Wikipedia:Reference desk/Archives/Science/2012 May 28

= May 28 =

Separating catenane links
The article on Catenane says that "The interlocked rings cannot be separated without breaking the covalent bonds of the macrocycles", but no source is cited. Is this correct? As two covalent bonds come closer to crossing one another, couldn't the entangled electrons of one bond tunnel through the point of the other pair and hence break the chain without breaking either of the two macrocycles? 203.27.72.5 (talk) 03:37, 28 May 2012 (UTC)
 * Although tunnelling would be possible, it would be very very unlikely, as you would also have to move the whole of more than one atom and not just the electrons, so say instead of a one in a million chance it may be one in a zillion chance. However you may be interested in living cells there is Type II topoisomerase which can pass DNA through another strand. Graeme Bartlett (talk) 12:47, 28 May 2012 (UTC)
 * How unlikely? Like if you had a massive catanane 1km long wouldn't the chain breaking at some point become extemely likely as time passes? 1.124.213.55 (talk) 08:58, 1 June 2012 (UTC)

Comparing Heat Conductivities
In general, out of all the different materials that water bottles are made up of, which has the lowest heat conductivity. The other day, I saw a Voss bottle (which is cool because it is made up of glass). So I started thinking about is a plastic bottle better or glass. I want the water to stay cool as long as possible in ambient air temperature so that it doesn't warm up quickly. I understand that it would also make it tougher for the refrigerator to cool the water down (low heat conductivity works both ways, right?). So someone who knows more about the types of plastics and glass used to make consumer grade commercial water bottles, which kind is better? I don't use a thermos or anything. I just buy bottled water and then just use the bottle and replace it maybe every six months or so. Doesn't plastic also break down quicker (into carcinogenics) with heat acting as a catalyst? I remember my chemistry teacher vaguely saying something like this. -  Looking for Wisdom and Insight! (talk) 05:45, 28 May 2012 (UTC)


 * I have a suspicion the glass bottle might feel cool to the touch because it conducts heat (away from your hand) better - which is the opposite of what you want. --Demiurge1000 (talk) 14:19, 28 May 2012 (UTC)

That is true that the glass bottle does feel much cooler but the water also feels cooler to me longer than it would from a plastic bottle. So the glass takes the heat in from its outside environment (because it is hotter) and then transfers that heat to the water more efficiently to heat it up? So a glass bottle warms up the water better until the inside and outside reach thermal equilibrium? Could it be just a weird perception error on my part? Like I touch the bottle, it feels very cool so I say to myself that the water is cool too while it may not really be? Or is there a scientific explanation for this and the glass bottle really does keep the water cooler for longer? I am thinking heat capacity, if the glass has high heat capacity then wouldn't it just absorb the heat from both sides and keep both sides cool? Cool to the touch and cool water? - Looking for Wisdom and Insight! (talk) 20:15, 28 May 2012 (UTC)


 * Yes, something like that. Also, a dark plastic bottle would absorb solar heat more than a clear glass bottle with a clear liquid inside.


 * And why not consider a thermos bottle ? It would keep your water cold and you won't get those nasty chemicals leaching from plastic. StuRat (talk) 04:00, 29 May 2012 (UTC)

Blind Spot in space travel

 * "Ships disappear in the Blind Spot. No puppeteer would go too near a singularity in hyperdrive; yet still they disappeared, in the days when our ships carried pilots.  I trust the engineers who built the Liar.  Hence I trust the cabin gravity.  It will not fail us.  But even the engineers fear the Blind Spot."

That's taken from page 103 of my copy of Ringworld. This Blind Spot is mentioned a few other times previously in the book and I didn't think too much of it because I figured some explanation of it would come. I don't think I've come across one though. Can anyone tell me what this Blind Spot would be? Thanks, Dismas |(talk) 10:42, 28 May 2012 (UTC)


 * It's a fictiony thing Niven invented; it's explained in Known Space. -- Finlay McWalterჷTalk 11:01, 28 May 2012 (UTC)


 * (EC) I'm pretty sure this is something that's primarily in-universe. The first and third internet search results for 'blind spot ringworld' for me, i.e. Known Space and seem to answer the question although they may also contain spoilers (although I also wonder if the answer is a spoiler). Nil Einne (talk) 11:06, 28 May 2012 (UTC)
 * Not particularly spoilery, as I seem to recall that Niven explained it at its first introduction.
 * It's not a spacial location, despite the quote above, in which Niven is being metaphorical. Essentially, when one travels faster-than-light in Niven's version of hyperspace, one cannot properly visually perceive hyperspace itself, so if one's ship has a porthole or other transparent hull aperture (Puppeteer ships' hulls, which many other species use, can be made selectively or entirely transparent, according to convenience), it is as if a human's normal blind spot expands to cover the whole field of hyperspacial view, such that object either side of the porthole (say) appear to be next to each other with nothing between them perceptible. Additionally, however, many intelligent species (including Puppeteers and Humans) are psychologically drawn to stare at the hyperspacial Blind Spot, and individuals usually enter a kind of trance state in which thought and movement cease, which may persist until some mechanism or a still-un-tranced crewmate (where the ship is not a one-person craft) interrupts the view.
 * Hence, for a ship to have "disappeared in the Blind Spot", the pilot/crew has/have become hypnotised by it and ceased to navigate the ship, which will either crash or at least become permanently lost in hyperspace. {The poster formerly known as 87.81.230.195} 84.21.143.150 (talk) 12:15, 28 May 2012 (UTC)


 * It's thirty years since I read the stuff, but that sounds right to me. —Tamfang (talk) 21:07, 28 May 2012 (UTC)

Thanks for all that. I was hesitant to read too much about the book or the universe in it for fear of any spoilers. Dismas |(talk) 00:23, 29 May 2012 (UTC)

Algae on the Moon?
Timo Vuorensola, the director of Iron Sky says in this BBC article that algae was found on the moon. I cannot find anything on the internet about this, and it is the first time I've heard it. Surely, if it were true, it would be common knowledge, being a pretty sensational discovery. Is it true? Can anyone find any reliable reference about it? KägeTorä - (影虎) ( TALK )  13:17, 28 May 2012 (UTC)


 * He's the director of a comedy film involving Nazis living on the dark side of the moon, so how could that qualify him as an expert on real lunar exploration? Roger (talk) 13:31, 28 May 2012 (UTC)
 * (EC) Certainly, I do not dispute that. However, for him to say something like that in a serious interview, I would expect there to be at least some information somewhere. I doubt he just made it up on the spot. Anyway, my question is asking for any links to information. I'm not here to provoke a discussion on the subject.  KägeTorä - (影虎)  ( TALK )  13:40, 28 May 2012 (UTC)
 * If you read it again, you will see that he puts that comment into the context of one possibility, it is not stated as a fact. 217.158.236.14 (talk) 13:38, 28 May 2012 (UTC)
 * Sure, it is spoken in the context of a possibility, but the wording states it as fact: "Twenty years after the Nazi era, ice was found there, and algae". Perhaps he is confusing it with some stories I heard in the past about algae having 'possibly' been found on Mars, and not the Moon.  KägeTorä - (影虎)  ( TALK )  13:43, 28 May 2012 (UTC)
 * I'd agree that is a possibilty. He is incorrectly remembering the widely reported discovery of supposed "micro fossils" in a Martian meteorite Allan Hills 84001. Roger (talk) 13:53, 28 May 2012 (UTC)

"New form of LSD"
Followers of the zombie genre have little difficulty explaining a recent face-eating cannibal attack in Miami. But police are quoted claiming it was due to "a new form of LSD". Now of course there is only one lysergic acid diethylamide, and my understanding is hallucinogens of this class are generally credited with leaving an unaffected "watcher", some part of the brain which continues to monitor self-preservation and basic morality. (Henbane/scopolamine, on the other hand, who knows?) Anyway - anybody know what "new kind of LSD" that the police might be talking about? Wnt (talk) 21:55, 28 May 2012 (UTC)


 * It doesn't sound like that assessment is based on any deep understanding of chemistry — sounds like a policeman saying the equivalent of, "it's probably some crazy new drug I've heard about." "...their organs are burning up alive" is not a statement that reflects any attention to biological precision, either. Anyway, the "take your clothes off and do crazy, violent, even cannibalistic things" sounds like the "classic" symptoms of extreme PCP consumption, so I'm surprised it was not brought up in the report (or by the cops). --Mr.98 (talk) 22:07, 28 May 2012 (UTC)
 * Considering PCP isn't really in the news much any more, it may be PCP that the officer is referring to and he simply doesn't realize that it's an older drug. Dismas |(talk) 00:15, 29 May 2012 (UTC)
 * I suspect the officer may have said "PCP" rather than "LSD" and the reporter got it wrong, but that's just speculation. I doubt the officer doesn't know the difference — all law enforcement folks in big cities know that PCP is bad news and LSD is just annoying (from a police perspective). --Mr.98 (talk) 00:25, 29 May 2012 (UTC)
 * Chemically, there aren't really any "forms" of LSD. Either something is lysergic acid diethylamide or it isn't. The first impression I had upon hearing of the story (particularly of the fact that it took around four gunshots to drop the guy) is that PCP was involved. Else, very few people are going to be able to remain upright and physically active after the first gunshot, let alone the subsequent ones. Just speculation, though. Evanh2008 (talk 03:55, 29 May 2012 (UTC)
 * The "bath salts" class of designer drugs has been in the news recently which may be what you're talking about. Whatever substance it is, it may be on the list at Designer drug, or could be something as old as a Mandrake (plant) derivative, which itself has a very interesting history. Shadowjams (talk) 16:28, 29 May 2012 (UTC)
 * It looks like the press is moving in that direction - though it is hard to connect the reports with any certainty. I suppose that the plan is to get some new felony involving methedrone, methylone, and methylenedioxypyrovalerone passed before the results from the forensic lab come back (See also Pamela's Law) Wnt (talk) 01:03, 30 May 2012 (UTC)
 * Well, some of what you named aren't innocuous substances, and some I believe are already illegal under the Analog Act (the designer drug article talks about it and links to the article). The Controlled Substances Act is at times alarmingly specific, and at other times alarmingly vague. I don't have a science background, but I read through the statute once and it's very interesting to see the specificity (I believe the DEA has rule-making power so a lot of the designer drugs that are made illegal are done so under the CFR... but I could be wrong about that... so what's in the U.S. Code is a small segment of the actual law). And of course the categorization of some controlled substances is quite arbitrary. Shadowjams (talk) 07:02, 30 May 2012 (UTC)
 * According to the DEA cathinones can produce similar symptoms to LSD. This seems very unlikely since they are stimulants, not psychedelics. 'Bath salts' appears to being used synonymously with designer drug in the US - i.e. an unidentified white powder. The only designer psychedelic I can think of is Bromo-DragonFLY. As you point out, there is no lab data yet, so anything is entirely speculative. Remember the Kony guy being found naked on the street? Sometimes the mind can do weird things without any chemical input. Considering the recent history of media reporting of mephedrone in the UK and the US (I've seen articles in very RS saying that people were snorting real bath salts to get high) I'm extremely skeptical to believe what they report. SmartSE (talk) 19:39, 31 May 2012 (UTC)