This is a common problem given in first year physics majors. One of the interesting things is creating an repulsor field that would keep pretty much any matter outside of it in this way. There was a working (albeit accidental) example of one at a 3M factory for making tape [1]
Heh, wasn't there a Larry Niven SF story where an alien weapon would zero out the charge of electrons, so the nuclei would fly apart? Our undergrad phys-101 had calculating the force between two (copper!) pennies 1M apart, with all electrons removed from one and deposited on the other.
Later I realized that it would have been even more impressive to estimate the energy-equiv of kilotons of TNT which would be released when the meter-long spark brought the two pennies back into equilibrium.
Another: calculate the width of one coulomb. It's about half a mm, like a grain of sand. That's assuming its the mobile electrons in copper wire (so, not Cu's electrons, but just one free electron per atom.)
It was actually in a number of his short stories in the Known Space universe: the slaver disintegrator. I had a physics teacher in high school who gave us an assignment to describe what the effects of a sci-fi device would actually be like. The disintegrator was probably the most interesting one of the bunch.
The example of static electricity holding a balloon up against the Earth's gravity is a good one. I like it better than the one I always heard, which is a refrigerator magnet resisting Earth's gravity.
As energy is conserved, I would say that it takes a Coulomb bomb's worth of energy to extract 1% of one's electrons, plus overhead due to inefficiencies.
40MC is a lot. Another way to think about it is that a force on the order of that many tons would be needed to rip out 1% of your electrons from your neutral body in the first place. That's why we don't see charging up to that scale in day-to-day life.
The author probably came upon this idea from reading Richard Feynman's Lectures on Physics, in which he says this:
> And all matter is a mixture of positive protons and negative electrons which are attracting and repelling with this great force. So perfect is the balance however, that when you stand near someone else you don't feel any force at all. If there were even a little bit of unbalance you would know it. If you were standing at arm's length from someone and each of you had one percent more electrons than protons, the repelling force would be incredible. How great? Enough to lift the Empire State building? No! To lift Mount Everest? No! The repulsion would be enough to lift a "weight" equal to that of the entire earth!
Getting attracted to the ground wouldn't be a problem, since you would already have exploded due to the repulsion of your constituent parts from each other. This happens to charged things in nature, and it has a cool name: https://en.wikipedia.org/wiki/Coulomb_explosion
This is called out in the article, before the attraction to the ground is mentioned:
> Suppose, for example, that in their rush to escape my body, those 40 million Coulombs split in half and flowed to opposite extremities. Say, each hand suddenly acquired a charge of 20 million Coulombs. The force between those two hands (spread apart, about 6 feet) would be 10^{24} Newtons, which translates to about 10^{23} pounds. Needless to say, my body would not retain its structural integrity.
That's the video from before they published (which is still interesting). There is also a more recent video[1] (post-publication[2]) that covers how they got the data (which supports the coulombic explosion hypothesis).
While it is mentioned at the end of the newer video, I highly recommend watching the 500fps footage[3] of a drop of NaK burning (just before it explodes) on the top of water. There is a striking color change as it starts to interact with the water, and right the NaK explodes... the metal turns completely transparent.
But they can't get anywhere near this energy level. Why not make a piece of metal .xx1% charged and encase it in a big insulator, glass? Seems like it would be an awesome battery no?
No, a Van de Graaff generator doesn't get anywhere close to 0.xx1% charged.
As the article says, loosing 1% of electrons leads to a voltage potential of 40 exavolts. As https://en.wikipedia.org/wiki/Van_de_Graaff_generator points out, the best a Van de Graaff generator can do is "about 25 megavolts" due to "arcing and corona discharge."
The sequence is mega-, giga-, tera-, peta-, exa-. That corresponds to 0.000,000,000,000,1% charge, though you should double check me as I'm not used to working with that many powers of ten.
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[ 3.4 ms ] story [ 61.0 ms ] thread[1] http://amasci.com/weird/unusual/e-wall.html
Heh, wasn't there a Larry Niven SF story where an alien weapon would zero out the charge of electrons, so the nuclei would fly apart? Our undergrad phys-101 had calculating the force between two (copper!) pennies 1M apart, with all electrons removed from one and deposited on the other.
Later I realized that it would have been even more impressive to estimate the energy-equiv of kilotons of TNT which would be released when the meter-long spark brought the two pennies back into equilibrium.
Another: calculate the width of one coulomb. It's about half a mm, like a grain of sand. That's assuming its the mobile electrons in copper wire (so, not Cu's electrons, but just one free electron per atom.)
> And all matter is a mixture of positive protons and negative electrons which are attracting and repelling with this great force. So perfect is the balance however, that when you stand near someone else you don't feel any force at all. If there were even a little bit of unbalance you would know it. If you were standing at arm's length from someone and each of you had one percent more electrons than protons, the repelling force would be incredible. How great? Enough to lift the Empire State building? No! To lift Mount Everest? No! The repulsion would be enough to lift a "weight" equal to that of the entire earth!
> Suppose, for example, that in their rush to escape my body, those 40 million Coulombs split in half and flowed to opposite extremities. Say, each hand suddenly acquired a charge of 20 million Coulombs. The force between those two hands (spread apart, about 6 feet) would be 10^{24} Newtons, which translates to about 10^{23} pounds. Needless to say, my body would not retain its structural integrity.
https://www.youtube.com/watch?v=xMfQSV4ygHE
The explanation was only discovered this year.
While it is mentioned at the end of the newer video, I highly recommend watching the 500fps footage[3] of a drop of NaK burning (just before it explodes) on the top of water. There is a striking color change as it starts to interact with the water, and right the NaK explodes... the metal turns completely transparent.
[1] https://www.youtube.com/watch?v=LmlAYnFF_s8
[2] http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.ht...
[3] https://www.youtube.com/watch?v=BIGMfai_ICg
http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.ht...
As the article says, loosing 1% of electrons leads to a voltage potential of 40 exavolts. As https://en.wikipedia.org/wiki/Van_de_Graaff_generator points out, the best a Van de Graaff generator can do is "about 25 megavolts" due to "arcing and corona discharge."
The sequence is mega-, giga-, tera-, peta-, exa-. That corresponds to 0.000,000,000,000,1% charge, though you should double check me as I'm not used to working with that many powers of ten.