Lightning Emits X-Rays

Makarand writes "Scientists have now confirmed that lightning does emit X-rays according to this BBC News article. That lightning might emit high energy radiation was first suggested in 1925, however, confirmation had proven difficult because of the sporadic nature of lightning and the electromagnetic "noise" it generates. A team at the University of Florida built a special tower allowing them to study lightning in detail by firing rockets trailed by grounded wire into storm clouds to trigger strikes. They detected X-Ray bursts that typically lasted less than 100 microseconds. The breakdown of air by strong electrical fields when the lightning creates a path from clouds to ground may generate these X-rays."

Aha!

[xyphus]

Science has finally explained why lightning always reveals Donald Duck's skeleton!

Re:Aha!

[Simon Field]

Now if we could just get him to wear pants...

Seriously, though, how do you shield your X-ray detector so you can prove to yourself that what you are seeing is not just the effect of power spikes and RF interference in your instruments?

I'm sure they did a good job of it -- but as a geek thing, I'd like to see how it was done.

Re:Aha!

[Viadd]

They had two photomultiplier tubes (PMTs): one was coupled to a scintillator (crystal that makes light when X-rays hit it), one wasn't. There was a hefty signal in the PMT that was coupled to the scintillator, the other showed a flatline.

Re:Aha!

[Christopher Thomas]

Seriously, though, how do you shield your X-ray detector so you can prove to yourself that what you are seeing is not just the effect of power spikes and RF interference in your instruments?

Almost certainly just by putting the instruments and a few batteries in a metal cage or inside a thin metal shell. Plenty of things will block radio noise without blocking X-rays.

You could get readings without any electronics at all by using something akin to the radiation sensing badges worn at nuclear power stations, but that would only tell you the total exposure, not give you intensity-vs-time information.

Re:Aha!

[maunleon]

I agree. This was not offtopic at all.

Unless funny == offtopic.

hands

[Hadlock]

hell, i could have told you this. i live in a suburb just north of dallas, from about march-november we see thunder about once a week on average. on more than one occasion i'd convince a girl you could see the bones in your hand if you held it in front of you when lightning stuck.

of course, i never actually saw this happen, a couple of the girls i told this to believed it, but it's all psychosematic in the end. telling them my dad worked on the original mamogram/soft tissue imaging systems (he did, his name is on a couple of patents for the original mamogram) helped with my credibility considerably. a good, fairly original line that will get you far :)

Re:hands

[rubicon7]

psychosomatic, adjective

1 : of, relating to, concerned with, or involving both mind and body
2 : of, relating to, involving, or concerned with bodily symptoms caused by mental or emotional disturbance
---
mammogram, noun

: a photograph of the breasts made by X rays
---
Merriam-Webster can be your friend.

Re:hands

[Yarn]

What a pick up line... "Want a free mammogram, my dad invented them"

You lucky, lucky man.

Re:hands

[cperciva]

Any bright light will allow you to see the bones in your hand -- you don't need x-rays. We're really not nearly as opaque as we think we are.

Re:hands

[Hadlock]

hunh. so maybe there was a bit of truth in it afterall. my dad mentioned somthing about sparkplug sparks being about the right wavelength to go through flesh while we were changing the sparkplugs on our old '75 chevy.

Re:hands

[looseBits]

X-Rays wouldn't work anyway as your eyes can't detect them (your eyes are as transparent as your flesh to high frequency radiation). And even if our eyes were opaque, we don't percieve light that blue (our eyes are opaque to low frequencies of UV but we still can't see them).

Re:hands (OT)

[Cy Guy]

i live in a suburb just north of dallas, from about march-november we see thunder about once a week on average.

WOW! I've never seen thunder in my life. Could you describe what it looks like?

a couple of the girls i told this to believed it, .... telling them my dad worked on the original mamogram/soft tissue imaging systems helped with my credibility considerably. a good, fairly original line that will get you far :)

So how successful was this to convince them that you were also an expert at performing manual breast exams, and they should let you demonstrate on them?

Re:hands (OT)

[Hadlock]

yeah yeah, thunder, lightning. either way, it's not how it looks, it's the atmopshere, which is a very romantically "charged" one. Success rate was 100%, not that i'm particularly suave, but because i'm not one to take my chances with a girl. More than three.

Re:hands

[Thuktun]

So how many times have you been struck by lightning, anyway?

Re:hands

[Hadlock]

none, so far. i heard it's a life changing experience though.

Re:hands

[Christopher Thomas]

from about march-november we see thunder about once a week on average. on more than one occasion i'd convince a girl you could see the bones in your hand if you held it in front of you when lightning stuck.

You can do this with an ordinary flashlight, if you turn off the lights and let your eyes adjust, and if you make sure your hand covers all of the aperture.

Similar techniques were proposed for medical imaging, though both the equipment and the principles were more complicated. They looked for light that passed through you without scattering, in order to give a sharp image. It takes much fiddling to distinguish this from the scattered light that arrives just behind it.

Now THERE'S a cool job

[Anonymous Coward]

Firing rockets from a hundred-foot tower into the heart of a raging thunderstorm? And getting paid to do it? Fuckin' A, that's the life.

Re:Now THERE'S a cool job

[rco3]

Not only that, but we drive bucket trucks and Army surplus deuce-and-a-half trucks around in the sand.

The tower's only about 11 meters, though.

The real source is

[Technician]

Just my humble opinion, but in an X-Ray tube, the X-Rays are produced when high speed electrons strike a hard target (tungston in the tube). I wonder if the X-rays do not originate from the lightning strike itself, but from the high current striking the metal (the wire) that has been added to the mix in their test. Any data on a strike minus the added metal?
My guess if a strike hits a radio tower, the only portion of the bolt generating X-rays is at the point of the electrons striking the metal tower (assuming cloud negative strike). Just a hunch. I could be completely off base on this one.

Re:The real source is

[DrFlounder]

The radiation from an X-ray tube is a special case of bremsstrahlung, or braking radiation, that occurs when a charged particle is accelerated (or decelerated). Often this happens when an energetic electron is decelerated by hitting metal, but anything that changes a electron's trajectory will cause it to radiate.

The real story here is not that X-rays are emitted, but that there are high energy electrons produced by lightning (called runaways because they gain more energy from the accelerating electric field than they lose from collisions with the background particles). Existing models of lightning don't predict the creation of these electrons. In this sense, it doesn't matter what caused the electrons to radiate. What matters is that electrons were created that had enough energy to produce the X-rays, which means that our models need to be corrected.

Wrong title for story...

[tellurian]

"... by firing rockets trailed by grounded wire into storm clouds to trigger strikes."

Why isn't this story titled "Firing rockets with grounded wires into lightning clouds"? It would certainly get more attention.

...and we get paid to do it.

[rco3]

Yes, that's right, we get paid to shoot rockets into thunderstorms. It may be the coolest job I've ever had - maybe, hell! It is.

Not only that, but our launch site runabouts are Army surplus deuce-and-a-half trucks. We have another mobile launcher on the boom of a bucket truck. I've got the most kick-ass set of home movies...

Plus, of course, we work with top-notch researchers from around the world, doing real science.

Oh, and we're very pro-Linux around the ICLRT.

Did I mention we get paid? The money's not anything to start a family on, but the tuition waiver for those of us in the grad program is worth it.

Hmmm... methinks we need more website action going on.