[__ Science __ ] Thunder

[HeIsRisen2018]

Thunder is the result of lightning.
When there is a lightning discharge, the air is heated to a plasma state due to the enormous release of energy. That comes with a lot of noise.

Well I finally found the time to watch the whole entire video and holy crabapples! 2The title of the video wasn't misleading at all! That lightning got freakishly close and I wouldn't want to be anywhere near it! I sure hope that the people in the airplanes were alright.

 

[Jim Parker]

Well I finally found the time to watch the whole entire video and holy crabapples! 2The title of the video wasn't misleading at all! That lightning got freakishly close and I wouldn't want to be anywhere near it! I sure hope that the people in the airplanes were alright.

Here's a lightning strike on a river

 

[HeIsRisen2018]

Here's a lightning strike on a river

Wow, that's incredible! 2 I didn't think that lightning hit the open water very often, but I saw it happen twice in this thread.

 

[Razeontherock]

Wow, that's incredible! 2 I didn't think that lightning hit the open water very often, but I saw it happen twice in this thread.

Yup, just a tiny bit of salt and water attracts electricity rather well. Stick a metal pole going up some 35' to hold up sails on a boat, way out in the ocean ...

 

[HeIsRisen2018]

Yup, just a tiny bit of salt and water attracts electricity rather well. Stick a metal pole going up some 35' to hold up sails on a boat, way out in the ocean ...

Well I live near Lake Erie so I probably won't even have that kind of trouble. It's fresh water.

 

[Razeontherock]

Well I live near Lake Erie so I probably won't even have that kind of trouble. It's fresh water.

Don't be fooled! An Olympic sized swimming pool will attract electricity as soon as you go in it, due to the salt from your body getting absorbed. It doesn't take much! Now think of all the critters living in the great lakes. (I'm less than an hour from Lake Michigan myself)

That water is a potential hazard in an electrical storm. Lifeguards clear the water at the first sign of lightning with good reason!

 

[HeIsRisen2018]

Don't be fooled! An Olympic sized swimming pool will attract electricity as soon as you go in it, due to the salt from your body getting absorbed. It doesn't take much! Now think of all the critters living in the great lakes. (I'm less than an hour from Lake Michigan myself)

That water is a potential hazard in an electrical storm. Lifeguards clear the water at the first sign of lightning with good reason!

Oh yeah, I guess I didn't think about that part. Duh! 2

 

[Razeontherock]

Unless you want a free perm? No, I saw that video of lightning striking that river. Wow!

 

[Jacks Bratt]

Sounds about right except for the fact that a lot of thunder is also caused when two clouds hit each other (like in a thunderstorm) and I do believe that the friction causes the lightning strike. Of course I'm not a hundred percent certain on that one.

Can you check this for sure. From what I understand is that clouds are basically accumulated droplets of water. They have no actual solid surface that could "collide" with another cloud. It would be like colliding two handfuls of suds from your dish water.

All thunder is from lightning... It's just that we do not always see the flash.

As someone already stated, lightning burns the air and causes rapid expansion of the gasses. This is the cause.

Heat lightning, dry lightning, fork lightning, sheet lightning, chain lightning... all different ways that the static charges are released and what source and destination of the movement of the electron imbalance takes as a path.

Either way... it is one of the most visible and tangible examples of how powerful God is... It is one of my favorite things to watch and enjoy.

 

[Jacks Bratt]

Actually lightning that strikes the ground starts at the ground and goes up to the clouds. I find that pretty interesting.

I have heard this too. However, I don't think that there is any rule it must follow.

From what I understand electrons flow one way. I'm not an electrical expert but this is what I remember.

Clouds and the ground can have either a negative or positive charge. So, depending on which has what charge, the direction will always go from... I think..... the negative charge to the positive?

Have you not watched a bolt of fork lightning, like it was in slow motion, stretch across the sky and move in one direction.. Sometimes from the sky to the ground?

I bet that the majority are from the ground to the sky. However, I love watching thunderstorms and many stretch and grow and move from the sky and end up on the ground.

 

[Razeontherock]

I have heard this too. However, I don't think that there is any rule it must follow.

From what I understand electrons flow one way. I'm not an electrical expert but this is what I remember.

Clouds and the ground can have either a negative or positive charge. So, depending on which has what charge, the direction will always go from... I think..... the negative charge to the positive?

Have you not watched a bolt of fork lightning, like it was in slow motion, stretch across the sky and move in one direction.. Sometimes from the sky to the ground?

I bet that the majority are from the ground to the sky. However, I love watching thunderstorms and many stretch and grow and move from the sky and end up on the ground.

No, I have never seen lightning that reaches the ground start in the sky. The only time I've actually seen it strike was when I was looking at the ground first. Quite bright at the ground, and sudden. Then moving up slower from there. (Which is a sample size of maybe .0000001% of lightning strikes, or less)

 

[WIP]

Can you check this for sure. From what I understand is that clouds are basically accumulated droplets of water. They have no actual solid surface that could "collide" with another cloud. It would be like colliding two handfuls of suds from your dish water.

All thunder is from lightning... It's just that we do not always see the flash.

As someone already stated, lightning burns the air and causes rapid expansion of the gasses. This is the cause.

Heat lightning, dry lightning, fork lightning, sheet lightning, chain lightning... all different ways that the static charges are released and what source and destination of the movement of the electron imbalance takes as a path.

Either way... it is one of the most visible and tangible examples of how powerful God is... It is one of my favorite things to watch and enjoy.

All thunder is the result of lightning. It's the result of the super-heated air expanding at incredibly high rates of speed. You can read about it at the link I provided later in this post.

A similar thing is experienced when we clap our hands. The sound we hear is the result of the air between our hands being rapidly compressed and not from the skin colliding. To prove this point, try just clapping the heals of your hands together and you'll notice very little sound. When you clap the palms together, the shape of your hands are slightly cupped so air get trapped and compressed and the harder you clap the louder the sound as the compression happens at higher rates of speed.

No, I have never seen lightning that reaches the ground start in the sky. The only time I've actually seen it strike was when I was looking at the ground first. Quite bright at the ground, and sudden. Then moving up slower from there. (Which is a sample size of maybe .0000001% of lightning strikes, or less)

You are familiar with an 8-segment display like the image below. When a number is displayed, such as a number 6, not all parts are lit up simultaneously. Each segment is lit up in a sequence. For example, it might start with the top cross bar, then the left upper vertical followed by the left lower vertical, bottom cross bar, right lower vertical, and then center cross bar. This sequence takes place so fast that our eyes and brain are unable to detect each one independently so we see what appears to be all parts lit up at once.



Another example. Ever notice that when you look at a wheel turning, it appears to be going backwards when the vehicle was actually moving forward? This is especially noticeable with a video of a wheel. The reason for this is in how our eyes and brains process the information coming in. The wheel is spinning too fast for our eyes and brains to see it and process it in real time. Instead, our eyes and brain might capture a spoke at a particular point in its rotation and with each capture being slightly advanced or retarded in position from the previous one. If advanced or earlier in the rotation then it appears to be moving in reverse and if retarded or later in rotation the wheel will appear to be moving forward.

A lightning strike or any electrical discharge for that matter, happens in much the same way. The bolt of lightning is actually a series of short jumps that happen too fast for our eyes and brains to process in real time. What we see is actually something after the fact and what looks like a strike from ground up could actually be the reverse because it happens so fast that our brain is not able to process it in real time.

Assuming more accepted electron theory (there are some that still hold to the conventional flow theory or hole theory), all electrical strikes are the result of electrons traveling from a highly negative charged area (excessive electrons) to a highly positive charged area (lacking electrons). In most cases but not all, when lightning strikes between clouds and the earth, it is usually the result of electrons flowing from clouds to the earth but our eyes and brains may see it and process it in reverse.


Here's an explanation that I found online at the National Severe Storms Laboratory website. Hope this makes sense.

Does lightning strike from the sky down, or the ground up?
The answer is both. Cloud-to-ground lightning comes from the sky down, but the part you see comes from the ground up. A typical cloud-to-ground flash lowers a path of negative electricity (that we cannot see) towards the ground in a series of spurts. Objects on the ground generally have a positive charge. Since opposites attract, an upward streamer is sent out from the object about to be struck. When these two paths meet, a return stroke zips back up to the sky. It is the return stroke that produces the visible flash, but it all happens so fast - in about one-millionth of a second - so the human eye doesn't see the actual formation of the stroke.

 

[Jacks Bratt]

No, I have never seen lightning that reaches the ground start in the sky. The only time I've actually seen it strike was when I was looking at the ground first. Quite bright at the ground, and sudden. Then moving up slower from there. (Which is a sample size of maybe .0000001% of lightning strikes, or less)

Hmm, it's quite a sight.... I have, many times , watched as a bolt of lightning walks it's way to the ground, forking out in three or more bolts.

I think that it has to do with whichever location is positive and which is negative. Clouds can be positive or negative. This is where you get cloud to cloud strikes. Ground can be positive or negative and this is where, I believe, you would see a bolt go whichever direction is dictated by the polarity of the ground and cloud.

 

[Barbarian]

Yes, it can go both ways, but generally, the bolt comes down from the cloud. But not always. It depends where the negative charge builds up. It is the excess electrons that ionize the air, and that is what you are seeing. Ionized atoms of gas give off light.

 

[WIP]

Hmm, it's quite a sight.... I have, many times , watched as a bolt of lightning walks it's way to the ground, forking out in three or more bolts.

I think that it has to do with whichever location is positive and which is negative. Clouds can be positive or negative. This is where you get cloud to cloud strikes. Ground can be positive or negative and this is where, I believe, you would see a bolt go whichever direction is dictated by the polarity of the ground and cloud.

Actually, the ground's polarity doesn't change that much. It is the passing of electrons from one cloud formation to another that creates the imbalance of negative and positive charges in the atmosphere. Remember, a positive charge is the lack of electrons. When those charges build up enough to overcome the resistance of the air between, the discharge occurs and this is the lightning. If that charge in the clouds is positive relative to ground the electrons can flow up and vise versa.

I've also shared earlier that it typically takes about 100,000 volts to overcome the resistance of air in a 1/4" gap. This can vary a little depending on what contaminants are in the air but essentially, this figure is pretty close. So, when lightning is crossing a mile or two through the air, imagine the level of voltage we're talking about. It can be in the millions or even billions of volts.

 

[jasonc]

Actually lightning that strikes the ground starts at the ground and goes up to the clouds. I find that pretty interesting.

cloud to cloud, and also ground to air and air to ground. I live near the lightening capital of the world and the test site was on blanding where I often trained. I saw that facility once. lets wait for a storm and launch st rockets with a wire attached and observe. once that place caught on fire . imagine that

 

[jasonc]

Actually, the ground's polarity doesn't change that much. It is the passing of electrons from one cloud formation to another that creates the imbalance of negative and positive charges in the atmosphere. Remember, a positive charge is the lack of electrons. When those charges build up enough to overcome the resistance of the air between, the discharge occurs and this is the lightning. If that charge in the clouds is positive relative to ground the electrons can flow up and vise versa.

I've also shared earlier that it typically takes about 100,000 volts to overcome the resistance of air in a 1/4" gap. This can vary a little depending on what contaminates are in the air but essentially, this figure is pretty close. So, when lightning is crossing a mile or two through the air, imagine the level of voltage we're talking about. It can be in the millions or even billions of volts.

amperage is also deadly

 

[Barbarian]

The spark that jumps from a doorknob to your hand has a huge voltage. But it has so little amperage that it won't hurt you. It will fry delicate electronics, though.

As Jason says, amperage is the killer.

 

[WIP]

amperage is also deadly

Now you're getting into Ohm's law. Voltage by itself is not necessarily deadly. It is the current through the heart that disrupts the beating of our heart. We can withstand pretty high voltage without serious risk (on average). For example, ever get a shock from an engine spark plug? Typical voltage for vehicles from the days of points and condensers was somewhere around 30,000v. I'm not sure about today but based on spark plug gaps I'm guessing 50,000 is not far off. Yet, it is possible for a person to be at serious risk with voltages as low as 110v. Why is that? It has to do with the amount of current that is capable of passing through our heart.

A typical dry human body from finger tip to finger tip has a resistance of about 100,000 ohms. A typical current that is lethal is about 100mA. Using Ohm's law we can do the math to determine the likely lethal voltage given these values. Ohm's law says E=IR where E=volts, I=Current (amps), and R=resistance. With a 100,000 ohm resistance and a lethal current of 100mA (.1A) we can calculate the lethal voltage required.
100,000 x .1 = 10,000v

As you can see by this formula, the higher the voltage, the higher the amount of current that can overcome the resistance. In the same way, as resistance drops so does the amount of voltage required to "push" a deadly current through our body.

The thing is, one must remember that these values are typical and not necessarily always true. There are many variables that affect this such as moisture and other contaminants that can lower our body's resistance. For example, body sweat contains a lot of salt and salt is a conductor which means it lowers our resistance therefore a lower voltage could become deadly. Every body is a little different and each has a different resistance.

The best thing to do is avoid electric shock. Consider this. A typical dc welder only uses about 25 - 35 volts. I dropped a wrench one time on top of a car battery and it welded the wrench to the battery posts in seconds. My reaction was stupid because I quickly grabbed the wrench and dislodged it from the battery. I was very lucky that I didn't burn my hand or the battery didn't explode because lead acid batteries emit explosive hydrogen gas.

 

[WIP]

The spark that jumps from a doorknob to your hand has a huge voltage. But it has so little amperage that it won't hurt you. It will fry delicate electronics, though.

As Jason says, amperage is the killer.

Yup. 10,000 - 20,000 volts.