quantum
pontiff | March 11, 2010Hm, today we seem to have a posting from beyond the grave, arXiv:1003.2133:Proof of the Ergodic Theorem and the H-Theorem in Quantum MechanicsAuthors: John von Neumann
Abstract: It is shown how to resolve the apparent contradiction between the macroscopic approach of phase space and the validity of the uncertainty relations. The main notions of statistical mechanics are re-interpreted in a quantum-mechanical way, the ergodic theorem and the H-theorem are formulated and proven (without "assumptions of disorder"), followed by a discussion of the physical meaning of the mathematical conditions…
pontiff | February 15, 2010And here I thought I was the king (err Pontiff) of quantum Bacon, but no: follow @kenfagerdotcom on twitter who describes himself as "Inventor of Quantum Bacon and accomplished lover."
drorzel | February 12, 2010There have been a bunch of stories recently talking about quantum effects at room temperature-- one, about coherent transport in photosynthesis , even escaped the science blogosphere. They've mostly said similar things, but Thursday's ArxivBlog entry had a particular description of a paper about entanglement effects that is worth unpacking:
Entanglement is a strange and fragile thing. Sneeze and it vanishes. The problem is that entanglement is destroyed by any interaction with the environment and these interactions are hard to prevent. So physicists have only ever been able to study and…
oracknows | January 20, 2010Last night was grant crunch time to get a truly serviceable draft to my collaborators today as promised, leaving enough time to revise it by the February 5 deadline. That means the blog has to take a hit today, which is a shame, because Joe Mercola and Age of Autism have laid down some idiocy this week that I'm just dying to take down. Oh, well, it'll wait, and if it won't I'm sure there'll be new idiocy to take down (or, if I need a break, some good science to discuss) when I come up for air again. (In the case of Mercola, it's part one of a promised three part series; so waiting until he's…
pontiff | January 12, 2010Richard, a long while back (yes, I'm cleaning my inbox!), sent me some cartoons that were apparently floating around in the 70s when he did his BS in Chemistry that are quite amusing:
pontiff | October 23, 2009Oh man sometimes even I, a staunch Caltech grad, wish I could be at MIT. The MIT QIP seminar this next Monday looks...intriguing (Monday 10/26 at 4:00 in 36-428 silly MITers and their numbered buildings, so cold.):
David Kaiser (MIT)
How the Hippies Saved Physics
Abstract:
In recent years, the field of quantum information science-an amalgam of topics ranging from quantum encryption, to quantum computing, quantum teleportation, and more-has catapulted to the cutting edge of physics, sporting a multi-billion-dollar research program, tens of thousands of published research articles, and a…
pontiff | October 21, 2009The Dutch book argument of Bruno de Finetti is an argument which is supposed to justify subjective probabilities. What one does in this argument is gives probabilities an operational definition in terms of the amount one is willing to bet on some event. Thus a probability p is mapped to your being willing to make a bet on the event at 1-p to p odds. In the Dutch book argument one shows that if one takes this operational meaning and in addition allows for the person you are betting to take both sides of the bet, then if you do not follow the axiomatic laws of probability, then the person…
pontiff | October 20, 2009Two notes on chairs. Michael Green is the new Lucasian chair of Mathematics replacing the esteemed Stephen Hawking. Green helped sparked the great optimism in string theory by discovering with John Schwarz the Green-Schwarz anomaly cancellation mechanism.
Elsewhere, the Perimeter Institute has named ten new distinguished research chairs, among them a host of the quantum computing afflicted:Dorit Aharonov is a Professor in the Department of Computer Science and Engineering at Hebrew University in Jerusalem. She has made major contributions to the theoretical foundations of quantum…
pontiff | October 12, 2009Update 10/13/09: corrected for ice cream flavor and location, thus merging two related universes.
There is a story about Richard Feynman that while he was at Princeton MIT he had a hard time with dessert. Apparently they always served either chocolate or vanilla ice cream and Feynman would agonize over which he wanted that night. Then one day he decided that he was wasting his time making this decision and so he would solve this by only choosing vanilla chocolate and from that point on in life that is what he did. He no longer wasted time choosing, and, apparently, ate a lot of vanilla…
pontiff | September 23, 2009Over at Asymptotia, Len Adleman (the A in RSA, founder of DNA computation (but not the A in DNA!), and a discoverer of the APR primality testing algorithm) has a guest post about the foundations of quantum theory. Len suggests, if I understand him correctly, that one should attempt to understand the uncertainty arising in quantum theory as being of the same nature as the fact that there exists statements which cannot be proven true or false within a fixed set of powerful enough axioms.
First of all, I know I've heard a similar argument before, but can't seem to find the reference! Any…
pontiff | August 10, 2009March is ages away, but it is time to start planning for the APS March meeting, to be held in the beautiful rose city, Portland, Oregon (Note to skiers that Mt. Hood is just a short distance away :) ) Anyway an important part of the March meeting are invites sessions and the quantum computing/information/foundations topical group GQI is in charge of a few of these sessions. Want to nominate a session or invited speaker? Now's your chance. Here's the email that was sent out Friday:Dear GQI members,
This is an email to solicit from you proposals for GQI sponsored invited sessions and…
pontiff | July 30, 2009Okay this one from ScienceDaily made my day. No it made my week. The title is "Police Woman Fights Quantum Hacking And Cracking." Intriguing, no? Who is this mysterious police woman in quantum computing? I don't know many police offers involved in quantum computing, but yeah, maybe there is one who is doing cool quantum computing research ("cracking?" and "hacking?" btw.)
I open up the article and who is the police woman? It's Julia Kempe! Julia was a graduate student at Berkeley during the time I was there, a close collaborator of mine, and well, last time I checked, Julia described…
pontiff | July 27, 2009A new entry in the best title every contest, arXiv:0907.4152:Born Again
Authors: Don N. Page
Abstract: A simple proof is given that the probabilities of observations in a large universe are not given directly by Born's rule as the expectation values of projection operators in a global quantum state of the entire universe. An alternative procedure is proposed for constructing an averaged density matrix for a random small region of the universe and then calculating observational probabilities indirectly by Born's rule as conditional probabilities, conditioned upon the existence of an…
pontiff | July 16, 2009David Poulin sends me a job announcement for quantum information processing in the solid state at the University of Sherbrooke:Permanent position for a Canada Excellence Research Chair (CERC) on solid state quantum information processing
University of Sherbrooke is seeking candidates for a Canada Excellence Research Chair (CERC). The successful candidate will obtain a permanent full professorship in the Physics Department of University of Sherbrooke in the Faculty of Sciences. The CERC program aims to attract and retain the world's most accomplished and promising minds. This program will…
pontiff | July 14, 2009A friend sent me a link to QuantumCamp:Have you ever wondered how the microscopic Universe works? QuantumCamp is a one week journey through this strange but beautiful world - seeing nothing less than how every atom in our universe is working!
We begin with Dmitri Mendeleev's periodic table of the elements. We move from Albert Einstein's idea of quantization and end up seeing the hydrogen spectrum while contemplating the ideas of Niels Bohr and Werner Heisenberg.
We witness the explosive beauty and inner order of the elements which begs for deeper investigation. We dive in and immerse…
pontiff | July 9, 2009The report from the Workshop on Quantum Information Science has now been posted. Color commentary soon :)
pontiff | July 9, 2009Among the winners of the Presidential Early Career Awards for Scientists and Engineers this year I find a few familiar quantum names: Sean Hallgren (poor Sean was forced to share an office me at Caltech), Adam Smith, and Jason Petta. +10 tenure points awarded. Via @fortnow.
pontiff | June 24, 2009An old friend from my undergrad days sent me a link to Physics discussion ends in skateboard attack:A homeless man is on trial in San Mateo County on charges that he smacked a fellow transient in the face with a skateboard as the victim was engaged in a conversation about quantum physics, authorities said today.
Jason Everett Keller, 40, allegedly accosted another homeless man, Stephan Fava, on the 200 block of Grand Avenue in South San Francisco at about 1:45 p.m. March 30.
At the time, Fava was chatting with an acquaintance, who is also homeless, about "quantum physics and the splitting of…
pontiff | June 15, 2009First came the qubits quiz show, and now the qubits construction toy. Okay this later one is cool because...well because it's an awesome toy for kids of all ages (yes, I'm the guy who gives your kids blocks as a present):