The Physics in Mosh Pits

source: http://news.nationalgeographic.com/news/2013/2/130219-heavy-metal-physics-particle-mosh-pit-science-music/Heavy metals in science are elements on the lower part of the periodic table. But to two researchers, heavy metal as the aggressive music genre can be the answer to deciphering extreme situations like panicking and uncontrolled crowds during emergencies, natural catastrophes and everyday disasters.

Older people might never get the liking of younger people’s affinity to head-banging rock and roll type of music and concerts, but to Matt Bierbaum and Jesse Silverberg-both in Cornell University’s department of Condensed Matter Physics as doctoral students-the loud and chaotic happenings and violent dancing contain answers to scientific human behavior and of physics. Ever since the year 2011 and 2012, Bierbaum and Silverberg had done research and studies at unlikely places for scientific matters -heavy metal concerts. The two used theories of collective motion and physical properties of gasses to have a clearer understanding of the metal-heads’ chaotic dancing. Moshing is a way of dancing wherein concert goers or rock and roll fans slam bodies with one another. Anthropologies have compared this type of wild dancing to possessions of spirits for its dynamic and violent nature. Silverberg and Bierbaum were interested on how humans behaved in similar excited states as of gaseous particles. Gaseous particles float in groups, like people in mosh pits; they also bash, bump and run into each other which send the elements flying around in chaotic patterns.

The scientists were provided by mosh pits a way to observe collective movement of people without causing death or injury. The two have recorded hours of footage from different concerts and several trips to bars and clubs where Heavy Metal or rock bands play. Bierbaum and Silverberg, after analyzing what they have caught on tape, recognized the particulate physical patterns in mosh pits. Two forms of heavy metal dancing were differentiated: the mosh pit, which follows the gaseous pattern and the circle pit wherein metal heads bump and slam and dance together in circular rotations that adheres to a vortex pattern of particulate behavior. With these observations, the two scientists made a computer model that interacts and depicted the behavior. Animals that have herds have the same spirit as the molecules and heavy metal goers. Simple rules can be made to individuals in crowds and big groups to better know and unriddle what looks to be such complicated behavior, just like a school of fish, a flock of migrating birds, a pack of wolves or a herd of buffalos. With this, modeling is possible where computers are allowed to re-create huge number of actions in a matter of a few seconds. Models can then be used to design spaces that will lessen injury and trampling on bodies and to better responses to natural and man-made disasters such as fires and bomb attacks.

Silverberg, a true blue heavy metal music fan himself, shared which band produced the best results to his and Bierbaum’s research: “Killswitch Engage, always gets the crowds ballistic and all over the place, but of course, everyone else has their own favorites.”

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The Beating Heart of “Father Time”

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Photo by Andrew Brookes/National Physical Laboratory

National Physical Laboratory (NPL)–the place where the first atomic clock was made, have made recent development in ways to measure time even more accurately. According to their website, the current atomic clock system at NPL is the basis of all UK time, and the cutting-edge research being carried out is working to improve timekeeping accuracy even further.

Scientists at NPL built a super-accurate timekeeper, an optical atomic clock that promise significant advances than the ones that uses microwave frequencies.

When it comes to stability, optical atomic clocks are more reliable than atomic clocks operating at microwave frequencies because visible light has a frequency roughly 100 000 times higher than that of microwaves.

Potential applications of atomic clocks range from improved satellite navigation systems and better tracking of deep space probes to sensitive tests of general relativity and measurements of fundamental physical constants. They could even lead to the SI unit of time, the second, being redefined in future.

But how does this device work?
Every tick of this “clock” is governed by a single ion of the element strontium. This ion is trapped in an electromagnetic field within the small cube at the center and cooled with lasers to just fraction above absolute zero. The lasers are fired through three of the glass emanating from the cube, but must be carefully directed out of the other side to prevent them scattering within the clock, which is why there are six shafts in total, as reported by Jacob Aron.

Once the ion is cooled, another laser makes it resonate between two energy states with an incredible regularity governed by quantum mechanics. It gives off a regular pulse of optical radiation exactly 444, 779, 044, 095, 485 times per second, said in an article published online by Newscientist.com.

Thanks to NPL’s caesium fountain, NPL-CsF2, the currently most accurate clock in the world, able to measure the SI second more precisely than any other clock. This conclude that NPL plays a major role in the worldwide accurate time systems.