Wikipedia:Reference desk/Archives/Science/2021 November 1

= November 1 =

Berberine for diarrhea
This involves the following two discussions:
 * User talk:Guy Macon/Yes. We are biased.
 * Reference desk/Archives/Science/2021 January 21

Do the sources listed in the above discussions support a claim that Berberine is an effective treatment for diarrhea? My conclusion is that the sources supporting that claim do not meet the requirements of WP:MEDRS. Am I correct? --Guy Macon (talk) 04:43, 1 November 2021 (UTC)


 * If the issue is the interpretation of WP:MEDRS, then the talk page of that guideline may be a better place for a discussion. Just refer to the specific sources allegedly supporting the claim; the prior discussions seem to be more about the appropriateness of the guideline rather than its interpretation, and so are not particularly relevant. --Lambiam 09:37, 2 November 2021 (UTC)

Can activated carbon destroy acetic acid?
I want to thicken distilled vinegar (so to make a vinegar paste), with activated carbon.

Can activated carbon destroy/sabotage the vinegar's acetic acid molecules (or, at least, is activated carbon a chemical base)?

Thanks, 182.232.42.121 (talk) 12:36, 1 November 2021 (UTC)
 * We had another IP user wanting to thicken vinegar, with answers here. I have no idea why you would use activated charcoal but it will be inert to the vinegar, being neither an acid nor a base itself. Mike Turnbull (talk) 14:54, 1 November 2021 (UTC)
 * I think that this other question from me as a person and not as an IP :) isn't related. I thought that activated carbon may have medicinal properties and is worth checking. I found activated carbon as a wonderful vinegar thickner, actually the smoothest and least residual I have tried, but it can be very "messy" to work with due to color stains. 2001:44C8:42CD:E478:AC74:4933:5B45:8BAB (talk) 04:05, 3 November 2021 (UTC)

Solar radius instead of diameter
Why solar radius rather than solar diameter has been chosen as standard? One can assume that diameter gives a better idea of the star's size, whereas radius gives only half of the value. Thanks. 212.180.235.46 (talk) 15:18, 1 November 2021 (UTC)
 * By convention, spheres are defined by their radius; as one convenient definition of a sphere is every point in three dimensions located a distance, r, away from a single point. That distance, r, is the radius, and needs to be manipulated by multiplying it by 2 to get the diameter.  Since 1) It is entirely arbitrary whether to use the radius or the diameter and 2) we already have definitions that use radius, it seems perfectly fine to use the radius.  All other measures (surface area, volume, etc.) can also be defined from r.  They could be defined from d too, but it isn't any easier or harder to do so, so we stick with one measurement (radius) instead of 2 (radius for some measures, and diameter for others).  -- Jayron 32 15:22, 1 November 2021 (UTC)
 * The NASA ephemeris gives angular size in diameter not radius and not everyone knows that 2pi is tau, it's not radius always. I suppose using r but pi makes these more elegant than the other 3 conventions: .5τr² πr² τ/8d² π/4d² • 2τr² 4πr² .5τd² πd² • .$\overline{6}$τr³ 4/3πr³ 1/12τd³ 1/6πd³. Sagittarian Milky Way (talk) 19:52, 1 November 2021 (UTC)
 * Yes, angular size is in diameter, and most people understand how to multiply or divide by 2. It's not difficult math.  -- Jayron 32 11:22, 2 November 2021 (UTC)
 * Yes it doesn't matter which one gets the name. I was mentioning that it was circumference over diameter that got the famous Greek letter for some reason (I'm not sure why) and not circumference over radius which would be more "pure". Sagittarian Milky Way (talk) 17:09, 2 November 2021 (UTC)
 * The conversion is pretty easy: if the radius of a star is 3 solar radii, then the diameter of that star is 3 solar diameters. --Amble (talk) 18:23, 1 November 2021 (UTC)