# Static Electricity Question

#### OniSensei

Joined Jan 21, 2024
3
Hello, sorry if this is the wrong place to ask this, I just made an account now to ask this question in the hopes that someone here can explain this to me. The question is that I just don't understand what's going on in this video:

Sorry about the poor audio, but in the video, the paper beneath the wood/metal starts dancing, and it doesn't matter where I put the "fun fly stick" (which is like some kind of van de graaff generator I believe) Is this an example of charging by induction? Multiple sources that I found online say that charging by induction is only possible with conductors, so why does the wood work? Note: a glass beaker also works exactly the same way as the wood and metal.
Are the electrons of the wood and metal migrating to the closest surface to the fun fly stick or aligning themselves like a magnet? Why does the metal seem to take longer to become charged? Why does touching the wood disrupt the charge? (note: it doesn't matter who touches the object, someone across the room from the fun fly stick operator touching it has the same effect.) Also how come I can get the dancing paper effect to work while holding plastic or a balloon (I forgot to video this), but it doesn't seem to work at all if I'm holding metal or glass (it will sometimes work with wood). Note about the fun fly stick: it uses the operator's body as a ground while pushing the button. The inside components are copper brushing against Teflon I believe. Feel free to make fun of me if I'm an idiot, but I would appreciate any helpful insight or answers.

#### MrChips

Joined Oct 2, 2009
30,819
Static electricity experiments are not always easy to explain. Sometimes the experiment fails to work. Charge separation and buildup depends and many unseen properties such as types of material and especially on humidity.

Wood can be considered an insulator in some instances. In reality, wood consists of cellular organic matter and is a conductor, though a rather poor one.

The metal tray has higher electrical capacity and hence takes more charge to reach a high voltage. V = Q / C.

Hope this helps.

#### OniSensei

Joined Jan 21, 2024
3
Static electricity experiments are not always easy to explain. Sometimes the experiment fails to work. Charge separation and buildup depends and many unseen properties such as types of material and especially on humidity.

Wood can be considered an insulator in some instances. In reality, wood consists of cellular organic matter and is a conductor, though a rather poor one.

The metal tray has higher electrical capacity and hence takes more charge to reach a high voltage. V = Q / C.

Hope this helps.
Thank you for explaining the tray delay, that adds up perfectly with what I'm seeing. I'm not sure about the wood being a poor conductor explanation because I get the exactly same result with a glass beaker. I would like to Chalk up the wood to humidity in Japan, but I can't explain the glass. However with plastic I can touch it as much as I want and it will still attract the paper. New video:

#### MisterBill2

Joined Jan 23, 2018
18,538
Wood in the real world is both a poor conductor and a poor insulator. For lower voltages, DRY wood is an adequate insulator, but even at the lower mains power voltages wood is generally not an acceptable insulator.
Static electricity will flow on the surface of most wood, and that can provide a lot of confusing results. Consider that nylon carpet is a fairly good insulator, and yet coupled with some shoe materials makes an excellent static electricity generator..

One of my favorite show tricks long ago was drawing an arc thru plate glass material while holding it in my hand just a few inches away from the arc. . The fact is that evidently melted glass is not such a good insulator.

#### OniSensei

Joined Jan 21, 2024
3
I am fairly certain at this point that this experiment will work with any material provided it is small and thin and humidity is in check. I asked my coworker and he said the fun fly stick creates charged dipoles in the insulators. The electrons spend more time on the side facing the positive charge but no migration of electrons. What we still don't understand is why touching some objects, especially glass, affects the result. I'm going to experiment with different types of glass when I get the chance and see if that makes any difference.

#### MisterBill2

Joined Jan 23, 2018
18,538
Many good insulators are also good dielectrics, and so produce interesting effects when they become charged on one side. The results can be difficult to explain, given that static electricity is so difficult to see.

#### sparky 1

Joined Nov 3, 2018
758
Your questions and experiments show that you have an instinct ability for electricity,
The materials can have different affinity for charge either positive or negative.
The rule I learned is that "opposites charges attract" and " like charges repel."

In nature we find random positive and negative charges here and there.
When the charges are separated, I call that a charge separating mechanism.
Often times an electrical charge will find a pathway to return to neutral, some say the accumulated charge leaks away.
In one experiment causing hair to fly up the person is asked to stand on a small stool above the floor.

You can imagine the electric field, there can also be another component which is magnetic.
The magnetic field is perpendicular to the electric field. We mainly use electromagnetic current to do practical work.
We abbreviate that to electrical current and it is assumed that both electric (static) and magnetic components are present in a conductive material.

More advanced topics using acceleration and focusing the motion of electrons in crossed electric and magnetic fields is the basis of the magnetron tubes, i.e., oscillators used for generating microwave energy. Ancient televisions used an electron gun and outside were electric magnets affecting the path of electrons. The subject can get complicated as we get away from a uniform field. With static electricity experiments the surface of the material at an atomic level differs as we examine beyond surface. The second layer begins to show some dimension and geometry. When we study a capacitor, we have to consider the surface area for defining a rate of charge. A physics teacher would do a better job at explaining this than me.

The history of one of the mathematical quantifications of charge was Coulomb and how he did this in his basement.

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