All Questions
Tagged with electricity lightning
116 questions
39
votes
1
answer
2k
views
Can lightning be used to solve NP-complete problems?
I'm a MS/BS computer science guy who is wondering about why lightning can't (or can?) be used to solve NP complete problems efficiently, but I don't understand the physics behind lightning, so I'm ...
- 525
30
votes
4
answers
3k
views
What causes the direction of lightning flashes?
During a lightning strike, the flashes appear as cloud to ground or cloud to cloud. Why is this the only manner of propagation? Why do the flashes not go upwards from the clouds into the sky?
- 1,774
30
votes
6
answers
48k
views
Lightning strikes the Ocean I'm swimming in - what happens?
I'm swimming in the ocean and there's a thunderstorm. Lightning bolts hit ships around me. Should I get out of the water?
- 463
25
votes
4
answers
50k
views
If air cannot conduct electricity, how can lightning happen?
If air cannot conduct electricity, how can lightning happen?
- 277
24
votes
1
answer
5k
views
Is it possible to overload a lightning rod?
A couple of weeks ago we had a big storm roll through the Chicago area. I watched as the city's skyscrapers were struck multiple times by lightning throughout the night and told my coworker about it ...
- 351
19
votes
4
answers
27k
views
Does Fire Conduct Electricity? Why?
Recently, I have stumbled upon a YouTube video by Veritasium describing the conductivity of fire. My question is: how exactly does fire conduct electricity? I am a high school student; therefore ...
- 317
15
votes
3
answers
7k
views
Tree vs lightning rod: why does one burn and the other not?
I have this simple question, but I cannot find the answer.
I saw this video about a plane getting hit by lightning. In it, Captain Joe explains why people do not get electrocuted. This has a simple ...
- 314
15
votes
5
answers
19k
views
Why do lightning rods have a sharp point at the top?
We know that a lightning rod or lightning conductor is a metal rod or metallic object mounted on top of an elevated structure and, if we look closely, most of them have a sharp point at the top. What ...
- 1,850
13
votes
5
answers
4k
views
Why does lightning generate multiple branches?
Everyone have seen and knows how lightning occurs. But then I realized that lightning never occurs in straight lines but it follows branching. But Why is that so? Why can't lightning goes in straight ...
- 1,850
12
votes
6
answers
16k
views
Why does lightning emit light?
What exactly is causing the electric discharge coming from the clouds to emit light while traveling through the air. I've read and thought about it a little but with my current knowledge I cant really ...
- 758
12
votes
4
answers
75k
views
Can Gases conduct Electricity?
Liquid electrolytes ionize and hence a current can pass through them. So if a gas can ionize, can it conduct electricity too? If so, what are a few such gases?
- 833
11
votes
5
answers
854
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How could lightning have killed 322 reindeer at one time in Norway?
Lightning is supposed to have killed 322 reindeer within an area that's about 50-80 meters in diameter on a mountain plateau in Norway. Nearly the entire herd died.
Sources: (1, 2, 3, 4)
Photo: ...
- 656
11
votes
3
answers
2k
views
Is it possible for a lightning strike to hit the ground if there are high rise buildings nearby?
Say we have pointed conductors connected to the top of the high rise buildings. Will the strikes hit the nearby ground in such a case?
- 672
9
votes
3
answers
8k
views
Tying knots in power cables to prevent power surge from lightning strikes
There are plenty of references to this claim on the internet that tying knots in power cables will prevent a piece of equipment e.g. television or computer from a power surge.
How can this be ...
- 191
8
votes
5
answers
27k
views
Can the lightning be captured and used as power source?
I would like to update my knowledge in this area, that is really out-of-dated and stopped somewhere like ten years ago.
I asked the very same question on my physics lecture at my studies and got the ...
- 258
8
votes
1
answer
70k
views
How much energy is in a lightning strike?
According to Wikipedia an average lightning strike has $1$ TW power, the whole world used $16$ TW of power in 2006.
The lightning strike lasts for $30$ microseconds. Does this mean that you get $100$...
- 495
8
votes
1
answer
7k
views
Does rubber insulate lightning more effectively than air?
Last week, an Ars Technica writer was struck by lightning. He says that the 911 operators were concerned about whether or not he was wearing shoes at the time, but he didn't think it would make much ...
- 183
7
votes
2
answers
14k
views
How does lightning "know" where to go?
If lightning comes down in, say, a large flat field with a lightning rod sticking out of the middle, the lightning will strike the rod.
How does it "know" the rod is there?
Will it always strike the ...
- 1,554
7
votes
1
answer
636
views
Why can't we generate electricity from Earth's electric field?
This may be very silly, but I need to understand this to get my concepts right.
Consider the fact that the electric field b/w the Earth's surface and the ionosphere is on an average $100$ V/m, then ...
- 73
7
votes
2
answers
683
views
What causes the color difference of lightning flashes?
Some flashes of lightning are seen in a blue shade while some have a yellowish/orange appearance .What is the possible cause of colour difference?
- 1,774
7
votes
1
answer
712
views
Why doesn't lightning stop when it starts raining?
According to my understanding, lightning happens because the clouds get charged due to friction from the moving clouds and the ground gets polarized by the nearby charged clouds. And the two opposite ...
- 176
6
votes
2
answers
23k
views
Do high voltage power lines attract lightning strikes?
I always thought that high voltage power lines would attract a lightning strike more than other structures in the same area. Turns out I was wrong. My neighbor's chimney got struck by lightning and it ...
- 63
6
votes
1
answer
2k
views
Does a Tesla coil work in space?
If I took a Tesla coil into space, and then turned it on near, but not touching metal objects- would charge jump to the metal objects? It's my understanding I wouldn't see a flash, since the lightning ...
- 175
5
votes
1
answer
9k
views
Noise heard simultaneously with lightning
During a recent thunderstorm in an urban area, I saw lightning strike within about half a mile, estimated as such because I heard the thunder about 2 seconds after I saw the strike. What surprised me ...
- 10.4k
5
votes
2
answers
10k
views
Is wearing metal armor during lightning safe?
I recently saw in a television show that wearing a metal armor during lightning is good because metal provides the path of least resistance for electricity to flow to the ground. Now my question is,is ...
- 785
5
votes
1
answer
4k
views
Would rubber shoes offer any form of protection against cloud-to-ground lightning strikes?
I was reading an article from abcnews about Why so many people survive being struck by lightning. Later in the article it says the following:
But direct strikes make up only a minuscule portion of ...
- 51
5
votes
3
answers
27k
views
Lightning Conductor Working
During a thunderstorm charges collect on clouds until a field which is more than the air's dielectric strength is created. Because now there is a potential difference between the ground (0 Volts) and ...
- 467
5
votes
0
answers
395
views
Lightning through helium gas
Assuming that some distant planet had an atmosphere of helium and(due to extremely cold temperatures) a "water cycle" of neon, what would happen if the theoretical neon clouds acted in a ...
- 51
4
votes
3
answers
2k
views
How did a spark generate electromagnetic fields that radiate to places?
In the video and pictures below, this guy is trying to replicate Hertz's experiment to generate electromagnetic fields from a dipole antenna. How did a spark generate electromagnetic fields? I thought ...
- 364
4
votes
2
answers
1k
views
Algorithm of Lightning Strikes? [duplicate]
Given an array of charge for a given area (2D or 3D), what algorithm would describe the path that lightning takes?
An example algorithm would be from the highest charge of the cloud, find the lowest ...
- 41
4
votes
2
answers
7k
views
Is it possible to calculate the energy of a spark?
I am not a physicist, but this question came to me and I need to answer it, and I think that you guys can help me.
Is it possible to calculate the energy in a spark? For example in a lighter with ...
4
votes
2
answers
3k
views
Could you use magnetic fields to direct a bolt of lightning?
Would it be possible to direct the flow of electrons in a lightning bolt in a certain direction, using magnetic fields?
Furthermore, would it be possible to direct the lightning in a long straight ...
- 141
4
votes
0
answers
251
views
What happens to the positive charges in the cloud after a lightning discharge?
The clouds before a lightning strike contains ice crystal at upper part of the cloud that is positively charged and lower part of the cloud becomes negatively charged. When enough electrons ...
4
votes
0
answers
160
views
Why do lightnings generated by a tesla coil also move upwards?
I was recently watching some videos of Tesla coils, and the behavior of the rays caught my attention. In the picture below, you can see how the coil is emitting lightnings, some of them towards the ...
4
votes
1
answer
278
views
At what distance is lightning dangerous for someone lying down?
My 8 yo child told me that they learned at school that they should lay down flat on the ground in case of lightning. I told him that the more correct position is crouching down with feet together, but ...
- 518
3
votes
2
answers
782
views
How much energy is transferred to a human hit by lightning?
Wikipedia tells me that a bolt of lightning releases roughly 1 GJ of energy, but I'm guessing that's along the entire length of the bolt and that most of it is dissipated as heat and light to the ...
3
votes
1
answer
5k
views
What is the difference between electric spark and electric arc?
In my student book they separate these two and indicate that sparks need high voltage to occur while arcs need low voltage with normal or low pressure and electric arcs CAN come with heat and bright ...
- 59
3
votes
2
answers
397
views
Loopy lightning
What causes lightning to follow the path it does ?
picture from BBC news: http://news.bbcimg.co.uk/media/images/62891000/jpg/_62891901_untitled-1copy.jpg main page: http://www.bbc.co.uk/news/in-...
- 869
3
votes
1
answer
3k
views
What is the average range of voltage of lightning in sky?
I wondered how much energy is required to produce , such a loud sound? What is the average range of voltage in sky? Is there any possible way to store it ,and use when needed?
- 803
3
votes
1
answer
398
views
Does lightning have a thickness?
We have calculated (probably measured) the speed, temperature and voltage of lightning so does lightning have a thickness?
Note:
When a lightning occur it heats up the air rapidly causing the air to ...
- 13.1k
3
votes
1
answer
761
views
Why is lightning going from the Earth to the clouds while the electrons are going from the clouds to the Earth?
The lightning is often a discharge in advance. The (negative) charge slide occasionally a little further on in the conductive channel, wherein said channel is highlighted each time something. The ...
- 3,368
3
votes
1
answer
297
views
Electricity from lightning
According to the internet, a lightning strike contains about 5 billion joules or 5 GJ. How was this calculated?
Another thing: Once the lightning strike a metal grounded rod, a current will flow. ...
- 413
3
votes
0
answers
73
views
Nature of electricity [duplicate]
Suppose a lightning strikes and there is an iron rod and a coconut tree. How does the electricity know that rod is the least resistant path before hand.
2
votes
3
answers
352
views
Lightning Power?
What is the power source of a lightning? It doesn't consume fuel, nor an atomic fission/fusion, but it discharges a large amount of energy. Is it feasible to create an artificial lightning using the ...
2
votes
1
answer
2k
views
Can lightning actually weld fillings in your teeth?
So, I remember sometime in my childhood, someone was teaching me about lightning safety, and they explained that it was important to crouch low but keep as little contact with the ground as possible, ...
- 127
2
votes
1
answer
3k
views
Why do nuclear bomb explosions create an array of visible electric discharges in the form of lightening in the upper atmosphere?
I've seen videos on the internet, showing nuclear bomb test explosions, and there appears to be a large amount of visible lightening discharging numerous times over the development of the mushroom ...
- 448
2
votes
1
answer
2k
views
Danger to swimmer from lightning?
Having been swimming a few times recently when a thunderstorm developed, I've started wondering what the actual dangers are (please note - I'm more interested in this from a science perspective; I get ...
- 141
2
votes
2
answers
1k
views
Why do my lights become brighter during a thunderstorm?
Today, during a thunderstorm, the lamps in the room suddenly flickered and then gradually became brighter in less than a second. The lamps remained brighter than normal for a few seconds before ...
- 69
2
votes
4
answers
2k
views
What could cause a small shock from an umbrella being held near a lightning strike?
I was just outside holding an umbrella when lightning struck very close by. In the instant it struck, I saw and felt a little shock from the shaft of the umbrella into my thumb. It felt quite small.. ...
- 21
2
votes
1
answer
230
views
How are electric sparks produced?
Here's what I have understood so far.
(Im talking about electric spark we see in a gas lighter,as shown in the picture)
When high voltage is generated at the central metal piece, electrons fly off ...
- 1,306