Tag: physics

DARPA's New Machine for Blowing Out Fires—With Sound Waves

By Sophie Bushwick | July 17, 2012 12:03 pm

Music may have charms to soothe the savage breast—but it can also do a number on flames. In the above video, a blast of sound easily conquers fire. When researchers from the Defense Advanced Research Projects Agency, or DARPA’s, placed two speakers on either side of the burning liquid fuel, the sound waves increased the air velocity and thinned the fire. As for the fuel itself, the higher velocity led to more fuel vaporization for a wider and cooler flame. Both effects made the blaze easy to snuff out.

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One Near-Light-Speed Pitch Would Liven Up a Baseball Game—And Destroy It

By Sophie Bushwick | July 12, 2012 8:00 am

The last thing you’ll ever see?

Baseball is a leisurely game—some would say achingly boring—with no ticking clock forcing the players to hurry. But what if you could speed baseball up? Way, way up, up to a relativistic pace: What would happen if the pitcher wound up and released a baseball at 90 percent the speed of light?

Randall Munroe, the mind behind stick-figure comic XKCD, has a background in physics and computer programming, which heavily influences his work. Recently he launched a new weekly feature called “What If?” in which he answers readers’ hypothetical questions. Like how to hit a baseball that is moving so fast, normal mechanics no longer apply and the rules of relativity come into play. The answer is that in relativistic baseball, you don’t hit the ball; the ball—or rather the plasma shockwave that the ball creates—hits you…and everyone else.

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Let's Make Robots From Everything—Even Mexican Jumping Beans

By Sophie Bushwick | July 4, 2012 8:45 am

jumping beans Robots like this? That’s nuts.

If mechanical engineer David Hu ruled the world, it would be crawling with robots based on mosquitoes, snakes, and Mexican jumping beans. Hu’s lab studies animal locomotion, but the research goes beyond the traditional slow-motion footage of creatures running. Instead, Hu examines topics like how water striders and rafts of ants stay afloat on water’s surface, the mechanics of giant pumpkins collapsing into amorphous blobs under their own weight, how snakes’ scales affect their slither, the optimal way for furry animals to shake off water, and how mosquitoes survive collisions with comparatively huge raindrops. His group has even analyzed the motion of Mexican jumping beans, which is due not to some inherent magic in the “beans,” but rather to temperature-sensing moth larvae in hollow seeds. (When the ground heats up, the larvae sense the change in temperature and make their seedy houses twitch into rolling movements towards cooler, shadier ground.) These topics are weird and interesting enough to have garnered Hu’s work plenty of media coverage. But when it comes to earning funding, “weird and interesting” doesn’t always cut it. What’s the practical purpose of this research? Instead of shrugging and saying, “Now we know how mosquitoes struggle out from water droplets 50 times their size! That’s pretty cool!” Hu has come up with a standard one-size-fits-all application. At the end of his papers, he adds that whatever wacky phenomenon he studied could inspire…robots! Read More

The Laws of Physics, Officer, Outrank the Laws of California

By Veronique Greenwood | April 18, 2012 9:38 am

I think this picture says it all, officer. Clear as day!

To all those police officers out there on traffic duty: Be real careful about ticketing physicists. You might be proven wrong in elaborate mathematical detail.

Dmitri Krioukov, a physicist at UC San Diego, was pulled over for running a stop sign. However, he had not in fact run it, and his sense of injustice was apparently so inflamed that he undertook a rigorous mathematical explanation of what had happened, eventually posting a paper on the ArXiv showing that the police officer had fallen prey to a perceptual illusion (although the paper was posted on April 1, if it’s a joke, Krioukov is sticking to his guns; he’s spoken to PhysicsCentral about the work). At the stop sign, he had seen Krioukov’s car, a Toyota Yaris, disappear on the far side of a station wagon in the lane closest to the officer and subsequently accelerate away, but he mistakenly concluded that Krioukov had not stopped during that moment, because—this is the clincher—he had been visually measuring not the linear but the angular speed of the car! To put it in Krioukov’s own words:

“Police officer O made a mistake, confusing the real spacetime trajectory of car C1—which moved at approximately constant linear deceleration, came to a complete stop at the stop sign, and then started moving again with the same acceleration, the blue solid line in Fig. 5—for a trajectory of a hypothetical object moving at approximately constant linear speed without stopping at the stop sign.”

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CATEGORIZED UNDER: Crime & Punishment

Science Sing-Alongs: Higg Boson vs Google Periodic Table

By Joseph Calamia | September 9, 2010 10:53 am

If the 2008 Large Hadron Collider rap didn’t appeal to your musical sensibilities, you might try two science songs now making the internets rounds.

The first isn’t really new at all: Joe Sabia has employed Google Instant for a pastiche based on Tom Lehrer’s 1959 Elements Song, which in turn parodied Gilbert and Sullivan’s 1879 Major General’s Song.

[via Boing Boing]

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Hunting Sharks Are the Mathematicians of the Seas

By Joseph Calamia | June 10, 2010 2:30 pm

sharkSure, when blood hits the water, sharks know exactly where to go. But how do they hunt for less-obvious meals? New research says they use math.

How exactly the sharks move seems to vary with how much food is around.

Imagine yourself in a Walgreens, picking up a few necessities on your way home from work. You might make short movements, darting between aisles, crossing and recrossing your path as you debate between generic and name-brand. Apparently, sharks do the same thing when they have a lot of food in one area. Scientists even suggest their pattern is Brownian, no more intelligent than the aimless sway of microscopic particles buffeted by water molecules.

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Tiger Woods' Fave Physics Book Rocketing Up the Charts

By Andrew Moseman | December 4, 2009 5:15 pm

tigerbook425Since the crush of press stories about Tiger Woods is more or less inescapable, you’ve probably heard about his little auto accident (and many of the less savory details). But if you take a close look at this photo released by the police, you’ll notice something besides the mess of debris—the book that the world’s great golfer has been reading. It’s Get a Grip on Physics by John Gribbin.

While the accident and the tawdry personal accusations that resulted therefrom could damage Woods’ reputation permanently, it provided nothing short of a bonanza for author Gribbin, since Americans want to do whatever celebrities are doing. From The Independent:

“This is one of my older and lesser known books – a guide to new physics for non-scientists. I can only guess that Tiger has been interested in the various stories about the Large Hadron Collider, and wanted to learn more. Several of my books have been doing better than usual this year,” Dr Gribbin said yesterday.

The book was 2,268th position on the Amazon sales list, up from 396,224th the previous day.

Though Tiger was tight-lipped about the circumstances of the wreck, Gribbin has to be on to something here. Woods was probably so distracted thinking about the awesomeness of physics that he couldn’t concentrate on driving.

Related Content:
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Image: Florida Highway Patrol

How Long Would It Take a Physics Lecture to Actually Kill You?

By Brett Israel | September 16, 2009 5:22 pm

sleeping_student_webTo honor the start of a new school year, we bring to you the following Fermi problem: How long would a physics lecture have to be to actually kill you?

Or more precisely, from Physics Buzz:

Assuming you’re not in a big lecture hall and the professor shuts the door at the start of class, how long does it take for you and your classmates to deplete the oxygen enough to feel it?

The mathletes at the Buzz make a few assumptions about the classroom, but in a 16-foot by 16-foot classroom with a 10-foot ceiling, packed with 34 bleary-eyed students and one Red Bull fueled professor the answer is…2 hours and 51 minutes!

Of course you’ll probably be brain dead long before that point.

Check their math here and then tell us why they’re right or wrong, or if you’ve ever survied such a physics marathon.

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DISCOVER: Fairway Physics

Image: flickr / Rober S. Donovan

MORE ABOUT: death, physics

Looking for Dark Matter? Dig Deeper…Literally

By Allison Bond | June 24, 2009 11:49 am

cosmosScientist hoping to prove the existence of dark matter are bringing their search deeper underground, thanks to a lab that at certain points will reach nearly 8,000 feet below South Dakota’s Black Hills.

The laboratory is being constructed beneath an old goldmine, which itself was once the site of renowned physics research. The fact that it’s sheltered from cosmic rays makes it a great potential locale for the mysterious dark matter particles, which may make up a quarter of the universe’s mass and do not “feel” the electromagnetic forces that affect ordinary matter. According to the AP:

The research team will try to catch the ghostly particles in a 300-kilogram tank of liquid xenon, a cold substance that is three times heavier than water. If they tried to detect dark matter above ground, the highly sensitive detector would be bombarded by cosmic radiation.
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MORE ABOUT: dark matter, physics

If Mark Twain Had Taught Physics

By Lizzie Buchen | April 10, 2008 11:49 am

physics.jpgThe next time you’re interested in a healthy dose of physics (with a generous splash of literature), resist the temptation of your Wikipedia bookmark, take a step back from the harried, irreverent blogosphere, and dive into the enrapturing prose of pre-Soviet Russia.

In 1913, Yakov Perelman wrote an enchanting book called Physics for Entertainment, and it’s just what Jules Verne and H.G. Wells would have turned out—had they any desire to teach the fundamental laws of the universe. Perelman’s book was only recently translated to English, and seeks (successfully) to “arouse the activity of scientific imagination, to teach the reader to think in the spirit of the science of physics…with all that he normally comes into contact with.”

In chapters like “How to Work Miracles,” “Mathematics and Imagination,” and “Fairy Tale Railway,” Perelman associates the laws of physics with an ample variety of both everyday phenomena (knots, eggshells, fire, jumping from a moving vehicle) and the wildest fantasies of H.G. Wells, Jules Verne, Cyrano de Bergerac, Gogol, Mark Twain, Voltaire, Pushkin, and Edgar Allan Poe. Blending flowery prose with equations, neither of which are burdensome, he weaves his own delightful narrative with the imaginations of a great writer, producing a highly engaging piece of educational literature.

Some excerpts, illustrating Perelman’s merging of science fiction with physics non-fiction: Read More

MORE ABOUT: education, physics

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