Wikipedia:Reference desk/Archives/Science/2021 October 18

= October 18 =

Inconsistency on Tesla Coil harming humans
I discovered that from wiki media, a Tesla coil producing high-frequency current that is harmless to humans, but lights a fluorescent lamp when brought near it. But here, it says Tesla Coil can harm humans. Which is correct? Rizosome (talk) 05:16, 18 October 2021 (UTC)
 * The risk is strongly related to the power output of the Tesla coil, and the frequency also plays a role. If the power is sufficiently low, a high-frequency Tesla coil will be harmless. --Lambiam 06:35, 18 October 2021 (UTC)


 * A fluorescent tube requires very little current..--Shantavira|feed me 08:30, 18 October 2021 (UTC)


 * The OP's question is a bit like asking "I heard that getting shot with a bullet is harmful to humans, but I touched a bullet and didn't die". The level of harmfulness is dependent on the energy transferred.  A fast moving bullet shot from a gun is much more dangerous than, say, the same bullet thrown lightly from your hand.  In the same way, the amount of energy imparted by the tesla coil to a person will have a big effect on how harmful it is.  -- Jayron 32 13:39, 18 October 2021 (UTC)

Switching from some genes to different ones as the organism matures
I know there should be a mechanism to activate some genes at certain stages of development. What is it?: AboutFace 22 (talk) 13:31, 18 October 2021 (UTC)
 * See Epigenetics and Regulation of gene expression for some introductions to the process. -- Jayron 32 13:37, 18 October 2021 (UTC)