<![CDATA[Jalopnik: Physics]]> http://cache.gawker.com/assets/base/img/thumbs140x140/jalopnik.com.png <![CDATA[Jalopnik: Physics]]> http://jalopnik.com/tag/physics http://jalopnik.com/tag/physics <![CDATA[ Traffic Jam Torment: Physics Proves That Bottlenecks Are Bulls**t ]]> Traffic_Jam.jpgTraffic jams stand no chance under the onslaught of giant throbbing Japanese physicist brains! Well, to be accurate, physicists from the Land of the Rising Sun haven't exactly cracked the traffic-jam conundrum. But they have figured out why it took me four mother!@#$ing hours to crawl up the mother!@#$ing I-5 from San Diego to L.A. last week.

It's my own fault for choosing to live and drive in SoCal and on certain occasions regrettably choosing to drive to drive on major freeways between 3 and 7PM. Thanks the Lords of Cobol that I now have an explanation. No more will I pound my forehead helplessly into the steering wheel of my '98 Saab, baffled, dismayed, enraged, confused as I stab fruitlessly at the radio, trying to find a traffic-jam-compensating soundtrack of Cool Jazz.

Knowledge is power. Here's what the Japanese researchers discovered and published this month in The New Journal of Physics, under the rubric "Traffic jams without bottlenecks—experimental evidence for the physical mechanism of the formation of a jam":

A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam.

In a nutshell, when you're trapped in the keening hell that is a traffic jam, it's pointless to salivate over the eventual, if sort of inverted, money shot: the final witnessing of the bottleneck that caused all the trouble. Coz the bottleneck isn't a cause; it's merely a symptom of the inherent instability of a whole mess of particles (cars) interacting (driving) in a flow state (on the freeway).

Upshot? Traffic jams are a "physical phase transition"—put too many cars on the road and they just happen. Get past a point of "critical density" and you're gonna find yourself inevitably offering nasty opinions of the other guy's mama.

Obviously , this throws a wrench into the idea that uniform speed flows can solve the problem. Still, according to this report, the sacrifice of free will to the Skynet might be the answer.

Don't you just effing love science?

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Jalopnik-363736 Tue, 04 Mar 2008 15:45:00 EST Matthew DeBord http://jalopnik.com/index.php?op=postcommentfeed&postId=363736&view=rss&microfeed=true
<![CDATA[ Foot-Pounds vs. Newton Meters: Jalopnik Goes to School ]]>

So we mentioned in our R10 post from earlier that we didn't get the whole lb. ft. And because our addled little brain is somewhat screwy when it comes to physics (we did well in Honors Bio but struggled through high-school Chemistry and didn't bother with physics if it involves math, forget it). And we could've saved ourselves a lot of embarrassment if we'd just looked up a conversion table on this glorious interweb at our fingertips. But we didn't. Anyway, kindly reader Weston writes in and explains the whole damn thing. Click through to humiliate us further.

I'm hoping you guys were kidding when you said that you couldn't figure out the conversion from Newton*meters to foot*pounds. If not, I'll explain it. First of all, Newtons and pounds are both units of force, not energy, and 1 Newton = 1 (kilogram*meter)/seconds^2. Therefore, you can write 1100 Newton*meters as 1100 kilograms*(meters^2/second^2). Next, you convert kilograms to slugs, the English unit of mass, by multiplying by approximately 0.0685. Then, you convert square meters to square feet by multiplying by approximately 10.764. It looks like this:

1100 kilograms*(meters/second)^2 * 0.0685 slugs/kilogram * 10.764 feet^2/meters^2 = 811.07 slugs * (feet/second)^2

Since slugs*feet/second^2 is pounds, this turns into 811.07 foot*pounds or 811.07 pound*feet, whatever you prefer. Sorry for the science lesson, but I thought you might want to know. You could also take the easy way out and just type "1100 N*m to ft*lb" into Google (without the quotes, obvs) to get 811.32 foot*pounds. Car companies should consider listing torque in slug*feet square/second squared because "slug" sounds more manly than "pound".

Related:
Audi R10 Propaganda Broadside [Internal]

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Jalopnik-161165 Fri, 17 Mar 2006 00:22:42 EST Davey G. Johnson http://jalopnik.com/index.php?op=postcommentfeed&postId=161165&view=rss&microfeed=true