Wikipedia:Reference desk/Archives/Science/2011 June 3

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June 3

E. Coli Outbreak

How fast it is affecting its victim? roscoe_x (talk) 06:07, 3 June 2011 (UTC)

Bacterial food poisoning takes 12-72 hours for primary symptoms to appear. -- kainaw™ 13:46, 3 June 2011 (UTC)

The media tell something about 8 to 10 days. I would not belive any of them.--Stone (talk) 13:49, 3 June 2011 (UTC)

Eight to ten days is consistent with the data in this case. People are still falling ill after having stopped to eat raw vegetables. Also, it is known that you only need to ingest a few becteria, which will multiply over a period of days before any symptoms appear. You can wash a cucumber, but that won't remove all bacteria that are on it, so the initial recommendations of washing vegetables is not good enough in this case. That's why the new recommendation is to not eat raw vegetables at all. Count Iblis (talk) 16:29, 3 June 2011 (UTC)

Countermeasures against RFID

It's become tradition for me to take any new pair of shoes and microwave them on HIGH for 30 seconds, due to paranoia about RFID spying. It doesn't seem to hurt anything, or even warm them much. While other clothing items can be found with RFID tags at the supermarket, what I've seen of earlier such tags was bulky and not readily concealable. I was always most suspicious of shoes because they are difficult to take apart completely. But it isn't 2000 any more, and this isn't really my field...

• Do microwaves really kill RFID chips for sure - even the new ones which are much smaller, or designed to be incorporated in fabric?

• Is it now feasible to hide RFID chips in clothing fabric in such a way that no one would notice them?

• Is there any cheap handheld device available by now that can be used to sweep a house for RFID chips the way people in a spy movie sweep for bugs? Which would detect any possible RFID chip, not just one model and frequency? (Ideally it should also detect if other electronic devices are operating as base units to detect RFID chips in the area)

Wnt (talk) 10:41, 3 June 2011 (UTC)

References

The RFID in the new German passports is to track you (even if all-wise government denies). So it would be probably made illegal if many people do what you are doing. 95.112.137.166 (talk) 12:20, 3 June 2011 (UTC)

You're probably looking for a nonlinear junction detector. A handheld rfid reader/writer isn't cheap. Generally, rfid chips are supposed to be degaussed at the store, though it depends on the local law. Microwaving does disable most (non-military) rfid chips. Alternatively, rather than destroying the chips, you could clone them, or recode them to exploit buffer overflows, though this may be illegal in certain areas.Only the Paranoid Survive =P. Smallman12q (talk) 12:32, 3 June 2011 (UTC)

One thing (at least) that I don't understand here. Even granted the hypothesis that someone or some agency wants to track your movements in the first place - why would they do that using RFID tags in your clothing or shoes ? Surely the data trail that you create every time you use a debit/credit card, use your mobile phone, use a season ticket on public transport or drive your car past a traffic camera is much more extensive and reliable than depending on something that only possibly works if you are wearing your new shoes or shirt. Microwaving your new shoes would seem to give you very little privacy protection unless you already walk or cycle everywhere and only ever use cash and landlines. Gandalf61 (talk) 13:33, 3 June 2011 (UTC)

If you value your privacy, there are three simple things to do. First, stop using cards (credit cards, frequent shopper cards, discount cards, etc...). Those are specifically designed to track you. Second, get rid of your cell phone. By design, the towers track your phone. Third, stop using the Internet - especially social websites. The absolute worst offender is Facebook - if you have a Facebook account, they keep track of every single website you visit that has one of those "like" buttons on it. So, simply using the Internet tracks what you are looking at. Even the queries you type into search engines can be used to identify and track you (consider the stink about AOL releasing "deidentified" queries for research purposes). After you do all of that, then worry about RFID. -- kainaw™ 13:40, 3 June 2011 (UTC)

Having done all these things, go home to your cave, safe and secure that nobody is paying attention to you... --Mr.98 (talk) 14:12, 3 June 2011 (UTC)

Has someone hijacked Wnt's account? Assuming it's actually a serious question he's posing (the irony of which has already been hinted at by the responses), probably the most useful thing that nuking your new shoes could do would be to kill off any residual foot-fungus left by folks who had previously tried on those shoes before you bought them. Or would it? ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:02, 3 June 2011 (UTC)

I suspect that foot fungas is reslient enough to survive 30 sec in a microwave, but I would be surprised if someone has done an actual study on that method. Googlemeister (talk) 15:14, 3 June 2011 (UTC)

There's kind of an urban legend about sterilizing underwear via microwave, and random selections in google strongly advise against it. (Of course, they might be just trying to keep folks from zapping the tracking devices.) ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:36, 3 June 2011 (UTC)

You can get very simple RFID readers that plug into a laptop for less than $200 these days. Most will beep (or otherwise respond) when they get a signal in the right frequency range, even if they can't interpret what it means (for example due to secret encoding). In addition, with the advent of near field communication one can expect that many next generation mobile phones (and some already available phones) will be able to read RFID chips. In general these devices require you be pretty close to the chip in order to pick it up, so it would take quite a while to scan over your possessions if you really intended to be thorough. Dragons flight (talk) 15:30, 3 June 2011 (UTC)

If you ever find yourself hopelessly lost in the middle of a desert, or break your leg while climbing an obscure peak in the Alps, or whatever, the ability to be tracked might come in handy. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:33, 3 June 2011 (UTC)

An RFID chip isn't that kind of tracking. It's more of a "you walked past this detector at this time on this date" sort of tracking, not the "I know where you are right now" sort of tracking. (There would have to be a detector in the middle of the desert for them to know you were there.) --Mr.98 (talk) 16:01, 3 June 2011 (UTC)

To find a RFID chip in the middle of the desert, they would have to blanket the area with waves, and the reply from the chip could only be detected from a few meters of distance. Basically, they would have to comb the whole area until they happen to pass a few meters away from it.

Could be very useful, though, to find people buried in snow avalanches, since the buried people would be in a relatively small area. A run-of-the-mill detector would limit the search to a area a few meters wide. A custom detector could be able to detect the direction and distance to the chip (it beeps stronger when the reply from the chip gets stronger, it is able to tell and display the direction the reply signal is coming from), and pinpoint the almost exact location of the chip. --Enric Naval (talk) 16:38, 3 June 2011 (UTC)

A simpler version of this system exists - see RECCO. It doesn't use RFID, but a directional radio reflector instead (on the principle that you don't need a coded signal as you don't really care who the buried person is - hopefully you are going to dig them out whoever they are!).Equisetum (talk | email | contributions) 11:52, 5 June 2011 (UTC)

The consensus here seems to be:

• "military" RFID chips are immune to microwaves. What makes them special? How do you know some commercial chips don't work the same way?
• cheap handheld devices to detect RFID are available. Which makes me wonder --- are people finding chips when they scan through their possessions?

I am disappointed to see some people still wondering why such tracking should bother them, or assuming all their privacy is forever lost already. The existence of companies like Facebook or supermarkets with shopper cards is evidence that someone finds all this personal information to be profitable, and if they're making money, probably the subject of their efforts is losing money, somehow or another. Even if it's only the legendary money you can make filling out shopper surveys on the Internet, the loss of privacy can be evaluated in tangible financial terms.

The suggestion that "next generation mobile phones" would detect these chips is particularly disturbing, though it clashes with the $200 price tag mentioned above. While the chips can only be detected within "a few feet" (around 100 in actual tests) the prevalence of phones would mean that they would be more or less continuously tracked in populated areas. One expects a repeat of what I've read about certain GPS phones, where you have people in a "free country" carrying around devices that are tracking their movements to be used against them by prosecutors, but which they are not themselves permitted to access because they "don't have the software". There is such an strong feeling of contempt that pervades when people are expected to buy and care for the things that spy on them, and aren't even able to use the devices for their own purposes. Wnt (talk) 17:13, 3 June 2011 (UTC)

Those who have nothing to hide have nothing to fear. :) ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:27, 3 June 2011 (UTC)

Er, I'm sorry, but your assertion that when somebody else is making money, the subject must be losing money, is pretty fallacious. Wealth is not a zero sum game (if it were, we'd still be using stone tools), and information certainly is not (it can be replicated, shared, exploited "without cost" to anyone in many cases), and just because someone can make money off of knowledge about me, doesn't mean that I'm losing anything by that fact, at all. That's an awful argument in favor of privacy, anyway. The real argument probably ought to be couched in terms of possible abuse of information or potential negative effects. --Mr.98 (talk) 18:35, 3 June 2011 (UTC)

While paranoia about privacy is good, I've never been impressed by RFID paranoia. To me it seems like mostly fear of a buzz-word. Some people will physically recoil if you consider using RFIDs in place of a barcode! Most of the "tracking" with RFIDs that people freak out about has been going on since long before RFIDs were invented. They've ALWAYS kept track of who crosses national borders, they don't need the chip in your passport to do that. Supermarkets have always tried their best to track their inventory, a more technological bar-code doesn't suddenly make it sinister. Even the chips implanted in pets and livestock are just replacing older forms of tagging.

If you honestly think anyone is going to implant RFIDs in your shoes and then implant RFID readers on the sidewalks, you're behind the curve, paranoia-wise. Doing all that would represent a significant expense, and a serious risk of negative media exposure. All that's needed to track people as they walk down the street is cameras and fancy computer-vision software. (So long as at least one camera get's a good look at your face or car license plate.) That's far more cost effective and the public has already accepted cameras.

As discussed above, the readers wouldn't be in the sidewalk but in the cell phones in the pockets of the people passing you (together with GPS data). Also, whether or not people have accepted cameras, my impression is that facial recognition software is not very reliable, and most of them are not even networked. Wnt (talk) 23:16, 3 June 2011 (UTC)

All that said, RFID readers are fun toys and not very expensive. I recommend buying one if you're interested in the topic. I haven't tried it, so I can't personally recommend it, but this looks like a fun beginner's kit. APL (talk) 18:04, 3 June 2011 (UTC)

I must reiterate what others have said here: The potential risks of privacy invasion or identify theft that come just from using the internet, appear to be far greater than the potential risks connected with a "tracking chip". ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:47, 3 June 2011 (UTC)

I think these are different kinds of risks. For example, tracking someone's physical position on a daily basis is more useful for serious physical attack, robbery, kidnapping, etc., whereas the content of the e-mail would suggest more when and why someone might want to do that to you. Wnt (talk) 23:16, 3 June 2011 (UTC)

Your typical criminal just wants your money. A high-tech criminal is most likely to want to steal your identity, and the greater your electronic presence, the greater likelihood of such theft. I have trouble imagining why someone would go to all the trouble of putting chips in your shoes, when they can do what they always do: look for vulnerabilities. They don't need to steal everyone's stuff - just the stuff from the path of least resistance. For example, they might try to open the back door of every house in a given neighborhood. The one they're going to break into is the one who left it unlocked. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:27, 3 June 2011 (UTC)

If someone is planting RFID readers all over town, paying off local businesses to put RFID transmitters into my shoes, and building up massive database of my movements around town just to corner me and take the $20 I have in my wallet, then I would gladly turn it over. You have to admire such a coordinated high-tech effort. I'd be proud to be targeted by such professionals. APL (talk) 22:28, 4 June 2011 (UTC)

In any case, if it is as easy as boiling one's shoes, it would be relatively easy to defeat any future nefarious uses once they were uncovered. This makes this sort of paranoia a lot less threatening to me than medical records, spending records, e-mail interception, net use logging, and so forth, which are much hard to disentangle oneself from even if one knows probable abuse is taking place. The RFID approach seems rather clunky to me, by contrast to the type of data that we know the NSA and probably other agencies can and do collect. --Mr.98 (talk) 19:45, 3 June 2011 (UTC)

Has anyone bothered to tell the workers in YY factories that they are meant to be inserting RFID chips into the sneakers they make ? That's a lot of chips. Sean.hoyland - talk 20:11, 3 June 2011 (UTC)

The employees in the factories making credit cards didn't raise any special ruckus when RFID chips were added to some of them; that was left to consumers. But really, my question here wasn't about all privacy, which is too broad a topic to cover well - I was asking specifically about RFID because it's something I don't know as much about the capabilities of. Wnt (talk) 23:24, 3 June 2011 (UTC)

If the RFID chip isn't disabled when you purchase the item, a more important reason why you may want to kill it is because you don't know when it's going to set off a store anti-theft security alarm which while not dangerous (unless you are actually a thief) tends to be annoying. I know someone who had a jacket that used to set off such an alarm, possibly in one store or chain only. I believe it didn't happen were the item was purchased (which was Kathmandu (company)).

On a personal note, I once had one of those cloth shopping bags which I eventually worked out was the reason I kept setting off such alarms. From memory it wasn't consistent i.e. I didn't always set off the alarm in some stores. Strangely there was also one store where I would sometimes/usually? set off the devices when entering the store (and usually no one paid attention), but not on the ones at the checkouts (i.e. exit). Funnily enough the store most likely to search me was the one who sold the bag. Eventually I worked out it was probably one of my shopping bags (I had purchased 2 recently from different stores) and found a RFID embedded in the bag which I bent a few times and that resolved the problem. I guess a conspiracy theorist would suggest it intentional from the plastic bag manufacturers.

I've read other stories of similar problems. One person even claimed they set off the alarms at the Israeli border (or some other high security area) which seems a bit strange (why would the security devices detect RFIDs or if they did why didn't they at least tell the operators what it was?).

Perhaps with the growing usage things are improving, this was a few years back.

BTW I don't know if I'd entirely agree with some of the above. I don't know about the sidewalk thing but it seems to if unique RFID were widely present in shoes it would be a good way for stores to track the way people move about their stores, where they stop, how long they stop etc. This could be primarily for general purposes, to see what displays work, whether the layout needs redesigning or stuff like that. But this info could also be tied to transaction cards or loyalty cards for individualised profiles.

I don't think mobile phone network tracking would have sufficient resolution to do this, unless perhaps you install a lot of picocells. And you'd need the cooperating of the networks in any case. You could do it with Bluetooth, something similar is done on motorways in NZ [2] [3] but that relies on people leaving a Bluetooth device on and unhidden. You could perhaps do it with cameras, which would also enable you to do things like see precisely what people look at, for how long etc. But I'm not convinced this would be cheaper or the software is there yet, particularly for stores to be able to do it for most people in the store. However I'm not saying this is actually happening, I'm sure it isn't since most people don't have unique RFID in their shoes so it's not going to be worth it. And it would also potentially violate the law in a number of countries.

P.S. [4] [5]

Nil Einne (talk) 08:53, 4 June 2011 (UTC)

How much calories does it burn?

I am an adult fat man who weigh 180 pounds, so if I stand for one hour how much calories dies it burn? Wut if u sit for one hour? Wut if I lie down for one hour awake? Wut if I sleep fir one hour — Preceding unsigned comment added by 166.137.138.50 (talk) 12:45, 3 June 2011 (UTC)

Basal animal metabolic rate is a good place to look. There are some formulae there that you can use to do some calculations. Just bear in mind, if, as you say, you are 'fat' then you will burn less calories than a 180 lb man who is muscular, as muscle burns more energy that fat even when you're resting. --jjron (talk) 14:23, 3 June 2011 (UTC)

Creating phylogenetic trees

What are the best tools for taking a collection of related DNA from many organisms (for example, that for 16S ribosomal RNA) and turning it into a phylogenetic tree? I am aware of Clustal, but I am wondering if there are other widely used tools for generating the branch structures, and whether there may be superior tools in terms of creating an attractive and/or easily manipulated graphical representation of the result. Dragons flight (talk) 15:12, 3 June 2011 (UTC)

You could try the R_(programming_language), which has many packages for phylogenetics here:[6]. I can recommend R as a free, powerful general computation tool, but I have not used any of the phylo packages. SemanticMantis (talk) 19:28, 3 June 2011 (UTC)

Phylip is a very commonly used program to generate trees for phylogenetic analysis. It takes input from various alignment formats, including Clustal, and is quite easy to use. --- Medical geneticist (talk) 00:52, 4 June 2011 (UTC)

Finding the source of the German E. Coli outbreak

If the symptoms start to show up within 12 - 72 hours, as pointed out above, shouldn't it be a piece of cake to discover where it comes from? You question the people about everything they did in the last 12 - 72, what for he most wouldn't be difficult to remember. On the basis of that, you'll find some common elements and given the high number of infected patients, that should be a very limited group of common elements. Quest09 (talk) 15:55, 3 June 2011 (UTC)

First, you have to determine an outbreak - which will be days after the symptoms appear, which is around 2 days after consumption of the tainted food. So, you are asking people to list everything they ate last week. Then, you try to find something common - which is hard. Then, you have to find some of that food and verify it is tainted. Then, you recall the food and you try to track it to a distributor. From there, you are on a paperwork trail - which may or may not be valid. Food goes to a lot of places before it reaches a store. Even if you track the whole line the food went through, it isn't necessarily the farm that tainted it. One case in the United States was traced to group of farms in Mexico, but the farms were clean. The source of the bacteria turned out to be a vegetable packing station that was completely separate from the farms. -- kainaw™ 16:13, 3 June 2011 (UTC)

And it is not 2 days, it's more like 8 days with very low amounts of bacteria ingested. I've read that ingesting just a dozen of this strain of E-Coli bacteria will maky you ill 8 days later. Count Iblis (talk) 16:33, 3 June 2011 (UTC)

Agree with Kainaw. I've been involved in a couple of investigations and it can be confoundingly difficult to pin things down. On the one hand, we have an unprecedented ability to track and monitor shipments, but on the other hand, the food web we've is so far reaching and complicated that there's a crazy amount of data to go through. Matt Deres (talk) 17:22, 3 June 2011 (UTC)

This is not that easy if you have 100 patients and they ate 20 different things a day for 8 days you have a lot of tests. If you have a quicktest for the EHEC you are searching for it gets easier, but in the beginning you have to look at an E. Coli you find. --Stone (talk) 17:30, 3 June 2011 (UTC)

Perhaps the cause is the drought in Western Europe? Farmers are spraying water on their fields a lot more than usual and they want to reduce the cost for that. So, they may use water from ditches, the water in there can be contaminated by cows. Count Iblis (talk) 03:10, 4 June 2011 (UTC)

Assisted suicide vs. euthanasia

What is the difference between assisted suicide and euthanasia?--188.146.40.115 (talk) 18:16, 3 June 2011 (UTC)

Assisted suicide implies that the death is desired by the person dying. Euthanasia is not as clear on that point — it says more about the intentions of the person assisting than it does about the intentions of the one dying. Voluntary euthanasia is the same thing as assisted suicide, but there is also involuntary euthanasia. There is no involuntary assisted suicide. --Mr.98 (talk) 18:29, 3 June 2011 (UTC)

One is a method of helping someone kill themsevles and the other is a phonetic spelling for a person who rarely logs in to edit Wikipedia (sorry, I couldn't help but answer this one). Really, euthinasia doesn't require the person to kill themself. Youth in Asia (talk) 18:31, 3 June 2011 (UTC)

Euthanasia as a word originally meant "happy death",[7] and has come to mean "mercy killing". As noted above, assisted suicide is voluntary on the part of the human receiving it. Euthanasia toward a human might or might not be. When an animal is put down, obviously it's not voluntary on the animal's part. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:43, 3 June 2011 (UTC)

Well, there are animals that seem to commit suicide, like whales that beach themselves. I suppose you could argue that this behavior is the result of instincts, rather than a decision to die. There are also old and sick animals with the instinct to go off and die alone (probably so as to not infect others related to themselves). StuRat (talk) 23:30, 3 June 2011 (UTC)

That doesn't qualify as assisted suicide, nor is necessarily even a conscious effort to die. Animals that go off to themselves to die might do so just to feel safer somehow. Your typical animal is ignorant of micro-biology. I assume this has come up because Kevorkian died today? ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:45, 3 June 2011 (UTC)

It would be assisted if you then finished off a whale that beached itself, etc. StuRat (talk) 02:56, 4 June 2011 (UTC)

Is it not assisted if the pack leaves an old wolf to die alone? – b_jonas 12:00, 5 June 2011 (UTC)

How about the mother spider which sacrifices herself so her spiderlings can eat her alive ? This make the spiderlings assistants in her suicide, right ? StuRat (talk) 06:18, 6 June 2011 (UTC)

Wikipedia has an articles about Assisted suicide and Euthanasia. For the do-it-yourself enthusiast (euthanasiaphile?) there are Euthanasia devices such as the Thanatron, Mercitron, Deliverance machine and Exit International device. Cuddlyable3 (talk) 18:58, 3 June 2011 (UTC)

"Librarians have moved to ban the suicide 'do it yourself' book, Final Exit, from their shelves, not because they object to the content, but rather since nobody ever seems to return the book." -:) StuRat (talk) 01:08, 4 June 2011 (UTC)

relationship between forces

What is the relationship between infrared light and heat that allows you to see heat using it? And also what is the relationship of electrons in electricity and light, that is made up of photons, yet makes up Electromagnetic radiation; while you can use magnets to make electricity? Bugboy52.4 ¦ =-= 18:23, 3 June 2011 (UTC)

Infrared light is heat...which is thermal radiation which is a form of electromagnetic radiation. Infrared light is seen with a infrared thermometer which measures the frequency of photons in a certain wavelength. Electrons are in a sense made up of photons...additionally see wave–particle duality.Smallman12q (talk) 23:15, 3 June 2011 (UTC)

"Electrons are in a sense made up of photons" - no, not in any sense I'm aware of. Both electrons and photons display wave–particle duality, but they are otherwise quite different. In particular, an electron has rest mass and electrical charge, while a photon has neither. --Stephan Schulz (talk) 07:42, 4 June 2011 (UTC)

I think it's more correct to say that warm objects give off infra-red light (and hot objects can give off visible light, starting with "red hot" then going up to "white hot", or even "blue hot")). StuRat (talk) 23:20, 3 June 2011 (UTC)

Infrared EMR carries heat away from the source. When the infrared EMR irradiates a target, the target absorbs the infrared EMR with its heat. The target converts some of the heat into different forms of energy, the rest is reemmited back in the form of EMR. The EMR may include visible, infrared and others. Infrared is a medium for heat or thermal energy, as energy can only be passed from one medium to another.

Electrons interact with EMR by absorbing and emmiting it, leading to the transferal of energy. Plasmic Physics (talk) 00:30, 4 June 2011 (UTC)

Note also that a black body at high enough temperatures will radiate electrons and positrons. Count Iblis (talk) 02:58, 4 June 2011 (UTC)

You don't even need a black body for that, you just need high frequency gamma radiation and a cloud of gas. See pair production. Note, moving magnets don't produce electrons. They simply energise them from their ground state, and creates a current of flowing energised electrons. Plasmic Physics (talk) 11:33, 4 June 2011 (UTC)

You can have heat with nothing but photons. It's a misconception that heat is just about kinetic energy of massive particles. Heat is random energy, period; doesn't have to be kinetic. If you have an evacuated chamber at 3000K, with ideally black walls, the contents of the chamber will be a mix of photons at 3000K, and it's perfectly correct to say that the chamber has a temperature of 3000K even if there is no matter in it at all. --Trovatore (talk) 11:57, 4 June 2011 (UTC)

Photons are fundamentally connected to electricity: they're the auditors in charge to make sure electromagnetic force works. Electrons are not related in any such fundamental way: they're just one of the particles with an electric charge that happen to be the most convenient carriers to make electric current in the materials practically available to us. However, even with our technology, we can have electric current pass through a solution where the carriers are ions, it's just not very practical to work with. (Positronic brains are just fiction.) – b_jonas 11:56, 5 June 2011 (UTC)

All light, incident on any object, will heat it up to some degree. Infrared light, however, is particularly good at it; better in fact than light of shorter wavelength (like visible, or UV) or longer wavelength (like radio) of an equivalent intensity. The reason for this is that most molecules have vibrational energies which have energy levels in the IR range. Vibrational energy is one form of heat energy, so IR light which is incident on many substance will efficiently absorb that light and convert it into increased vibrational energy very efficiently, which is why infrared energy will heat objects up so well. The reverse is also true; objects will emit IR photons in buckets as they cool off, which is why "night vision" or "infrared vision" cameras are able to "see heat". There is some pretty good discussion on the relationship between IR and molecular vibrations at Infrared_spectroscopy#Theory. --Jayron32 19:11, 5 June 2011 (UTC)

Sideways gravity

An experiment in 1774 was to calculate the horizontal attraction of a mountain by measuring the tiny deflection from the vertical of a pendulum nearby. The normal vertical had to be found by painstaking observations of the stars and the pendulum deflection was measured in arc seconds. If one repeated the experiment today using a CCD digital camera looking upwards as the pendulum, how small deflection angle could one measure? What precautions would be necessary? Cuddlyable3 (talk) 18:42, 3 June 2011 (UTC)

Commercially available star trackers publish angular resolution limitations. I think we've entered the era of "as many decimal places as you can afford," out to 10 or 20 or maybe even 30 decimal places bits. (So, ~ 6 to 10 decimal places).

I guess one issue, since you are measuring from the ground, is that atmospheric thermal aberrations will cause noise in high-resolution star position measurements. Equipment vibrations can be easily compensated for by adaptive optics, but atmospheric distortion must be estimated in software and compensated; so your algorithm (or your software developer) will be your limiting factor. Nimur (talk) 00:18, 4 June 2011 (UTC)

The lead of the article (adaptive optics) says it is used for atmospheric distortion though. Rmhermen (talk) 17:54, 4 June 2011 (UTC)

Yes, but of course that correction is not accurate to infinite decimal places; the correction can only be as good as the estimate of the distortion. Nimur (talk) 02:48, 6 June 2011 (UTC)

Suppose we use star position measurements to find latitude and longitude. Does anyone have accuracy numbers? Cuddlyable3 (talk) 08:49, 6 June 2011 (UTC)

Could the E. Coli outbreak be the result of a bio-terror attack?

Could someone grow a deadly strain of E. Coli, inject that using a syringe in vegetables stored at some farm and cause a deadly outbreak like the current one in Germany? I guess that injecting E. Coli inside vegetables could explain why nothing has been found, because investigators are collecting samples from the skins of vegetables. Count Iblis (talk) 21:21, 3 June 2011 (UTC)

I don't really know but I doubt heavily that it could work that was. Take a clean, unused syringe needle and poke into some vegetables. Leave them in the fridge for 3 days. I bet you will see brown degradation at those spots big enough that those specimens would be sorted out. 95.112.137.166 (talk) 22:20, 3 June 2011 (UTC)

Since pathogens find their way into vegetables in accidental outbreaks, I think this can be done; I'm not sure I should really bother to think up cleverer ways to do it though. I think that as a rule, the less technology involved in a biological attack, the greater its chances of success. The 1984 Rajneeshee bioterror attack is an example of a quite nearly successful attack - but some technology they didn't need led to their eventual prosecution. Wnt (talk) 23:40, 3 June 2011 (UTC)

I think maybe that article is misnamed. It was certainly a reprehensible action, but I'm not sure it was terrorism. To me terrorism is an attempt to frighten a population into submission. Here it seems that any fear was a byproduct; they just wanted people to be too sick to go to the polls. (Note that I'm not saying that's better than terrorism, just different.) --Trovatore (talk) 07:16, 4 June 2011 (UTC)

Well, the article says people were afraid to go out, that restaurants were affected economically. It's true that by not seeking immediate publicity and recognition the Rajneeshis differed from many contemporary terrorists; though the damage and risks were different, somehow the attack seems more comparable to anonymous goons who burn down synagogues by night. But we were writing the article I'd say we have to stick with reliable sources; here I'll say, terrorism is a word, not a black bordered category coded in the laws of physics, and like all words it is prone to elastic definition by a wide range of cultural forces. Wnt (talk) 15:05, 4 June 2011 (UTC)

Yes, and I think that Bin Laden's last message referred to the KISS principle. :) Count Iblis (talk) 03:02, 4 June 2011 (UTC)

Crop dusting plane? Seriously though, getting the right pathogen is often much harder than deploying it (though anthrax might be an exception). Dragons flight (talk) 06:57, 4 June 2011 (UTC)

I think the answer is, yes, it COULD be a bio-terror attack, but far more likely is incompetent handling and/or negligence, possibly of the criminal kind. But not a deliberate attack. HiLo48 (talk) 07:24, 4 June 2011 (UTC)

Organs to donate

How many anatomical organs one can donate and retain relatively normal life capability afterwards (and what are they)?--178.180.38.43 (talk) 21:42, 3 June 2011 (UTC)

One kidney, part of your liver, and one lung. Count Iblis (talk) 21:52, 3 June 2011 (UTC)

Skin, bone marrow, blood and blood vessels could also be recycled leaving the donor alive. But as in liver, this is not a whole organ, and could be termed a tissue donation. Graeme Bartlett (talk) 23:07, 3 June 2011 (UTC)

As above, if we allow partial organs, we can throw in partial pancreas. There's also no technical barrier to a living donor giving up a single cornea for transplant, though there are obvious and serious ethical issues. A single ovary can be transplanted from a living (female) donor; as far as I know this procedure has only been performed between identical twin sisters. See also our article on transplantable organs and tissues. TenOfAllTrades(talk) 04:05, 4 June 2011 (UTC)

What serious ethical issues could arise from a single cornea transplant as long as the donor is willing? 173.2.165.251 (talk) 13:58, 4 June 2011 (UTC)

There is a common view in medical ethics that you shouldn't harm one person to help another, even if the person being harmed consents ("first, do no harm"). Most people accept that the harm from donating a kidney, say, is small enough that they are willing to make an exception. Being blinded in one eye (or at least having your vision in that eye significantly impaired) is quite a bit more harmful. --Tango (talk) 22:58, 4 June 2011 (UTC)

Uterus transplantation has been tried, but not successfully according to the article.Sjö (talk) 06:35, 5 June 2011 (UTC)

Could one donate a finger to a close relative? A teeth? I guess there's no need for the latter because it's more practical to use prosthetics. – b_jonas 11:46, 5 June 2011 (UTC)

Even replainting a tooth from an individual back to him- or herself (say, for instance, it avulsed completely) is less predictable than current dental implant technology (and required multiple procedures with to allow it to remain in the mouth properly (root canal therapy, possible post and core, and a crown). DRosenbach ^{(Talk | Contribs)} 03:45, 6 June 2011 (UTC)

You probably could donate a finger. Modern medicine can re-attach severed fingers with a very high success rate so I can't see why they couldn't attach another finger instead if the original one was too badly damaged. I'm not sure it would be worth having to take anti-rejection drugs for the rest of your life, though. Fingers are very useful, but hardly essential for life. One thing I have heard of is grafting a toe onto a hand - since it comes from the same person, there isn't the same risk of rejection. Also, the loss of a toe isn't as harmful to them as the loss of a finger (particularly a thumb, which is the most important finger so the one usually replaced) would be to you. --Tango (talk) 16:59, 5 June 2011 (UTC)

Pretty sure you could donate more than one lung, so long as it was still rather less than two. --Dweller (talk) 19:02, 5 June 2011 (UTC)

John and Lorena Bobbitt are to be awarded a Geld Medal for their work on reversible organ reduction. Cuddlyable3 (talk) 08:45, 6 June 2011 (UTC)

I have doubts that you you live a realitively normal life after donating a lung. I would think that the capability to do aerobic activity like jogging would be seriously limited. Jogging with 2 lungs is hard enough. Googlemeister (talk) 13:28, 6 June 2011 (UTC)

A beatiful question about Parrots and their voice producing system..

We all know that Parrots can Imitate Human language (are they the only one's on the planet?)..

well, i ask, is this ability Neural, or is it because of their unique Vocal-producing-Throat system (which i believe to be Human-like)?...

sorry for the ignorance.

blessings. 109.67.42.106 (talk) 22:52, 3 June 2011 (UTC)

Both. They need the physical ability to make those sounds, and they need the brain power to hear a sound and convert that into the appropriate nerve signals required to duplicate it. A dog might be an example of of an animal with sufficient brain-power to imitate human speech, but which lacks the physical equipment. Thus, when you try to get a dog to say "I love you", it comes out "rawr raw rawr". Also, there are other species of birds which imitate sounds, including human speech, such as the myna bird. StuRat (talk) 23:09, 3 June 2011 (UTC)

Common_Raven#Vocalization 95.112.137.166 (talk) 23:32, 3 June 2011 (UTC)

"Nevermore!" Looie496 (talk) 23:44, 3 June 2011 (UTC)

You may be interested in our articles on bird vocalization and more particularly lateralization of bird song, which discusses the neurophysiological work that goes into the vocalizations of songbirds. Put briefly, it's not terribly human-like. For one thing, they essentially have a two-part vocal apparatus called a syrinx (compare with the human larynx). Matt Deres (talk) 02:25, 4 June 2011 (UTC)

Some parrots are talented enough to work for large corporations.[8] ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:19, 4 June 2011 (UTC)

Incidentally, Jules Verne: Dick Sand, A Captain at Fifteen, chapter 6 mentions in passing “a dog that could actually pronounce quite distinctly nearly twenty different words”. (Find links to full text of both the original and the English translation from the article.) – b_jonas 11:44, 5 June 2011 (UTC)

Were two of them rough and ruff? Googlemeister (talk) 19:28, 7 June 2011 (UTC)

Canines

Is it true that dogs can't recognise most phonetics of a phrase, except for ones like vowels? So that the phrase, "fetch the newspaper" sounds like, "etch e ews-a-e". This means that you can essentially substitute most consonants and they won't even notice the difference. I'm talking about recognition not vocalisation. Plasmic Physics (talk) 00:07, 4 June 2011 (UTC)

That's also true of humans, though (to some extent). Our article on Speech Recognition algorithms outlines the physiology and psychology of human language and phoneme recognition, and methods to model it using machinery (particularly, software / computers). Nimur (talk) 00:14, 4 June 2011 (UTC)

[9] [10]. Deor (talk) 01:17, 4 June 2011 (UTC)

This is pure WP:OR, but in an experiment I just now conducted, dogs can definitely hear the difference between the words "small" and "ball", which only involves a difference in consonants. Red Act (talk) 01:28, 4 June 2011 (UTC)