Wikipedia:Reference desk/Archives/Science/2012 October 14

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October 14

Hypnosis and alcohol blackouts

Can hypnosis aid in recovery of the memories lost to a blackout drunk? What I've read suggests that they're never properly stored, thus leaving nothing to recall in the first place, but has anyone compared the accuracy of recovered memory to impartial evidence (recordings, etc.)? And if so, what did they find? 71.248.115.187 (talk) 00:29, 14 October 2012 (UTC)

It's really unlikely that there would be any data specifically addressing that question, because I can't imagine that an Institutional review board would ever approve a study that involved inducing blackouts in subjects. That being said, this is an area where I'm sort of an expert, and my best guess is that there would never be any substantial recall, but it's possible that elements of the experience could be brought back by providing the person with cues that are associated with them. That's what often happens when you deal with people with amnesia, anyway. I doubt that hypnosis would be helpful. It could easily make the person invent pseudo-memories and believe that they are real memories, but if you are looking for genuine memories, those pseudo-memories would just get in the way. Looie496 (talk) 02:37, 14 October 2012 (UTC)

You're an expert on alcohol-induced amnesia ? Might I suggest Alcoholics Anonymous ? :-) StuRat (talk) 02:48, 14 October 2012 (UTC)

Recovered-memory therapy is probably quite relevant. Just btw, there are many different study designs which would not necessarily need to "induce" a black out. Case-control study, prospective and Retrospective cohort study could all gather completely relevant data specifically addressing this question. Louie's referring no doubt to the "gold standard" of trials, a double blind Randomized controlled trial, which I agree would probably be tricky to get passed by a ethics review board. And I completely agree with his conclusion, sounds highly implausible. Hypnotism is a widely misunderstood topic. Vespine (talk) 21:46, 14 October 2012 (UTC)

Does Capsaicin harm plants or their roots?

I have some houseplants I like to keep outside until first frost, but I have a problem with squirrels digging in their pots to the point of entirely uprooting some. I have tried capsaicin in small amounts before (cryy powder) but this wasn't enough to deter them. I am thinking of going all out with some chopped jalapenos or mustard powder on the soil, but am afraid I may hurt the roots. There are a few anecedotes on the web and a high school student experiment with sunflowers that say there will be no effect on the plant. Any good sources that will confirm this, especially on the roots? Thanks. μηδείς (talk) 16:49, 14 October 2012 (UTC)

Won't birds just eat the jalapenos ? Sean.hoyland - talk 16:57, 14 October 2012 (UTC)

I was going to chop them up and spread them in surface of the soil. μηδείς (talk) 17:00, 14 October 2012 (UTC)

Lots of links at Google "Capsaicin effect on plant roots". Never mind, of course you've already done that :-) hydnjo (talk) 19:27, 14 October 2012 (UTC) c/e strike by hydnjo (talk) 19:49, 14 October 2012 (UTC)

Actually, that was a good suggestion, and I did find the first link very helpful. μηδείς (talk) 20:00, 14 October 2012 (UTC)

Well I'll be darned for outguessing you/me outguessing me/you! hydnjo (talk) 20:28, 14 October 2012 (UTC)

Guess I'll bring them inside now, thanks. μηδείς (talk) 19:33, 14 October 2012 (UTC)

As far as next year, you might want to consider a physical barrier to the squirrels. One method is to hang them from trees using a long wire. Some type of cage around pots on the ground might also work (perhaps a birdcage) ? StuRat (talk) 19:49, 14 October 2012 (UTC)

Well, I like your idea of hanging the squirrels from trees using a long wire. But a cage around the plants somewhat defeats the purpose. (They arepoinsettias I keep over the summer and reflower each year.) μηδείς (talk) 19:58, 14 October 2012 (UTC)

LOL. But, seriously, bird cages can be attractive. StuRat (talk) 20:54, 14 October 2012 (UTC)

These plants are at a relative's in NJ, the idea of cages wouldn't go over too well, although a small cage with a much smaller-leafed and spreading flowering plant might actually be attractive. I'll post a picture of my favorite after it begins to flower. The main problem is that these are the only potted plants in that yard that don't spread out over the soil (they have a small tree-like growth form) and with the bare soil they are the only ones the squirrels pick on. So far no disasters this year, but in the past they have knocked them over and split the plants, which are brittle, in half. μηδείς (talk) 21:03, 14 October 2012 (UTC)

I have heard of putting chicken wire on the ground to prevent squirrels digging up flower bulbs. Maybe something similar would work.75.41.109.190 (talk) 22:51, 14 October 2012 (UTC)

The plants I have in mind are kept in pots, moved outdoors in March, and indoors at the end of October, and replanted yearly. I have already moved the last one indoors this afternoon, on the assumption that the two extra weeks I might get outside will not be worth the work, cost, and risk.μηδείς (talk) 23:21, 14 October 2012 (UTC)

Sounds sensible. If you want something attractive, you definitely don't want chicken wire. StuRat (talk) 08:14, 15 October 2012 (UTC)

You bury the chicken wire just under the surface of the soil in the pot. You don't see it, but it makes it difficult for a squirrel to dig.209.131.76.183 (talk) 13:46, 15 October 2012 (UTC)

I just wanted to mention how successful and popular StuRat's suggestion to hang the squirrels from trees using a long wire has been. Three relatives, a loved one, and two local librarians (they buy huge poinsettias yearly, and I have convinced them to take them home and reflower them rather than throw them out) have all broken out laughing when I relayed his advice. μηδείς (talk) 21:48, 15 October 2012 (UTC)

Glad I could help, if only by making them wet their pants while laughing. :-) StuRat (talk) 02:45, 17 October 2012 (UTC)

I've had my own run-ins with squirrels. One came down my chimney, made himself at home, found a loaf of bread, chewed it up and formed it into little balls. He apparently planned to take them back up the chimney and store them for winter, before I came home and, with great difficulty, ejected him from my house. On the plus side, I seemed to scare him enough not to try that again. StuRat (talk) 02:49, 17 October 2012 (UTC)

Honors thesis project

I am currently researching coastal armoring for my Honors Thesis. I am looking to expand this Honors Thesis into a senior project that I can present at the Northeastern Geological Society of America conference. I still am in the process of creating a thesis statement for the project. Does anyone have any suggestions, specifically about what questions or issues about coastal armoring (particularly in Connecticut are the best to explore? I intend on doing fieldwork of my own for this project. Thanks.--99.146.124.35 (talk) 18:26, 14 October 2012 (UTC)anonymous

It would have been helpful to explain what coastal armoring is. Apparently it's methods used to prevent shore erosion. I would think a cost/benefit analysis of various methods would be a good thing to study. That is, which methods are more economical than simply abandoning the shoreline and moving inland ? Another option is to look at the effects of global climate change on shore protection efforts. I suspect that methods formerly used are no longer effective when faced with rising sea levels and increased storm intensity. StuRat (talk) 19:08, 14 October 2012 (UTC)

Coastal management may be of interest. hydnjo (talk) 19:20, 14 October 2012 (UTC)

How about: which zones are more prone to erosion than others; which are zones are most important to protect, from an environmental perspective, and from an infrastructure perspective; is it economical to have your cake and eat it, if not what compromising schemes are available that balances both?Plasmic Physics (talk) 23:22, 14 October 2012 (UTC)

• My first thought is, how does greenhouse effect interact with coastal armoring, especially if the collapse of major ice shelves occurs more quickly than imagined? There is a paper [1] which makes a number of recommendations for "federal/regional government actions", e.g. "Congress should amend the Coastal Zone Management Act (CZMA) to require relevant state agencies to consider sea-level rise in coastal management plans in order to qualify for federal funding assistance; prohibit federal subsidization of infrastructure development and coastal armoring in areas subject to sea-level rise; and encourage public and private land acquisition of coastal habitats and upland buffers." I'd think your project might explore whether the list of actions recommended by the organizations that produced this report for Florida are things which Connecticut should endorse or oppose. (I have absolutely no idea at all myself) Wnt (talk) 00:27, 15 October 2012 (UTC)

• I think that you are going to have to narrow your topic, otherwise you will have too much to read and write about! Graeme Bartlett (talk) 10:38, 15 October 2012 (UTC)

How about the economical difference between manual replenishment with bulldozers and temporary pumping rigs versus a permanent replenishment system similar to water or sewer systems? Usually there are certain places that always get the extra sand and places that always lose it.165.212.189.187 (talk) 13:04, 15 October 2012 (UTC)

StuRat, read Armor (hydrology). 2001:18E8:2:1020:749C:5B76:1D8E:3D22 (talk) 16:45, 15 October 2012 (UTC)

Magnetic propulsion

I've read that magnetic motor is impossible due to magnetic equilibrium, but in this video for example a computer cooler seems to spin very well due to repulsion between magnetic poles (that is, one pole interacts with several opposite ones, constantly pushing them). I've browsed the internet further, but still don't get why the magnetic repulsion cannot be used as a source of free mechanical energy (especially considering strong magnets).--176.241.247.17 (talk) 21:41, 14 October 2012 (UTC)

Magnetic propulsion requires electromagnets (not just permanent magnets) and they are powered by electricity. Therefore, it's not "free".StuRat (talk) 21:56, 14 October 2012 (UTC)

Magnets apply a force, but force is not energy. This is a distinction which can be very counterintuitive and there are many people who have spent a LOT of time pursuing the futile dream of extracting free energy from a magnet. Our Free energy device article has asection which discusses magnets. Vespine (talk) 23:52, 14 October 2012 (UTC)

Indeed, many people have wasted years of life trying to get free engergy with magnets. It's also been a way to scam others. Take Steorn, for example, who took millions of dollars of investors money on the promise of "unlimited free energy". Needless to say they produced nothing of value, and failed year after year to prove any of their claims.217.158.236.14 (talk) 11:02, 18 October 2012 (UTC)

Flooded skyscrapers

In the movie A.I. Artificial Intelligence, Manhattan is flooded due to global climate change. However, the top floors of at least one skyscraper continue to be occupied. My quetions:

1) I assume that flooding existing skyscrapers would quickly cause the supports to rust out and fail. Is this correct ? How quickly ?

2) Is there a cost effective way to retrofit the existing supports to make them survive ? Some type of waterproofing ?

3) Could new supports be added to the existing building in a cost-effective manner ? StuRat (talk) 22:17, 14 October 2012 (UTC)

It was an artistically appealing image. Corrosion to failure should take decades, at the most.[2]. Why would anyone with the resources to do so retrofit those buildings a portrayed in that movie? μηδείς (talk) 23:16, 14 October 2012 (UTC)

Well, if they could be retrofitted at a lower cost than creating new buildings, that would be a reason. Or, in the case of significant historic buildings, they might be preserved even if this costs more than rebuilding. StuRat (talk) 23:19, 14 October 2012 (UTC)

You might want to link to an article on contemporary retrofitting. I don't think you'll find much on the history of retrofitting in the distant future. μηδείς (talk) 23:59, 14 October 2012 (UTC)

It's a sci-fi scenario, so there are a lot of possibilities. For example, you could produce some sort of nanobots that home in on sources of dissolving iron and chemically modify any exposed surfaces to passivate them. Or at least you might have more convenient drones for working underwater that you can use to rustproof the exposed materials more easily. There's also the simpler possibility that stronger fireproofing materials that have been or will be developed in the wake of the September 11th attacks turn out to be so tenacious that they block water corrosion as well as a bonus.Wnt (talk) 00:31, 15 October 2012 (UTC)

It's a sci-fi scenario, so it's asking for speculation, opinion, and debate, and it should be hatted. We have no relevant references. μηδείς (talk) 00:33, 15 October 2012 (UTC)

Just because you don't have a source, that doesn't mean there isn't one. Note that numerous sci-fi scenarios, like communications satellites, later became reality. StuRat (talk) 00:41, 15 October 2012 (UTC)

^ "Just because you haven't a source..." hydnjo (talk) 03:27, 15 October 2012 (UTC)

Fixed, but not in your manner, as that's entirely too British English for me. :-) StuRat (talk) 05:33, 15 October 2012 (UTC)

So, in the future, buildings that are already standing today, will become corrosion resistant because...it's the future? Let's just please provide some refs if we're going to continue this one. μηδείς (talk) 00:45, 15 October 2012 (UTC)

A lot depends on how much flooding you have in mind, and probably also the rate of flooding. I don't recall the scenes in the movie that you are referencing, so I'm not sure what scale of inundation you have in mind. Defending against 2 to 6 feet of sea level rise (typical projections for this century if global warming continues), probably could be accomplished with sea walls, pumps, and other basic barriers. However, complete melting of Greenland (20 ft of sea level equivalent) and Antarctica (200 ft equivalent), would seem very hard to fight against. On the other hand, humans do build oil platforms over 250 ft that are fixed to the sea floor (as opposed to the floating ones used in very deep water), so the idea of skyscrapers that are grounded hundreds of feet under water probably isn't impossible, though I wouldn't want to speculate on what issues would be involved in such a conversion. Dragons flight (talk) 01:29, 15 October 2012 (UTC)

It was hundreds of feet. The Statue of Liberty was submerged to the base of the torch (but the World Trade Center was alive and well).StuRat (talk) 05:29, 15 October 2012 (UTC)

Bioconcentration

Is it feasible to use cultivars to bioconcentrate soil-polutants, such as heavy metals, which can then be removed through harvesting the plants?Plasmic Physics (talk) 23:08, 14 October 2012 (UTC)

Certainly! Phytoremediation. Vespine (talk) 23:14, 14 October 2012 (UTC)

Possible, but doesn't seem very feasible to me. For one, you end up with a large volume of plant matter containing a small percentage of heavy metals. What do you do with that ? StuRat (talk) 23:15, 14 October 2012 (UTC)

Burn it. This is rather basic. μηδείς (talk) 23:17, 14 October 2012 (UTC)

Then you risk releasing some of those heavy metals into the air. Mercury vapor, for example, is bad stuff. There's also the risk that insects or animals will eat the plants, at which point the heavy metals enter the food chain, which is exactly what we want to avoid. StuRat(talk) 23:20, 14 October 2012 (UTC)

More specifically Phytoextraction process describes pretty much exactly what the OP is asking about. Burning it might be the best thing to do in some specific isolated cases, but I doubt it's a good idea as a rule of thumb. Vespine (talk) 23:21, 14 October 2012 (UTC)

Gasification? Plasmic Physics (talk) 23:25, 14 October 2012 (UTC)

Is there a plant that concentrates mercury? I have heard of those that do arsenic and copper. Surely this would be done industrially, and not in back yard barbecues. μηδείς (talk) 23:26, 14 October 2012 (UTC)

No terrestrial plants naturally concentrate mercury to a significant degree. There are currently efforts at multiple laboratories to engineer such plants with genes from bacteria that metabolize organic mercury (the bacteria use this to salvage hydrocarbons). In theory, this would cause inorganic mercury to concentrate in the plants, and it seems to work in the lab: [3].Someguy1221 (talk) 23:56, 14 October 2012 (UTC)

Maybe no terrestial plants, but Plankton certainly concentrate mercury, a casual search has not revealed to me if that also specifically applies to phytoplankton, or any other members which might be considered "plant", (if there are any). Vespine (talk) 23:58, 14 October 2012 (UTC)

What if the the deposits the polutant in nodule-like growths, which renders it inert? The plant would ideally act as a molecular pump, not simply as a spunge. Plasmic Physics (talk) 01:34, 15 October 2012 (UTC)

GMO is not excluded. Plasmic Physics (talk) 01:36, 15 October 2012 (UTC)

Nice idea. If we could do that, we could also finally mine seawater, bΝy having those plants collect all the substances we want and sequester them in those nodules for us to collect later. Get those genetic engineers to work ! StuRat (talk) 05:25, 15 October 2012 (UTC)

Sorry, I'm not good with sarcasm; is that genuine? Plasmic Physics (talk) 05:33, 15 October 2012 (UTC)

(My sarcasm is always genuine.) But no, this is not sarcasm. It may all be possible, some day. StuRat (talk) 05:40, 15 October 2012 (UTC)

Well, that's bitter sweet - it may be a million dollar idea, but I'm not capable of undertaking such endevour. Plasmic Physics (talk) 06:16, 15 October 2012 (UTC)

Maybe not sponges (not sure) but sea quirts have vanadocytes which concentrate the metal to an extraordinary degree. Of course, that's only a few cells, and so it isn't really economically feasible as encountered, yet... it inspires the imagination. Wnt (talk) 14:01, 15 October 2012 (UTC)

So someday we may be able to use them to sponge off the ocean ? :-) StuRat (talk) 16:17, 15 October 2012 (UTC)

In my comment, I was not refering to Porifera. I as refering to the final destination of the polutants - by "as a sponge", I was refering to the polutant remaining inside the cells, poisoning them. The second scheme, which I suggested, is for the polutant to be transported and sequestered from the cells at a common destination, leaving the plant unaffected. A sponge can only absorb a limited amount of water before it becomes fully saturated, a pump can transport as water as long as it is supplied with energy. Plasmic Physics (talk) 06:48, 16 October 2012 (UTC)

StuRat, you may be surprised to find that we do mine seawater: Magnesium#Occurrence. Buddy431 (talk) 16:49, 15 October 2012 (UTC)

Great, now I want to mine gold and platinum. :-) StuRat (talk) 06:50, 17 October 2012 (UTC)

Research has shown that dust sourced from road surfaces, is a rich source of valuable metals such as rhodium and palladium. Plasmic Physics (talk) 10:29, 17 October 2012 (UTC)

To help any less technical people who are reading this - as that article says, magnesium is present in about 1/8 the quantity of ordinary sodium (in salt), which we also "mine" from the sea. Wnt (talk) 17:07, 17 October 2012 (UTC)