Wikipedia:Reference desk/Archives/Science/2014 August 23

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August 23

Furnace cement

Furnace cement seems to have little in common with Portland cement. Wikipedia does not appear to have an article on it. In particular, per its material safety data sheet, "Imperial Hi Temp Stove & Furnace Cement" by Kel Kem LTD, Ontario, Canada is an asbestos-free product for filling chinks around a fireplace or like high-temperature applications. It is a blend of Silica quartz (40-70%), Hydrous Aluminum Silicate (15-40%), Sodium Silicate (10-30%) and Sodium Hydroxide (1-5%). (I don't understand the stated extremely wide variation in their own statement of the composition). The directions say wet the surface, then apply with a wet trowel, allow to air dry for 24 hours, the heat it up gradually to cure it. It says it must be heat cured, and that it is not for exterior applications. it is rated for use up to 1482C (2700F). So my question is, is there some chemical reaction when it is heated to cure it, and what would that reaction be? Does some form of glass appear when it is heated, like Porcelain,or does it just dry and get hard because the water goes away? None of the chemicals seem similar to the clays which go into Pottery. Thanks. Edison (talk) 00:33, 23 August 2014 (UTC)

I've got a tub of fireclay, tho it actually calls itself refractory mortar. I'd say it just dries out but there is some chemical reaction as it doesn't immediately soften when wetted again. Greglocock (talk) 00:48, 23 August 2014 (UTC)

The chemicals listed do not appear to be "clay" right? If you heat clay, you get pottery or porcelain. If you heat Portland cement or concrete in a furnace, it gets crumbly and falls apart. But what is going on here? Edison (talk) 01:04, 23 August 2014 (UTC)

Try Refractory, under the 'Castable' heading. The link there to Fire clay also looks promising. --Heron (talk) 08:50, 23 August 2014 (UTC)

But not the same ingredients. Clay minerals lists " hydrous aluminium phyllosilicates." Is the "Hydrous Aluminum Silicate" the same? Are the chemicals in this product the same as other clays listed in Clay minerals, but with different nomenclature? ("Dickite" for instance. hahaha) Edison (talk) 17:32, 26 August 2014 (UTC)

Song identification after one musical note

I've decided to post the question here (and not in Entertainment) since it may (or may not) involve the brain's cognitive abilities. I've been briefly watching the Polish version of Name That Tune and there many folks correctly identified songs after hearing just one note (not even two). Even though they are given hints, I think it's almost impossible to ID a song after one note (I remember the old Russian version hosted by Valdis Pelšs, where players normally decided to hear at least two notes, but not one). Is it actually true or there's some foul play involved in guessing just after one note? Brandmeister^talk 11:10, 23 August 2014 (UTC)

If it was the first note of A Hard Days Night, it wouldn't be too hard. HiLo48 (talk) 11:27, 23 August 2014 (UTC)

AHDN is introduced by a chord which is several notes. Just a drumroll is enough to bring an audience to their feet singing the national anthem - if you happen to be in a British theater where the queen is expected to arrive. Music is shaped by expectation. Could the first note of this be anything other than this? 84.209.89.214 (talk) 11:43, 23 August 2014 (UTC)

So it's not just the note, it's the orchestration, right? If the host of the show were at a piano and simply hit some particular key, it seems unlikely they could do any more than guess. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:44, 23 August 2014 (UTC)

Yes, but the hints can be pretty good give-aways; that's the trick on the "one note" guess. Someone good with music trivia doesn't need notes at all; they just know enough pop music to be able to get the song from the clues alone. --Jayron32 19:35, 23 August 2014 (UTC)

When Name That Tune was on UK television (many, _many_ years ago), the contestants generally worked out the tune from the description, and didn't really need the single note to confirm their answer. Tevildo (talk) 14:03, 23 August 2014 (UTC)

Plan a half hour to listen to this properly but any Norwegian can tell what it is from the first note. We like you to enjoy. 84.209.89.214 (talk) 22:29, 23 August 2014 (UTC)

To which there is only one possible response... Tevildo (talk) 22:41, 23 August 2014 (UTC)

Whey protein

Can whey protein cause ibs or stomach issues in the long term? 82.132.216.31 (talk) 13:27, 23 August 2014 (UTC)

See Whey protein and irritable bowel syndrome for our articles. As the causes of IBS aren't known, it's not possible to say whether or not any particular diet can affect it. Tevildo (talk) 15:44, 23 August 2014 (UTC)

The scientific method could be used here, where one group of test subjects has a diet devoid of whey protein, and another group has a diet identical to the first group, except for the presence of whey protein. After the test period, the two groups could swap their diets for a 2nd test period of the same length. Questionaires would be used throughout, to tell if there is any noticeable difference in IBS symptoms. Or you could simply count the number of bowel movements per day, to make it less subjective. StuRat (talk) 21:31, 23 August 2014 (UTC)

Double-blind trial and Koch's postulates might be better starting points. Tevildo (talk) 22:49, 23 August 2014 (UTC)

The first link is applicable, but the 2nd is for diseases caused by organisms, while, if whey protein contributes to IBS, it would be likely due to an allergic reactions. StuRat (talk) 17:17, 24 August 2014 (UTC)

Despite the known sciency-ness of responders to the Wikipedia help desk, I doubt scientists have overlooked the scientific method. Rather I suspect both IBD, diets, allergies and whey protien to have far more intricate levels of interaction that have so far escaped science. Putting people on regimemted diets will affect them. So will consumption of foods (see latex allergy for the gradual emergence). The permutations and sample size along with subjective criteria will make definitive causation to be scientifically elusive. Even the time spans are difficult as the experiment has to be long enough to initiate the effect yet short enough not to be affected by other uncontrollable events such as seasons, aging or even as short as monthly hormonal cycles. To summarize, eat it. If you puke, get diarrhea, constipation or die - stop eating it. If you develop a condition over time, stop eating it. Note that it will be nearly impossible to physically isolate your IBD to Whey protein. However, your own empirical observation, (whether physical in origin or psychological or random) is probably more important to you as you assess your situation in the WC think tank. --DHeyward (talk) 05:21, 25 August 2014 (UTC)

One of IBS's top theories is related to bacterial flora, which are "organisms." --Wirbelwind(ヴィルヴェルヴィント) 23:25, 26 August 2014 (UTC)

Yes, based on my decidedly non-scientific survey of sources online (googling "whey protein and IBS") as well as my own recollection of nutritional research into the adverse health effects of cow's milk in general. On a common sensical/biological level, you might wonder why humans are the only species to drink another species' milk (cow, goat, etc) and even those species don't drink their mother's milk after a certain young age... but then maybe I'm a bit biased as a vegan. El duderino ^(abides) 13:40, 25 August 2014 (UTC)

Lactase persistence which enables adult humans to digest milk and dairy products beyond infancy is often cited as an example of recent human evolution correlated with the rise of dairy farming. As dairy farming originated in Europe, Europeans were exposed to increased lactose nutrition provided by dairy products, resulting in positive natural selection. The supply of fresh milk leads to the favoring of the lactase persistent trait.

Unlike ovo-lacto vegetarians, vegans object to dairy farming where female calves are separated from their mothers within 24–48 hours of birth and fed milk replacer, so that the cow's milk is retained for human consumption, and will be kept pregnant through artificial insemination to prolong lactation. 84.209.89.214 (talk) 14:32, 25 August 2014 (UTC)

Measurement of a standing object's stability

How the stability of a free-standing object is measured (in what units)? For example, of a one-legged torchère vs. three-legged tripod? Or of persons with different weights or of two persons with one's legs close to each other and the other person with his legs apart for more stability?--93.174.25.12 (talk) 19:57, 23 August 2014 (UTC)

You may find this lesson or maybe this lesson a good introduction; the relevant Wikipedia articles would be at center of gravity and moment of inertia. Stability is determined by whether or not an objects center of gravity is raised or lowered as a result of a force. An object's position is inherently unstable if its center of gravity is easily lowered by a small push in any direction. An object is inherently stable if no motion could lower the center of gravity (that is, the center of gravity is in the lowest possible position). An object would be metastable if the center of gravity is NOT in the lowest possible position, but where any push would still result in an initial raising of the center of gravity (that is, you would have to lift the center of gravity some before thw object spontaneously fell over). If you wanted to put a number on stability in this way, these concepts can be quantified using gravitational potential energy; the difference in gravitational potential energy between an object's current position and its most stable position would be it's instability, the SI unit for such measurement would be the Joule. If you are familiar with chemistry, this quantification of positional stability is exactly analogous to the Reaction coordinate diagram used in chemical kinetics and thermodynamics. Indeed, the concept of "stability" in this way is universal in physical sciences; the difference is in applying the general idea to specific situations, whether it be chemical reactions or things falling over. --Jayron32 20:10, 23 August 2014 (UTC)

Also, there can be dynamic stability, such as a spinning top that is stable so long as it spins, then falls over when it slows down. StuRat (talk) 21:25, 23 August 2014 (UTC)

The simplest answer is probably 'degrees'. In tests like this, they just tilt the object until it starts to fall over. The angle of tilt is a good measure of stability. --Heron (talk) 08:22, 24 August 2014 (UTC)

For boats, metacentric height (measured in units of length) is the relevant parameter. It would be easy to calculate this for a land-based structure, but I don't believe this is done routinely. Tevildo (talk) 09:12, 24 August 2014 (UTC)

Skyscrapers do something similar and to counteract sway (which can be substantial in upper levels), they often place a large mass at the top that is moved around to limit sway and nausea. Damping is the term I would use to describe stability but it leaves out cases that appear stable until perturbed (i.e. ball ot top of a hill -> meta-stable?). Resonance is another related concept to stability. --DHeyward (talk) 05:32, 25 August 2014 (UTC)

houseplants peperomia obtusifolia trouble

I took cuttings of my Peperomia Obtusifolia that had a severe accident, and have been attending them for the past week or so. I left them unnoticed (I have a lot of plants) for a few days, and noticed that they are dry to the bottom. It's four in the afternoon, very cloudy, and an apt. building wing blocks the direct Sun from my windows. Do I water anyway, or wait for the sunny day tomorrow? Thank you for your interest. Ed Meissner

This is a question, not an answer, because I have not grown Peperomia for years. But I'm wondering why you think you maybe should not provide water when it is dried out. C7nel (talk) 21:16, 23 August 2014 (UTC)

The OP seems to think that plants should only be watered when sunlight is on them. I've not heard that, but I suppose it might keep mold down. Personally I think watering them whenever they are dry is best. StuRat (talk) 21:23, 23 August 2014 (UTC)

I agree with StuRat, you should keep them damp and I think you should not allow direct sun onto the cuttings. Richard Avery (talk) 07:11, 24 August 2014 (UTC)