Thunderstorms.

[Gambit]

now I know

And knowing is half the battle!

[Mountain_King]

Thunderstorms are best in the perfect climate. If you have a relatively dry climate but still temperate, it makes for some really great thunderstorms. You can just sit inside and watch the thunderstorm through the window. The stars are out, and so is the lightning. In the words of a famous hamster, "Fully AWESOME!!!"

[wesfreak]

I remember learning that lightning happens most often within clouds (or maybe from one cloud to another...).

But something I find even more awesome is ground to cloud lightning: regular lightning, but in reverse, with the bolt leaping from the ground to the clouds (don't know much about it). It's almost as if the sky and the earth are at war, blasting away at each other in some endless battle.

[HomerJ]

But something I find even more awesome is ground to cloud lightning: regular lightning, but in reverse, with the bolt leaping from the ground to the clouds (don't know much about it). It's almost as if the sky and the earth are at war, blasting away at each other in some endless battle.

Yaj!

Lightning always comes from both ends, being it cloud/cloud or cloud/earth. In most extreme slow motion footage this can be seen. Reasoning behind it is the follwoing:

What we see a bold of lightning is a electric current that flows between two oppositely (statically) charged poles (earth/cloud or cloud/cloud). However, since the medium the effect takes place in is air (which is an isolator) it requires a huge charge difference which grows bigger until at one point the air is ionized.
So the air ionizes from both sides and when ionization meets in the middle BLAAM! charges are exchanged.
So what we see is the energetically most favorable path of plasma (as in ionized gas molecules) between the poles.

That's also the reason why you could not dodge a lightning, even if there was time for reaction, which closes the circle to Delfadors magic ranged attack.

Edit: Forgot to mention: The ionization/temperature change during the lightning increases the volume of the air which results in a wave of pressure which we notice as sound and call it thunder.

Next lecture: Why would clouds and earth be oppositely charged anyway...?


Greetz
HomerJ

[hhyloc]

I wish I had that weather where I live...its been ~month of over 90 degrees + humid

Well, consider you are lucky, during the rain season in my country, temperature can go up to 40 °C (about 100 °F) and it's rain in 12 hours (relatively)

Next lecture: Why would clouds and earth be oppositely charged anyway...?

Oh, me me me, I know I know
Well, its hard to explain this in English without vocabulary/grammar errors, but I'll try anyway...
Ok, here goes...
The wind blow through the cloud --> the ice and the water drops rubbing each other --> ice gains a positive charge then move upward while and water gains a negative charge and move downward --> then it's raining --> as a result now the upper part of the cloud is positive charged while the lower part (where it's raining) is negative charged --> now the lower part become a electromagnetic field, it pushes electrons of the earth away (only positive charged atoms remain) ---> now clouds and earth are oppositely charged.

(Hope there are nothing wrong with my paragraph)

Edited: Typo

[HomerJ]

Ok, here goes...

Nerd!
...
just kidding...

Greetz
HomerJ

[wesfreak]

I don't get one huge part of Homerj's post: He said that charges are exchanged, but protons can't move from place to place, only electrons. Electrons also move from a positively charged area to a negatively charged one.

This would mean that lightning goes from one end, not from both, but the ionized path through which lightning travels comes from both ends, right?

[Gambit]

He said that charges are exchanged, but protons can't move from place to place, only electrons

[citation needed]

Electrons also move from a positively charged area to a negatively charged one.

[citation needed]

[HomerJ]

I don't get one huge part of Homerj's post:

He said that charges are exchanged, but protons can't move from place to place, only electrons.

Maybe it didn't get clear enough that we are talking about static charges, the same as in rubbing a glass rod on a piece of leather (or what ever that was, my physics lecture was almost 10 years ago). As hhyloc said, charge sepparation happens because different kind of mater "rub" against each other, [place here something about different energetics of abstraction of electrons from the surfaces], so one part "gains" electrons and is negatively charged, whereas the other part remains positive.

Electrons also move from a positively charged area to a negatively charged one.

The other way round, otherwise the positive charged area would become even more positive.

This would mean that lightning goes from one end, not from both, but the ionized path through which lightning travels comes from both ends, right?

Yes that's correct.


Greetz
HomerJ

[Midnight_Carnival]

I don't get one huge part of Homerj's post: He said that charges are exchanged, but protons can't move from place to place, only electrons.

So only the electrons in my fingers are moving as I type?

actually that would be a faster way I typing, I think, like a selectively ionisable plate which you put your whole hand or head over and change the charges and then all this beautifully written WML code come pouring out and the campaign you had in mind is written in 5 seconds flat!

[HomerJ]

So only the electrons in my fingers are moving as I type?

actually that would be a faster way I typing, I think, like a selectively ionisable plate which you put your whole hand or head over and change the charges and then all this beautifully written WML code come pouring out and the campaign you had in mind is written in 5 seconds flat!

Ah, someone finally gets the concept of quantum computing...


Greetz
HomerJ

[Bowers3333]

Has anyone ever considered how ironic thunderstorms are?

Really. It's like, some random day, Mother Nature or God or Eloh or Slaanesh or something, in a fit of vitriolic frustration, decided to punish the planet by inventing this awesome concept called 'electricity' and make it so that it is easily transmitted through water.

And then he or she or it arbitrarily decides to make a natural phenomenon made completely out of electricity called 'lightning', and program it to only happen when it rains.

WTH.

I mean, who would come up with such a monstrous torture? I know, let's cover half an acre in water AND THEN ELECTROCUTE IT! In fact, let's do it several times! Because this is a lightning storm!

I mean, if thunderstorms didn't exist, people would be shocked (excuse my pun) that such a horrendous natural occurence might exist on any planet. And it happens regularly!

...Maybe it's just my annoyance at two consecutive weeks of rain and lightning.

I LOVE thunderstorms. We don't have nearly enough of them here on the Washington State Coast. I used to have a Golden Retriever that was afraid of them, though. One day when I was coming home from work during a thunderstorm, she had crawled out the upper story bedroom window and was on the roof barking at the storm.

[Zarel]

Great, another opportunity to use this one
There is no pure de-ionized water in a non ultra clean laboratory environment since it always takes up CO2 from the air which forms protons and hydrogen carbonate anions. Acid rain also comes from gaseous compounds like SO2 which can be oxidized to SO3 which forms sulphuric acid with water.

Look at you, saying "protons" instead of "hydrogen ions". "Hydrogen ions" is more accurate, you know, since 0.02% of those "protons" are actually deuterium ions.

P.S. You forgot that even in an ultra clean container, pure water will have hydrogen ions and hydroxide ions. That's why pure water has a pH of 7 - there are 10^-7 moles of hydrogen ions in a liter of water. The Wikipedia article shadowmaster quoted mentions this.

P.P.S. For those of you that are interested, the chemistry behind why water exposed to air will contain dissolved carbonic acid:

H2O (water) + CO2 (carbon dioxide in air) -> H2CO3 (carbonic acid) -> H+ (hydrogen ions) + HCO3- (bicarbonate ions)

P.P.P.S. For those of you that are interested, the chemistry behind why liquid water in an ultra clean container will still have ions:

H2O (water) -> H+ (hydrogen ions) + OH- (hydroxide ions)

P.P.P.P.S. For those of you wondering why I said "container" instead of "vacuum", it's because water in a vacuum would be a gas, not a liquid.

P.P.P.P.P.S. For those of you wondering about the "hydrogen ion" and "proton" distinction - 99.98% of hydrogen atoms are protium - a single proton and a single electron. 99.98% of hydrogen ions are protium ions - a single proton. However, 0.02% of hydrogen ions are deuterium ions - a single proton and a single neutron. Thus, unless you're specifically talking about protium ions and not hydrogen ions (which you aren't, if you're talking about things dissolved in water), it's better to say "hydrogen ion" instead of "proton".

P.P.P.P.P.P.S. An even better reason to say "hydrogen ion" instead of "proton" is so people understand that you're talking about the ion, not the subatomic particle it consists of. For instance, wesfreak probably wouldn't have been confused if you said "hydrogen ion" instead of "proton".

P.P.P.P.P.P.P.S. An even better reason to say "hydrogen ion" and not "proton" is that any chemist talking about carbonic acid not trying to make a bad joke would say "hydrogen ion" and not "proton" (and for good reason - namely, the two I mentioned above).

P.P.P.P.P.P.P.P.S. Science!

He said that charges are exchanged, but protons can't move from place to place, only electrons

[citation needed]

wesfreak probably means that, outside of nuclear reactions, protons can't move from one atom/ion to another while electrons can, which is true. HomerJ neglected to mention that the protons in question are hydrogen ions (hydrogen atoms minus one electron).

Your link, by the way, describe reactions in which electrons are gained or lost, and does not contradict his statement.

[HomerJ]

Look at you, saying "protons" instead of "hydrogen ions". "Hydrogen ions" is more accurate, you know, since 0.02% of those "protons" are actually deuterium ions.

Hydrogen ions? see below...

P.S. You forgot that even in an ultra clean container, pure water will have hydrogen ions and hydroxide ions. That's why pure water has a pH of 7 - there are 10^-7 moles of hydrogen ions in a liter of water. The Wikipedia article shadowmaster quoted mentions this.

Of course you are right, but remember, I'm a chemist. We say stuff like celite, brine and THF, non of which lets you deduce the chemical composition. "Deionized water" as well as "aqua dest." in our lab terms is used for the water that comes out of the reverse-osmosis apparatus.

P.P.P.P.P.S. For those of you wondering about the "hydrogen ion" and "proton" distinction - 99.98% of hydrogen atoms are protium - a single proton and a single electron. 99.98% of hydrogen ions are protium ions - a single proton. However, 0.02% of hydrogen ions are deuterium ions - a single proton and a single neutron. Thus, unless you're specifically talking about protium ions and not hydrogen ions (which you aren't, if you're talking about things dissolved in water), it's better to say "hydrogen ion" instead of "proton".

Good point. I will use this in my thesis defence if I'm desperate for a laugh.

For instance, wesfreak probably wouldn't have been confused if you said "hydrogen ion" instead of "proton".

Is that so wesfreak? My feeling would be the exact opposite since to the best of my knowledge academia/education uses "protons" in connection with acid/base chemistry.
I will ask our students if I get a chance.

P.P.P.P.P.P.P.S. An even better reason to say "hydrogen ion" and not "proton" is that any chemist talking about carbonic acid not trying to make a bad joke would say "hydrogen ion" and not "proton" (and for good reason - namely, the two I mentioned above).

Quite frankly, I have read the term hydrogen ion for the first time right now and my undergrad studies started 2001.
You are also missing the important fact that "ion" does not imply the positive charge, so your term is ambiguously usable for the hydride anion H-.

P.P.P.P.P.P.P.P.S. Science!

I totally support this statement.

However, lets not spam this topic with our science-brabble, but we can take this to pm if you are desperate for answering my post.


Greetz
HomerJ

[pauxlo]

And, actually, the Hydrogen ions do not really occur freely in water, but they grab the next water molecule and form a hydronium-ion H3O+ each. There is an equilibrium reaction:

H3O+ + OH- ↔ H2O + H2O