Struck by lightning

[DFINITLYDISTRUBD]

I have a question about thunder. It is apparently caused by shock waves as superheated air expands. Does an arc welder--or a Tesla coil--not produce thunder because it doesn't heat the air enough?

But they do...the difference is size....as best I can explain is as follows a set of headphones even at full volume is dwarfed by even the most pathetic of pc speakers it's the same song same frequencies but much less air displacement...a snapper vs.a stick of dynamite...etc.etc.

 

So many persons victimized by voltage... guess I'm in good company.....safety in numbers and all that rot...course too many of us in one place at the same time would very likely ver very dangerous for all:hihi:

[lemit]

Thanks, DD. I've also heard that thunder is a sonic boom, but I can't verify that anywhere. Since there apparently are questions about the directionality of lightning, that seems unlikely.

 

I grew up with intense lightning, inadequately installed wiring, electric fences, and lots of mud. Maybe that explains why although I'm in my sixties I still have the attention span of a week-old chicken.

 

--lemit

[HydrogenBond]

Lightning is partly due to positive charge within the clouds. The aspect of lightning from the earth or ground is due to electrons. Positive charge going down is mathematically the same as negative charge going up. Unlike electricity in wires, where only electrons move, lightning is interesting because it goes both ways, observationally, while mathematically going one way. Because it uses two charges there is a canceling of charge potential as the current flows. This makes it an inefficient wire which gets hot; heat for the bang. If lightning was only due to electrons or to positive charge, lightning would be quiet.

[Qfwfq]

Thanks, DD. I've also heard that thunder is a sonic boom, but I can't verify that anywhere. Since there apparently are questions about the directionality of lightning, that seems unlikely.

It is a shock wave that soothes into a sound, so is a sonic boom, but this doesn't make them necessarily the same thing. However, if the thermal effect is mainly due to ions and propagates rapidly along the path (which can sometimes be noticed) then I'd say it could be so.

[GAHD]

Did you check you butt or heel for another burn? One of my dad's friends was hit by lightning directly, it burned a hole to the bone in his foot exiting, and he's got a bald patch on his head from the entrance. :rolleyes:

[modest]

Anyway, as you can see, 117 watts for a fraction of a sec would be schmuck if it were just heat alone. It's the chemical changes that cause the damage and of course neural stimulation stuns and causes wild contractions.

 

I'm still not quite getting this. I know power in watts is equal to voltage time current, but power is a function of time. We didn't figure current as a function of time—we just figured that the total current would have to be below a certain value. Since the total current would have been less than a second, would that make the total power necessarily larger than 117 watts?

 

I think it would. If the current were 70 mA and it lasted for 1 second with a voltage of 1,666 V, I think that would make for 117 watts. But, less time would make for more. Of course, the current is the same in either case, and I think total current would be proportional to total tissue damage rather than power.

 

Would that be right?

 

 

 

how ya feelin' now sparky? :eek: any new quantifiable effects that you can relate to physics?

 

No, but this could be an ongoing series at Hypography. "What physics experiment has Modest made of his body this week". :hyper:

 

Well, today I subjected myself to a magnetic field of 10 teslas. :rolleyes:

 

 

 

 

 

Did you check you butt or heel for another burn? One of my dad's friends was hit by lightning directly, it burned a hole to the bone in his foot exiting, and he's got a bald patch on his head from the entrance. ;)

 

Yikes! That is scary.

 

The only burn, I checked well, was on my ear. My foot was tingling after the incident (like my head, neck, and shoulder), but no burn there. I can't say as to why. I don't recall how my feet were situated except that I was barefooted on hardwood flooring.

 

~modest

[Jay-qu]

I'm still not quite getting this. I know power in watts is equal to voltage time current, but power is a function of time. We didn't figure current as a function of time—we just figured that the total current would have to be below a certain value. Since the total current would have been less than a second, would that make the total power necessarily larger than 117 watts?

 

I think it would. If the current were 70 mA and it lasted for 1 second with a voltage of 1,666 V, I think that would make for 117 watts. But, less time would make for more. Of course, the current is the same in either case, and I think total current would be proportional to total tissue damage rather than power.

 

Would that be right?

 

Let me break down the units to make it a bit more transparent for you:

 

Power is measured in Watts (W) = joules per second (J/s)

Current is measured in Amps (A) = coulombs per second (C/s)

Volts, voltage, potential difference are measure in Volts (V) = joules per coulomb (J/C)

 

If you didnt know already a coulomb is essentially an amount of electricity (more correctly charge) which corresponds to 6.2x10^18 electrons.

 

So current measures the speed or amount of charge passing through something and potential difference (voltage) tells you how much energy those electrons lost over their path.

 

So if you take those two and multiply them together, and just look at the units:

 

current * voltage = [C/s] * [J/C] = [J/s]

 

You get joules per second, a measure of how much energy was deposited in a system per second.

 

Hope this helps

[modest]

We didn't figure current as a function of time

 

Current is measured in Amps (A) = coulombs per second (C/s)

 

 

I am so ridiculously embarrassed.

 

Thank you, Jay.

 

~modest :)

[lemit]

Did you check you butt or heel for another burn? One of my dad's friends was hit by lightning directly, it burned a hole to the bone in his foot exiting, and he's got a bald patch on his head from the entrance. :hihi:

 

I knew there was something missing from this discussion. Of course, Almighty GAHD, deliverer of lightning bolts, would remember that electricity doesn't somehow get absorbed by the body. The electrical input and output should be just about the same. Sometimes the exit point can be just that, not much more than the head of a pin, or at least that was the case with Missouri lightning.

 

I remember hearing a joke in High School about an inept railroad employee who was struck by lightning and not bothered in the least because he was just that bad a conductor. Modest, have you ever worked for a railroad?

 

--lemit