Wikipedia:Reference desk/Archives/Science/2020 October 5

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October 5

Raw eggs are messy

Anyone's who's dropped one on a kitchen floor will know that cleaning up raw eggs is a real nuisance. The liquid flows in an apparently unpredictable manner, is both absorbed and not absorbed by things that normally clean up liquids efficiently and is generally a bit of a nightmare.

What's the scientific reason behind this?

Do human beings use this principle for any useful technologies?

Shell I go clean up my mess while you lot chick that out. Looking forward to some eggcellent answers, and no doubt a few really bad jolks along the way. --Dweller (talk) Become old fashioned! 11:49, 5 October 2020 (UTC)

For starters, this is why we often have tile floors in kitchens. And are careful with anything that could spill. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:13, 5 October 2020 (UTC)

That wasn't even funny. White you do that? --Dweller (talk) Become old fashioned! 08:10, 6 October 2020 (UTC)

Eggs dropped on a grass floor usually do not break – perhaps an argument for having grass floors in kitchens.  --Lambiam 22:20, 6 October 2020 (UTC)

I'm always amused when I see a carpeted floor in a kitchen, dining room, bathroom, or laundry room. That's just asking for trouble.--Khajidha (talk) 11:47, 7 October 2020 (UTC)

Eggs are messy (but also useful for cooking!) because of the balance of proteins, fats, water, and emulsifiers like lecithin. The same thing that makes eggs important for binding ingredients in baked goods, also makes it bind to your floor and fabrics really well. --Jayron32 14:34, 5 October 2020 (UTC)

Cheers, that helped me unscramble some of it. --Dweller (talk) Become old fashioned! 08:11, 6 October 2020 (UTC)

• There are two physics phenomena to look at.

One is the weird flow of liquid. The keywords for that are "rheology of non-Newtonian fluids". There are tons of applications (from oil extraction to beauty creams to chocolate fountains to toothpaste consistency etc.). A basic explanation of the egg case: the chemical species have long molecular chains (keyword: polymer) and therefore exhibit more complex interactions than (say) water molecules. That can be demonstrated by running egg white from one half-shell to the other; you do that much more easily than you could with water, or with cooking oil (even though the latter has about the same viscosity) - the egg stuff tends to stick together fairly strongly instead of falling in-between.

The other is that it does not stick to standard tissue. This might be due to surface tension effects, but I am not sure. This post and answer tends to support the idea that the contact angle of water is much lower than that albumen on most surfaces, but I could not get my hands on any hard numbers of surface tension. If true, the theory is that water wets textiles easily and therefore wiping off water is easy (because the water you did not swipe well will still get "sucked in") whereas egg white is harder (because it refuses to wet the textile).

Tigraan^{Click here to contact me} 16:18, 5 October 2020 (UTC)

That's an eggsellent answer, thank you. Al bu mentioning you next time I eggsplain this. --Dweller (talk) Become old fashioned! 08:10, 6 October 2020 (UTC)

Obviously Dweller had been hatching this question for some time to include his list of clichéd and very old jokes. Richard Avery (talk) 07:36, 8 October 2020 (UTC)

Who get to scientifically and/or legally decide which dog is a pit bull and which is not?

Some of you might know about the recent major AfD and deletion review for the article List of fatal dog attacks in the United States. The proponents of deletion have accused this stand-alone list of being part of a major anti-pit bull advocacy campaign due to the fact that it lists the dog breed for each attack based on their respective source and pit bulls make up the majority of those listed by far. They also alleged that the news media often misidentify dog breed causing pit bulls to be unfairly stigmatized.

• Which specific group of people or organization possesses the scientific and/or legal authority to determine if a dog is a pit bull, at least in the United States?
• Is the concept of dog breed firmly grounded in DNA evidence to begin with? Does DNA actually distinguish each and every single dog breed from one another?
• Are dogs that are mixed-breed from pit bull-types also themselves generally considered pit bulls?

StellarHalo (talk) 18:35, 5 October 2020 (UTC)

The definition of any particular banned breed of dog will be contained in the specific ordinance or law that is being applied. It can vary from one jurisdiction to another. See Breed-specific legislation.--Shantavira|^{feed me} 08:43, 6 October 2020 (UTC)

In Britain it depends on whether a dog looks sufficiently like one of the prohibited types: Pit Bull Terriers, Japanese Tosas, Dogo Argentinos and Fila Brazilieros. In particular for Pit Bull Terriers, an appearance like the description given in the American Dog Breeders Association standard of conformation as published in the Pit Bull Gazette, vol 1, issue 3 1977.[1] See Dangerous Dogs Law Guidance for Enforcers where Pit Bulls are discussed in Annex 2.[2] Thincat (talk) 09:49, 6 October 2020 (UTC)

Why is it not Perro? There's a Dogo Cubano too. Now Doggo Extincto. Sagittarian Milky Way (talk) 17:30, 6 October 2020 (UTC)

It is short for perro dogo, which is used for mastiffs or dogs with a similar body type. French dogue and German Dogge have the same meaning.  --Lambiam 22:17, 6 October 2020 (UTC)

I once heard, "Any dog shot by police is a Rottweiler if it's black and a pit bull otherwise." This was well before the spate of news stories about police shooting dogs indiscriminately. —Tamfang (talk) 02:42, 7 October 2020 (UTC)

Eyeball question I've been wondering for many years

If a micron-wide sphere of cornea (halfway through and at center of field of view) suddenly turned to antimatter that's a concentrated ~hectojoule suddenly appearing there which is bad, how much would it hurt if it's instead 100 nanometers wide or 10 nm or 1 or 1 atom? How big do you need to see the point of damaged cornea or briefly see a 6th magnitude star? Sagittarian Milky Way (talk) 23:22, 5 October 2020 (UTC)

How do you plan to quantify pain? How much does it hurt to hit your thumb with a hammer? Compared to what? How much does it hurt to have to try to answer this question which makes no real sense? 86.150.105.98 (talk) 08:20, 6 October 2020 (UTC)

Can you at least rule in and rule out pain yes or no from any of those which are 3 whole orders of magnitude apart except for the 1 nanometer versus 1 atom? Sagittarian Milky Way (talk) 17:22, 6 October 2020 (UTC)

Where the hecto does this "hectojoule" come from? Taking the density of the cornea to be the same as for water, ${\tfrac {4}{3}}\pi r^{3}\;\mathrm {kg} ~c^{2}=~?$ The radiation may hurt your brain if it didn't do so already, so please be careful with such experiments.  --Lambiam 10:24, 6 October 2020 (UTC)

Okay ~94 joules if it's the density of water but it's probably more, still well above the ~1 joule allowed in airsoft guns which mandate ballistic goggles for playing. In addition there's ionizing radiation which I'd forgotten about so that would be bad. Can we now narrow down which orders of magnitude of sphere size would not be bad? Is an electron okay? Or a hydrogen atom? More? How big before you notice it if dark-adapted? Sagittarian Milky Way (talk) 17:22, 6 October 2020 (UTC)

A hectojoule is roughly right for a cubic micron. The eye can sense something with about 10 light photons as a flash. One antiatom decomposition would certainly have enough energy for this, but will the energy turn into light, or heat or mostly escape from the eye? If you can make a cubic micron of antimatter, I am sure many labs and governments will want that knowledge! Graeme Bartlett (talk) 00:01, 7 October 2020 (UTC)

And half that cubic micron will be annihilated normal cornea if everything reacts locally. Sagittarian Milky Way (talk) 01:09, 7 October 2020 (UTC)