Wikipedia:Reference desk/Archives/Science/2009 February 22

= February 22 =

Cardinal repeatedly flies into window
A male Cardinal is repeatedly flying into my windows, from dawn until evening. There is the fire escape and bamboo outside the windows for the cardinal to sit on. I assume it sees its reflection and thinks its another bird (competition) and tries to attack it. Apparently it's not hurting itself, since this has been going on for months.

I'm thinking of putting up window clings, such as the Halloween decoration ones that might be scary to the bird. But, it's not halloween, so Halloween decorations are probably not available now :( What type of window clings can I get this time of year (in the Maryland/DC/Virginia area) that would scare the bird?  and what stores would sell them? Would a craft store (e.g. Michaels) have them?  or would Home Depot have something to help solve my problem?

Or what other (inexpensive) suggestions might work to deter the bird from doing this? Any ideas would be appreciated. 75.196.30.110 (talk) 15:24, 22 February 2009 (UTC)


 * I have a window sticker in the shape of a raptor, which I got from a pet store (in the same department that sells wild bird feeders and food). It has successfully dissuaded similar bird attacks. 87.112.17.229 (talk) 15:42, 22 February 2009 (UTC)


 * I have to assume the bird suffered from brain damage the first time, which might explain why it never learns. :-) How about cat-shaped stickers ?  Also, if you have lights on behind the window it will make the reflection less noticeable relative to the light.  A more expensive option would be to install louvered window shutters.  If you don't care about the bird you could also poison it.   StuRat (talk) 16:13, 22 February 2009 (UTC)


 * It doesn't matter what you stick on the windows, as long as there is something there. In Switzerland I believe it is required by law to put such stickers on any glass larger than a certain size (they almost all use silhouettes of birds). --Tango (talk) 16:21, 22 February 2009 (UTC)

Gold
I have always ask this question ,,, why would any one buy gold ,,, what's the point ,,, its not usefull ,,, there's no god reason to buy this metal with that big amount of money. and the most confusing ,,, why countries take the gold as auniversal coin ,,,??? from my opinion gold worth nothing ... as amatter of fact even iron could be more usefull than gold.


 * That's not true - gold is used pretty extensively in electronics manufacturing - all of the connectors on circuit boards have a thin layer of gold plated on them. The tiny chip of silicon inside a the plastic or ceramic packaging of an integrated circuit is connected to the pins on the outside of the package with thin gold wires.  Gold has practical uses.  SteveBaker (talk) 19:15, 22 February 2009 (UTC)


 * See gold. You will find that there are applications for which gold is useful and for which creates value.  If you are wondering why certain metals are precious, you might try reading precious metals. --  k a i n a w &trade; 18:52, 22 February 2009 (UTC)
 * Gold:
 * Does not corrode. Ever.
 * Is an excellent conductor of heat and electricity.
 * Has an unusual and generally desirable appearence.
 * Is relatively rare.
 * I'm sure there are more reasons, but these qualities alone make gold in high demand for electronics, medical applications, and jewelry. Thus, a high cost. - Running On  Brains  18:53, 22 February 2009 (UTC)
 * Although what the above posters have said is true, Gold is still probably not worth $1000 an ounce. The desirable appearance that RunningoOnBrains mentioned is probably what emotionally influences people enough to want to buy it as a safe haven. I personally would buy honey or something else widely useful which has a very long expiry date and low (or preferably negative) depreciation. See also: diamond-water paradox. This is what the richest man in the world has to say about gold:
 * "Buffett emphasized the non-productive aspect of gold in 1998 at Harvard: 'It gets dug out of the ground in Africa, or someplace. Then we melt it down, dig another hole, bury it again and pay people to stand around guarding it. It has no utility. Anyone watching from Mars would be scratching their head.'" --Mark PEA (talk) 20:53, 22 February 2009 (UTC)


 * To fully understand the value of gold, we should dig back in time to the era before stock markets and internet banking. Creating a universal currency boosted the trade and economy (it's easier to trade with gold, than barter two cows for five sheep, for example) It was rare enough for a small quantity of it to have a good value. If money would be made out of stones, everyone would gather tons of it, leading to an inflation where you needed a wagonload of it to buy a chicken. (With most of our money being created by banks and not having any physical form, this scenario could be not that far from being reached :P ) --131.188.3.20 (talk) 23:22, 22 February 2009 (UTC)

We just had this question a few days ago on the Miscellaneous reference desk. You will want to read the thread over there. --Anonymous, 00:21 UTC, February 23, 2009.


 * Actually, the non-utility of Gold is exactly what makes it a good medium for money. If gold had a use, then its utility value may someday exceed its monetary value, which would be bad indeed for the economy.  Look at other materials once used for money: Salt was used by the Roman Empire as a means of exchange (hence, "salary").  However, salt is inherently useful in preserving and seasoning foods, and other applications.  So if your money is salt, either a) you have to let food rot, because its too valuable to waste salt when you could be spending the salt to buy other things; OR the salt is needed to be used as a preservative, at which point it must be pretty worthless as money, since if it HAD monetary value, you wouldn't want to waste it.  Good money has some common properties: 1) It is rare and hard to counterfeit 2) It is otherwise useless.  You need both in order to have good money.  Salt failed on both counts.  Look at wampum as an example of of money.  When made by hand, it had both properties, being hard to make, and it also had no use except as money.  When the Europeans came along and figured out how to mass produce wampum in factories, it very quickly lost its rarety, and then just became worthless trinkets.  Gold, silver, and copper in the ancient world were far to soft to be useful for what you would normally want metal to do, and they were all relatively rare compared to other metals.  Thus, they made excellent metals to make money out of.  --Jayron32. talk . contribs  03:28, 23 February 2009 (UTC)


 * See Gold standard. Cuddlyable3 (talk) 20:20, 23 February 2009 (UTC)

"Audible Drugs"
I just found this but I doubt that it is a proper name. What is it called? --211.243.241.178 (talk) 18:27, 22 February 2009 (UTC)


 * The article you linked clearly names them i-doser. Notice, that link is blue.  That means that if you were to type it in the search box on the left and click Go, you would find an article on the topic. --  k a i n a w &trade; 18:48, 22 February 2009 (UTC)


 * Hmm, the redirection link was created quite recently (21 Feb 2009) and when I searched it didn't exist. Thanks anyway. --211.243.241.178 (talk) 19:08, 22 February 2009 (UTC)


 * And the article doesn't contain any information about them being like drugs, either. --98.217.14.211 (talk) 19:40, 22 February 2009 (UTC)


 * So... it means that some kids decided to take something that is well over 100 years old, give it a new name, and hype it up to be something it isn't. It isn't all that surprising, is it? --  k a i n a w &trade; 21:24, 22 February 2009 (UTC)


 * Without doubt, certain music and audio can create a psychological effect. But unless it creates a psychoactive effect with measurable neurological effects, I don't think it can be classified as "drug-like."  Lots of behaviors can create feelings of euphoria or elevated perception without being "drug-like" ... From our article drug,

A drug, broadly speaking, is any chemical substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.
 * Evidently, until a reliable medical, legal, or pharmacological source makes a specific mention of audio-induced psychoactive response, these sorts of things will not be widely considered "drug-like." Nimur (talk) 15:37, 23 February 2009 (UTC)

Bubble´s prediction
What is the best way of predicting bubbles? Is any price increase x times above average inflation a sign of one?--Mr.K. (talk) 19:37, 22 February 2009 (UTC)


 * I'm pretty sure if there was some tried-and-true way of predicting bubbles, fewer people would be caught out when they burst. --98.217.14.211 (talk) 19:54, 22 February 2009 (UTC)


 * Do you have an infinite believe in human intelligence? Would people use a tried-and-true way of predicting bubbles or would they believe that they use an-even-better-tried-and-true way of predicting bubbles? Anyway, I want to know what are the signs of bubble forming, not necessarily how to predict when it will explode. --Mr.K. (talk) 20:00, 22 February 2009 (UTC)
 * If you could predict whether something was a bubble, you could make an awful lot of money. There was a very big and rapid one last summer. A certain Mr. Soros claimed oil was a bubble at $135 a barrel, it peaked at $147 per barrel (pb) and is currently at $39pb. I think the low since $147pb is about $30pb, so had Soros sold short 10,000 barrels at $135pb and bought back at $35pb, he would have made $100 * 10,000 = $10,000,000. I don't know whether he did, and if he did, what quantity (probably alot more than 10,000 as $10m profit is kinda small change to someone worth $9 billion). --Mark PEA (talk) 20:42, 22 February 2009 (UTC)
 * You can tell a bubble situation when the price is well above what it is worth, and it is purchased because of the belief that the price will rise. It is harder to notice then the pop will happen.  But a good clue is when the item become unaffordable for those that have to buy it. Graeme Bartlett (talk) 20:50, 22 February 2009 (UTC)
 * Indeed, something that is supposed to serve a purpose being traded more by speculators than by consumers is generally a good sign of a bubble. --Tango (talk) 22:00, 22 February 2009 (UTC)
 * I disagree with your logic. Saying "a price is well above what it is worth" is impossible to know.  No one can estimate the price consistently better than the market can.  Otherwise they'd be filthy rich.  So the best estimate most people (like the OP) can use for the price of a good is simply the market price.  Thus the price is never more than what it is worth. Speculators aren't dumb.  They buy when they think prices are going to rise.  Often the speculators are right (or else they would have lost all their money long ago).  Despite the portrayal of oil speculators recently by the media, speculators don't "artificially" increase the price.  They increase the price based on uncertain factors which could potentially make the stock worth quite a bit more.  When google offered their IPO, if I buy it because I think they'll do well their first year, that is speculation, but it also moves the price to where it SHOULD be, I'm not artificially increasing the price.
 * To answer the OP's question, you can't always tell by the price if something is a permanent change or temporary change no matter how much it changes. The best way to see a bubble coming is to look for factors that would shift a price from what it would be in a fair market.  In a true free market there would not be bubbles.  Most bubbles are caused by politians trying to manipulate the economy.  Both President Bush and President Clinton made speeches, especially when addressing hispanic audiences, about trying to make it easier to get low income and minorities into affordable homes.  By the Federal Reserve artificially adjusting the interest rates and passing laws to incentivize first time home buyers they caused the price to increase far above what market value would have otherwise been.  Now that President Obama has passed the bailout which gives a $8,000 tax credit to any first time home buyers during calendar year 2009, again it is pushing the price far from the market value and as such is a very dangerous move.Anythingapplied (talk) 07:29, 23 February 2009 (UTC)
 * If you buy Google stock because you think Google will do well next year (fundamental analysis), that corrects the price. If you buy it because you think the stock price will go up, with no regard to the company, (technical analysis) then that "artificially" changes the price and results in bubbles. Saying "price greater than worth" doesn't make much sense without clarification. To calculate worth, in this context, you need to look at what the item is useful for and compare it to possible replacements. If genetically engineered blue rice is 1000 times the price of regular rice, despite it going just as well with a Chicken Korma, then that's a clear sign that there is a bubble on blue rice. People aren't buying it because they think it's worth that amount of money, they're buying it just so they can sell it later after the price has gone up. --Tango (talk) 12:12, 23 February 2009 (UTC)
 * Eye of newt, and toe of frog, wool of bat, and tongue of dog work for me. (Guaranteed to double, double your investment, without toil and trouble.) Bill "Lowest Commission" Shakespeare (talk) 08:13, 23 February 2009 (UTC)
 * I didn't know that there was actively traded market for those commodities... Dragons flight (talk) 15:43, 23 February 2009 (UTC)


 * The trouble is that it's a self-non-fulfilling prophesy. If you have an equation that predicts the moment when the bubble will burst, investors will buy stock knowing that the bubble is still growing and that they can safely sell on the trading day immediately before the equation says it'll burst.  However, if the equation is sufficiently widely known that people would tell you about it on the Wikipedia reference desk then you can bet that all serious investors will know it.  Hence they'll all sell their holdings on the day before the bubble bursts - the stock price will tank because every big investor dropped their holdings in the stock at once - and the bubble bursts a day before the equation says so (and if everyone knows that - then two days before - or a month before...) - and the equation is thereby proven useless.  So not only is there no such equation - but there cannot ever BE such an equation so long as investors are aware of it and are able to take advantage of it. SteveBaker (talk) 23:29, 23 February 2009 (UTC)


 * OK, there is no way of predicting when it will burst. However, a partial question is how can we know the market is building a bubble? (if we can at all know that a bubble is growing).--Mr.K. (talk) 09:20, 24 February 2009 (UTC)
 * @Mr.K.: You can't know. You are effectively asking the question "What will the price of X be in the future?", but in an indirect fashion. If anyone can figure out that something is a bubble, but not know when it bursts, you can short sell it. However this assumes that when the bubble bursts, the price will be less than that you shorted it at. --82.21.28.65 (talk) 18:04, 24 February 2009 (UTC)
 * @Steve: That sounds like a variation on the unexpected hanging paradox. --82.21.28.65 (talk) 18:04, 24 February 2009 (UTC)
 * (Which is perhaps the only paradox that really seems paradoxical to me...the others seem entirely trivial to dispel. The only halfway reasonable way to explain it away is to assert that 'unexpectedness' is not a binary thing - there are degrees of unexpectedness.  However, one would expect an equation to produce a definite answer.  But you're right - and it could be that a 'when will the bubble burst' equation would be possible if it only predicted a statistical likelyhood of the bubble bursting at any given moment.  As the predicted probability of the 'bust' happening increases (per the equation) - the risk-averse investors would pull out first with fewer and fewer of the high-risk-tolerant people staying around...that would allow the equation to predict the probability of a bust on any given day - despite all of the investors knowing about it.) SteveBaker (talk) 21:14, 24 February 2009 (UTC)

It's easier to spot a bubble from outside, rather than being inside the bubble. eg Most people working in McDonalds etc would be fairly aware that profitting by buying and selling commodities without adding any value to the commodity cannot continue forever. In other words look for the price of something increasing for no good reason beyond that explained by common or garden inflation. —Preceding unsigned comment added by 213.249.232.187 (talk) 15:51, 24 February 2009 (UTC)

electrical conductivity
I would like to measure the electrical conductivity of distilled water versus ionized water (for my sister's science fair). How would you do this with a voltmetre? I tried sticking a copper penny to one end of the voltmetre and a zinc nail to the other and putting this into the solution. Would this work? —Preceding unsigned comment added by 70.52.47.166 (talk • contribs) 15:25, 22 February 2009
 * No, that measures (approximately) the amount of voltage generated (you are creating a battery), not the amount of voltage blocked (the conductivity/resistance). to measure resistance, you need an external source of power and then measure how much of it is lost/blocked by the liquid you are testing. DMacks (talk) 20:36, 22 February 2009 (UTC)
 * You are measuring the voltage from a small cell. However since you want resistance, you need to use an Ohmmeter not a voltmeter.  Your two electrodes should be the same as each other and not easily reacting.  Two copper or two gold electrodes could be the way to go. The conductivity will depend on the geometry of electrodes and temperature, so record these. Graeme Bartlett (talk) 20:43, 22 February 2009 (UTC)


 * (ec) I'd say no without knowing what you mean by "ionized water" (Our article "Water ionizer" looks like voodoo baloney to me.). Electrical conductivity is the inverse of electrical resistance (ohms). With your dissimilar metals, you would be demonstrating something else, the galvanic cell. To measure conductivity, you could measure the resistance with the multimeter and divide that into 1, maybe using two long pieces of tubing, one for each water. If you really do have a voltmeter, you could measure the voltage across a resistor in series with a battery and the water, then use Ohm's Law. Two things: distilled water will insulate like glass, and salt water will have practically no resistance (extremely low conductivity and extremely high, respectively). Oh, one more thing: you can't get anything at all in the distilled water, not dust, not your finger, not a drop of tap water, not a probe that has any salt water on it. --Milkbreath (talk) 20:59, 22 February 2009 (UTC)


 * I suspect that the original questioner meant Deionized water, since ionized water doesn't make much sense. edit: Unless the purpose is debunking the aforementioned water ionizers. I'd expect the conductivity of distilled and deionized water to be very similar. --NorwegianBluetalk 22:02, 22 February 2009 (UTC)
 * Careful with copper or other metals that can do redox chemistry...you might wind up transferring the metal atoms from one electrode onto the other. In the process, you get ions of the electrode itself in solution, which alters the ionic content of the water. DMacks (talk) 22:52, 22 February 2009 (UTC)


 * There are special things called Conductivity cells. From memory, they comprise a cylindrical vessel that has 2 conducting metal rings on the inside surface a small distance apart (could be 1cm but don't quote me). It has 2 terminals on the outside to which you connect an ohmmeter. I think the cell is rigged to give a direct reading of conductivity in Siemens.

Thank you very much. BTW, by ionized water I just meant water with salt in it.