Paul Krugman on Interstellar Trade

In 1978 Paul Krugman took on the pressing problem of how to set prices when goods are traveling near the speed of light. His opus, "The Theory of Interstellar Trade" [PDF] takes the relativistic economics head-on:

"These complications make the theory of interstellar trade appear at first quite alien to our usual trade models; presumably it seems equally human to alien trade theorists... I do not pretend to develop here a theory which is universally valid, but it may at least have some galactic relevance.

The remainder of this paper is, or will be, or has been, depending on the reader's inertial frame, divided into three sections. Section II develops the basic Einsteinian framework of the analysis. In Section III this framework is used to analyze interstellar trade in goods. Section IV then considers the role of interstellar capital movements. It should be noted that, while the subject of this paper is silly, the analysis does make sense. This paper, then, is a serious analysis of a ridiculous subject, which is of course the opposite of what is usual in economics."

Via Slashdot.

The Oxford Book of Modern Science Writing

A new anthology edited by Richard Dawkins is now hitting bookstores. It features popular science writing from a truly impressive array of several dozen authors.

The publisher, Oxford University Press describes the book:

Edited by best-selling author and renowned scientist Richard Dawkins, this sterling collection brings together exhilarating pieces by a who's who of scientists and science writers, including Stephen Pinker, Stephen Jay Gould, Martin Gardner, Albert Einstein, Julian Huxley, and many dozens more. Readers will find excerpts from bestsellers such as Douglas R. Hofstadter's Godel, Escher, Bach , Francis Crick's Life Itself , Loren Eiseley's The Immense Journey , Daniel Dennett's Darwin's Dangerous Idea , and Rachel Carson's The Sea Around Us . There are classic essays ranging from J.B.S. Haldane's "On Being the Right Size" and Garrett Hardin's "The Tragedy of the Commons" to Alan Turing's "Computing Machinery and Intelligence" and Albert Einstein's famed New York Times article on "Relativity." And readers will also discover lesser-known but engaging pieces such as Lewis Thomas's "Seven Wonders of Science," J. Robert Oppenheimer on "War and Physicists," and Freeman Dyson's memoir of studying under Hans Bethe.

I recall Dawkins asking for suggestions via his forum at RichardDawkins.net I see many of the most suggested, including the wonderful Lewis Thomas, made the cut. (Alas my candidate, Heinz R. Pagels does not appear on the list.)

Seeing the list of hugely popular and influential writings, this looks like it may be the closest to a definitive collection yet published. I have some science writing anthologies on my shelf but this looks far more comprehensive.

Busy, Busy...

I've had a lot going on recently and I expect to be busy for the next while. This week, I won't be able to post very frequently but I will try to keep up as best I can. Stay tuned...

Hope You had a Happy Pi Day

Pi Day was march 14th (3.14) and the day seems to get a little more popuar every year. Since it fell on a Friday this time, it was the subject of a geekily delightful segment on NPR's Science Friday. Part of the segment is devoted to Pi Limericks and Pi-Ku.

I once wrote a song about pi which was comprised of singing the digits while playing an Am-G-F-E progression on the guitar. While I did this just for a lark, it became one of my most requested tunes. Still, others have composed better songs.

Pi Day originated 20 years ago from San Francisco's Exploratorium. The celebration is two-fold as 3/14 is also Einstein's birthday.

The world record for memorizing the decimal expansion of pi is held by Chao Lu of China. It took him slightly over 24 hours to recite 67,890 digits. According to the rules of the competition there can be no gaps longer than 15 seconds. So he had no meals or bathroom breaks.

The record for computing pi is held by a team led by Yasumasa Kanada who have calculated the number to 1,241,100,000,000 (1.24 trillion) digits. For comparison, you only need 39 digits to calculate the circumference of the visible universe to the precision of a hydrogen atom. 63 digits gives you Planck scale precision.

Maybe a million digits will do for you. If not, here are 70 billion. Actually, everyone's favorite way of celebrating pi day is pretty obvious.

Tips for a Better Live Science Presentation

Of Two Minds posts this video featuring some simple yet extremely useful tips on improving science lectures. Good tips and a good sense of humor.

The video was made by Timothy Marzullo and Gregory Gage from UofM.

Shockwave Traffic Jams

From New Scientist:

The mathematical theory behind these so-called "shockwave" jams was developed more than 15 years ago using models that show jams appear from nowhere on roads carrying their maximum capacity of free-flowing traffic – typically triggered by a single driver slowing down.

After that first vehicle brakes, the driver behind must also slow, and a shockwave jam of bunching cars appears, travelling backwards through the traffic.

The theory has frequently been modelled in computer simulations, and seems to fit with observations of real traffic, but has never been recreated experimentally until now. more...

Via the mighty 3 Quarks Daily

Earth, Water, Air and Factcheck

Dan Phiffer's blog posts this image he found on an Internet message board. On the left is all of Earth's water gathered in one place. On the right, all the air. Both are set relative to the scale of the planet.

The image is getting a lot of attention (I found it via BoingBoing). But a question remained. Is it accurate?


A reader, Pat Stanton, does the math:

My son sent me a link to the image of spheres representing all the water and air on Earth. He was skeptical and suspected it was an example of “tree-hugger shock media.”

I decided to do the math, starting with the data provided by Andrew Nowicki. The math appears to verify the posted image. Although I applaud my son’s skepticism, tree-hugger shock media sometimes brings us an important and informative message.

General approach:

1. Measure the spheres representing Earth, water and air in the image. Obtain the diameter in pixels of each sphere. Also, identify relevant physical constants.

2. Starting with data independently provided by Andrew Nowicki, calculate the diameters of spheres that would contain Earth’s water and air.

3. Normalize the results from Step 2 into pixels and compare with measurements from Step 1.

Detailed results

Pat details his calculations in the full post -- and the image is legit. Impressive work all around. The image does emphasize the thin film our known biomass occupies.

Are We Alone - Art and Science

The good people at the Are We Alone podcast have put together another great show. This week, they hit a topic near and dear to my heart and blog. How do science and art overlap?

• mp3 - Higher Quality
• wma - Faster Download

They talk with Jonah Lehrer, author of Proust Was a Neuroscientist, on the subject of artists' insights into human experience which are finding experimental validation today. Their dependably funny radio theater imagines putting DNA on the ceiling of the Sistine Chapel. They look at the work of Leonel Moura who designs robots which make art. They also discuss the possible evolutionary advantages of our artistic sense with evolutionary biologist David Sloan Wilson. And more stuff too. Highly recommended.

Stephen Hawking on Charlie Rose

The most quotable moment comes from Rose asking Hawking about God and religion:

Hawking: "Physicists believe that the universe is governed by scientific laws. These laws must hold without exceptions or they wouldn't be laws. That doesn't leave much room for miracles or God. I regard the afterlife to be a fairy story for people that are afraid of the dark."

The end of the interview is pure Charlie Rose:

Rose: One last question. Is there a word -- "determination" "passion" "will" -- that has enabled you to survive, and to be the force you are around the world, and to have people see in you a representation of the great quest to understand who we are and how we fit?

Hawking: I had just always done what seemed the obvious thing to do.

Rose: That says it all.

Now available on Google Video. From the Charlie Rose site:

A conversation with Dr. Stephen Hawking & Lucy Hawking. They discuss their book George's Secret Key to the Universe, an adventure story about two children who find a sort of computer portal through which they can slip into the solar system and beyond.

"We are Inhabitants of a Planet Called 'Earth' and We Bear a Message Brought to You by Doritos"

From Science Daily:

The British public is being asked to shoot a 30-second ad about what they perceive life on earth to be as part of Doritos 'You Make It, We Play It' user-generated-content campaign. The winning advert in the competition will be beamed past the earth's atmosphere, beyond our solar system and into the Universe, to anyone 'out there' that may be watching. The winning ad will also be broadcast on terrestrial TV.

On 12th June, the space-bound ad will be broadcast from a 500MHz Ultra High Frequency Radar from the EISCAT Space Centre in Svalbard, which lies in the Arctic Ocean about midway between northern Norway and the North Pole.

The transmission is being directed at a solar system just 42 light years away from Earth with planets that orbit its star '47 Ursae Majoris' (UMa). 47 UMa is located in the Great Bear Constellation (also known as "The Plough") - easily identifiable to even the most amateur stargazer. It is very similar to our Sun and is believed to host a habitable zone that could potentially harbour small terrestrial planets and support life as we know it.

Maybe we can send "My Speech to the Martians" by Jack Handey (audio from Studio 360, text from the New Yorker).

Image from UCSD Bookstore.

The Geometry of Music

Dmitri Tymoczko is a composer and music theorist who explores the geometry of music. His site includes visualizations of musical patterns including "Smoke on the Water" on a Möbius strip (mov) and Chopin's prelude in E minor on a circle (mov) and in 4D space (mov). His ChordGeometries 1.1 application represents chords and voice leadings in a variety of 3D geometrical spaces.

From Science News:

Music theorists have long found Chopin's E minor prelude puzzling. Although the chord progressions sound smooth to the ear, they don't quite follow the traditional rules of harmony. When Tymoczko looked at the piece and watched the composition's motion through his geometrical space, he saw that Chopin was moving in a systematic way among the different layers of the four-dimensional cubes. "It's almost as if he's an improviser with a set of rules and set of constraints," Tymoczko says.

The image above is from Andrew Lipson's Lego Page.

Physicist Elected to Congress

Particle physicist and Democrat, Bill Foster has just won a special election to replace former House Speaker Dennis Hastert.

Foster worked at Fermilab for 22 years. He is credited, among other things, for developing equipment and data analysis software for the Collider Detector at Fermilab. His equipment helped find the Top Quark.

Now if he can make a detector to find some spine in those Washington Democrats, am I right people? Eh? Eh? Is this thing on?

Science bloggers are rejoicing from Pharyngula to Bad Astronomy to Cosmic Invariance.

Foster's first term will be very short as his Illinois district will have its regular election in November.

Beaumont Hospitals Plan a Proton-Beam Site to Target Cancers

The Detroit Free Press reports:

In a move generating controversy among Michigan's top hospitals, Beaumont Hospitals announced plans Thursday to team up with an Indiana company to build a $159-million proton-beam cancer radiation facility on its Royal Oak campus.

The debate centers on a type of cancer radiation therapy offered at about a half-dozen U.S. sites called proton-beam therapy. By comparison with traditional radiation therapy, which uses X-ray or photon light particles to zap tumors, proton-beam therapy releases tiny atomic particles that are expected to more closely target a tumor without hurting nearby tissue as the energy moves in and out of a cancer site. more...

Study: Snapping Three Times Leading Way To Recall Movies, Actors

From the Onion:

According to a study published Tuesday in the Journal Of Neuroscience, snapping three times in rapid succession is the most effective method for remembering the names of films and actors that have slipped one's mind. "When denied access to IMDb, subjects who were able to correctly remember semi-obscure movie trivia invariably used the tri-snapping method," head researcher Dr. Ward Connell said of the study, which consisted of asking volunteers several questions pertaining to a photograph of Dermot Mulroney.

Via Of Two Minds

Researchers control growth rate of replacement blood vessels, tissues

University of Michigan researchers have developed a new technique for administering growth factor to heal injuries. It combines nanotechnology with platelet-derived growth factor (PDGF). As Wikipedia puts it, PDGF is "one of the numerous growth factors, or proteins that regulate cell growth and division. In particular, it plays a significant role in blood vessel formation (angiogenesis), the growth of blood vessels from already existing blood vessel tissue."

The following is from the UofM News Service:

Researchers put platelet-derived growth factor into nanoparticles and then attached them to a lattice-like, biodegradable scaffold. In experiments, the growth factor recruited cells that stimulate the body's own machinery responsible for healing, said (Peter) Ma, whose lab developed the scaffold and the nanoparticles.

As the tissue grows, it crawls into the scaffold, which eventually dissolves.

"Growth factor is typically dumped in and releases over a period of hours," said (William) Giannobile, who also directs the Michigan Center for Oral Health Research. "With certain wounds you might want a lot (of growth factor) in the beginning, and with others you might want a little released over a longer period of time. We've basically found a way to dial up or dial down the release rate of these growth factors."

Their results are available at the Public Library of Science.

More information on the images above.

UK May Shut Down Jodrell Bank Observatory

Jodrell Bank observatory may shut down according to a UK funding proposal (via Bad Astronomy). The observatory is comprised of several radio telescopes including Lovell, the third largest steerable radio telescope in the world. The proposed budget cuts would save the UK £2.5 million per year. Perhaps Lovell can be converted (again) to an outdoor movie screen. (Cross-posted from MetaFilter.)

Mathematician Sophie Germain

Science News posts a two-part series on Sophie Germain [Wiki] -- a mathematician born in France in 1776. The article describes Germain as "the first woman known to have discovered significant mathematical theorems." (Hypatia from the 4th Century is worth noting, though she is not known for any particular theorems)

Germain assumed the identity of a male student and took classes from Lagrange. She read class notes and sent in assignments under the name of the male drop-out. Lagrange found out her secret:

According to a commentator at the time, Lagrange "went to her to express his astonishment in the most flattering of terms," and the commentator goes on to say that "the appearance of this young 'geomètre' made quite a stir." Nevertheless, the barriers against Germain's inclusion in the mathematical community didn't come tumbling down.

Later, she corresponded with Gauss under the male pseudonym, "Antoine-August LeBlanc." Gauss too discovered her real identity:

In 1806, Napoleon's armies were marching into Prussia, and Germain became concerned that Gauss might be in danger. She asked a friend who was a commander in the French artillery to find Gauss and ensure his safety. Her friend followed her request—but revealed her identity in the process.

Gauss initially responded with delight, writing to Germain: "The taste for the abstract sciences in general and, above all, for the mysteries of numbers, is very rare.… But when a woman, because of her sex, our customs and prejudices, encounters infinitely more obstacles than men in familiarizing herself with their knotty problems, yet overcomes these fetters and penetrates that which is most hidden, she doubtless has the most noble courage, extraordinary talent, and superior genius."

Gauss broke off correspondence with her shortly thereafter -- saying he was turning to astronomy and would have no more time for math.

Germain worked in isolation, taking on one of the most difficult problems in math, Fermat's Last Theorem. (It was not until 1995 that the theory was proven by Andrew Wiles, and that was in a roundabout fashion.) She defined what would be called Sophie Germain primes and worked on the math of elastic surfaces.

Gauss convinced the University of Göttingen to give her an honorary degree. Unfortunately she died in 1831 before receiving it.

The two-part series on Sophie Germain: 1, 2.

Foodsel

Foodsel is a site that visualizes the energy represented in food. How much exercise is implicit in a candy bar? What is its equivalent in batteries or sugar cubes?

Interesting tool. I am curious how nutritionists would evaluate the site.

It could benefit from some redundancy in its navigation. To compare a variety of foods, I did find myself shuttling back and forth a lot. It would also be nifty to have English units in addition to the metric units (for we poorly educated Americans).

For such an ambitious site, I'm not going to get too critical. It's quite a project.

(I wonder how many hours of blogging it takes to work off a bowl of ramen. Hm.)

Via Dave Faris at MetaFilter.

Visualization of Einstein's Special Relativity

This is a recent visualization showing Einstein's theory of special relativity. A couple moments are not entirely intuitive, but the main idea is very well illustrated. Using a third spatial dimension to represent time is surprisingly effective. Well done.

Another visualization from the same person(s) is of the Coriolis and centrifugal forces also very well done. (No audio on either video.)

Saturday Morning Physics Returns

Saturday Morning Physics is a very popular lecture series in Ann Arbor. UofM offers fascinating physics lectures to the public -- plus coffee, donuts and bagels! It took a two-week hiatus for spring break but returns this coming Saturday morning with "Modeling the Cosmos -- Observations and Simulations:"

Cosmology has been "the study of the Universe in its totality". Both sky observations and simulations have taken huge steps forward in the recent past. Dr. Rasia will explain the most important successes achieved in our understanding of the Universe and its main components: dark matter and dark energy. She will discuss the future of this field, and UM’s involvement in one of the biggest future sky surveys.

It starts at 10:30 but it's a good idea to show up pretty early. The lecture hall at 170 Dennison fills up quickly.

The schedule of presentations includes PowerPoint downloads of the recent presentations on string theory.

Videos of previous Saturday Morning Physics.

Primer, Fractal Mazes and Mulholland Drive

I just finished re-watching (again) the 2004 movie "Primer." It's brilliant. I'm willing to give a film major points just for being unlikely. This does much better than just "unlikely." At only an hour and 17 minutes, it takes about four hours of repeat viewing to get a handle on the intricate plot.

I won't be spoiling much to explain the movie is about time travel. It confronts the paradoxes of time travel and concludes that duplicates of people can alter their own past without disappearing (in contrast to Michael J. Fox's hand in "Back to the Future").

I'll get to the complexity of the plot in a minute. First, it's worth mentioning that the movie is stylistically very slick for such a low budget. It's very cleverly shot and the acting of the two leads is surprisingly good. The world the movie shows is a hyper-realized cosmos of pale shirts and power-ties of high-tech entrepreneurs. They even wear ties when they scavenge for metal parts.

At it's heart the movie is a very elegantly designed puzzle. Here are some of the rules:

• The characters in-the-know have access to two storage-box-sized time machines
• These characters can change their own past without nullifying themselves
• Anyone who travels back it time will have their time-line overlap with their earlier selves
• Time travel can be done repeatedly
• A character might time travel without letting the audience know
  

Can a character go back to a time before the time machine was invented? Right now, I'd argue this is an open question. It does not seem to follow from the logic of the machine but there are some tantalizing clues in the script which suggest otherwise.

The rules of "Primer's" plot are similar to puzzles called fractal mazes. Fractal mazes are recursive and so is the plot to "Primer." Pathways are used repeatedly to different ends.

My guess is, that like a fractal maze, "Primer" is open to a variety of solutions. Though not all attempts at solutions work.

It's very easy to run into a dead-end in a fractal maze. In "Primer," not all story interpretations work. Any plot-solution that contradicts the logic (including growth of facial hair or Aaron's use of headphones) runs into its own "dead-end."

Rather than explain how fractal mazes work, better you just give 'em a try via the links below:

For a JavaScript version of the fractal maze to the left, go here. The page also includes a variety of solutions.

For a more complex fractal maze, try this. (Various solutions here.)

My guess is, the plot was designed with a particular solution in mind. Shane Carruth (writer, director, producer and actor for Aaron) is a mathematician and engineer. (YouTube interview here.) So I'm guessing he pieced this together with a particular solution in mind. But, again, clues to various solutions abound.

There is an online subculture of people trying to solve the plot. This post is fairly close to my current grokking. This thread offers additional interpretations.

And then there is this ambitious piece of work which I think might be more confusing than the movie.

If there is a specific solution to the "Primer" puzzle, these all may still be wrong. Then again, more than one may fit logically.

Maybe I'm wrong. When I first saw "Mulholland Drive," I simply accepted the plot as surrealism -- open to any dream interpretation. I've since been convinced otherwise by the site Lost on Mulholland Drive which offers a very persuasive analysis of the movie in logical terms.

Others are way ahead of me on the view-count for "Primer." I'll see if I can get a better picture of the story soon.

Image to the left from LOL Science.

This is Your Brain on Brands

The Neurocritic has a refreshingly skeptical post about neuromarketing:

Advertisers, neuroscientists combine forces to produce outlandish headlines:

Advertisers, neuroscientists trace source of emotions in brain
Tuesday, February 19, 2008

GAINESVILLE, Fla. — First came direct marketing, then focus groups. Now, advertisers, with the help of neuroscientists, are closing in on the holy grail: mind reading.

At least, that’s what is suggested in a paper published today in the journal Human Brain Mapping authored by a group of professors in advertising and communication and neuroscience at the University of Florida [Morris et al., 2008].

Not only outlandish headlines, the holy grail of "mind reading" is within the grasp of their PR department. more...

I've been following the neuromarketing thing for a few years now (Google alerts be thanked). The story of neuromarketing actually started with the Pepsi Challenge ad campaign. People in a blind taste-test actually do prefer the taste of Pepsi. So why so people still prefer to buy Coca-Cola?

To answer this question, functional magnetic resonance imaging (fMRI) was put to use, measuring the activated parts of the brain of cola drinkers.

From Frontline's The Persuaders:

Coke "lit up" the medial prefrontal cortex -- a part of the brain that controls higher thinking. Montague's hunch was that the brain was recalling images and ideas from commercials, and the brand was overriding the actual quality of the product. For years, in the face of failed brands and laughably bad ad campaigns, marketers had argued that they could influence consumers' choices. Now, there appeared to be solid neurological proof. Montague published his findings in the October 2004 issue of Neuron, and a cottage industry was born.

Neuromarketing, in one form or another, is now one of the hottest new tools of its trade. At the most basic levels, companies are starting to sift through the piles of psychological literature that have been steadily growing since the 1990s' boom in brain-imaging technology.

There is a great deal of hype in the field of neuromarketing. (They're marketers after all.) For a recent example, here's a press release excerpt on the brainwaves of subjects watching Hillary and Obama YouTube ads (see if you can spot any selection bias):

Researchers found that the Obama "Yes We Can" viral video generated the highest brain response.

The study involved 25 subjects under 30 years of age who were tested using caps with electrodes that are linked to electroencephalography (EEG) equipment, which measured and recorded brain activity in millisecond increments.

Michigan Pharyngulite Meet-Up

Michigan fans of the PZ Myers' blog Pharyngula are looking to organize a meet-up in Ann Arbor.

If you're interested in participating, just send me an email: PAT HAT 32 at HOT MAIL dot COM.

People Power on OTM

On the Media has a very interesting segment about the changing behavior of audiences inside the InterTubes:

There's a new era of online community and it's challenging our notions of entertainment, activism and audience. Clay Shirky’s new book, Here Comes Everybody, depicts this online world, driven by networks that grow and act in never-before-seen ways.

This link takes you to the transcript and downloadable audio for the segment.

(Disclaimer: I confess, I find most ruminations on the "unprecedented nature" of net phenomena pretty tedious. But this is an exception. -- Pat)