Wikipedia:Reference desk/Archives/Science/2016 August 10

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August 10

Helix not a helix

I made Bicentennial Lighthouse, a lighthouse article, and described it as helical. Is it? Thanks. Anna Frodesiak (talk) 11:29, 10 August 2016 (UTC)

Our article on the similarly-shaped Skylon (Festival of Britain) dodges the issue by calling it "cigar shaped". Alansplodge (talk) 12:24, 10 August 2016 (UTC)

Alan, all lighthouses are cigar-shaped. Take, for example the Castro Lighthouse, pride of Cuba with its orange light and fine, mellow flavour. Anna Frodesiak (talk) 12:41, 10 August 2016 (UTC)

Also, Skylon is defined as a tensegrity. A tensegrity, of course, refers to a compression structure or any Bruce Willis movie. However, sometimes the term is used to describe structures like this, which would look the same before and after any natural disaster. So, back to the first question, helix? :) Anna Frodesiak (talk) 12:49, 10 August 2016 (UTC)

Apologies, I didn't look closely enough at your image. It bears some resemblance to a propeller blade. Alansplodge (talk) 15:42, 10 August 2016 (UTC)

You could say "twisted". DMacks (talk) 12:47, 10 August 2016 (UTC)

Twisted is not bad, degrees total would be a good thing to add too. Anna Frodesiak (talk) 12:49, 10 August 2016 (UTC)

Looks like about a 90 degree twist, to me. StuRat (talk) 17:46, 10 August 2016 (UTC)

Agreed. Here's a clearer perspective of that[1]. DMacks (talk) 18:01, 10 August 2016 (UTC)

We hit on a linguistic Q, whether a portion of a thing is still called that thing. A partial circle is called a "circular arc", not a "circle". So, I would suggest that less that one revolution of a helix might be called "a partial helix". StuRat (talk) 19:04, 10 August 2016 (UTC)

Thank you all! Anna Frodesiak (talk) 20:20, 10 August 2016 (UTC)

Is it possible to pickle my Hamster?

Blocked.
The following discussion has been closed. Please do not modify it.
Is it possible to pickle my Hamster? I miss him now he's gone and I'd like to keep him but I'm told that he'll rot now he's dead. Would it be possible to keep him pickled in a Jar? I'm not a troll, :( --2.29.52.11 (talk) 18:07, 10 August 2016 (UTC) I'm not sure pickling would be the preferred method of storing a dead animal long term (have you looked into taxidermy?). If you are set on wet preservation, this article has a general overview of storing specimens. The author suggests using a fixative such as formalin followed by long-term storage in diluted isopropyl or ethanol alcohol. Basically, there's a lot of preparation involved and you can't simply put a mammal in some liquid and hope it keeps. clpo13(talk) 18:38, 10 August 2016 (UTC)

Why escalator stairs' steps have sharp edges?

I imagine there must be a pretty good design reason for the sharp edges of an escalator's step. They obviously imply an extra security safety risk. So, I suppose there is a trade-off between security and something else. --Llaanngg (talk) 18:37, 10 August 2016 (UTC)

Who says the edges are sharp? ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:40, 10 August 2016 (UTC)

[2]--Llaanngg (talk) 18:45, 10 August 2016 (UTC)

Next time I'm on an escalator, I'll check out that theory (gently, of course). ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:47, 10 August 2016 (UTC)

Please, use your pinky, baby toe, or any other protruding body part that you don't really need. --Llaanngg (talk) 18:49, 10 August 2016 (UTC)

Note that the edge doesn't have to be sharp like a knife for people to hurt themselves on it; it just has to not be rounded. For example, if you trip and fall while on the moving escalator, your upper body is going to descend at least a few feet or probably more than a meter—and farther than that if it's a down escalator. Your upper body will pick up enough speed that any non-rounded edge can do injury. Also note that in order for you to be able to step off the escalator while walking forward (which is much easier to use than the old "shunt" design where you had to step off sideways), each step surface is made up of individual ribs that go under the comb plate, and each rib has its own edges. At one time those ribs might have been made of wood rather than metal, so they'd do you less of an injury if you hit them, but wooden parts on an escalator are a fire hazard. --69.159.9.219 (talk) 20:40, 10 August 2016 (UTC)

The escalators to the 8th and 9th floor of Macy's, the world's second largest store, are the original wood ones from the store's 1902 opening or so. The entire escalator is wood. It even sounds woody. It creaks constantly and the creaks and the other sounds it makes sound so extremely woody it's probably the closest thing you can ever experience to an anachronistically steampunk escalator. There are also buttloads of lit Christmas trees in the wood escalator zone after like Columbus Day. Also dozens of Santa Clauses. And hundreds of Persian carpets, books, children, burnable toys, lots of pianos and furniture and thousands of wood floorboards (though maybe not all at the same time) Sagittarian Milky Way (talk) 23:03, 10 August 2016 (UTC)

Sure, even a fall on wooden stairs can gouge your shins or whatever. But I very much doubt that it's a problem to put your hand on it. However, if I don't follow up, you'll know what happened. :( ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:20, 10 August 2016 (UTC)

Not sure how security comes in to it, but safety obviously does. However I'm pretty sure it's safety both ways. Sharp edges are obviously a safety risk due to increased likelihood of injuries from a fall or simply kicking the edge. However the design of escalators requires sharp edges. A rounded edge would mean things are likely to fall in or get caught between the step and the comb on the end plate at the top and bottom. I can't find great sources but these hint at it [3] [4]. To put it a different, if you think falling on an stair edge is nasty, imagine getting your foot stuck caught and dragged when you reach the top or bottom because there's a gap between the step and the end plate due to a rounded edge. Nil Einne (talk) 19:00, 10 August 2016 (UTC)

A rounded edge would make it more likely people would slip and fall. A sharp edge sticks into rubber soles on the bottom of shoes and holds them in place better. StuRat (talk) 19:07, 10 August 2016 (UTC)

Do you have a source for this? Hofhof (talk) 01:38, 11 August 2016 (UTC)

I also don't understand what Stu is getting at, unless he's being funny. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:44, 11 August 2016 (UTC)

Looks like we need a diagram:

         | 
         |     
   ______|  Flat step.
   |
   |

         / 
         |     
     ____| Rounded step.
   /
   |

As you can see, the rounded step has less level surface area on which to stand, making it more likely people will slip off. You could counter this effect by making the steps larger, but that has down sides too. As far as the advantage of sharp metal for holding a shoe in place, do an experiment where you step on a sewer grating (the kind with an open grid) and try to slide your feet. Now do the same thing on the pavement. I bet you find your shoes move easier on level pavement. This is because rubber extends down between the grates and physically hits the grating. The hotter the shoes and the softer the rubber, the more effect this will have. A pattern on the shoes soles makes this more noticeable, too. StuRat (talk) 03:23, 11 August 2016 (UTC)

OK, I see what you're getting at about the steps, but I was envisioning just a tiny rounding off of the edge, to smooth off the "square" face it typically has. As for the steps, they are already a peculiar size, larger than normal steps. Just try climbing a stopped escalator. It's an effort. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:16, 11 August 2016 (UTC)

It's a little peculiar reading some of these responses. No one seems to have directly mentioned the obvious answer. The stairs are the shape that they are so that they fit back together into a flat surface at the top and bottom. I don't see how any "rounded" design could fit that constraint. --Trovatore (talk) 22:37, 10 August 2016 (UTC)

Nil Einne implied this idea. Rounded edges imply that things are likely to fall in at the top.

If people cared to read those reports about injuries linked above, they would discover that some accidents occur when things are not combed out by the comb at the end of the escalator. A cigarette stub could get caught and ignite all kind of stuff that also got caught there. Hofhof (talk) 01:37, 11 August 2016 (UTC)

Sure, but one would think that the very edges of the steps could be rounded off slightly without affecting the overall operation. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:46, 10 August 2016 (UTC)

I suppose they are the less sharp possible, but still able to avoid the problem mentioned above. Hofhof (talk) 01:37, 11 August 2016 (UTC)

Think StuRat has got it right. Here is a Escalator Step with a sharp edge that affords better non slip grip. In a domestic setting with carpeted stairs, a rounded edge would make since as the carped affords grip (upon a miss footing placement), the step hight is lower and a sharp edge would quickly wear the carpet away on the edges (which is where stair carpets wear the most). Posh homes with un-carpetded stone stair cases have sharp edges. Communal stairs (like in my apparent, local hospital, town hall, etc.), all seem to have sharp edges too. It is the balance of safety and use that denotes the edge of escalators to require a sharp edge. Escalators do indeed have larger than normal steps because the escalator removes the effort (when they are working) of climbing. Hence, they can be shorter and less expensive to install when using high steps. I remember as a child having to trust in the balance of my ear canals to know which way was vertical when descending very steep subway escalators. My visual senses tried to tell me I was leaning the wrong way because the higher step made the escalator appear at lesser angle than ordinary stair and under ground escalators don't afford a horizon line to visually check the vertical. Found the same affect when exploring a beached fishing vessel. Familiarity, told my visual senses that floors were always horizontal and the walls vertical but gravity kept pulling me into the corners. . So and finally, the OP also linked to a litigation layer who can kid people that escalators are more dangerous than static stairs and because they are mechanical, and the owners would rather settle out of court than suffer high litigation cost to show it was really the fault of the litigant’s own clumsiness (lack of every day boring Situation awareness. One can walk through a Nation Park and still sprain and ankle or encounter a copper head etc. It is the balance of risk that is paramount. --Aspro (talk) 10:56, 12 August 2016 (UTC)

How high are the subway escalators you saw? If they're in a long enough diagonal tube and you look down their axis they can look vertical or horizontal. Especially if you try to imagine it's horizontal or vertical. This must be a byproduct of the visuo-braino system being trained since birth that orthogonal walls are oriented to gravity like you said (cavemen with tent/style architecture wouldn't have this problem) Low tens of feet is high enough to have this effect. Sagittarian Milky Way (talk) 22:39, 12 August 2016 (UTC)

The Angel station has London’s Underground's longest escalator at 60m/197ft, with a vertical rise of 27.5m. [5] back then (if I remember it rightly) before refurbishment took place. The only vertical clue was the up-lighter pedestals that shone light on to the ceiling. Today the image show load of advertisements on the wall and they may offer the same visuo-braino correction factor. Can't remember if they had the adverts back in those days. Just remember very clearly the sensation that was a bit like vertigo and thrilling to experience. May be the same experience that people get in the Upside down house.--Aspro (talk) 13:18, 13 August 2016 (UTC)

• The risk of impact injuries from falling on an escalator is relatively small. The biggest risk is from getting caught in it and dragged into the machinery. So gaps are a real problem for escalator design. Better a sharp edge with an injury hazard than rounded edges which formed a trap.

One principle used to be that if a gap was small, only a small thing (a piece of fabric) could be caught in it and when trapped, that would tear off - hence the ubiquitous toothed combs where steps re-enter the platform. This principle was recognised to have changed in the 1970s, with the widespread advent of strong synthetic fabrics. A nylon webbing luggage strap (as a likely example) could now be both small, trappable, yet of enough tensile strength to drag the rest of the luggage or garment into the machinery. Andy Dingley (talk) 11:32, 12 August 2016 (UTC)

Something about the Theory of Global Warming doesn't quite add up

Scientists say that global warming is now irreversiable and the only way for the human species to survive is to colnize other planets. However this always seemed strange to me, since if humans had the knowhow to colnize other planets, all of which are far more inhospitiable than even the worst global warmming senerio, then surely we would have the ability to make earth hospitiable again. Or humans would have to live in space ships, but again surely that same technology could enable humans to live in the sea in big underwater ships? Explain to me how terraforming Mars or living in outaspace is preferable to terraforming Earth or living in the sea, which would surely be easier and cost less money? — Preceding unsigned comment added by 112.213.94.36 (talk) 20:11, 10 August 2016 (UTC)

Your question is based on a false premise. I don't know of any scientist who says that the only option for human survival is colonization of other planets, and I would be very surprised to hear (a competent) one express such an opinion.

It is generally held that there are irreversible human-driven changes underway (at least, irreversible on human timescales) to our atmosphere and climate, some of which are likely to result in tremendous costs (both social and economic) in the coming decades. None are likely to render Earth's surface completely uninhabitable. If increasing sea levels flood Manhattan (again...), humans will tend to resettle (at great expense) further inland, wherever the new shoreline happens to end up. See, for example, this article for a bit more information. TenOfAllTrades(talk) 20:26, 10 August 2016 (UTC)

Agreed. Note that the cost is largely dependent on the speed of climate change. If it's slow enough, we can just abandon shoreline buildings when they outlive their usefulness due to age. StuRat (talk) 20:59, 10 August 2016 (UTC)

#AbandonVenice Sagittarian Milky Way (talk) 21:06, 10 August 2016 (UTC)

Well, you might simply consider the opposite of the Atlantropa plan, and protect Venice behind a dike, rather than connecting it to a shrunken Mediterranean with a canal. There a several dcumentaries of the idea. https://www.youtube.com/results?search_query=atlantropa μηδείς (talk) 21:30, 10 August 2016 (UTC)

Seawater filled Ground Zero, 75% of the road tunnels to Manhattan and 9 subway tunnels which would cost maybe $2,300,000,000.00 per mile to completely replace. Abandon that. And that was only 9.88 feet of storm surge. Sagittarian Milky Way (talk) 22:25, 10 August 2016 (UTC)

The L train tunnel must be completely fucked up because it'll be closed for 1 and a half years for Sandy repairs. Sagittarian Milky Way (talk) 22:33, 10 August 2016 (UTC)

The problems facing Venice are mostly caused by land subsidence due to withdrawal of water from aquifers under the city rather than climate change-induced sea level rise. The big increase in frequency of acqua alta events mostly took place between 1950 and 1970. SLR due to climate change does of course reinforce the land subsidence effect. Shock Brigade Harvester Boris (talk) 00:38, 11 August 2016 (UTC)

Of course there are many many more effects of global warming than having to move human settlements, which you can read all about in said article. The original poster mentions living in the sea. Sounds great, but where you do grow all the food to feed people? Scientists have seriously discussed "terraforming the Earth", also known as climate engineering or geoengineering, though it's generally considered a last resort, as it's something we've never done before. It's probably not a great idea to conduct an experiment on the only habitable planet we have. --71.110.8.102 (talk) 08:31, 11 August 2016 (UTC)

Unfortunately it looks like some such effort will have to be done and maybe quite soon. Anyway the article Climate change mitigation talks about various ways of coping with climate change. Dmcq (talk) 09:12, 11 August 2016 (UTC)

• To those of us paying attention, the OP is more or less correct and notes an interesting paradox. Humanity is currently experiencing what is referred to as the sixth extinction, sometimes known as the Holocene extinction or Anthropocene. Given that 99% of all species that ever existed on planet Earth are already extinct, it is highly unlikely that humanity will survive the next several hundred to several thousand years in its current form based on the known state of the planet which has been rendered all but useless by our greed, delusion, and hatred for non-human life forms, a diverse set of species and niches that we require for survival. The OP accurately notes the technological paradox that many here conveniently ignore due to paradigm blindness. To briefly summarize: since humanity is doomed on Earth for multiple reasons, many beyond our own control and doing, it is recommended that we stop putting all of our eggs in one basket and explore the Solar System and later the nearby star systems to further our survival. However, the very technology required to make space settlement possible is also the same technology needed to fix our problems at home. Many will deny this, few will accept it. — Preceding unsigned comment added by 107.77.227.100 (talk) 04:47, 12 August 2016 (UTC)

Never have I felt a stronger urge to put {{cn}} templates on a talk page comment.

That 99% of species have disappeared does not validly indicate humans have a 99/100 chance of going extinct; humans are very different from the "average species" if we go by numbers alone (that species must be some kind of insect, it would be more relevant to have extinction stats for mammals for example), and it is the first species whose main risk of extinction is driven by nuclear warfare. I do not see any reason that space exploration research leads to climate engineering advances or vice versa either. And climate change will not drive humanity to extinction - it may decrease population by 90% by violent means of war, water shortages and the like, but we have the transportation technology to relocate at least the wealthiest of us to livable areas.

Anyways, that kind of speculation does not belong to the reference desk. Tigraan^{Click here to contact me} 11:35, 12 August 2016 (UTC)

With the greatest of respect, everything you've written is wrong. Extinction is the outcome for most species; the difference now as to opposed to the deep past, is that humans are driving extinction, which in turn accelerates their own. Nuclear warfare is not and has never been our "main risk" of extinction, and I'm curious where you got that from. Our main risk of extinction is and always has been humanity itself. Your claims are directly refuted and put to rest on the global catastrophic risk page, so there is no need to discuss it. As for the technology paradox that the OP correctly and accurately described, the knowledge needed to build and maintain a sustainable space settlement, either on a planet or an orbiting platform or colony, is the same knowledge and technology needed to repair and sustain our planetary system here at home on Earth. — Preceding unsigned comment added by 107.77.227.199 (talk) 18:44, 12 August 2016 (UTC)

Age of American Chemical Society logo

Does anyone find out the year when the logo of the American Chemical Society was created? It can't be later than 1951. --Leyo 23:03, 10 August 2016 (UTC)

Indeed, in 1951, it was already used:

According to Kaliapparat: "A stylized symbol of a kaliapparat is used in the American Chemical Society logo, originally designed in the early 20th century by Tiffany's Jewelers". There is a source there, that you could follow for a more precise answer.

--Hofhof (talk) 01:19, 11 August 2016 (UTC)

Thanks a lot. Unfortunately, I don't have access to the cited literature. --Leyo 08:15, 11 August 2016 (UTC)

No thanks at all. Fortunately, Leyo, you can request access to pay-walled journals at Wikipedia:The_Wikipedia_Library.--Hofhof (talk) 17:29, 11 August 2016 (UTC)

Thanks, I will do this later. BTW: Revent found that the trademark registration shows that the logo was initially 'used in commerce' in December of 1909. Unfortunately, the link he provided has expired. --Leyo 22:06, 11 August 2016 (UTC)

(grr) http://tsdr.uspto.gov/#caseNumber=73130570&caseType=SERIAL_NO&searchType=statusSearch should work permanently. Revent^talk 22:09, 11 August 2016 (UTC)