Rubbing your hand on a surface of a material that is non-conductive like for example rubber or certain plastic/clothes can result in you getting a shock when touching metal or another person afterwards. How does this work?
In: 14
Believe it or not, the answer is “we don’t know”
Triboelectricity (which is the formal term) causes electrons from one surface to move over to another surface when they are rubbed against each other, but we really have no idea of *why* that happens. It just sort does
Believe it or not, the answer is “we don’t know”
Triboelectricity (which is the formal term) causes electrons from one surface to move over to another surface when they are rubbed against each other, but we really have no idea of *why* that happens. It just sort does
While the other commenter is correct that we don’t have a strong understanding of triboelectricity, it shouldn’t be too surprising that it can work with non-conductive materials. Conductivity represents how easy it is for electrons to pass from atom to atom throughout the interior of a material. In contrast, in the phenomenon you’re mentioning, electrons are being removed from atoms at the surface of the material in response to physical contact. The electrons are stored on the surface of an insulator until they come to a conductor and can all be offloaded.
An analogous question might be “If blood only pumps through a human body thanks to the heart, how can we store blood in a bag and transfuse it to another human?” The answer is that you’re only tapping into the human temporarily at the surface to obtain the blood, and then later another human is ready to receive it. There’s no need for pumping blood to be able to store blood.
Similarly, there’s a difference between being able to move electric charge, and being able to store electric charge. Insulators can still store charge.
Believe it or not, the answer is “we don’t know”
Triboelectricity (which is the formal term) causes electrons from one surface to move over to another surface when they are rubbed against each other, but we really have no idea of *why* that happens. It just sort does
While the other commenter is correct that we don’t have a strong understanding of triboelectricity, it shouldn’t be too surprising that it can work with non-conductive materials. Conductivity represents how easy it is for electrons to pass from atom to atom throughout the interior of a material. In contrast, in the phenomenon you’re mentioning, electrons are being removed from atoms at the surface of the material in response to physical contact. The electrons are stored on the surface of an insulator until they come to a conductor and can all be offloaded.
An analogous question might be “If blood only pumps through a human body thanks to the heart, how can we store blood in a bag and transfuse it to another human?” The answer is that you’re only tapping into the human temporarily at the surface to obtain the blood, and then later another human is ready to receive it. There’s no need for pumping blood to be able to store blood.
Similarly, there’s a difference between being able to move electric charge, and being able to store electric charge. Insulators can still store charge.
While the other commenter is correct that we don’t have a strong understanding of triboelectricity, it shouldn’t be too surprising that it can work with non-conductive materials. Conductivity represents how easy it is for electrons to pass from atom to atom throughout the interior of a material. In contrast, in the phenomenon you’re mentioning, electrons are being removed from atoms at the surface of the material in response to physical contact. The electrons are stored on the surface of an insulator until they come to a conductor and can all be offloaded.
An analogous question might be “If blood only pumps through a human body thanks to the heart, how can we store blood in a bag and transfuse it to another human?” The answer is that you’re only tapping into the human temporarily at the surface to obtain the blood, and then later another human is ready to receive it. There’s no need for pumping blood to be able to store blood.
Similarly, there’s a difference between being able to move electric charge, and being able to store electric charge. Insulators can still store charge.
While the cause of triboelectric effect is correctly identified as being unknown, the reason this occurs with poorly conducting materials and not good conductors is that charges are relatively immobile in an insulator. With a metal (or other good conductor) the excess charge will be quickly and easily carted away. With an insulator (poor conductor) the charge will get trapped because it has a hard time moving.
While the cause of triboelectric effect is correctly identified as being unknown, the reason this occurs with poorly conducting materials and not good conductors is that charges are relatively immobile in an insulator. With a metal (or other good conductor) the excess charge will be quickly and easily carted away. With an insulator (poor conductor) the charge will get trapped because it has a hard time moving.
While the cause of triboelectric effect is correctly identified as being unknown, the reason this occurs with poorly conducting materials and not good conductors is that charges are relatively immobile in an insulator. With a metal (or other good conductor) the excess charge will be quickly and easily carted away. With an insulator (poor conductor) the charge will get trapped because it has a hard time moving.
It happens BECAUSE it’s non-conducting. When two objects rub against one another, electrons can be transferred from one to the other. If a material conducts, the electrons dissipate through it, massively reducing the charge density to the point where there’s not enough of an imbalance to cause a shock. An insulator, however, will not allow the charge to move through it so it builds up on that point, causing the jump of electrons when you come near it.
Latest Answers