No, Mr. Bond, I Expect You to Annihilate!

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Lasers Provide Antimatter Bonanza

Hui Chen and Scott Wilks of the Lawrence Livermore National Laboratory in California and their colleagues now report that they have generated copious amounts of positrons with intermediate energies–in the range of a million electron-volts. They fired picosecond pulses with intensities of around 1020 watts per square centimeter from the Titan laser at Livermore’s Jupiter laser facility onto millimeter-thick gold targets. Positrons were produced via the “Bethe-Heitler” process, in which part of each laser pulse creates a plasma on the surface of the target, and the remaining part of the pulse then blasts electrons from the plasma into the solid. Next, the electrons are slowed down by gold nuclei, an interaction that generates gamma-ray photons. The gamma rays then interact with more gold nuclei and transform into electron-positron pairs.

Physics in Art

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Machines that Almost Fall Over

A system of sculptures that is constantly on the brink of collapse. My intention was to capture and sustain the exact moment of impending catastrophe and endlessly repeat it.

While at rest, or with the hammer slowly moving, the pieces stay upright because the center-of-mass is located somewhere over the base. The key is to make sure the impact doesn’t change that.

Also, there’s Conversation Piece

Film editor Walter Murch, who edited many of Francis Ford Copolla’s films, developed a theory about edits while working on The Conversation (1974) He noticed that in many cases, the best place to make a cut was when he blinked. Subsequently, Murch wrote about the human blink as a sort of mental punctuation mark: a signifier of a viewer’s comfort with visual material and therefore, a good place to separate two ideas with a cut.
This sculpture is a physical test of Murch’s principle. I watched The Conversation while wearing a custom device that recorded the pattern of my blinks during the film. Using this information, I created a display in which the left mallet taps out the paattern of my blinks, while the right mallet taps out the pattern of Murch’s edits. When the two match up, the cymbal chimes for success.

Beat notes, sort of.

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News of the Weir

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Google Earth reveals fish trap made from rocks 1,000 years ago off British coast

[M]odern technology has revealed this ancient fish trap, used at the time of the Norman Conquest.

They didn’t actually find it on Google Earth, but the image was there

Although it was only recently spotted on aerial photographs, an armchair archaeologist could have discovered the trap on Google Earth.

Google said the V-shaped structure has been visible on its collection of satellite and aerial photos since at least December 2006.

Sure enough, if you point Google Earth to the right spot, you can see it. Use these coordinates:
N 52° 06.550 W 004° 42.450

Works in Google Maps, too

Recognition

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OCR Terminal

What is OCR Terminal?
OCR Terminal is a free online Optical Character Recognition service that allows you to convert scanned images and PDF’s into editable and text searchable documents. It accurately preserves formatting and layout of documents.

Mired in Red Tape and Bad Business Practices

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A colleague’s computer crashed, and he’s having the IT department wipe and reinstall the operating system and the software on it. But the Microsoft Office suite is old (2002), and they want the recent package … but not too recent. They’ve standardized on Office 2003 but are about to move to Office 2007, so I was instructed to buy Office 2007, with a downgrade to the 2003 license, so they can install 2003 and upgrade to 2007 when the time comes. (Confused yet?) Since he already had the 2002 software, this was like Stokes scattering (a kind of Raman transition). Upgrade 2002 to 2007 and immediately downgrade to 2003. If we weren’t going to upgrade later, the intermediate state didn’t have to be a real product.

“Do this through Dell,” I am told. (Oh, frabjous day. I love Dell) So I tried to find this on their website — no good. I find out that there’s a special phone-ordering process: I have to call a number and choose a particular option, The, type in the extension of a particular customer rep, at which time I will be told that the customer rep is on maternity leave. At the end of that message, choose a particular option, that will take me to the customer rep who can help me. The only things missing were a red flag in the planter and a dead-drop.

But that’s not the whole story. Software and hardware have to comply with section 508 of the Rehabilitation Act, which means that it has to be accessible to those with disabilities. So I check the government’s compliance database, and Office 2007 isn’t listed. I have to go to Microsoft’s website and find it, and each of the programs in the site are listed separately — they total about 30 pages, which have to be printed out and included with the order paperwork. Every time someone orders the software. You’d think that for standard software, there would just be a master list that’s stamped “approved,” just to save everyone time and paper and toner, but you’d be wrong. That would make too much sense.

I read the fine print, though, and it turns out the software isn’t fully compliant. One of the requirements to allow people with certain vision-related problems to use the software is “Software shall not use flashing or blinking text, objects, or other elements having a flash or blink frequency greater than 2 Hz and lower than 55 Hz.” Microsoft’s response is

Minor exceptions in Office Excel 2007 involve minor flickering issues within components such as: formula bar, charts, text boxes, the Page Layout View (PLV) mode in Office Excel 2007.

Additionally, some dialogs in Office Excel 2007 have display issues when loading in a Windows Vista™ environment.

That’s right — there are more problems when running in Vista. At least I got a laugh out of this whole episode.

Blown Up, SIr!

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The Big Picture: Undersea eruptions near Tonga

Scientists sailed out to have a closer look at the eruptions of an undersea volcano off the coast of Tonga in the South Pacific Ocean today. Tonga’s head geologist, Kelepi Mafi, said there was no apparent danger to residents of Nuku’alofa and others living on the main island of Tongatapu. Officials also said it may be related to a quake with a magnitude of 4.4 which struck last March 13 around 35 kilometers from the capital at a depth of nearly 150 kilometres. (I know this is an off-day posting, but really, thought the images were worth it – 12 photos total)

Phone a Friend, or Ask the Audience?

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Welcome to Who Wants to be an Atomic Physicist?

Is It a Gas, Fluid, Solid, or All of the Above?

Because rubidium is magnetic, however, Stamper-Kurn and his Berkeley colleagues thought that the magnetic interactions between rubidium atoms in the gas might nudge them to adopt a type of regular spacing like atoms in a solid.

To look for this ordering, Stamper-Kurn’s team used a conventional laser trapping technique to confine a gas of millions of rubidium atoms in an oblong, surfboardlike trap. They then cooled the sample to below 500 nanokelvin. Lastly, they hit their collection of rubidium atoms with a beam of circularly polarized light, which is reflected differently by atoms with a different magnetic orientation and can, therefore, reveal the magnetic orientation of the atoms in the sample. What they saw was that within their optical trap, the rubidium atoms ordered themselves into an array of 5-micrometer-square domains, inside which all of the atoms adopted a similar magnetic orientation. What’s more, these domains adopted a crystalline-like ordering, with alternating domains with different magnetic directions. This ordering wasn’t perfect like the regular lattice of sodium and chlorine atoms in table salt. But it’s not random either (see picture). “There is some emergent order which shows up in this system,” Stamper-Kurn says.

Once the Berkeley researchers spotted the ordered makeup of the atoms, they decided to check whether the gas was coherent as well. Using another laser, they nudged two groups of rubidium atoms already in their trap. They found that the atoms interfered with each other in the same way that two coherent light beams create an interference pattern of light and dark stripes, an unmistakable sign of their wavelike quantum nature.

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I Swear I Did It

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Guilty Secrets Survey results revealed!

George Orwell’s 1984 tops the list of books that people pretend they have read, in a survey carried out for World Book Day 2009 to uncover the nation’s guilty reading secrets. Of the 65% who claimed to have read a book which in truth they haven’t 42% admit to having said they had read modern classic 1984.

Those who lied have claimed to have read:

1. 1984 by George Orwell (42%)
2. War and Peace by Leo Tolstoy (31%)
3. Ulysses by James Joyce (25%)
4. The Bible (24%)
5. Madame Bovary by Gustave Flaubert (16%)
6. A Brief History of Time by Stephen Hawking (15%)
7. Midnight’s Children by Salman Rushdie (14%)
8. In Remembrance of Things Past by Marcel Proust (9%)
9. Dreams from My Father by Barack Obama (6%)
10. The Selfish Gene by Richard Dawkins (6%)

1984 was a school assignment. We’ve always been reading it, just as we’ve always been at war with Eastasia. I also read #6, which was probably the last pop-sci physics book I ever read in its entirety — even before starting grad school, I didn’t need to read the spoon-fed version of quantum mechanics or relativity, so there isn’t much point. (I’ve read bits of other books in order to clear up misconceptions of what the author was talking about). I’ve read parts of #4. Haven’t read any of the others, nor have I claimed to.