Wikipedia:Reference desk/Archives/Science/2015 December 26

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

December 26

Gas on a planet and saterites

Can we have gas on moon, Mars, and Pluto? (I can not be surely back) Like sushi 49.135.2.215 (talk) 01:40, 26 December 2015 (UTC)

Yes, in all cases. Hydrogen remains a gas even at very low temperatures (20.271 K/−252.879 °C/​−423.182 °F), so there's no problem with it becoming a liquid or solid (and the Moon and Mars aren't all that cold, so they can have plenty of other gases, too, and even Pluto has a few other gases at those much colder temps). As for the lower gravity on those bodies, that just makes for a much thinner atmosphere. StuRat (talk) 04:51, 26 December 2015 (UTC)

Pluto has a thin atmosphere, read Atmosphere of Pluto. It is mostly nitrogen, as on Earth, but much thinner. The atmosphere of the Moon is extremely thin, and contains sodium and potassium. The Moon's atmosphere also contains levitating dust, see Lunar soil#Moon dust fountains and electrostatic levitation, but that is not a gas. The Atmosphere of Mars contains carbon dioxide, argon and nitrogen. It also can have dust. Graeme Bartlett (talk) 05:02, 26 December 2015 (UTC)

Cats and dogs and rock and roll

Do my cats (or your dogs) hear melodies and harmonies? When I'm rocking out, do they hear it as 'music' and rythm or do they just perceive white noise or a cacophony of random sound? And if we know, how do we know? — Preceding unsigned comment added by 94.210.130.103 (talk) 11:11, 26 December 2015 (UTC)

There has been some research into the effect of music on animals, see this list of papers. According to this author, based on the behaviour of dogs in competions, he believes that while dogs will respond to different kinds of music, they do not move in time to the music, but rather, are following the movements of their handlers. Any dancing motion by the dog takes it cues from the handler rather than the music directly.

To add my personal opinion: all human music is likely to be too drearily slow for a dog to want to dance to it, even if they do have that capacity. The natural body rhythms for a dog (heartbeat, breathing, walking/running paces) are just so much faster than humans. SpinningSpark 12:55, 26 December 2015 (UTC)

Splittercore 1001 beats per minute. This is the fastest genre on Earth. Sagittarian Milky Way (talk) 23:35, 26 December 2015 (UTC)

There is evidence that monkeys at least can tell the difference between consonance and dissonance (PMID 11731536). However as I understand it there is no clear evidence that they have a preference for consonance (PMID 16597745). Monkeys also are sensitive to auditory rhythms and can detect departures from them (PMID 24046732). More sophisticated aspects, such as the ability to detect when a melody resolves and take pleasure in it, have not been studied as far as I know. Looie496 (talk) 13:41, 26 December 2015 (UTC)

We have an article on Zoomusicology, which may be of interest. 99.235.223.170 (talk) 14:36, 26 December 2015 (UTC)

Engineering fields

In what ways are biomedical engineering and public health engineering different from traditional engineering fields? Are they different in the first place? 2A02:C7D:B91D:CC00:D9E:8951:C421:E7FC (talk) 12:07, 26 December 2015 (UTC)

Prince Rupert's sugar

Would a Prince Rupert's Drop made from sugar glass work? Meaning, will it withstand large forces on the bulb while shattering when the tail is broken? A quick google suggests that some people think it works, and that's my intuition too, but a little guidance and refs would be nice. Thanks, SemanticMantis (talk) 14:53, 26 December 2015 (UTC)

This exact question has been asked before here and a somewhat related one here. Might be worth a look. 99.235.223.170 (talk) 18:56, 26 December 2015 (UTC)

Engineering design

Can engineering design be done by anyone? Is it not like medical practice which can only be done by a registered doctor or auditing which can only be done by a chartered accountant etc or law partners/judges which have to be chartered legal execs? Is there no equivalent for engineering? — Preceding unsigned comment added by 89.242.5.123 (talk) 15:46, 26 December 2015 (UTC)

Some of the more serious engineering need some sort of qualification, not sure what field you interested in but have a browse at Category:Professional certification in engineering for an idea. MilborneOne (talk) 15:49, 26 December 2015 (UTC)

What do you mean by more serious? I think anyone is legally allowed to do engineering. 2A02:C7D:B91D:CC00:4807:48B4:9A8D:4075 (talk) 17:22, 26 December 2015 (UTC)

Obviously, laws vary by locale. In California, a state license is required to perform work as a "civil engineer", "mechanical engineer", "structural engineer", "electrical engineer", or even "professional engineer", and the standards are stringent. For example, only 38% of recent applicants for an electrical engineering license passed the test.Here's some basic information from the state license board. Cullen³²⁸ Let's discuss it 18:13, 26 December 2015 (UTC)

No. In all US states one must have a license to represent one's self as an engineer, at least in construction-related endeavors. The state licensing board has the power to prosecute those who practice without a license. In the UK the title is not protected in the same manner, but in practical terms, one must be a chartered engineer to practice. Acroterion (talk) 18:18, 26 December 2015 (UTC)

Regulation and licensure in engineering would seem the appropriate article to link to... 99.235.223.170 (talk) 18:58, 26 December 2015 (UTC)

"Licensure"? What barbarian came up with that abomination? Tevildo (talk) 23:13, 26 December 2015 (UTC)

Software engineers don't need a degree, AFAIK. Quality might vary. Denidi (talk) 21:22, 26 December 2015 (UTC)

Even in the most stringently legislated states ANYBODY can do an engineering design. Some states have restraint of trade, closed shop union type legislation to prevent those who aren't in the club from selling engineering services to the public, but that is not what you were asking. As an example, heavily engineered products like cars and aeroplanes are designed and tested and signed off by people who are not state licensed engineers. I am in two minds as to whether this is a good thing or not, I rather look forward to the bruised egos when the established engineering boards are invaded by a vast influx of experienced engineers with little tolerance for 'design to code' and other such crutches. Incidentally software engineers aren't engineers (99 times out of 100). Sorry about that.Greglocock (talk) 22:28, 26 December 2015 (UTC)

Anyone can certainly design and engineer an invention and apply for patent. To actually get approval to sell it to the public might require some credentials, though. StuRat (talk) 00:30, 27 December 2015 (UTC)

Do you actually know anything about the subject in hand? Design for manufacture, and inventors, are two examples where a PE is not required. Greglocock (talk) 03:25, 27 December 2015 (UTC)

You should avoid attacking other users in front of the OP. A simple correction should be sufficient. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:33, 27 December 2015 (UTC)

"Engineering" is a very broad and inclusive concept, which includes everyone from a person certifying that the design of a highway bridge is safe, to a programmer designing a smartphone game app. Governments, in general, tend to insist on licensing of people who represent that they are qualified to design the foundations of skyscrapers or highway interchanges, but not those who design furniture or computer games themed to the latest Hollywood blockbuster. Public safety is the compelling interest. Cullen³²⁸ Let's discuss it 04:24, 27 December 2015 (UTC)

well... except for things like aircraft and cars (and even nuclear power stations in some jurisdictions)Greglocock (talk) 05:08, 27 December 2015 (UTC)

Here's the definition of engineering: "The application of mathematics and the physical sciences to the needs of humanity and the development of technology". Note no mention that to do engineering you must have professional degrees and/or certification. Now certain industries may require that of their employees, but those are not essential qualifications to actually engage in engineering. As a comparison, look at being a "teacher". Anyone who teaches others is a teacher, regardless of if they possess an education degree or any other qualification. Of course, again, to be employed as a teacher in some positions may require those. StuRat (talk) 06:23, 27 December 2015 (UTC)

In the uk, all school teachers require a school teaching qualification by law. 82.132.217.90 (talk) 21:00, 28 December 2015 (UTC)

No, there are more than 17,000 unqualified teachers in England alone, and they have a special pay scale. Dbfirs 21:40, 28 December 2015 (UTC)

Does excessive strength training and exercise in youth really stunt growth?

^Topic ScienceApe (talk) 17:21, 26 December 2015 (UTC)

Have you read something that suggests it does? If so, what have you read, and where did you read it? Dolphin (t) 20:33, 26 December 2015 (UTC)

As a child I heard it before. There's also this. It may be a myth though. ScienceApe (talk) 05:20, 27 December 2015 (UTC)

Your website states that inadequate nutrition may have an adverse affect on health. It also says exercise in childhood is critical for good bone growth. It doesn't actually suggest that exercise and strength training will stunt growth. Dolphin (t) 11:50, 27 December 2015 (UTC)

Those shrimps Arnold Schwarzenegger and Lou Ferrigno would no doubt disagree. Clarityfiend (talk) 01:37, 27 December 2015 (UTC)

Did they do intense strength exercises as children though? ScienceApe (talk) 05:20, 27 December 2015 (UTC)

I'd rather avoid treating single cases as more than anecdotes. It's also relevant that Arnie and Lou were into weight-lifting, not simple strength training, which might include weights or not. For a couple of references about strength training in a young age see [1] and [2]. --Denidi (talk) 15:16, 27 December 2015 (UTC)