Wikipedia:Reference desk/Archives/Science/2019 December 20

= December 20 =

Do pigs enjoy music or other sounds?
If given levers which they can nudge to choose type and loudness, will they prefer some sounds over silence and pick out types to make louder?Rich (talk) 23:38, 20 December 2019 (UTC)
 * A simple websearch on "+pigs+music" returns (to me, at least) many hits suggesting that they do. Whether or not these reflect peer-reviewed studies rather than wishful lay thinking is a study I leave to you as an exercise. {The poster formerly known as 87.81.230.195} 90.199.211.222 (talk) 09:27, 21 December 2019 (UTC)
 * Music by Bach makes pigs grow better cites research by São Paulo University.
 * A sow's song - Student’s combination of Mozart, pigs leads to promising research from Ohio State University. Alansplodge (talk) 16:13, 21 December 2019 (UTC)

Definition of the derived quantity electrostatic potential as a function of base quantities like electric current
What is the algebraic relation (and how is obtained) for a derived quantity like electrostatic potential (a state quantity) as a function of only base quantities in SI like electric current which is a process quantity? Thanks!--109.166.135.195 (talk) 23:54, 20 December 2019 (UTC)
 * I am not so sure what you are asking. Process quantity does not appear to be what you want. Did you read Volt? The simplest definition along your text would be watts per ampere. If you want to integrate along a path, with an electric potential between the two ends, it will be simplest to assume that the current is going on that path. If this is not the case and you are dealing with current in a 3D solid, the you had better consider electric current density. Graeme Bartlett (talk) 11:42, 22 December 2019 (UTC)
 * 1 volt = 1 joule per coulomb if I remember correctly. 173.228.123.190 (talk) 12:00, 22 December 2019 (UTC)
 * Involvement of ampere as unit of electric current in the description of static electricity/electric charge and potential is/seems quite problematic since the static electricity excludes or does not require electric currents, no? If ampere is a base unit, then the quantity of static electricity or electric charge can not be measured without the electrokinetic method which involves the product of quantities electric current - time, the product being a non-static quantity of electricity Q which is somewhat different than the static quantity of electricity (or electric charge).--109.166.134.81 (talk) 18:35, 23 December 2019 (UTC)
 * It is very hard to measure the electric potential without draining some electric current. Today I saw a video of an "electrometer" that could measure down to 100 atto amps. The least load it could apply was a 250 Gig Ohm resister. There may also be probes that can measure the electric field, but even those will apply some capacitance and current will flow from the probe to some measuring device. Above we are really worrying about a definition of a unit, and actual measurement does not come into it. Graeme Bartlett (talk) 11:54, 24 December 2019 (UTC)
 * Seems similar to electrostatic discharge involving some (transient) current or Weston cell working by equilibrating EMFs, once done no currents flow.--109.166.134.81 (talk) 21:59, 24 December 2019 (UTC)
 * I see that there is an article electrostatic voltmeter.--109.166.134.81 (talk) 23:53, 24 December 2019 (UTC)
 * A similar (or equivalent) problem would be the measurement of electric charge by electrostatic means, a Coulomb-type scale or torsion balance, using the equilibrium of (electrostatic) forces.--109.166.134.81 (talk) 00:20, 25 December 2019 (UTC)