Physics Buzz

On the street, you can usually count on the steering wheel to point your car where you want it to go. On snow, a high speed race track, or in the dirt there's a lot more physics involved.



When I'm not sitting behind a desk blogging about physics you can find me and my son JP out racing through the dirt, mud and snow in JP's 2002 Subaru WRX. He has to drive it to school too, so we do our level best to keep from knocking pieces off during our weekends running with the Sports Car Club of America Rally Cross crowd.

You're at a stoplight. There is a car in front of you and you're both waiting for the light to turn green. In your rear view mirror, you see another car approaching the intersection at high speed, obviously unaware that the light is red. He is going to hit you. What should you do?

Should you just sit there and pray that you'll be alright? Should you stand on the brake pedal? Should you tap the car in front of you? To find out, we strapped a trio of accelerometers onto skateboards and crashed them together to see which scenario would result in the least acceleration for the car in the middle.

Buzz Skyline theorized that you could minimize your acceleration by inching up to the car in front of you, touching its bumper, and then applying heavy braking, turning yourself into the middle ball in an over-sized Newton's Cradle.

Welcome to The Physics of Cars week here on PhysicsBuzz and what better way to kick off the week than with an interview with Diandra Leslie-Pelecky, author of the Physics of NASCAR!

What are some of the biggest ways that Physics and NASCAR intersect?

How don’t they? I think probably one of the most interesting things is that I asked someone one time if they had people in physics working there because most of the people at NASCAR are engineers. And the person thought for a moment and said ‘No I don’t think we do because you guys think everything interesting is obvious.’ And If you think about it what racing is mostly about is friction and air resistance which is the two things that we tend to like to just ignore. Everything about making a car go fast on the track has to do with the friction between the tires and the track, and so you have to get into some fascinating things like the friction of rubber, which is different than anything we teach our students about because it’s a different…

Hurricane Irene is eyeballing the east coast, readied to ruin the weekend plans of those already shaken up by this week's earthquake. How bad will round two of the August East Coast natural disaster onslaught be? Moderate. And here's why...
[Hurricane Irene, still a category two storm as of mid-day Friday, eyes the North Carolina coast. Satellite photo by NOAA.]

Wind and Rain
Air flows clockwise around a high pressure system and counter-clockwise around a low in the Northern Hemisphere. Hurricanes are areas of deep low pressure, so their winds swirl counter-clockwise around the center of the storm - where the eye is located.

Hurricanes impacting the East Coast usually have a northwesterly track. That movement affects the wind speeds felt on the ground: The winds in the northeast quadrant of the storm which blow to the north (counter-clockwise around the eye) combine with the northwesterly movement of the storm.

Be sure to check in next week for The Physics of Cars week on PhysicsBuzz!


You'll laugh, you'll cry. You might learn something too. It all starts Monday!

Homeopathic remedies have a few things going for them - they're natural, safe, have no drug interactions and no side effects. The only drawback that I can think of is THEY DON'T DO ANYTHING AT ALL.

UPDATE: Boiron has dropped the suit against Riva. Smart move on their part, I imagine - even in these odd times I think it would be difficult to make a case for the legitimacy of their products. It's too bad, I'd hoped that the suit would be covered widely and help to educate people about the absurdity of homeopathy.

French homeopathic manufacturer Boiron is suing Italian blogger Samuele Riva for having the audacity to point out that the one thing you're least likely to find in in their flu remedy Oscillococcinum is a single molecule of active ingredient. It's a good thing that the supposed source of the medicine is probably fictional, because otherwise you'd be likely to get many times the recommended dose every time you take a drink of water.

[Teething treatmen…

People learn most of their science in school. No, really, they do. Where else could they be learning it? We need to make sure they are getting every possible advantage in schools. Our performance on standardized tests is well below that of the rest of the world and that needs to change. If that means less money is spent on learning in informal, “free-choice” settings such as science museums, aquariums and TV shows, so be it. The flying anvils on The Science Channel and the gross yet popular “Bodyworlds” exhbit are fun, but not that educational. And not that many people go anyway. This idea is so ingrained that it is almost heresy to question it. But recent research performed by John H. Falk and Lynn D. Dierking shows that most people learn their science outside of the classroom.As someone that does informal education as a profession, this is exciting news. When your basic job description is to “excite and engage the public in physics” it is hard to know what impact you are having. App…

The third largest earthquake in decades ever recorded to hit the mid-Atlantic region just rattled the windows here at the Physics Buzz headquarters.



A magnitude 5.9 quake makes for an exciting few seconds, but didn't do a lot of direct damage in our town of College Park, MD (there's word that some people began to panic in Washington DC, but that's life in the big city). The fascinating part for me and lots of my friends was just how useful social media networks were during this (somewhat minor) emergency.

A New York Times article this Sunday reported that General Electric (G.E.) has successfully used a new laser-based method to enrich uranium, the element used in both nuclear reactors and nuclear bombs.

The laser technique could help to produce enriched uranium, used in nuclear power plants, more efficiently than with current methods. Opponents of the technique, however, worry about the new method leaking to rogue nations wishing to make weapons.

[Hope Creek Nuclear Power Plant in southern New Jersey. Photo by the Nuclear Regulatory Commission.]

Natural uranium is made up of atoms from three different isotopes. The uranium-238 isotope accounts for about 99.3 percent of natural uranium while uranium-235 accounts for about 0.7 percent. (A scant bit, about 0.01 percent, is uranium-234). The less-prevalent isotope, uranium-235, is the kind that is used in energy production. These atoms can be split by the fission process to release energy which in turn creates heat that is used to make elec…

I guess you could say I have a thing for scale models of the solar system, which is why I was really excited to see the American Geophysical Union's building in northwest Washington, D.C., a few days ago.

The building was constructed with all sorts of solar system symbolism, from the design and interior of the building to the sidewalks outside.

The building is five stories tall, plus two stories below street level. Its exterior models the density of the Earth. White limestone, at the base of the street level, is topped by red brick, a material almost half as dense. I suppose the limestone represents the Earth's core while the brick must represent the mantle, but I'm not sure.
The top floor curtain wall (a lightweight outer covering that keeps out the weather) might, I think, represent the atmosphere.

Many scientists cite various things as igniting the initial spark that led them to research. As you might imagine, inspirational parents and science teachers, Star Trek, and natural talent for math and the sciences are important influences. But for me and lots of others, it was good old science fiction that first got us yearning to learn more about the universe.





Now, National Public Radio has compiled a list of their listeners' top 100 favorite SF and fantasy books. I'm sure the collection will be a bit skewed based on the demographics of NPR listeners, but after a quick look I can see that a lot of my favorites are on it. I plan to pick up at least a few of the ones listed that I haven't gotten around to.

Remember the physics demo that caused a brief shutdown of the Omaha, Neb., airport two weeks ago? The Transportation Security Administration has released a photo of the device which appears to be an experiment to simulate testing the oxygen saturation in a person's blood.

The TSA blog wrote a blog post intended to warn travelers that "homemade gadgets" can sometimes look a lot like an improvised explosive device to a TSA officer.

"Let’s be clear, it was completely innocent. He had no way of knowing his improvised mint tin would look like an improvised explosive device (IED) on our X-ray monitor," the blog said of the student involved in the incident.

At least the TSA didn't blow up his mint tin unlike this unlucky traveler. (Incidentally, the event was also the first of two temporary shutdowns of the Omaha airport in one week.)

Basic physics techniques including radar and thermal imaging are vital for the newly emerging field of aeroechology - the science of things that spend much of their lives aloft.


There are ecologists who study land, and ecologists who study the ocean -- but who looks up and studies the air that circles the entire planet? Until recently, not many.

In 1946, a man named Stanislavv Ulam had the idea to propel rockets with nuclear explosions. Ulam had worked on the Manhatten project and came up with the idea of nuclear pulse propulsion. Instead of a steady-burning chemical engine like those used in Apollo moon rockets, a series of nuclear explosions propels the rocket forward.

[Somewhat tongue-in-cheek TED Talk by George Dyson, son of nuclear pulse propulsion designer Freeman Dyson, filmed in 2002.]

The rocket would eject a small nuclear charge or explosive behind it. The charge would detonate about 200 feet from the rocket, its shock wave pushing against a thick blast plate at the back of the rocket. Each explosion would add about 30 miles per hour to the rocket’s speed, meaning several hundred nuclear explosions would be needed to get the rocket into orbit and then more to send it to Saturn or another gas giant.

“How many of you think you know what the gap is going to be [in] American capability to take things to low Earth orbit between the end of shuttle and the onset of the next American capability?" NASA Administrator Charles Bolden asked a packed room at the University of Maryland's Samuel Riggs IV Alumni Center on Thursday morning.

He opened the first NASA Future Forum of 2011 with a speech saying that though the shuttle days are over, NASA still has a future. What remained unclear that morning, though, was what exactly that future might be.

"It’s in terms of months," Bolden said. "We will be flying American vehicles to the International Space Station in less time than it took us to recover from Challenger or Columbia."

The American space program won't have to rely on the Russians, the Europeans or the Japanese, Bolden said, though of course we still want to work closely with our international partners. Private companies like Orbital Sciences and Space X …

Physicists from Sweden and Spain have created a router than can quickly and efficiently direct information at the tiniest possible level.

“If you want to make a real quantum network, you have to have the ability to do things like route photons – everything we do in a real communications network,” said Chris (C.M.) Wilson of the Chalmers University of Technology in Göteborg, Sweden.

[At left is a close-up photo of the chip containing one of the researchers' artificial atoms. Photo courtesy of Io-Chun Hoi/Chalmers University of Technology.]

Wilson and his colleagues Io-Chun Hoi, Göran Johansson, Tauno Palomaki, and Per Delsing, along with Borja Peropadre from the Instituto de Física Fundamental Serrano in Madrid, Spain, have done just that, creating a quantum bit that can route information to one of two outlets in nanoseconds. The achievement could help spur on the development of quantum information networking.

Can Neil deGrasse Tyson top Carl Sagan?



Carl Sagan was the most successful and inspirational promoter of science ever. He had an amazing talent for explaining grand scientific ideas in plain, but poetic, language. Mr. Wizard, Bill Nye, Brian Greene and the MythBusters, though all good, are nothing compared to Professor Sagan. His public television program Cosmos first aired in 1980, and is still the most popular PBS series in the world.

I never would have thought that anyone would come along to challenge the legendary Carl Sagan . . . until now.

Let me preface this with: DON'T TRY THIS AT HOME!

Let me add also: NO SERIOUSLY, DON'T TRY THIS AT HOME!

And this: WHAT PART OF DON'T TRY THIS AT HOME DON'T YOU UNDERSTAND!?

Last week, Richard Handl, a resident of Ängelholm, Sweeden was arrested for attempting to build his own nuclear breeder reactor in his kitchen. He said he wanted to split atoms as a hobby, but now realizes that in retrospect it may not have been a good idea. But don't worry! He had a Geiger counter to measure the radiation.

What is this and how does it work?

This is a liquid crystal thermometer. It's the kind of thermometer you'd see attached to a fish tank. It uses heat-sensitive liquid crystals to indicate temperature.

Liquid crystals are crystals that behave mechanically like a liquid but have the properties of a crystal. Changes in temperature cause the color of the crystal to change.

As you can see in the photo at left, it's somewhere near 78 degrees Fahrenheit at my desk. Or maybe closer to 75. That's one of the drawbacks of a liquid crystal thermometer; it's sometimes a bit ambiguous. (After about 10 minutes, the thermometer stabilized and only the 26 C/78 F appeared, which I'll accept because it's a pleasant kind of tropical at my desk right now.)

Those darn physicists are at it again...

Part of the Omaha, Neb., airport was shut down briefly on Wednesday after TSA security screening personnel found suspicious items in a carry-on bag that belonged to someone returning home from the American Association of Physics Teachers (AAPT) summer meeting.

According to an article from the Omaha World-Herald, the Omaha Police Department's bomb squad was called to the airport's Terminal B just before noon on Wednesday to attend to a "suspicious-looking item" in a carry-on bag. Screening was halted and the B concourse was evacuated, the World-Herald said, though operations in the airport's other terminal remained unaffected.

[At left, a voltmeter or a bomb? Photo by Thomas Hirsch.]

The newspaper reported that, according to an FBI spokesperson, an Oregon college student's science project was the culprit. The student had been at the AAPT meeting and had submitted his or her project in the meeting's apparatus competition…

Helmet and acoustics research might offer riders a quieter trip.


Before hopping on his motorcycle, Michael Carley puts on earplugs, followed by his helmet. It's a step many riders take. After accelerating, most of the sound that a rider can hear isn't from the bike engine or other vehicles on the road, but from the air rushing over and around his helmet.

Albert Einstein was a ladies man? Who married his first cousin? And he was how old when he re-invented physics?

From the cover of one of the latest Time Magazine special issues, Albert Einstein stares down grocery store shoppers and book store browsers, his iconic hair and mustache identifiable from aisles away.

Though his face may be recognizable around the world, who the real Einstein was and what he did in his lifetime may not be as familiar to all who know his name.

Time Magazine's Special issue "Albert Einstein: The Enduring Legacy of a Modern Genius" exhibits the ultimate physics superstar in 94 glossy pages packed with photos. Starting with his birth and education - including the saucy romances of his teenage years - author Richard Lacayo takes us through the genius's heyday and later years, interjecting several digestible doses of hard-core physics along the way. Lacayo intimates to us what Einstein was like as a real person - with his unkempt hair and his clot…

2011 X Games competitor Jackson Strong landed the first Motocross forward flip in competition, taking home the gold for this year's best trick event.



The forward flip is one of the most difficult moves you can pull on a motocross bike. While backwards rotating flips off a ramp are almost natural, rotating forward presents some serious challenges.

Art and physics come together again.

["A Sunday on La Grande Jatte" by Georges-Pierre Seurat. Click on the photo to see the individual dots of paint in the park scene. In her talk, Imogen Clarke used the painting to show that while the individual dots are discontinuous, the painting as a whole is continuous, much like the role of atoms in our lives.]
Last week, the American Institute of Physics (a society that, among a few others, shares our building) hosted a conference on the history of physics. A hundred or so graduate students and early-career physicists gathered to talk about topics stretching from the first uses of X-rays in medicine to the development of theory in physics.

Imogen Clarke, a PhD student of science history at the University of Manchester in the U.K., spoke Friday morning about the transition from classical to modern physics at the turn of the last century. In a talk titled "A 'Conservative Attitude'? Continuity, Discontinuity and the Contested…