantum computer that would be exceptionally stable and barely sensitive to external influences. This would avoid the central problem with all current quantum computers: the dreaded decoherence."

The article is based on this paper published last week in Science Express.

This video summarizes the experiment leading to the discovery:

Friday, April 13, 2012

Artificial Intelligence Could Be on Brink of Passing Turing Test has a post summarizing an article in Science which suggests recent advances in information technology could have us on the brink of strong AI capable of passing a Turing test. This means that if you had a conversation with the computer program you would not be able to distinguish whether you were talking to a program or real person. Kurzweil has predicted the first AI capable of passing the Turing test sometime in the latter part of the next decade.

“Two revolutionary advances in information technology may bring the Turing test out of retirement,” wrote Robert French, a cognitive scientist at the French National Center for Scientific Research, in an Apr. 12 Science essay. “The first is the ready availability of vast amounts of raw data — from video feeds to complete sound environments, and from casual conversations to technical documents on every conceivable subject. The second is the advent of sophisticated techniques for collecting, organizing, and processing this rich collection of data.”