Is there a deep relationship between string theory and quantum theory?

ScienceDaily (Sep. 2, 2010) — Researchers describe how to carry out the first experimental test of string theory in a paper published September 2 in Physical Review Letters.

Professor Duff recalled sitting in a conference in Tasmania where a colleague was presenting the mathematical formulae that describe quantum entanglement: "I suddenly recognised his formulae as similar to some I had developed a few years earlier while using string theory to describe black holes. When I returned to the UK I checked my notebooks and confirmed that the maths from these very different areas was indeed identical."

This relationship between the math of string theory and the math of quantum entanglement may allow for direct testing of string theory in the lab, at least to the extent that the relationship pertaining to quantum entanglement is testable.

Here is the link to the Science Daily story

Born in an infinite universe: a cosmological interpretation of quantum mechanics

This paper argues the Born rule is actually rendered redundant in an infinite universe in which all outcomes are realized.

this paper takes the conclusions of Page from the paper linked in the August 27 post immediately below a step further.
Page argued that Born's Rule would be insufficient in an extremely large universe due to the lack of definite projection operators.

We study the quantum measurement problem in the context of an infinite, statistically uniform space, as could be generated by eternal inlfation. It has recently been argued that when identical copies of a quantum measurement system exist, the standard projection operators and Born rule method for calculating probabilities must be supplemented by estimates of relative frequencies of observers. We argue that an infinite space actually renders the Born rule redundant, by physically realizing all outcomes of a quantummeasurement in different regions, with relative frequencies given by the square of the wave function amplitudes. Our formal argument hinges on properties of what we term the quantum confusion operator, which projects onto the Hilbert subspace where the Born rule fails, and we comment on its relation to the oft-discussed quantum frequency operator. This analysis unifies the classical and quantum levels of parallel universes that have been discussed in the literature, and has implications for several issues in quantum measurement theory. Replacing the standard hypothetical ensemble of measurements repeated ad inifnitum by a concrete decohered spatial collection of experiments carried out in different distant regions of space provides a natural context for a statistical interpretation of quantum mechanics. It also shows how, even for a single measurement, probabilities may be interpreted as relative frequencies in unitary (Everettian) quantum mechanics.

We also argue that after discarding a zero-norm part of the wavefunction, the remainder consists of a superposition of indistinguishable terms, so that arguably “collapse” of the wavefunction is irrelevant, and the “many worlds” of Everett’s interpretation are uniifed into one. Finally, the analysis suggests a “cosmological interpretation” of quantum theory in which the wave function describes the actual spatial collection of identical quantum systems, and quantum uncertainty is attributable to the observer’s inability to self-locate in this collection.

Infinite doppelgängers may explain quantum probabilities

AN IDENTICAL copy of you is also reading this story. This twin is the same in every way, living on an Earth and in a universe that looks exactly like our own. And there may be an infinite number of them. Such doppelgängers could be a natural consequence of our present conception of the universe. Now, some physicists say they could pose a serious problem for quantum mechanics. But a possible fix may also be in sight, and it could help tie abstract quantum concepts to concrete physical causes.

New Scientist article based on this paper.

Alien hunters should look for artificial intelligence

SETI astronomer Seth Shostak argues that the time between aliens developing radio technology and artificial intelligence (AI) would be short.

Writing in Acta Astronautica, he says that the odds favour detecting such alien AI rather than "biological" life.

Story by the BBC

Artificial life forms evolve basic intelligence

From Kurzweilai.net

Michigan State University (MSU) researchers have developed “digital organisms” called Avidians that were made to evolve memory, and could eventually be used to generate intelligent artificial life and evolve into symmetrical, organized artificial brains that share structural properties with real brains.

Gravity Doesn't Exist?

This paper argues that gravity "doesn't exist." More specifically the author Erik Verlinde, described by the New York Times as a respected string theorist and professor of physics at the University of Amsterdam, says gravity is emergent from the laws of thermodynamics.

If you have difficulty understanding the paper, do not be alarmed, according to this article in the Times: "some of the best physicists in the world say they don’t understand Dr. Verlinde’s paper, and many are outright skeptical."

The Myth of the Beginning of Time

This is a good article from 2004 in Scientific American

The Evolution of the Physicist's Picture of Nature By Paul Dirac

1963 Article interviewing Paul Dirac

What appears to our consciousness is really a three-dimensional section of the four-dimensional picture. We must take a three-dimensional section to give us what appears to our consciousness at one time; at a later time we shall have a different three-dimensional section. The task of the physicist consists largely of relating events in one of these sections to events in another section referring to a later time. Thus the picture with four dimensional symmetry does not give us the whole situation. This becomes particularly important when one takes into account the developments that have been brought about by quantum theory. Quantum theory has taught us that we have to take the process of observation into account, and observations usually require us to bring in the three-dimensional sections of the four-dimensional picture of the universe.

The special theory of relativity, which Einstein introduced, requires us to put all the laws of physics into a form that displays four-dimensional symmetry. But when we use these laws to get results about observations, we have to bring in something additional to the four-dimensional symmetry, namely the three-dimensional sections that describe our consciousness of the universe at a certain time.

Scientific American Magazine: "Twistor" Theory Reignites the Latest Superstring Revolution

A few months later Witten posted a dense 97-page paper that tied together twistors and strings—bringing twistors back to life and impressing even the harshest critics of string theory. In the past few years theorists have built on Witten’s work and rethought what space and time are. They have already spun off calculational techniques that make child’s play of the toughest problems in ordinary particle physics. “I have never been more excited about physics in my life,” says string theorist Nima Arkani-Hamed, who recently moved to the institute from Harvard University to immerse himself in the emerging field. “It is developing at a blistering pace right now, with a group of roughly 15 people in the world working on it day and night.”

twistor theory

"Quantum Mechanics Implies that the Universe is a Computer Simulation"

A Cybernetic Interpretation of Quantum Mechanics

This paper surveys evidence and arguments for the proposition that the universe as we know it is not a physical, material world but a computer-generated simulation -- a kind of virtual reality. The evidence is drawn from the observations of natural phenomena in the realm of quantum mechanics. The arguments are drawn from philosophy and from the results of experiment. While the experiments discussed are not conclusive in this regard, they are found to be consistent with a computer model of the universe. Six categories of quantum puzzles are examined: quantum waves, the measurement effect (including the uncertainty principle), the equivalence of quantum units, discontinuity, non-locality, and the overall relationship of natural phenomena to the mathematical formalism. Many of the phenomena observed in the laboratory are puzzling because they are difficult to conceptualize as physical phenomena, yet they can be modeled exactly by mathematical manipulations. When we analogize to the operations of a digital computer, these same phenomena can be understood as logical and, in some cases, necessary features of computer programming designed to produce a virtual reality simulation for the benefit of the user.

New York Times Article on the Singularity Movement

Humans are so yesterday

Possible evidence for Quantum Darwinism found in quantum dots

Quantum Darwinism is a theory explaining the emergence of the classical world from the quantum world as a process of Darwinian natural selection; where the many possible quantum states are selected against in favor of a stable pointer state.

A new study provides possible preliminary support for this theory.

"[A] team of physicists and engineers from Arizona State University and the Naval Research Laboratory in Washington, D.C., has performed experiments using scanning gate microscopy to image scar structures in an open quantum dot. Their results have revealed the existence of periodic scar offspring states that evolve and eventually contribute to a robust state, much in the way that the derivation of pointer states is predicted by quantum Darwinism."

New Evidence That Mirror Matter May Fill the Universe?

"However, mirror particles interact with each other in exactly the same way as ordinary particles. So in this scenario, the Universe is filled with mirror planets, stars and galaxies. That's a mind blowing idea."

LINK

Does Every Black Hole Contain Another Universe?

Like part of a cosmic Russian doll, our universe may be nested inside a black hole that is itself part of a larger universe.

In turn, all the black holes found so far in our universe—from the microscopic to the supermassive—may be doorways into alternate realities.

The idea that black holes may be worm holes to other universes isn't new. However, in a recent paper published in the journal Physics Letters B, Indiana University physicist Nikodem Poplawski presents new mathematical models that describe how wormholes are viable alternatives to the "space-time singularities" that Albert Einstein predicted to be at the centers of black holes.

National Geographic article on Poplawski's paper

Decoding Reality: The Universe is a Quantum Computer

Seth Lloyd reviews Vlatko Vedral's new book Decoding Reality, which asserts that everything is at its most fundamental quantum information, and the universe is a quantum computer.

Mysterious Cosmic 'Dark Flow' Tracked Deeper into Universe

The dark flow is controversial because the distribution of matter in the observed universe cannot account for it. Its existence suggests that some structure beyond the visible universe -- outside our "horizon" -- is pulling on matter in our vicinity.

Mysterious Dark Flow

The origin of the universe and the arrow of time. Sean Carroll

From SlowTV:

Juan Enriquez presentation on advances in medicine and robots leading to the "big reboot"

Our Universe as a Hologram?

New Scientists Article

For many months, the GEO600 team-members had been scratching their heads over inexplicable noise that is plaguing their giant detector. Then, out of the blue, a researcher approached them with an explanation. In fact, he had even predicted the noise before he knew they were detecting it. According to Craig Hogan, a physicist at the Fermilab particle physics lab in Batavia, Illinois, GEO600 has stumbled upon the fundamental limit of space-time - the point where space-time stops behaving like the smooth continuum Einstein described and instead dissolves into "grains", just as a newspaper photograph dissolves into dots as you zoom in. "It looks like GEO600 is being buffeted by the microscopic quantum convulsions of space-time," says Hogan.

If this doesn't blow your socks off, then Hogan, who has just been appointed director of Fermilab's Center for Particle Astrophysics, has an even bigger shock in store: "If the GEO600 result is what I suspect it is, then we are all living in a giant cosmic hologram."

Sean Carroll's Theory of Time

This is an interesting idea from Sean Carroll. In a virtually empty universe there is no causality, and therefore no clear direction of time. Just random fluctuations.
From these fluctuations new universes are born.

Wired magazine interview with Carroll.

Science's Alternative to an Intelligent Creator: the Multiverse Theory

This December '08 article from Discover magazine summarizes why the fine tuning for life of our observable universe suggests a large multiverse...or a designer.

Of course, multiverses would likely lead to intelligence capable of creation on a universal scale, raising the question of whether there is any clean way to completely remove a role for intelligence in an explanation of reality.

Multiverse versus Creator

Symmetry in the Subatomic World

"It reflects a beautiful property of the quantum system -- a hidden symmetry,"

Computational capabilities of physical systems

By David Wolpert: "In this paper strong limits on the accuracy of real-world physical computation are established."

Link