Greene, Susskind, 't Hooft, oh my! Scientists from all over the world convene in New York this weekend, talking about all kinds of scintillating stuff: the mathematical universe, parallel universes, music and spontaneity, and (my favorite) the holographic principle. Plus the festival Street Fair in Washington Square Park on Sunday, which is free and open to the public.
I'm reading The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos to prepare. See you there!
Showing posts with label Leonard Susskind. Show all posts
Showing posts with label Leonard Susskind. Show all posts
June 3, 2011
March 26, 2009
Foundational Questions Institute: "The Nature of Time"
Time is quixotic: the idea of it is fundamentally interesting because, on the surface, it's a man-made construction--calendars, clocks, time zones--designed for convenience, to enable a sophisticated working society to function. And, like most fundamental ideas, "time" is based on astronomy (the position and rotation of the earth around the sun) which in itself is, like our existence, a happy accidental byproduct of the formation of the universe. (An added quirk here is that, from a human perspective, space is time--the universe is so vast that light reaching us today is millions of years old.) So, does time really exist in the sense that the present is different from the past or future, or is it an illusion?
I suspect the latter, that "the past is present memory," to quote St. Augustine. According to Sean Carroll, a physicist at CIT, this places me squarely among the "presentists," a group championed by Julian Barbour and his seminal work The End of Time: The Next Revolution in Physics. However, Carroll recently wrote a paper arguing that "the universe is described by a quantum state obeying ordinary time-dependent quantum mechanics," and earned a second-place finish in the Foundational Questions Institute's essay contest for his trouble (it's worth noting, though, that Barbour's entry placed first). Titled "What if Time really Exists?" (itself a nod at the scientific community's reluctance to incorporate it) his essay raises some interesting questions. For example: Schrodinger's deterministic wave equation posits that knowledge of the state of a system at any one time is sufficient to determine its future and past evolution in time; however, "what if time exists, and is eternal, and the state of the universe evolves with time obeying something like Schrodinger's equation?" Thanks to string theory, physicists can attempt to answer this question by interpreting certain implications of quantum gravity, namely, duality. Duality brings us back to Susskind's Holographic Principle, a concept that has its applications with time: if quantum gravity in ten dimensions is equivalent to ordinary quantum field theory in four dimensions, as demonstrated by Juan Malcadena's gauge/gravity duality, then there should exist a description of the universe "consisting simply of a quantum-mechanical state evolving with time." Right?
What remains to be reconciled is that quantum mechanics operates under the assumption that time is infinite in all directions, but, as it related to entropy, "within our observable universe, time has an arrow," meaning that time is irreversable. The catch is that within the Schrodinger equation, quantum time evolution is information-preserving, meaning "we can reliably reconstruct the past just as well as the future." Obviously, to any observer living in the last four hundred million years, this just isn't applicable (unless LaToya Jackson really does know something we don't). But, the idea remains that as time marches on, it doesn't morph into the future, the future was already there: I sit here typing, and now I'm typing again, and suddenly the future is the present, ad infinitum. Free will makes this concept more complex, but doesn't negate it; mortality makes it more philosophical, but not mystical.
Carroll concludes by saying that because entropy can grow into the future and into the past, "the very far past of our universe could be experiencing an arrow of time directed in the opposite sense to our own." In an infinite-dimenstion Hilbert space, that seems to throw a lot of cold water on creationism, to say the least. But it does make for interesting fodder where thought and consciousness is concerned, because it implies that everything, ever, still exists and (theoretically) could be accessed. Move over, SAP!
Carroll also has a book coming out this year: From Eternity to Here: The Quest for the Ultimate Theory of Time.
I suspect the latter, that "the past is present memory," to quote St. Augustine. According to Sean Carroll, a physicist at CIT, this places me squarely among the "presentists," a group championed by Julian Barbour and his seminal work The End of Time: The Next Revolution in Physics. However, Carroll recently wrote a paper arguing that "the universe is described by a quantum state obeying ordinary time-dependent quantum mechanics," and earned a second-place finish in the Foundational Questions Institute's essay contest for his trouble (it's worth noting, though, that Barbour's entry placed first). Titled "What if Time really Exists?" (itself a nod at the scientific community's reluctance to incorporate it) his essay raises some interesting questions. For example: Schrodinger's deterministic wave equation posits that knowledge of the state of a system at any one time is sufficient to determine its future and past evolution in time; however, "what if time exists, and is eternal, and the state of the universe evolves with time obeying something like Schrodinger's equation?" Thanks to string theory, physicists can attempt to answer this question by interpreting certain implications of quantum gravity, namely, duality. Duality brings us back to Susskind's Holographic Principle, a concept that has its applications with time: if quantum gravity in ten dimensions is equivalent to ordinary quantum field theory in four dimensions, as demonstrated by Juan Malcadena's gauge/gravity duality, then there should exist a description of the universe "consisting simply of a quantum-mechanical state evolving with time." Right?
What remains to be reconciled is that quantum mechanics operates under the assumption that time is infinite in all directions, but, as it related to entropy, "within our observable universe, time has an arrow," meaning that time is irreversable. The catch is that within the Schrodinger equation, quantum time evolution is information-preserving, meaning "we can reliably reconstruct the past just as well as the future." Obviously, to any observer living in the last four hundred million years, this just isn't applicable (unless LaToya Jackson really does know something we don't). But, the idea remains that as time marches on, it doesn't morph into the future, the future was already there: I sit here typing, and now I'm typing again, and suddenly the future is the present, ad infinitum. Free will makes this concept more complex, but doesn't negate it; mortality makes it more philosophical, but not mystical.
Carroll concludes by saying that because entropy can grow into the future and into the past, "the very far past of our universe could be experiencing an arrow of time directed in the opposite sense to our own." In an infinite-dimenstion Hilbert space, that seems to throw a lot of cold water on creationism, to say the least. But it does make for interesting fodder where thought and consciousness is concerned, because it implies that everything, ever, still exists and (theoretically) could be accessed. Move over, SAP!
Carroll also has a book coming out this year: From Eternity to Here: The Quest for the Ultimate Theory of Time.
January 17, 2009
The Holographic Principle, Redux
There is some excellent work being done over at the British-German GEO600 experiment: New Scientist reports that the giant detector has identified some curious noise as "microscopic quantum convulsions of space-time," which would support the framework of the holographic principle theory put forth by Gerard d'Hooft and Leonard Susskind (see my earlier post on how this idea is explored in Susskind's The Black Hole War). Craig Hogan, director of Fermilab's Center for Particle Astrophysics, says, "If the GEO600 result is what I suspect it is, then we are all living in a giant cosmic hologram." This would be a physical manifestation of concepts heretofore demonstrated only within the comforting boundaries of theoretical math--the mind boggles!
If the noise detected does represent quantum jitters, this has profound implications for the future of the unified theory: suddenly, analysis of information at Planck length might be feasible via its much-larger "projection," which "brings microscopic quantum structure within reach of current experiments." This is nothing short of AWESOME. Stay tuned.
If the noise detected does represent quantum jitters, this has profound implications for the future of the unified theory: suddenly, analysis of information at Planck length might be feasible via its much-larger "projection," which "brings microscopic quantum structure within reach of current experiments." This is nothing short of AWESOME. Stay tuned.
January 14, 2009
Can SUSY Help Explain Quantum Consciousness?
Discover posted an interesting article today about quantum mechanics explaining photosynthesis, smell, antioxidant effectiveness, and (the best part) consciousness.
First, two definitions: Entanglement is the idea that two or more particles at quantum states are linked together, even if there is physical distance between them, in such a way that both would be affected if one were disturbed. Quantum Tunneling is the potential for a particle to (via probabilities related to its wave function) penetrate a barrier that (per classical mechanics) it should not have the energy to penetrate. Because it's impossible to narrow down a particle's energy and its location at the same time, scientists narrow down probable locations to a fuzzy wavepacket: some of the probable locations indicated in the wavepacket exist on the other side of the barrier, meaning that sometimes, the particle is on the other side of the barrier. That's tunneling.
Back to the brain. Tunneling and entanglement explain (theoretically) how neurons generate a consciousness field; Stuart Hameroff, director of the Center for Consciousness Studies at the University of Arizona, is paraphrased in the article: "Each section of the constantly shifting [neuron] system has an impact on other sections, potentially via quantum entanglement, leading to a dynamic quantum-mechanical dance. It is in this faster-than-light subatomic communication that consciousness is born." This is good stuff (and a continuation of theories that Evan Walker postulated in the 1970s), but what I want to know is how SUSY (supersymmetry) gets involved. If the Lie group SO(10) consists of rotations in ten-dimensional space, could particles tunnel in and out of plack-sized dimensions (or Calabi-Yau spaces?) in a way that could affect quantum consciousness? Sentience is tricky; Leonard Susskind himself answered a question I posed to him in an email by saying, "Probably the biggest mystery in science (at least for me) is the connection between physics and the mind."
The thing is, much like the standard model before the (hypothetical) unified theory, it feels right that the answers are within reach: so many cultures and disciplines over thousands of years have hinted at transcendence; the pineal gland has yet to reveal its secrets; psychokinesis suggests consciousness is a type of force field; Aldous Huxley wrote in The Doors of Perception that "To be shaken out of the ruts of ordinary perception, to be shown for a few timeless hours the outer and inner world, not as they appear to an animal obsessed with survival or to a human being obsessed with words and notions, but as they are apprehended, directly and unconditionally, by Mind At Large— this is an experience of inestimable value to everyone and especially to the intellectual."
Somehow, "extraordinary perception" must* have a quantum explanation; the Mind At Large must have something to do with supersymmetry. Nature is just too clever for it to be otherwise.
*Remember, I'm just pontificating--I'll leave the down-and-dirty analysis to real scientists.
First, two definitions: Entanglement is the idea that two or more particles at quantum states are linked together, even if there is physical distance between them, in such a way that both would be affected if one were disturbed. Quantum Tunneling is the potential for a particle to (via probabilities related to its wave function) penetrate a barrier that (per classical mechanics) it should not have the energy to penetrate. Because it's impossible to narrow down a particle's energy and its location at the same time, scientists narrow down probable locations to a fuzzy wavepacket: some of the probable locations indicated in the wavepacket exist on the other side of the barrier, meaning that sometimes, the particle is on the other side of the barrier. That's tunneling.
Back to the brain. Tunneling and entanglement explain (theoretically) how neurons generate a consciousness field; Stuart Hameroff, director of the Center for Consciousness Studies at the University of Arizona, is paraphrased in the article: "Each section of the constantly shifting [neuron] system has an impact on other sections, potentially via quantum entanglement, leading to a dynamic quantum-mechanical dance. It is in this faster-than-light subatomic communication that consciousness is born." This is good stuff (and a continuation of theories that Evan Walker postulated in the 1970s), but what I want to know is how SUSY (supersymmetry) gets involved. If the Lie group SO(10) consists of rotations in ten-dimensional space, could particles tunnel in and out of plack-sized dimensions (or Calabi-Yau spaces?) in a way that could affect quantum consciousness? Sentience is tricky; Leonard Susskind himself answered a question I posed to him in an email by saying, "Probably the biggest mystery in science (at least for me) is the connection between physics and the mind."
The thing is, much like the standard model before the (hypothetical) unified theory, it feels right that the answers are within reach: so many cultures and disciplines over thousands of years have hinted at transcendence; the pineal gland has yet to reveal its secrets; psychokinesis suggests consciousness is a type of force field; Aldous Huxley wrote in The Doors of Perception that "To be shaken out of the ruts of ordinary perception, to be shown for a few timeless hours the outer and inner world, not as they appear to an animal obsessed with survival or to a human being obsessed with words and notions, but as they are apprehended, directly and unconditionally, by Mind At Large— this is an experience of inestimable value to everyone and especially to the intellectual."
Somehow, "extraordinary perception" must* have a quantum explanation; the Mind At Large must have something to do with supersymmetry. Nature is just too clever for it to be otherwise.
*Remember, I'm just pontificating--I'll leave the down-and-dirty analysis to real scientists.
January 5, 2009
Memory and the Holographic Principle
I had a remaining thought after reading The Black Hole War. The turning point of Susskind's resolution of the black hole information paradox involved something called the holographic principle. Basically, the holographic principle states that all information lies at the boundary of a region of space, one dimension removed from the space its information describes. This would mean that our universe was really a three-dimensional "hologram" thrown by a two-dimensional ring of encoded information circling the universe. I couldn't stop thinking about whether this could be a new and provocative way to express the idea of universal consciousness or of the brain's extra-sensory aptitude. In The ESP Enigma, Diane Hennacy Powell writes about how memory itself might be a psychic phenomena, not a strictly neurological one. If the entire description of the universe exists as bits of information on the perimeter, Powell's theory that "all of space and time is represented in our personal consciousness field, even though most of it is unconscious," makes perfect sense: hypothetically, every bit of information within the universe is stored on the two-dimensional perimeter, and somehow our brains are able to access it and convert "bits" into "thought." (After all, on the smallest possible level, everything is composed of the same fundamental particles--even empty space--so the idea might not be so far-fetched.)
Weird, I know, but food for thought.
Weird, I know, but food for thought.
When Physicists Fight
Stephen Hawking is a famously stubborn agitator among his peers: for one thing, he's had a years-outstanding bet with Peter Higgs that Higgs' eponymous boson (also called The God Particle for its portended import: the Higgs boson theoretically gives everything its mass) will not be discovered. Recent excitement over at CERN has brought this wager back into the limelight, and it appears that Hawking, while acknowledging that the LHC's probability of proving the Higgs has increased by a probability of four, remains mischievous and declares that it would be "more interesting" not to find it, making the scientific community "think again." Higgs, for his part, is a good sport, but must be dying inside at the LHC's continued delays.
Another of Hawking's loud and controversial theories concerned black holes, an area of expertise that his name is practically synonymous with (and in fact, two definitions concerning black holes are named for him--Hawking radiation and Hawking temperature). Thirty years ago, Hawking claimed that nothing, not even information, can escape a black hole's singularity, and fellow physicist Leonard Susskind spent a good part of his career proving him wrong (and defending a fundamental law of physics in the process). The drama, in all its theoretical glory, is laid out in entertaining fashion in Susskind's new book The Black Hole War. In addition to the sex appeal of two scientists battling it out with mathematical equations, TBHW is a great primer on string theory and quantum field theory--and reinforces the notion that these guys are all helpless gamblers. In the epilogue, Susskind prints a contract drawn in 1980 between Hawking and another physicist, Don Page; on it, it confirms via thumbprint that Hawking conceded the black hole war in 2007. Maybe this explains his angst with the Higgs boson: regardless of international acclaim as one of science's greatest minds, the man just wants to win a bet.
Another of Hawking's loud and controversial theories concerned black holes, an area of expertise that his name is practically synonymous with (and in fact, two definitions concerning black holes are named for him--Hawking radiation and Hawking temperature). Thirty years ago, Hawking claimed that nothing, not even information, can escape a black hole's singularity, and fellow physicist Leonard Susskind spent a good part of his career proving him wrong (and defending a fundamental law of physics in the process). The drama, in all its theoretical glory, is laid out in entertaining fashion in Susskind's new book The Black Hole War. In addition to the sex appeal of two scientists battling it out with mathematical equations, TBHW is a great primer on string theory and quantum field theory--and reinforces the notion that these guys are all helpless gamblers. In the epilogue, Susskind prints a contract drawn in 1980 between Hawking and another physicist, Don Page; on it, it confirms via thumbprint that Hawking conceded the black hole war in 2007. Maybe this explains his angst with the Higgs boson: regardless of international acclaim as one of science's greatest minds, the man just wants to win a bet.
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