Monday, July 19, 2010

Cosmic rays explode tree at American Center for Physics?

According to the NOAA, lightning has been witnessed in volcanic eruptions, intense forest fires, surface nuclear detonations, snowstorms, large hurricanes, and now the American Center for Physics parking lot. Well, I didn't see it, but this tree did (or at least it would have if it had light-detecting organs).

Sometime over the weekend this little guy experienced an arboreal nightmare as hundreds of millions of volts of electricity shot through his body. Lightning strikes can be as much as 5 times hotter than the surface of the sun, and in an instant, that heat turned water into steam inside him-splitting his trunk vertically through his core and sending bark flying at least 50 feet in various directions.

Lightning strikes like this happen 4-million times a day on our planet, yet no one's sure what causes it (even the folks who park in this same parking lot).

According to this Scientific American post by lightning expert and physicist Joseph Dwyer, no measurement made inside a thunderstorm has ever found a strong enough electric field to cause a spark. However, some scientists-including a Russian physicist named Alex V. Gurevich-believe cosmic rays could stir movements of "large showers of energetic particles" and provide a conductive path that might possibly initiate a lightning strike.

Dwyer says that this phenomenon can be seen in spark chambers. When a significant voltage is applied across a gap it will spark, given that there are sufficient free electrons to start the process. However, as we've already established the electric fields inside of thunderstorms aren't big enough to cause a spark. To solve this with cosmic rays, Gurevich theorizes a process called runaway breakdown is occurring inside a thunderstorm.

"Runaway breakdown occurs when the drag force that electrons experience moving through air is less than the electric force acting upon them. In such cases, the electrons will "run away," gaining very large amounts of energy. As the runaway electrons collide with air molecules, they generate other runaway electrons plus x-rays and gamma rays, resulting in an avalanche of high-energy particles. Instead of rocks in a landslide, think of the runaway electrons as shrapnel tearing up a path through the storm cloud. According to the Gurevich model, this conductive path is what causes lightning.

Runaway breakdown can create large amounts of high-energy electrons, as well as x-rays and gamma rays. Interestingly, we know that runaway breakdown works for the low electric fields already seen inside thunderstorms. We also know that it does sometimes happen right before lightning, because we can see big bursts of x-rays and gamma rays shooting out of thunderstorms. In fact, these gamma rays are so energetic and so bright that they have been observed from outer space, 600 kilometers (373 miles) above Earth's surface."

Of course this still isn't proof and Dwyer himself goes on to voice skepticism about whether or not this is the solution. But I'm still sticking with my attention-grabbing, overly-speculative and wholly-unsubstantiated headline all the same. I'll even throw in this sweet Youtube video of what it might have looked like.

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