Sciencemadness Discussion Board

Thunderstorm experiments

chemkid - 27-7-2008 at 09:45

We are having a major thunderstorm where i am and i was wondering if there were any neat experiments i could do with regards to the thunder storm. I know a thunder storm produces additional ozone. Thought it might create some strange or interesting condition allowing for a cool experiment.

Chemkid

kilowatt - 27-7-2008 at 09:56

Well there's always rocket triggered lightning. That's messing with a LOT of power, though. You need a large dedicated rig and a lot of area. On the safer scale, Franklin's bells or other electrostatic experiments come to mind. Nothing chemical comes to mind.

vulture - 27-7-2008 at 11:38

An acquaintance of mine once described an experiment with a coil, a nail and a multimeter which could measure in the millivolt range. Apparently it is possible to predict a nearby discharge this way. I can't remember any specific details though.

ShadowWarrior4444 - 27-7-2008 at 13:13

Quote:
Originally posted by vulture
An acquaintance of mine once described an experiment with a coil, a nail and a multimeter which could measure in the millivolt range. Apparently it is possible to predict a nearby discharge this way. I can't remember any specific details though.


Generally hooking the coil to the multimeter should read the EM radiation given off by lightning. Using a radio on an empty channel is another trick to gauging how far away lightning strikes are. As for predicting strikes, one would need to measure how charged the air is--I believe there a professional tools designed to do this, but perhaps a nail in the air would be able to read a sharp rise in voltage directly before a strike.

You could always try something particularly fun! Hydrogen balloon and some wire. *smirks*

[Edited on 7-27-2008 by ShadowWarrior4444]

JohnWW - 27-7-2008 at 14:16

Benjamin Franklin was very lucky that he was not electrocuted, as the result of his electrostatic experiment of flying a kite in the eastern USA during a thunderstorm in the 18th century. Some people who tried to do the same thing (or using an hydrogen balloon) later were killed.

BTW I have an useful book on electrostatics, "Electrostatics And Its Applications", by A.D. Moore (Wiley-1973). I will have to scan and upload it (along with my extensive notes in the margins), when I find time. I am interested in the subject because of its applications to particle separations in chemical process engineering, electrophoresis in biochemistry, and the possibility of highly-charged (using at least several thousand volts) condensers in the form of closed surfaces like spheres being a means of obtaining anti-gravity as claimed by the patents of Dr T.T. Brown and others.

The book includes a good account of terrestrial and atmospheric electrostatics, in chapters 16 and 17. According to this, and what I have been able to infer and write in the margins, even in fine weather there is a weak electric field of the order of 100 V/m at Earth's surface, with the positive charge in the atmosphere and the equal negative on the ground. Integrated over the entire globe, the total fair-weather charge on Earth's surface is of the order of -1,000,000 coulombs. The fine-weather electric field decreases with altitude until it disappears near the ionosphere (which is a good conductor of electricity due to its ions). The total potential difference between the Earth and the upper atmosphere, by integration, is of the order of 300 kilovolts. This implies that the fine-weather capacitance C = Q/V = 1,000,000/300,000 = 3.3 farads. Moreover, measurements show that the fine-weather conduction current flowing to a square meter of Earth's surface is of the order of picoamperes; and summed over the entire Earth's surface, , the total current conducted is of the order of 1,000 amps. Hence the total available electric power from this is 300,000 x 1,000 = 300 megawatts, which unfortunately is only about that of one good-sized ordinary power station.

[Edited on 28-7-08 by JohnWW]

chemkid - 27-7-2008 at 17:51

I have tried the bell apparatus mentioned by killowatt unfortunately to no avail. I was not using a lightning rod but "harvesting" the voltage from an old TV screen by coaing it with aluminum foil. Never quite got it to work, but it was a very primitive set up so maybe i'll try again later.

I to am interested in electrophoresis JohnWW and have the components of making an apparatus but i can't find the agar medium.

The coil of wire nail and multimeter sound like a great apparatus. I would like to try that one out! To bad i don't have a multimeter with me (i am out of the lab but can get simple apparatus)

Chemkid

YT2095 - 28-7-2008 at 00:26

you could build a simple VLF radio, I have a few here that I use daily to monitor storm activity, one is an old 1970`s car radio that I converted down to the <22KHz range and used a simple long-wire antenna up in the attic.
you can also use your PC via the sound card and s/ware called Spectrum Lab to do this as well, but you`ll still need to build the front end (Pre-amp).
some Cameras come with remote triggering too, you could make a simple light sensor to trigger this and take pictures of the lightning.

be advised that you should also use a small neon bulb to go between any antenna and ground, this wont short out and signals but Will short out at any voltage above ~90v and thus protecting you and your equipment, this the bare Minimum of protection needed!

IrC - 28-7-2008 at 13:31

RADIO WAVES below 22 kHz

You will find this site very useful, especially this article written by myself, years old but still useful. I might add that one person gave me an idea I have never updated the article to include, namely adding a series electrolytic to the meter to allow it to auto zero on field polarity. Never tried his idea but if you do and it works mention it here on SCM.

STORM MONITOR

I designed and built this circuit myself and when Renato tried it he had to have permission to put it on the site, since it was so very cool to watch during storms. Over the years I thought of many changes and improvements but never had the time to revisit this project.

Maya - 28-7-2008 at 16:43

<< "Electrostatics And Its Applications", by A.D. Moore (Wiley-1973) >>


His books are the best home experimenters books that I've read for electrostatics.

"Electrostatics exploring, controlling and using static electricity" is also AWESOME! by the same author

I read the 1st edition and have the 2nd edition. Both these books I would highly recommend but the first one is more technical and the second one is much more applied