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Notes & Queries for the Weekend

Those who have toiled in the vineyards of literary studies may recognize the allusion in my title to Notes & Queries, a journal collecting short pieces on a variety of research topics. Back in grad school I was forever looking up odds and ends in its pages related to the Anglo-Saxon alliterative line. A far cry from the Kuiper Belt and extrasolar debris disks!

But I need the occasional short feature here that, like Notes & Queries, collects things I want to highlight, each interesting, I hope, and useful to the interstellar-minded.

  • The indefatigable Brian Wang offers a lengthy piece on External Pulsed Plasma Propulsion and nuclear rockets in general. Have a look to see a NASA study from 2000 and its design principles for EPPP, which uses thrust from plasma waves in ways reminiscent of Project Orion. The post also studies the old NERVA designs and offers numerous links for follow-ups. “We just have to have the courage to become a truly interplanetary civilization,” Brian argues in tones that Centauri Dreams readers will admire. But is nuclear the best way forward? Plenty of food for thought here.
  • John Cramer’s time experiment has occupied us before, and I won’t re-summarize that work other than to say that it focuses on what Einstein called ‘spooky action at a distance,’ the strange and seemingly connected behavior of entangled particles that have been separated (for more, see this older Centauri Dreams article). Can Cramer demonstrate an effect that seems to occur before its cause? The latest news, from Alan Boyle’s site, is that Cramer’s research fund has reached $40,000, from foundations and private donors. Just returned from Brookhaven National Laboratory, he aims to conclude the experiment by the end of September. On the other hand, maybe we’ll hear about it earlier if he succeeds?
  • Galaxiki is a virtual galaxy based on the Web 2.0 wiki concept, currently housing over a million stars and solar systems that can be explored. Since each system represents a single page on the wiki, site members can edit the pages to create a fictional galactic history for each. Because beings in different systems meet each other, writers have to work to keep their story-lines consistent (which should become a larger and larger challenge). The free Galaxiki may prove addictive to those who need the occasional break from peer-reviewed papers and have an empire to build.
  • I get less opportunity to read weblogs than I would like, but the various ‘carnivals’ keep me alerted to good postings. The 12th Carnival of Space is now available, this one hosted by Music of the Spheres. Stories range from the remarkable Galaxy Zoo project to a pilgrimage to the 100-inch telescope at Mount Wilson (this is where Edwin Hubble did so much to explain the nature of galaxies and the expansion of the universe). Similarly, Philosophia Naturalis is now up with its 12th iteration, looking at dark matter candidates, the history of the moon’s orbit and the implications of high-redshift galaxies for the epoch of reionization.

A final weekend thought: You may see some odd changes today and tomorrow as I examine new plugins and consider theme modifications to the site. Consider this a weekend of experimentation at this end, but the tests shouldn’t prove obtrusive and Monday should be business as usual.

Comments on this entry are closed.

  • philw July 21, 2007, 14:44

    Regarding the search for dark matter candidate axions…
    “For awhile the reasearchers thought they has obtained positive results. Sadly, no. Just a couple weeks ago the researches reported their earlier results couldn’t be reproduced: The existence of a hypothetical particle called the axion has been put into further doubt now that the team that first claimed its discovery has failed to reproduce their results. Physicists working on the PVLAS experiment in Italy say that the tiny rotation in the polarization of laser light that they reported last year does not support the existence of axions, but rather is an artefact related to how the experiment had been performed.”

    This is the essence of hard science. Reproducibility (or not) of results and falsifyability of hypothethes. Sadly, I believe that much of trendy current physics ‘String Theory’ lacks these aspects.

  • ljk July 1, 2008, 13:01

    Can Bell’s Prescription for Physical Reality Be Considered Complete?

    Authors: Joy Christian (Oxford)

    (Submitted on 19 Jun 2008)

    Abstract: An experiment is proposed to test Bell’s theorem in a purely macroscopic domain. If realized, it would determine whether Bell inequalities are satisfied for a manifestly local, classical system. It is stressed why the inequalities should not be presumed to hold for such a macroscopic system without actual experimental evidence.

    In particular, by providing a purely classical, topological explanation for the EPR-Bohm type spin correlations, it is demonstrated why Bell inequalities must be violated in the manifestly local, macroscopic domain, just as strongly as they are in the microscopic domain.

    Comments: 4 pages; This is a follow-up to arXiv:quant-ph/0703179 and arXiv:0707.1333

    Subjects: Quantum Physics (quant-ph); General Relativity and Quantum Cosmology (gr-qc)

    Cite as: arXiv:0806.3078v1 [quant-ph]

    Submission history

    From: Joy Christian [view email]

    [v1] Thu, 19 Jun 2008 19:12:50 GMT (10kb)

    http://arxiv.org/abs/0806.3078

  • ljk February 23, 2009, 18:17

    http://arxivblog.com/?p=1230

    Human eye could detect spooky action at a distance

    February 19, 2009 | by KFC |

    It’s almost a year since Nicolas Gisin and colleagues at the University of Geneva announced that they had calculated that a human eye ought to be able to detect entangled photons. “Entanglement in principle could be seen,” they concluded.

    That’s extraordinary because it would mean that the humans involved in such an experiment would become entangled themselves, if only for an instant.

    Gisin is a world leader in quantum entanglement and his claims are by no means easy to dismiss.

    Now he’s going a step further saying that the human eye could be used in a Bell type experiment to sense spooky-action-at-a-distance. “Quantum experiments with human eyes as detectors appear possible, based on a realistic model of the eye as a photon detector,” they say.

    One problem is that human eyes cannot see single photons – a handful are needed to trigger a nerve impulse to the brain.

    That might have scuppered the possibility of a Bell-type experiment were it not for some interesting work from Francesco De Martini and buddies at the Universityof Rome, pointing out how the quantum properties of a single particle can be transferred to an ensemble of particles.

    That allows a single entangled photon, which a human eye cannot see, to be amplified into a number of entangled photons that can be seen. The eye can then be treated like any other detector.

    This all looks like fun. The first person to experience entanglement –mantanglement–would surely be destined for some interesting press covereage.

    But the work raises an obvious question: why is Gisin pursuing this line? The human eyeball could be put to use in plenty of optics experiments, so why the focus on mantanglement?

    Could it be that Gisin thinks there is more to entanglement than meets the eye?

    Ref: http://arxiv.org/abs/0902.2896: Quantum experiments with human eyes as detectors based on cloning via stimulated emission