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Showing posts from September, 2007

Farewell from alpinekat

Well folks, this is it. I am leaving the APS for a temporary position at CERN, living among the mountains whose name I share. The alpinekat will become an endangered species on the Physics Buzz, but not quite extinct as I may make an occasional post about the goings-on with the new Large Hadron Collider.

In any case, thanks for reading (both of you).

Over and out!
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Image credit: flickr's peuplier

A Knotty Problem: Curly Hair vs. Straight

My sisters always wanted curly hair, but they were cursed with fine, straight blond hair from the Scandinavian part of our ancestry.

But I've known lots of people with curly hair who wished their hair was straight. Overall, I assumed it was just one of those things where the grass is always greener on the other side.

Well it seems I was wrong. Apparently the grass is truly greener -- on the curly side of the fence (no matter what you curly-haired folks say).

According to research published in the August 2007 American Journal of Physics, curly hair is less likely to get tangled than straight hair.

Jean-Baptiste Masson of the Laboratory for Optics and Biosciences at the Ecole Polytechnique in France developed a theory to describe hair tangling and confirmed his results by asking French hairdressers to count tangles in different types of hair that they encountered at work. (I wonder how he managed to track down enough hairdressers in Paris . . . oh, wait a minute, never mind.)

Masson h…

Pancakes with your nuclei?

A nucleus of protons and neutrons. Luckily, the liquid drop model of atomic nuclei is not specific about the liquid represented. New research to be published in Physical Review Letters shows that while the protons and neutrons in a nucleus are ordinarily like a drop of water, they're more like syrup if you give them an energy boost.

The liquid drop model basically says that the protons and neutrons in a nucleus are like the particles in a drop of liquid. The particles at the edge of a droplet are subject to different forces than those on the inside, namely surface tension. This attractive force pulls nuclei and water droplets alike into spherical shapes. Water droplets, held together by surface tension.

Viscosity is a measure of a liquid's resistance to flow. To bastardize a proverb, blood is more viscous than water. Luckily, the physicists who discovered the increasing viscosity of nucleons (protons and neutrons) chose a more pleasant viscous fluid.

Measuring the viscosity …

Physics (and firehoses) Levitates Car

OK, this is ridiculously cool. Click the video to see for yourself.

I liked it so much that I have nothing to say other than "Thank you, Isaac Newton."

Scientists Study Structures in Steamy Springs

Say that title five times fast, I dare you. But seriously, folks, a pair of physicists from the University of Illinois recently published research concerning the formation of limestone structures in the thermal springs of Yellowstone National Park. While their discussion also touched on the terraces, I'm sticking to domes and stalactites. If you want to know more, the article will be published soon in Physical Review E.
Making Travertine

The particular type of limestone is a porous calcite called travertine. Water seeps downward through the soil, eventually coming into contact with hot gasses rising from a magma chamber. These gasses heat the water and infuse it with carbon dioxide (CO2). Combining with water (H2O), carbonic acid forms (H2CO3).

Rising up through limestone layers, the weakly acidic water dissolves the limestone and gathers calcium ions. The carbonic acid loses a positive hydrogen ion and begins to react with the calcium in the water, forming calcium carbonate (…

The Art of Sliding

I say the "art" of sliding because I don't understand all the physics that goes into it, but here's a look at getting more speed on slides both wet and dry. If you understand more of the physics, feel free to enlighten us. I've been bothering my superiors with these questions all morning.

Last weekend, Greenbelt, MD held its annual Labor Day festival which was an interesting slice of small-town Americana in the midst of the sprawling DC suburbs. Still unable to resist the lure of the rides at the age of twenty-something, I acquired a wristband and rode. When some ten-year-old kid zipped past me on the Giant Slide, the manager at the bottom handing out the burlap bags advised me to lift myself onto my hands and heels, getting my rear off the bag. Lo and behold, it worked.

Why? Beginning mechanics courses teach us that friction doesn't depend on surface area, so shrinking my points of contact shouldn't make me go any faster. However, they always note th…