Wikipedia:Reference desk/Archives/Science/2021 July 15

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July 15

What flower is this?

https://imgur.com/a/Ks9Vbil

Wild flowers, located in Manchester England. White, kinda trumpet-shaped.

Thanks in anticipation. 86.24.168.231 (talk)‎ 04:23, 15 July 2021‎ (UTC)

Apparently some variety of Convolvulaceae (commonly known as 'bindweeds' or 'morning glories'), probably of the genera Calystegia or Convolvulus. A more detailed picture of the rest of the plant would be necessary to narrow the genus and species down, at least where yours truly is concerned, as my depth of familiarity with flower morphologies is just not that deep, and the variations between members of these genera vary slightly in that respect. Snow ^{let's rap} 05:24, 15 July 2021 (UTC)

Great, much appreciated! It does look very much like the pictures in that Calystegia article.

I'll try to get a picture of the rest of the plant ASAP; probably within a couple of days.

Thanks again. @@@@

You're very welcome, OP. :) Snow ^{let's rap} 18:15, 15 July 2021 (UTC)

Large Bindweed, Calystegia silvatica, is very common and in flower in the UK around now. Alansplodge (talk) 10:35, 15 July 2021 (UTC)

Or Calystegia sepium, the hedge bindweed, of which C. silvatica is considered a sub-species by some authorities. DuncanHill (talk) 13:00, 15 July 2021 (UTC)

I know this is the Science desk. But we have "So doth the woodbine the sweet honeysuckle gently entwine". Apparently, The Bard meant convolvulus, not a pack of these. Allegedly. Martinevans123 (talk) 18:32, 15 July 2021 (UTC)

If Delia Bacon were right, then maybe he did mean a pack of smokes. DuncanHill (talk) 22:08, 15 July 2021 (UTC)

Ah, bacon and spuds, my favourite. Martinevans123 (talk) 22:34, 18 July 2021 (UTC)

if water boiling point is 100 decree celsius then how wind from ceiling fan can dry wet floor?

if water boiling point is 100 decree celsius then how wind from ceiling fan can dry wet floor? My mom used to put fan on full speed after cleaning the room with water. Rizosome (talk) 17:47, 15 July 2021 (UTC)

Water also evaporates. Unless the room in question is already at 100 percent relative humidity, evaporation can occur. And a fan can speed up the process. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:27, 15 July 2021 (UTC)

Evaporation happens at temperatures below the boiling point. Technically, all liquids evaporate, and "boiling" is a special condition where the vapor pressure of the liquid is equal to or higher than the atmospheric pressure above the liquid. The reason why all liquids evaporate even below the boiling point is that at any given temperature, the atoms and molecules of a liquid are not all moving around with same amount of kinetic energy. There is a distribution of different energies known as the Maxwell–Boltzmann distribution, at any given temperature some of the molecules will be moving fast enough to escape the liquid phase and enter the gas phase, over time these escaping molecules is why a liquid will evaporate at any given temperature, even below boiling. Wikipedia's article on boiling has a short section that explains exactly this. --Jayron32 18:28, 15 July 2021 (UTC)

Does something interesting happen when a disappearing droplet becomes 100% Knudsen layer? Sagittarian Milky Way (talk) 18:52, 15 July 2021 (UTC)

Depends on what interests you. --Jayron32 19:02, 15 July 2021 (UTC)

So what is the fate of the last few hundred molecules? Sagittarian Milky Way (talk) 19:28, 15 July 2021 (UTC)

When the atoms or molecules with the highest kinetic energy are liberated from a liquid (evaporation) the remaining particles are those with, on average, less kinetic energy (evaporative cooling). The cooler liquid then absorbs more heat from the environment in order to regain thermal equilibrium. That extra heat enables the particles with the highest kinetic energy to evaporate. The cooler remaining liquid then absorbs more heat from the environment, and so on, until all the liquid has evaporated. nagualdesign 20:26, 15 July 2021 (UTC)

Isn't there a layer of moisture on pretty much everything? ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:17, 17 July 2021 (UTC)

No.  --Lambiam 09:09, 17 July 2021 (UTC)