Moving while lighting, will be induced current in me?

AI Thread Summary
Moving during a lightning storm does not significantly increase the risk of induced current in a person, as lightning strikes are brief and the current primarily affects nearby conductive materials rather than the human body. A person standing still can still experience voltage due to the potential gradient created by a lightning strike, especially if their feet are not on the same equipotential line, which can lead to dangerous current flow through the body. The concept of induced current does not require a closed circuit; rather, the changing magnetic fields associated with lightning can affect electric charges. Most lightning is negatively charged, creating a potential difference between the cloud and the ground. In summary, while the risk of injury exists, standing still may not necessarily result in a shock if positioned correctly.
Physicsissuef
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ometimes people say that if you moving while lighting, there will be current induced in you, and you'll die, is it correct, and if so how the electrical circuit is closed? (They say if lighting strikes near you, from the electrical field, if you move, there will be induced current in you)
 
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The title and first sentence don't make any sense to me. What does "moving while lightning" mean? Is English your native language?
 
What he presumably means is; Will a lightning storm induce, in a person who is moving on the ground, a current sizeable enough to kill them? If so, to where does this current flow?
 
dst said:
What he presumably means is; Will a lightning storm induce, in a person who is moving on the ground, a current sizeable enough to kill them? If so, to where does this current flow?

Yes that's was the point. Thanks for correcting me. Actually the question is: "Will a lightning storm induce, in a person who is moving on the ground, a current? If so, how the electrical circuit will be closed?"
btw-English is not my native language.
 
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Here is some http://img81.imageshack.us/img81/5092/85498790am6.jpg"
 
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Physicsissuef said:
Yes that's was the point. Thanks for correcting me. Actually the question is: "Will a lightning storm induce, in a person who is moving on the ground, a current? If so, how the electrical circuit will be closed?"
btw-English is not my native language.

No. Everyday observation should convince you this is not so.
 
Physicsissuef said:
Yes that's was the point. Thanks for correcting me. Actually the question is: "Will a lightning storm induce, in a person who is moving on the ground, a current? If so, how the electrical circuit will be closed?"
btw-English is not my native language.

First, lightning strikes do not last long enough for you to move any significant distance.
However, you don't need to move since the lightning itself is moving charges.
So yes, a current will be induced in nearby objects, like you.
Electrical circuits do not need to be closed, in the sense that you are thinking of, for a current to flow.
 
NoTime said:
First, lightning strikes do not last long enough for you to move any significant distance.
However, you don't need to move since the lightning itself is moving charges.
So yes, a current will be induced in nearby objects, like you.
Electrical circuits do not need to be closed, in the sense that you are thinking of, for a current to flow.

Do I must move, so current will be induced, or I can just stand?
 
You can just stand.
 
  • #10
NoTime said:
You can just stand.

What will happen, if I stand? I mean how the current is induced?
 
  • #11
Moving charges (the electrons in the lightning) generate a magnetic field.
The changing magnetic field, as the lightning starts and stops, moves electric charges.
The same principal that the transformer is based on.
 
  • #12
NoTime said:
Moving charges (the electrons in the lightning) generate a magnetic field.
The changing magnetic field, as the lightning starts and stops, moves electric charges.
The same principal that the transformer is based on.

Yes, that was my point. But in the transformer there is electrical circuit closed. In the lighting case, there isn't any closed circular loop.
 
  • #13
Without a closed circular loop you have potential differences. In some ways you are a battery.
 
  • #14
In the normal sense of currents, nearby lightning strikes (say 30 m away) do not induce currents in a human body. There are currents induced in fences and wires which are metallic conductors but not in the body (unless you want to define small dislocations of ions as currents).
 
  • #15
TVP45 said:
In the normal sense of currents, nearby lightning strikes (say 30 m away) do not induce currents in a human body. There are currents induced in fences and wires which are metallic conductors but not in the body (unless you want to define small dislocations of ions as currents).

If I am close (let's say 10 meters) and the lighting strikes, will current be induced in me from the magnetic field, and how the electrical circuit will be closed?
 
  • #16
It would be impossible to answer all the "what-if"s about this situation. In general, you will not see a measurable current in the body. You do not need a closed circuit in order to have a current. And, to be more correct, it is not the current that is induced in such a case, but the voltage.

Is there a point to your question? Perhaps that might be more illuminating.
 
  • #17
TVP45 said:
It would be impossible to answer all the "what-if"s about this situation. In general, you will not see a measurable current in the body. You do not need a closed circuit in order to have a current. And, to be more correct, it is not the current that is induced in such a case, but the voltage.

Is there a point to your question? Perhaps that might be more illuminating.
I do not need a closed circuit in order to have current, please explain me how?
 
  • #18
A lighting strike creates a very large potential gradient in the Earth around it. If you are standing facing the strike then chances are good that your feet will each be on the same equipotential line, and no harm will come your way.

On the other hand if you are standing such that the strike in on your left or right chances are good that your feet will NOT be on equipotential lines and you will be come a conductor. The current path would then be in one leg and out the other, this can cause potentially fatal injuries.

The case of a lighting strike is a good example of when the Earth will NOT be at zero potential.
 
  • #19
Integral said:
A lighting strike creates a very large potential gradient in the Earth around it. If you are standing facing the strike then chances are good that your feet will each be on the same equipotential line, and no harm will come your way.

On the other hand if you are standing such that the strike in on your left or right chances are good that your feet will NOT be on equipotential lines and you will be come a conductor. The current path would then be in one leg and out the other, this can cause potentially fatal injuries.

The case of a lighting strike is a good example of when the Earth will NOT be at zero potential.

So the Earth will gain potential from the lighting? I mean when lighting strikes, the protons are going up, and the electrons down. So in the air high up, there is build of positive charge (+) and on the ground build of negative charge (-), right?
 
  • #20
Forget about the protons, only electrons need be considered.
 
  • #21
Physicsissuef said:
So the Earth will gain potential from the lighting? I mean when lighting strikes, the protons are going up, and the electrons down. So in the air high up, there is build of positive charge (+) and on the ground build of negative charge (-), right?

Most lightning is what is called negative lightning where the clouds become negatively charged on the bottom and the Earth below becomes positively charged. The stroke usually proceeds down from the cloud and, as it nears the earth, a positive streamer may rise to meet it.

A small percentage of lightning is positive where the clouds are positively charged on the bottom and the Earth below negatively charged. So-called heat lightning which occurs at a distance from a storm is often this.

Integral makes an excellent point. If you are caught in the open during a lightning storm, it is important to crouch as low as possible with feet together (the bird on a wire low potential trick).
 
  • #22
Physicsissuef said:
I do not need a closed circuit in order to have current, please explain me how?

It's easy. Most science students have seen it dozens of times. Many non-science students have seen it numerous times. I'll leave it to you to think about.
 
  • #23
Is it possible that I will not get injury, if I am standing on one leg? I can't understand, why while standing I will not get "shock", is it because of the fact that I need to move among magnetic field to induce current in me, like in transformer?
 
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