Wikipedia:Reference desk/Archives/Science/2009 July 27

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July 27

Chesty Coughs

When you have a chesty cought does it make any difference whether you cough up or swallow phlegm? Sometimes i'm too lazy to cough it up and just swallow it, assuming it will go into my stomach anyway, but i just wondered whether this was true or not? perhaps somebody could tell me. thanks! 140.247.249.83 (talk) 05:41, 27 July 2009 (UTC)

First let me tell you what phlegm is made up of.Then it is up to you to decide whether to swallow it or not.The respiratory and nasal passages are lined by mucous membranes.These are bronchial mucosa and nasal mucosa.They have epithelial tissue that secrete mucous.The main function of mucous is to trap the germs and bacteria that enter the respiratory passages.(another function is to keep the passages moist).So during fever there is surge in number of germs and hence the mucous production in the respiratory passages increase...the result of which you get chesty coughs.The components of phlegm are mucous,dead germs,proteins,lipids,immunoglobulins and many other inorganic ions that form the minor part of it.So best not to swallow it..because it may contain some live germs.Also the idea of swallowing dead germs may make you feel disgusted.So best eliminate it out of the body.Gd iitm (talk) 06:16, 27 July 2009 (UTC)

If you do, make sure you do it in a fashion that is not likely to infect other people, i.e. spit it into a tissue and dispose properly of the tissue. Don't just gob it on to the floor. This was illegal in some places!--TammyMoet (talk) 09:37, 27 July 2009 (UTC)

Whatever live germs you cough up will very likely be killed by your stomach acid. It's almost certainly harmless to swallow the phlegm. --Stephan Schulz (talk) 12:34, 27 July 2009 (UTC)

Gd iitm, that's a joke, right? Whatever live bacteria happen to be in your phlegm are going to be digested when you swallow them. Tempshill (talk) 15:53, 27 July 2009 (UTC)

nit: mucous is the adjective, mucus the noun. —Tamfang (talk) 22:38, 2 August 2009 (UTC)

99 % of bacteria get digested by HCl in the stomach.But doesnt the thought of swallowing 99% dead bacteria and 1% alive make u feel disgusted?? —Preceding unsigned comment added by 117.193.140.74 (talk) 05:48, 28 July 2009 (UTC)

I remember George Carlin once using a factoid in his routine that swallowing saliva is linked to cancer. I have to assume he didn't just invent this factoid, and that there was a real research paper on the subject. Also, traditional Chinese wisdom advises a person to spit rather than swallow. If you're too lethargic to get up and spit, perhaps improvise a spittoon. I used to do this. Expect people to complain. It's your life and your body though so don't worry too much, just be as discreet as humanely possible. Vranak (talk) 16:01, 27 July 2009 (UTC)

That's totally ridiculous! Saliva is crucial part of the digestive system - aside from lubricating the food, it contains an important enzyme that breaks down starch into sugars. (Try chewing a piece of dry, non-sweetened bread for longer than you really need to - and you can taste how it gradually becomes sweeter as the saliva turns the starches into sugar). Not swallowing the saliva is therefore impossible! SteveBaker (talk) 18:12, 27 July 2009 (UTC)

George Carlin was a comedian. He said a lot of very true things in his routine and, in a way, he's correct here too (or at least making the point) that living causes cancer. Vranak should have explicitly specified he was quoting a comedian, who was using the concept for rhetorical effect anyway. Matt Deres (talk) 19:04, 27 July 2009 (UTC)

Well regardless, I spit hundreds of times a day and I have never gotten sick since starting. Vranak (talk) 22:44, 27 July 2009 (UTC)

Now consider where the phlegm is going - into a handy bag full of hydrochloric acid. Best place for it. 213.122.53.30 (talk) 18:40, 27 July 2009 (UTC)

Indeed - put those (maybe) live bacteria outside your body and there is every chance that they'll get back in again through your nose and you'll have to fight them off all over again - or maybe they'll go on to infect someone else near and dear to you. Dumping the little buggers in vat of hot hydrochloric acid is a great solution to the problem! Heck, you'll even get some vitamins, protein and carbohydrates back from them - phlegm is practically a health food! (OK - I think I went too far!) SteveBaker (talk) 13:20, 28 July 2009 (UTC)

Yeah, I'd imagine most organisms don't end up possessing the ability to live in your stomach by accident. Germs tend to specialize—a cold virus won't find itself in your stomach and then just decide a vat of acid would be a good place to stay. So unless you happen to have cholera or something like that in your mucus for some reason, recycling might not be a bad idea. Alfonse Stompanato (talk) 21:17, 28 July 2009 (UTC)

I'm actually inclined to believe the opposite that spitting it is "better for you": http://www.davesdaily.com/bizarrenews/pickyournose_04-04.htm . Vespine (talk) 06:05, 30 July 2009 (UTC)

Common mistake

People make the common mistake of saying that their "weight" is xkg, rather it is the mass. I was reading the T-90 tank page and found that the weight is stated as 46.5 tonnes. Shouldn't it be mass? Thank you.--116.71.54.57 (talk) 07:17, 27 July 2009 (UTC)

Call me a descriptive linguist, but it seems unfair to call it a mistake when, in common usage, weight means mass. In engineering usage though, you're probably correct. AlmostReadytoFly (talk) 08:09, 27 July 2009 (UTC)

No it shouldn't be 'mass'. As AlmostReadyToFly notes - the term Weight (like a shockingly large number of terms in English) has more than one appropriate meaning (http://www.answers.com/weight) - it even referencs this in the opening section of the article. 194.221.133.226 (talk) 10:01, 27 July 2009 (UTC)

Weight means lots of things as the list on answers.com demonstrates but none of them is mass, which is the correct category for an object without a specified location. The weight of an object varies by several percent moving from pole to equator and the fact that it is locally equivalent to mass does not in my view suddenly make the error correct. --BozMo talk 10:59, 27 July 2009 (UTC)

Citation for the several percent? Aaadddaaammm (talk) 11:09, 27 July 2009 (UTC)

It's actually about half a percent. See Earth's gravity. Algebraist 11:25, 27 July 2009 (UTC)

Ok, half a percent at sea level and a bit more to the top of Kilimanjaro (the article isn't quite right but pretty close AFAICT). That's why the earth is oblate. --BozMo talk 12:43, 27 July 2009 (UTC)

Other way around: the strength of the gravitational field varies because the Earth is oblate. The Earth is oblate (primarily) because of its rotation. — Lomn 13:16, 27 July 2009 (UTC)

Nah. It is the rotation which makes the net weight less on the equator which makes things bulge. --BozMo talk 13:30, 27 July 2009 (UTC)

You are both kind of right. The rotation causes the bulge in the manner you describe, but gravity on the bulge is less because you are further away from the centre of the Earth (there is also a contribution from the rotation itself). --Tango (talk) 13:49, 27 July 2009 (UTC)

Weight isn't an 'incorrect' term - it has a perfectly simple, clear, valid meaning in physics and elsewhere - the only important things to understand is that (a) weight and mass are not the same thing - and (b) an object's weight will change depending on where you put it. Talking about the weight of a tank - which is pretty much only going to be trundling around on the surface of the earth - and highly unlikely to ever be driving around on the moon - is not at all unreasonable. Certainly there are small variations in the weights of objects depending on whether they are at the poles or the equator - parked on top of a mountain or near a magnetic anomaly caused by some particular flook of geology...but those differences are likely to be negligable compared to things like the amount of fuel and ammo the thing is carrying. So we should not be overly anal about our descriptions of things like that. Worse still, from an encyclopedic point of view, we are unlikely to be told either the mass of the tank or it's weight in Newtons. Since we're required to have references to back up what we write - it may actually be necessary to state the weight - and to give it in kilogrammes (with the implication that it's kilogrammes-force that we're really talking about). Most of our readers would have no clue what a Newton is anyway! There is utility in being useful, clear and understandable - and talking about the weight of a tank in kilo's is just fine. SteveBaker (talk) 18:06, 27 July 2009 (UTC)

Not to mention that almost no one knows their "mass". Scales, by definition of the way they work, measure weight, not mass. Besides, us stupid Americans still use pounds (scientists aside), which can describe both weight and mass.-RunningOnBrains^(talk) 18:31, 27 July 2009 (UTC)

The problem with allowing definition to become common usage and be divided by the lowest common denominator (warning: mathmo alert: things do not fall to their lowest common denominator in maths as the LCD of a list of numbers is larger than any of the numbers, they fall to their highest common factor or become divided by their lowest common denominator) is that education becomes nigh impossible. We make a lot of effort with kids when they are aged about 12 to understand the different between mass and force, speed and velocity etc just as we are careful in teaching kinds the difference between strength toughness etc. So commonplace poor usage should not be "just fine". --BozMo talk 18:38, 27 July 2009 (UTC)

If you consider "weight" to be short for "weight on earth", can you accept it as an accurate description of a quality of a tank? Words in context carry all kinds of subtextual meanings. Between the lines of the blankly-stated statistics of the tank we can read the assumption that people only very rarely care what it weighs on other planets. This may be a good thing. 81.131.54.159 (talk) 19:24, 27 July 2009 (UTC)

Accurate, just about. Optimal in terms of opportunity to be more educational, no. --BozMo talk 20:18, 27 July 2009 (UTC)

Like I say, missing an opportunity to educate readers into being engineers and physicists may be a good thing. The world also needs other kinds of people. 81.131.54.159 (talk) 20:25, 27 July 2009 (UTC)

That statement is so absurd, I don't know where to start. You're saying that we should take people who otherwise would be scientists and engineers and...not educate them? What "other kinds of people" did you have in mind? -RunningOnBrains^(talk) 20:34, 27 July 2009 (UTC)

Golfers, taxidermists, and so on, you know. People who quite rightly don't want to distinguish mass from weight. Maybe even some scientists, like botanists. It's desirable that they don't waste their attention on such matters, unless interested. I'm not sure why those people would be looking at the T-90 tank article, but it takes all kinds, is what I'm saying. 81.131.54.159 (talk) 20:52, 27 July 2009 (UTC)

It's also desirable that they don't get frustrated or irritated and go read Britannica. APL (talk) 00:50, 28 July 2009 (UTC)

Not everything has to be an opportunity for education. Stating the weight of a tank in Newtons will have precisely one consequence: Not one single person who actually wants to know the answer will actually understand it - and not one of them would bother to look up "Newton" to find out. Nobody wants to know the mass of the tank either...for any concievable practical purpose, the weight is the thing you need to know.

Just as scientists have to know not to use more precision in stating a result than is actually appropriate - just as we know that it's pointless to talk about having to go out and cut the Chloridoideae (when we are really going to mow the lawn) - we have to understand that there are times when a more approximate take on things like this is actually more appropriate than strictly adhering to the underlying physics. Nobody (and I mean NOBODY) gives a damn what the tank would hypothetically weigh on the moon. Nobody cares that the weight might be 'off' by a few percent because we weighed it at the equator rather than in the tropics. Our bathroom scales measure in pounds and kilos - every measurement of weight throughout all of society EXCEPT a very few physicists and other science nerds is in pounds or kilos. So what? So long as the people who need to know are aware that this "mistake" is made everywhere - we're OK. How many members of the public would understand if you said that you accelerate your car by putting your foot on the brake pedal? How many could tell you why 'velocity' is not the same thing as 'speed'? There is a place for rigor and a place for getting the message across in a comprehensible manner...and this falls firmly into the latter category.

Sure, we have a responsibility to educate people - but pissing them off by making these tiny pedantic statements does precisely the opposite - it completely alienates them. We need to teach them the scientific method - that homeopathic medicines are just water - that evolution is real - that the greenhouse effect is killing our planet - that you can't buy a herbal capsule that'll make "certain parts of your body" larger. Pick your battles - mass versus weight isn't one of them! SteveBaker (talk) 01:00, 28 July 2009 (UTC)

<deindent>
I'll second Steve's point that we should aim to teach the scientific method instead of fixating on scientific terminology. In fact, I would go further and say that a skill even more basic and indispensable that the scientific method is to learn to read and interpret statements in context, rather than try to parse them like automata. Fortunately, we humans are quite good at that! For engineers collaborating on a project, it is critical to get their units right; however, if a lay reader is actually confused by the statement that "tank x weighs y kgs", they have missed out on a basic cognitive and linguistic skill.
If one is talking to an elementary school kid about the T-90 talk, it is much better to tell her that the tank weighs as much as 700 grown men, than to talk about 46.5 tonnes or (worse) 460kN. On the other hand, if I am driving the tank across a bridge, I better know its weight (including that of the men, fuel and arms onboard) and the bridge's load-bearing capacity (along with the applicable margins). In short: context matters, and understanding that is more important that false precision and pedantry. Abecedare (talk) 01:48, 28 July 2009 (UTC)

I agree with the point of view expressed above by Steve and Abecedare. Context does matter. I am a physics teacher but I have no problem with the statement that a tank weighs 46.5 tonnes. I also have no problem with telling my kids to close the fridge to keep the cold from coming out. Some of my colleges pedantically state that the cold does not come out, and that we I should say that the heat is going in. I also have no problem with stating that the station is stationary while the train is moving, eventhough I know that movement is relative. Dauto (talk) 04:44, 28 July 2009 (UTC)

We obviously don't share a common perception of the kind of person who comes to Wikipedia for info on how much a tank weighs or what its mass is. If someone is relying on that to build a bridge they haven't read the disclaimer. The fact your scales aren't in Stone though is a give-away that you live in the land of loose language usage so the consistency I see. --BozMo talk 13:22, 28 July 2009 (UTC)

Is there some honest confusion that you are legitimately worried might occur? I am having a hard time imagining a scenario where a person, curious about the weight and/or mass of a tank would be confused by the articles as they stand.

I can see how this current system might confuse martians, but that works in our favor. It will lead them to believe that our Earth militaries are three times more powerful than they really are. p.s. This is the Reference Desk, changes to wikipedia policy go in the wp:Village Pump. APL (talk) 18:35, 28 July 2009 (UTC)

But the tank page says Weight: xkg. Any guy with a little knowledge of physics will tell you the problem is that weight and Kg are not same. It should be either Newtons, which would not help the average reader, or mass. I dont see where the problem is.--116.71.34.182 (talk) 16:47, 28 July 2009 (UTC)

The real issue here is that reliable sources and tank experts conventionally describe tanks in terms of their weight, not their mass. There appears to be no standardization to account for variation in weight in different locations, and consequently we have no access to the actual mass data for these tanks. Hence the question of which to describe is moot, because only the weight is known. Dcoetzee 19:48, 28 July 2009 (UTC)

There is no problem. We are only pointing out that the word weight can be used as a synonim for mass in coloquial language just as the words 'work' and 'field' have different coloquial meanings than the ones used by physicists. That's why context matters. There is no possibility of confusion since the units make clear wheather one is talking about mass or force. Dauto (talk) 20:08, 28 July 2009 (UTC)

But wouldnt a kid, assuming he is reading the page, be misguided and hence confused between what he learned in class and read here on wikipedia. I was just saying that here on wikipedia, with genius guys like Steve Baker, Runningonbrains (list goes on forever), such a mistake would be like 2+2=5.--116.71.34.182 (talk) 20:07, 28 July 2009 (UTC)

Kids also can learn that words have different meaning depending on the context. Dauto (talk) 20:11, 28 July 2009 (UTC)

Exactly. Training kids to be deliberately confused when someone tells them a weight in kilos is POINTLESS. By all means tell them that in formal scientific writing you have to be really careful not to make this faux pas - but that in normal usage, telling someone the mass or specifying the weight in Newtons is just as bad. If that's the hardest lesson a kid ever has to learn in science class, (s)he's doing pretty good! Words are just words - we can make them do whatever is convenient. Having that underlying understanding is important - but having a tolerance for the daily screwups of well meaning non-scientists is just as vital. SteveBaker (talk) 21:55, 28 July 2009 (UTC)

Knee surgery procedure

Hi,

I'm looking for the name of a operation. In it, the part of the femur where the patella ligament attaches is cut off, and moved to the side or down. I think it starts with an L, and I'm thinking something like "Lithuan". Any ideas? Aaadddaaammm (talk) 11:08, 27 July 2009 (UTC)

Lateral Release [1] Livewireo (talk) 15:29, 27 July 2009 (UTC)

Thanks for the reply, but that's not it. The ligament going down from the patella attaches to the tibia/femur (not sure which) at a certain point. In this operation, the bone is cut, and moved with the ligament still attached. —Preceding unsigned comment added by Aaadddaaammm (talk • contribs) 16:03, 27 July 2009 (UTC)

The only other thing I can think of would be patellar luxation which is pretty common in dogs (and people with ACL damage). It doesnt describe the procedure, but rather the diagnosis. Most knee surgeries can be performed with an arthroscopy without having to perform an open surgery. Livewireo (talk) 20:57, 27 July 2009 (UTC)

Not with an L but it sounds as though you're looking for Osteotomy or more precisely one subform of that. 71.236.26.74 (talk) 01:53, 28 July 2009 (UTC)

Automotive suspension

What are the necessary equations or formulas used for designing the automotive suspension and also to know its load carrying capacity? —Preceding unsigned comment added by 41.220.75.15 (talk) 13:37, 27 July 2009 (UTC)

Wikipedia has many articles about automobile suspension. An independent suspension for one wheel is a Dashpot that comprises a compression spring that can be treated by Hooke's law and a Shock absorber. Cuddlyable3 (talk) 15:16, 27 July 2009 (UTC)

Carrying capacity is generally estimated from materials strength. Because a suspension often has a complex geometry, simple equations are not very helpful, so Computer Aided Design and finite element analysis are used to compute the stresses. Nimur (talk) 15:28, 27 July 2009 (UTC)

The problem with Hooke's law is that it's only an approximation - and also there are many other constraints - the ability to set toe-in and camber angles for example. If there are formulae out there - they aren't simple! It would help us to know what exactly you're trying to do. Calculating the load carrying capacity for a particular vehicle is tricky - it's rarely possible to find out the spring stiffnesses and shock absorber parameters for any particular car. If you're trying to design a suspension to carry a particular load, then that's another matter - but you have lots of other constraints to consider. We need more information about what you're attempting to do. SteveBaker (talk) 17:51, 27 July 2009 (UTC)

Powering a guitar amplifier outside (in DRY conditions, of course)

Hey guys, little bit of a dillema for those good with technology to help me sort out.

Me and my friend are keen musicians, and when we're writing we often head out to a field somewhere (in bright, sunny weather, might I add, so the following need not be waterproof) to play. Usually this just consists of us heading out with our acoustic guitars and a pen and paper, so there's not much need for anything to power us. However, I'm now starting to considering taking a really small amplifier out with us so I can play a bit of electric guitar along with his acoustic. Something like this should do the trick nicely. It's advertised as a 15-watt amplifier, but the speaker is at least 20W so I presume I need something that can power 20W for a few hours.

Now here's the catch. I know I can just buy a simple petrol or diesel generator to power this and anything else I might need with it, but I don't fancy having to keep topping up with petrol everytime I want to out, even though it is only a semi-regular occurance. I was thinking that a solution might be using a solar power supply/generator. My problem is I'm having issues finding anything that would sufficiently power this amp for at least 2-3 hours. Does anyone have any ideas, or alternate solutions, to this issue?

Thanks in advance!

Regards, --—Cyclonenim | Chat  16:37, 27 July 2009 (UTC)

Your best bet is to get a battery-powered travel amplifier. Some of these operate on reasonable batteries (I think my Vox practice amp (one of these) can be powered off 8 D cells six C batteries, though I don't ever really bother). Solar power is going to be a lot of trouble (panels are fragile, heavy, and unreliable). The Vox DAs are not tubes, but I challenge you to tell the difference on a double-blind test! Nimur (talk) 16:45, 27 July 2009 (UTC)

Also, a note about power ratings - there is "power rating" and there is "actual power consumption." These two numbers are not necessarily at all correlated, thanks to the magic of marketing B.S. - and electrical power may have absolutely no meaningful bearing on acoustic power out. Your 15 watt amp has a 20-watt rated speaker, but that means that drawing more than 20 watts will damage it. The actual power consumption depends on a lot of things - steady-state current flow, and also the dynamic power (which will depend on how loudly you play). On some amps, static power draw is so high that there's no penalty to "battery life" if you crank the volume. On other amps, keeping the volume low will dramatically increase your play-time. The Voxes have a power level switch to hard-limit power to various wattages (at very slight expense to tone quality). Nimur (talk) 16:50, 27 July 2009 (UTC)

Heh, I can't believe I'd completely forgot about the possibility of using batteries. This should more than meet my needs. Thanks :) Regards, --—Cyclonenim | Chat  17:05, 27 July 2009 (UTC)

If you seriously want to use a proper power amp - get a car battery and a 12 volt 'inverter' (you can pick them up in most car accessory places). That will give you a regular 110volt power outlet that you can just plug your amp into. How long the battery will last depends on how much power the amp draws - but I think you should be OK for at least a couple of hours. Then you can recharge the battery with a regular car charger. SteveBaker (talk) 17:31, 27 July 2009 (UTC)

I am curious to hear how acoustic plus electric guitars plus a petrol or diesel generator would harmonise. The advertised 15W amplifier appears to be a single-tube Class A design that must consume continuously over 30W plus tube heater. The claim that the speaker can handle 20W says nothing about the amplifier power consumption, but is nice to know. As the OP realizes, a transistor amplifier/speaker combo running from batteries is a better choice for outdoor use. Most economical transister audio amplifiers are Class B designs that consume much less power that Class A. There are a couple of cautions:

• If you like to crank up the volume then valve amplifiers are almost indestructable while transistor amplifiers may be unforgivingly vulnerable and die expensively in a millisecond.
• SteveBaker dazzles us with the wonders of automotive technology but if you plan to run a 12VDC-->110VAC inverter from your own car battery then at the 110VAC output you can draw less than 0.9x 9% of the amp-hour capacity of the battery (and the real amp-hour capacity decreases from the day the battery was put in the car) and then your car won't start. Cuddlyable3 (talk) 22:42, 27 July 2009 (UTC)

According to (for example) [2], a typical car battery will produce 45 amp/hours...which means you can pull maybe 40 amps out of it safely - and if you do, it'll run down in an hour or so...but there is no way your guitar amplifier pulls 40 amps! Picking a guitar amp more or less at random: [3] says that a 2x30Watt Roland amplifier pulls 68 Watts at 110v (yes, I know - it's easy to get confused between audio watts and electrical watts - but these are honest-to-goodness 110volt electrical watts)...that's like one lightbulb... Watts=Volts x Amps - so you'll need about a half an amp of electricity if you have the amplifier turned up full. The inverter isn't anything like 100% efficient - so let's assume you need an entire amp to run your amp! That means you'll be able to play for several days before you have to recharge the car battery...and perhaps we'll quietly ignore Cuddlyable and you could forgo lugging a car battery around and just plugging the inverter into the aux outlet on your car. The aux outlet on my car has a fuse on it that'll blow if you try to pull more than about 2 amps - so if the fuse doesn't blow - the theory says that you're good for maybe 10 hours of hard outdoor rocking before the car won't start! However, your battery might be a crappy one that's about to fail anyway - so I'd want to start the car and run the engine for 10 minutes every few hours just to keep the battery topped up. SteveBaker (talk) 00:36, 28 July 2009 (UTC)

I've got a car, but I'll be honest I'm no good with them mechanically. Does running the engine actually recharge the battery, or does it just kind of keep it level? If it recharges it, I'm more than happy to use this idea of just using my car's battery to power the amp. Do inverters plug straight into the cigarette lighter? If so, I already have one which I can plug mains stuff into. Regards, --—Cyclonenim | Chat  13:19, 28 July 2009 (UTC)

A decent car alternator puts out 200 amps when the car engine is running at between 2000 and 3000 rpm. The battery holds around 45 amp-hours - so expect an utterly dead battery to recharge in about 15 minutes if the engine is revving. However, you're not going to get the battery that dead are you? (If you did, the car wouldn't start). So after a few hours of guitar playing, it's probably going to recharge in 10 minutes at idle - maybe 5 minutes at 2000 to 3000 RPM. The wheels don't have to be moving to recharge the battery - you can leave the car in neutral or park with the engine running and a brick on the gas pedal and that'll work just great. Don't rev the car much above ~3000 rpm because it'll probably overheat if it's not moving (if you do - keep an eye on the temperature gauge!). Some inverters plug into the 12v cigarette lighter socket - but those are somewhat limited on the amount of 110volt current they can produce because it'll blow the fuse in the car. The wires running to the cigarette lighter are usually rather flimsey and not meant to carry a lot of current. Not knowing what capacity of fuse your car has - I can't say whether that'll happen with the guitar amp or not...but my guess is not. The inverter I have can connect via the cigarette lighter outlet and produce 50 watts - which is a bit marginal for a large guitar amp - but more than enough for a practice amp. But my inverter also has another cable you can plug into the back that has heavy-duty cables and two big crocodile clips (just like the ones you find on jumper/booster cables). You can clip those directly onto the car battery (Red to '+', Black to '-'!) - thereby bypassing the fuses in the car and using the nice chunky wires. In that mode, it'll easily produce enough power to run a TV, my laptop and a table lamp for an hour or two when the power drops out during a storm. I have a couple of old truck batteries lying around at home that I keep charged for just that eventuality - truck batteries hold more amp-hours than car batteries. If you can find a cheap marine battery - you could do even better - but your needs are SMALL. SteveBaker (talk) 21:47, 28 July 2009 (UTC)

Just to clarify, if your amp actually draws 68 watts, then assuming a 12-volt battery your inverter-amp combo is going to draw almost 6 amps per hour (assuming the inverter is 100% efficienct), so you'll pull 40 amp-hours out of the battery in about 7 hours. (If I read Steve right, he seems to be assuming a 110-volt car battery.) 4.255.43.12 (talk) 02:01, 29 July 2009 (UTC)

What percentage of its charge does a battery recover during 10 minutes running time in a German retro copy of an undersized British box on wheels ? Cuddlyable3 (talk) 13:30, 28 July 2009 (UTC)

My experience is that you need to either rev the engine or actually drive the car at speed to get actual recharging. A ten minute tour will charge up the battery. Ten minutes idle won't do much. But I haven't done the car party thing much since the later engine management systems have come around. Cuddlyable, are you being mean? Didn't SB get his Mini miniaturized on the highway a few months ago? Or has he got a new one? Franamax (talk) 14:28, 28 July 2009 (UTC)

My wife and I now have two shiney red MINIs ("Captain Scarlet" and "Poppy" - one paid for by the insurance company in exchange for the cold, dead corpse of poor "Chubb-Chubb") - both 2009 models - and I have a rather fetching British Racing Green 1963 Mini called "Toad" (or, more often, "Towed").

But back to the question. Yes, the battery will recharge at idle - although it'll take longer than if the engine is revving a bit higher. However, it's totally unrelated to the wheels rotating - so you can put the car in neutral and place a brick onto the gas pedal and it'll charge the battery faster than idling it...the higher the revs, the faster the battery will recharge. The precise amount of time it takes to recharge the battery depends on the car - some have bigger alternators than others - some have bigger batteries than others - some use more current because they have computers and electronic dashboards and such. On my car, the battery would recharge faster by revving the engine when in neutral than if you drove it round the block a few times because the car has an electric power steering pump that consumes power whenever you turn the steering wheel. However, the battery will recharge pretty quickly in any eventuality...I would certainly just let it idle for 10 minutes every couple of hours. SteveBaker (talk) 21:12, 28 July 2009 (UTC)

How come it's supposed to be slightly difficult and time consuming to do then? Or is that only if the battery runs out entirely? Regards, --—Cyclonenim | Chat  22:46, 28 July 2009 (UTC)

I offer condolences on the loss of poor Chubb-Chubb, taken from you when his odometer was yet in its prime, in the certainty that he abides in the Great Wrecking Yard from which at the last toot-toot all good Minis shall be recycled. Amen. The OP wants to play music and not have to mess with fuel. If SteveBaker gets his way the OP will have to stop playing every few hours and rev up his car for a very uncertain time. I don't see any calculation of how long and how often that has to be. No one has mentioned the limitation of having to be joined by a cable to a car when one wants to play in a field somewhere. I think I last saw the brick-on-accelerator trick in a B-movie about a faked suicide. When the music stops and the OP's car won't start, Steve should offer to send the 46-year old Toad a-fetching home from that field two musicians, an inverter and a 110V mains powered amplifier (none operational). I don't wish to sound mean but a lead-acid car battery has a bad power-to-weight ratio for this application. It is optimised to deliver a brief huge starting current, which is no use here. I understand the enthusiasm to exploit someone else's car as a generating station but it is no improvement on Nimur's fitting recommendation. That was to use a battery-powered amplifier. With the money saved by not repeatedly driving a car to go nowhere and not buying an inverter, cable, connectors etc., buy instead NiCd cells that are lightweight and chargeable anywhere. It's not difficult to work out how long playing time they give, and the OP can play that time to the full and still get home before it rains.Cuddlyable3 (talk) 13:39, 29 July 2009 (UTC)

A final point - car batteries are not designed to be "deep-cycled" - that is, allowed to repeatedly discharge most or all of their capacity. They are instead designed to produce a lot of current for short periods for when the car starts. That's why car batteries typically list their "charge cranking amps". Deep-cycling conventional batteries repeatedly will drastically shorten their life. If you want to do this, you can buy deep-cycle batteries; they're used for things like powering electric motors for bass fishing boats.

XTraordinary stuff !!!

Can things which are against the laws of science such as levitation, mind reading, controlling ones mind exist ??? Also does the much hyped spoon bending due to pshycic powers exist???There are just claims but has anyone really witnessed it???gdsrinivas 17:02, 27 July 2009 (UTC) —Preceding unsigned comment added by Gd iitm (talk • contribs)

Everything you've mentioned there can be classified under pseudoscience in the sense that some people proclaim it's all real and true, when really there's absolutely no evidence in favour, and often evidence against, their plausibility. There's nothing about science which says these things won't be possible in the future with the advancement of civilization, but I suspect it's quite a way off and by no means available at the moment. Regards, --—Cyclonenim | Chat  17:07, 27 July 2009 (UTC)

There’s a $1,000,000 prize available to the first person who can show that any paranormal phenomenon like that is real. Although the prize has been available for 13 years now, it has yet to be collected. So either not a single person who can do paranormal stuff like that is bothering to take the time to collect their $1,000,000 for some inexplicable reason, or paranormal stuff like that doesn’t really exist. Red Act (talk) 17:15, 27 July 2009 (UTC)

If they could be shown conclusively to exist - they wouldn't be outside the laws of science because scientists would be revising the laws to include them. The reason they lie outside of those laws is because they don't exist - and have been shown to be fraudulant. Uri Geller (of spoon-bending fame) was conclusively (and very publically) shown to be a total fraud by James Randi in that famous 1973 episode of the Tonight show...and on at least two subsequent occasions. These days, it is REALLY safe to say that all of this paranormal stuff is junk. Treat paranormalists as you would a stage magician - by all means be amused by their capers - but keep a careful and skeptical eye out for the trickery that you KNOW is going on somehow, someway. SteveBaker (talk) 17:27, 27 July 2009 (UTC)

Steve "If they could be shown conclusively to exist - they wouldn't be outside the laws of science because scientists would be revising the laws to include them" is semi profound. We cannot really talk about "against science", just consistency of the scientific world. Of course Science is incredibly consistent (statistically at least) whenever we measure it and even many (?most) religious people regard "miracles=signs" as demonstrations of a wider narrative theme but not to be scientific inconsistencies. There is a little wrinkle there somewhere though. Extremely deep in the scientific assumptions are some dogmas about observation/decision/understanding (one step up from cognito ergo sum) and these include assumptions about the existence of an observer not interfering with whether laws apply. These kinds of dogmas like the assumption we are not a brain in a vat are things scientists to a degree take on trust; although we are completely right to do so they cannot really be completely ironed out. --BozMo talk 17:54, 27 July 2009 (UTC)

While we're taking all the wind out of your sales, it's worth noting that the scientific world has presented bountiful alternatives if you want to know about bizarre, freakish, yet totally true phenomena. I think that mind-altering parasites are, for example, waaaay more "xtraordinary" than some guy who claims he can bend a spoon (even if he could do it with his mind, it's still just a spoon, whoop-dee-doo). --98.217.14.211 (talk) 17:51, 27 July 2009 (UTC)

Scientists have not had a great track record of gracefully accepting as "science" things running contrary to their beliefs. From the early 19th century to the present, establishment science has denied many things that had good evidence: that stones can fall from the sky, evolution, germs as a cause of disease, relativity, and various forms of speech by animals (Washoe the chimpanzee, Alex the parrot) The deniers often go to their graves not accepting scientific revolutions, as described in "The structure of scientific revolutions" by Kuhn. "Science" eventually accepts the new paradigm, even if many working scientists do not. The pseudoscience phenomena mentioned above lack the robustness of the earlier things rejected as pseudoscience, in that they are not reproducible in the labs of skeptics., and a simpler and adequate explanation of a bent spoon is that it was bent by human hands and conjurer's skills, rather than by mysterious psychic abilities. Edison (talk) 19:42, 27 July 2009 (UTC)

In other words: none of the paranormal things the OP refers to have been shown to actually happen beyond reasonable doubt, but this don't mean that they fundamentally cannot happen, or cannot conceivably be scientifically proven and explained at some point in the future. The search for the truth is an ongoing process. 98.234.126.251 (talk) 23:29, 27 July 2009 (UTC)

No - it's more than that - the things our OP refers to have never, not even once, been successfully demonstrated in any kind of rigorous experiment. That's emphatically NOT because scientists don't want to do that. The very existence of the James Randi $1,000,000 prize proves that. If you can do one of these miraculous things - go and show James Randi and he'll give you A MILLION DOLLARS! Why is it that not one single person has done that? The pseudo-science nut-jobs claim that science is denying their abilities - and that's true, and it'll continue to be true unless someone with real, honest-to-goodness magical abilities comes forward, is tested and ISN'T shown to be a charlatan. So far, of the hundreds of people who've tried, every single one of them has proven to be a charlatan when the bright light of scientific testing is shone on them. There is a deep misunderstanding of what scientists are like...we love nothing more than to have some important law or theory overturned - that's the most exciting thing we can imagine - that's the thing that would open up more fruitful areas of study than anything else. But we've tried all of this stuff - we had people with decks of playing cards with circles, squares, triangles and waves on them, we did statistical studies on telepathy and god knows what else right through the 1960's and 70's...and it's all bullshit. Worse even than that is that most laypersons are happy to say "Wow! This guy can bend spoons with his mind!"...and kinda leave it at that. The bigger question is "Where does the energy come from to bend the spoon?" - if it comes from the guy's mind - then how come we can't detect any magnetic field, gravitational or radio waves, no light, no cosmic rays...what could possibly be transmitting that energy? The only answer could be some entirely new force that we have no inkling of whatever. But what are the odds that just one person can produce these forces - that we can't measure in ANY other way than by large chunks of metal being bent? How come nobody through all of history has ever come across any effect that's even remotely like this? How did the guy who bends the spoons learn to do it? If this one, single paranormal thing were true - pretty much all of science would have to be rewritten. What are the odds that all of the things we've successfully designed and built actually works - despite this massive hole in our understanding? It really does seem impossible for anything that major to have escaped our careful searching for a couple of hundred years. So that's what's on one side of the 'scales of truth'. What's on the other side? Well, we have the word of one person who claims to be able to do this - minus all of the professional magicians who claim to be able to reproduce the exact same demonstration using techniques which they openly admit are pure trickery. It hardly balances does it?

By comparison, the other examples you gave were pretty minor.

• Not believing that rocks can fall out of the sky was an error - but when we finally figured out what it was, it hardly required us to change our ideas of how the universe worked at all. We already knew about comets - the idea that something like that could fall out of the sky wasn't really very profound. Not one existing law of nature had to be rewritten. Gravity, light, matter, energy, magnetism, mechanics, chemistry...all of those things were still 100% as they'd been described.
• Evolution filled a hole in our understanding - it didn't overturn ANY well respected existing scientific theory. It pissed off a whole load of religious people - but science simply didn't know how speciation came about - and this explanation filled a hole.
• Germs as a cause of disease - pretty much the same deal. We didn't really know how that stuff worked - this was a great explanation.
• Relativity - is actually the only one of your examples that is a REAL case where our current understanding was actually completely overturned...but it didn't come about because of an EFFECT that science was denying. We knew there was something odd about the nature of the speed of light and we'd been doing experiments for decades to try to understand why we couldn't detect a universal Luminiferous aether. When Einstein's explanation appeared, there was reasonable skepticism...but within months of the experiments that measured the displacement of stars during a solar eclipse, pretty much the entire scientific community changed direction and lined up behind the new theory.

SteveBaker (talk) 00:06, 28 July 2009 (UTC)

There are many cases where the leading lights of the scientific establishment (Lord Kelvin) proclaimed something was impossible a couple of years before someone demonstrated it, such as the "subdivision of the electric light," i.e. the invention of electric lights which culd furnish 16 candlepower or so to illuminate one room efficiently. There were doctors in the late 19th century who still practiced medicine, denying the "germ theory" of disease. Which scientists before evolution was written about acknowledged the "hole" that you say it filled? Wasn't heavier than air flight said to be impossible (Lord Kelvin)? The "leading scientists" denied radio waves and said it was "merely induction" when Preece and Thomas Edison ("etheric force") demonstrated wireless transmission of radio signals[4], until Hertz demonstrated the same phenomena with a mathematical basis in Maxwell's work. See [5] for some examples of the scientific establishment making asses of themselves. Edison (talk) 05:43, 28 July 2009 (UTC)

But almost all of your examples are not holes in fundamental scientific laws and theories - they are engineering matters. Sure, Kelvin believed that it was an impossible engineering problem to produce a 16 cd electric light - but I very much doubt he had basic theory proving that it was impossible. I very much doubt that we'll ever be able to send a living human to Alpha Centauri...but that doesn't mean that it's impossible. The laws of physics permit it - it's just an engineering problem that I don't believe we can overcome. Now, if I'm proven wrong, that's not great for my reputation - but it wouldn't in any way undermine the laws of physics. However, when I say that we'll never travel faster than the speed of light - that's a much more solid claim. We have laws of physics that guarantee that's true. In order to refute THAT claim, we'd have to rewrite huge swaths of solid physical laws and theories...it would be a major thing indeed if that were somehow to be found to be possible. Almost all major advances in science and technology are either exploiting well-known physical principles in a more extreme manner than previously expected (electric lights, heavier-than-air flight) - or they are filling in gaps in our scientific theories (evolution, radio waves, germ theory). Not one of the things you describe changed any pre-existing law or theory of nature...the number of times THAT has happened over the 150 to 200 years since we started following "the scientific method" you can count on the fingers of one hand...relativity is the only one I can think of right now...and that isn't something that affects 'normal' day to day life - it found an error in an existing law that only affects the most extreme condititions - it doesn't make any difference to how most simple day-to-day events are interpreted. To demonstrate relativity actually doing something requires some pretty extreme experimentation. In Einsteins' day - the only way to prove it was to measure the position of a star during a total solar eclipse! Levitation, mind reading, spoon-bending-with-the-force-of-thought are all things that would require us to rewrite fundamental laws/theories - in regions where they have been exceedingly well tested over 150 years. So the likelyhood that they are true is essentially zero. SteveBaker (talk) 13:11, 28 July 2009 (UTC)

When a scientist makes extraordinary claims, others often treat them with skepticism until irrefutable proof is presented. That attitude is perfectly fine, and doesn't mean every single theory that the scientific community doesn't believe in must be true. --Bowlhover (talk) 08:45, 28 July 2009 (UTC)

Agreed. "They said that about Einstein/Newton/Galileo too!" is a ridiculously common (perhaps *the* most common) pseudoscientist/crank rebuttal to sceptics. Doesn't make any sense whatsoever, if you think about it for a couple of minutes. Bonus points if they come out with something really fuckwitted, like "IT WAS BECAUSE OF PEOPLE LIKE THAT COPERNICUS WAS BURNED AT THE STAKE!" (and mean it). --Kurt Shaped Box (talk) 09:18, 28 July 2009 (UTC)

"...but they also laughed at Bozo the clown" is the standard retort. --Stephan Schulz (talk) 13:26, 28 July 2009 (UTC)

Edison, as a scientist my self I don't really give a crap what scientists "say". That is appealing to authority, as opposed to rational, free thinking which a scientist should be doing. Every scientist on the planet has an opinion on something, and that is fine as bias is hard-wired into us. As long as they don't show bias in their scientific method when conducting research, then I will respect their results. --Mark PEA (talk) 09:51, 28 July 2009 (UTC)

One way in which the scientific establishment mistakenly rejects new discoveries is by saying "Oh, this is just a rediscovery of such and such. Nothing new here." Pre-Hertz demonstrations of radio wave transmission and reception by Preece and Edison were dismissed as "mere induction." Radio might have been in general use several years earlier if the demonstrations had been accepted as a new phenomenon. Technicians and inventors often work years ahead of "scientists." If someone next month demonstrated some type of cold fusion, many would dismiss it without close analysis as a mere replication of the Pons-Fleischman experiment. Demonstrations of animal communication by Washoe (chimpanzee) and other chimps, or by Alex (parrot) are false dismissed as being a recreation of Clever Hans, the horse who just watched his master for cues, or as mere Operant conditioning. In the face of "irrefutable proof" scientists may redefine the terms. If science said that only humans use tools, and chimps are observed carrying around rocks to break open nuts, then rock use is defined out of being tool use, and it must be "make and use tools." If chimps are then seen fashioning sharpened sticks to spear bush babies in their hideyholes, the definition of tool use must be redefined again. Granted the "not invented here" attitude commonly applies to engineering devlopments or inventions. When Morse demonstrated he could instantly send telegraph messages between remote parts of the U.S. capitol building, politicians thought he was a madman, and said why not just send a messenger, instead of all that cumbersome apparatus, even though Morse had explained it was just as fast for extreme distances. When Chester Carlson demonstrated the Xerox it took many years to convince the business world that instant copying was useful to businesses. This was in 1948 ("They all laughed," by Ira Flatow, Harper Collins, 1992, chapter 11): "An interesting gadget, but no future." Tesla in 1898 demonstrated a radio steered torpedo, but no one could see the point of it, since they never had used one in a war. Another way in which mainstream science fails is by assuming something is impossible by analyzing it with the wrong model. The claims that electric lighting could not be "subdivided" were mathematically supported by leading physicists, but they assumed the light of 16 candlepower would be a grossly inefficient and impractical little bitty arc light, and did not allow for it being an incandescent light. We cannot send people to other star systems with rockets, so it is impossible. Physics says it would be easy if you could maintain a 1 G thrust the whole way, but we know of no present means of achieving that. A lab can also do an intentional nonreplication of some new phenomenon, to discredit the discoverer, and attribute the phenomenon to uncontrolled experimental confounds, thus delaying its general acceptance. Going way back to Newton writing that a prism could split sunlight into its spectral components, one of his competitors wrote that he could not replicate it, and that Newton probably just reflected the light off one face of the prism and the color was likely stained by dirt on the surface. The Edison effect, or one way flow of electricity from a filament to a charged plate, was denounced as just a stream of carbon particle breaking off the filament and carrying charge, delaying by years the "invention" of the vacuum tube diode and the advent of electronics. In the case of pooh-pooing by trivializing alternative explanations of a new discovery, the normal process of science should make things right over time, as others are able to replicate it or "reinvent" it, while carefully controlling the claimed confound. The cycle of "Discovery-alternative expl

Your examples are not scientific errors - they are errors of belief at the engineering level. Producing more and more of those example is very easy indeed - I could quote the guy who tried to solve the problems of determining one's latitude precisely in a sailing ship by killing a dog at exactly noon at the naval base and seeing when it's identical twin (which had been placed aboard ship) woke up and whined! But it doesn't help answer the OP's question in the slightest. Sure Tesla demonstrated a radio steered torpedo - but nobody previously said that science precluded that due to some fundamental law of nature. That the torpedo actually worked was a demonstration that Tesla had a better command of TECHNOLOGY than his detractors. But it didn't cause a single scientific law or theory to require modification in the slightest bit. If he'd found a way to power it with a perpetual motion machine - or control it via "thought waves" instead of radio - or make it travel faster than light...THEN he'd have produced a scientific breakthrough rather than a mere engineering marvel. That's not to detract from the cleverness Tesla provided - it's just that you're answering an entirely different question...one that I doubt anyone here is denying. Our OP is postulating things that - if true - would require a profound revisiting of most of what we think we know about how the universe works. A radio controlled torpedo is no more remarkable (in principle) than the next generation of iPhone...clever technology - but no new science whatever. SteveBaker (talk) 21:01, 28 July 2009 (UTC)

Mind reading, then is also just an engineering problem. Scientists already can determine an amazing variety of things about what someone is thinking by functional MRI. The denial of the possibility of subdivision of the electric light was not presented as an engineering statement but as a scientific one. I think you are making a false distinction between "science" and "engineering" (or technology). It would It should be a clearly disprovable assertion, or it is not science. The source should be a refereed scientific journal, a college level science textbook, or a distinguished scientist of the stature of Lord Kelvin, such as a Nobel laureate. I suspect that such listings are rare, because the writer would know he might be held up to ridicule if the stement were refuted. Examples might be like "Cold fusion is impossible," "Visits from or radio transmission from extraterrestrials are impossible." Would those be engineering or science statements? Edison (talk) 22:05, 28 July 2009 (UTC)

How did we get this far without a link to the relevant xkcd comic? — DanielLC 05:50, 29 July 2009 (UTC)

Just a thought to this thread; why do the FBI/Search and rescue Police force other Gov. people use so called psychic people who are blatantly fraudulent people! to help with the search for missing or dead people do any of these have results? if they dont why bring them in at all?????(there are many such cases were this has HELPED and documented -evidence yes/no); URI Geller just one and others have worked with many investigations and have provided vital clues for this exact purpose. Is that classed as evidence? if so case proved science wrong lets go home :) guessing science will say circumstantial not proved:) there for total fraud???? To dismiss these people as frauds when they are constantly used is seemingly strange>>>to say there is no evidence is down right daft due to the fact 1. people are found 2. killers caught 3. They keep being used ECT...does this go down the same road as pilots would not say they had seen a UFO as they would be ridiculed or it would affect there status as a pilot(many examples of this happening - again Evidence yes/no!!!! By saying something along the lines of prove you seen it and we give you 13,000,000 dollars but when you cant we say your a fraud??????? If i was in court for a crime and ten people say i did it case should be dismissed? as this is not evidence? So - the evidence is there; you just cant prove it scientificly yet to are understanding if it is indeed scientific. the other notion is that this is all a science i.e. brain wave manipulation will be discovered then it is know longer a psychic thing but a proven scientific method so the scientists were right all along. A difficult subject to discuss with science portal as they refute all knowledge other than scientific so no matter what you ask it will say fraud/not possible or scientific reasoning behind it. which could quite possibly be the caseChromagnum (talk) 10:23, 31 July 2009 (UTC)

You could provide further examples as evidence - Link between twins Evidence yes/no. Dog traverling across whole country to owners house evidence yes/no. Incidents like the Entity proven to have happened evidence yes/no. there are many many many cases that the science community happerly ignore in the name of science as they cannot explain them.

Maybe the TIGHAR team should hire a psychic to help them find that Electra 10-E! :-D 98.234.126.251 (talk) 05:16, 1 August 2009 (UTC)

There you go evidence of a typical answer pointed towards ridicule of anything other than the norm - Try next police mass murder investigation/missing person(or just use an old case file)... that uses psychic's if they help or helped in anyway have the Money reward given to the psychic and right a paper on it for the science communityChromagnum (talk) 07:13, 1 August 2009 (UTC)

That's very interesting -- can you give an actual example of an "old case file" of a missing person / murder investigation (BTW, TIGHAR's research surely qualifies as an "old case file" of a "missing person" search) where a psychic provided the vital clue that led to the case being solved? I'm downright intrigued by this question! :-D 98.234.126.251 (talk) 08:01, 1 August 2009 (UTC)

Resources for cultivated plant identification?

Hi all - I'm a Seattle resident looking to learn more about identifying plants, particularly flowering plants. I already found the National Audubon Society Field Guide to North American Wildflowers: Western Region and the Peterson Field Guide to Pacific States Wildflowers, but neither of these tells me anything about cultivated flowers. Most of the books I can find on cultivated plants are written for gardeners, which I am not. Any tips? Dcoetzee 18:29, 27 July 2009 (UTC)

Are you trying to source a plant for a situation or identify a plant you have found? --BozMo talk 18:45, 27 July 2009 (UTC)

I photograph plants in gardens and botanical gardens and I'd like to identify them (either at the time of photographing, or later based on the photograph). Sometimes they are labelled, but often they are not. I also have a personal interest in plant identification. Dcoetzee 20:17, 27 July 2009 (UTC)

Hi Derrick, I use a combination of two sites for identification of plants; one is the Wild About Britain identification forum and the other is the UBC (University of British Columbia) Botanical Garden forum. Between the two of them, I usually manage to get a definite genus and often a species match. Obviously, unless you plan to be travelling across the pond, the first link is no good to you, but the UBC forums are international and should hopefully be able to satisfy most of your needs. There is a good level of activity there, so it usually doesn't take too long to have queries answered. Hope that helps. Maedin\^talk 20:36, 27 July 2009 (UTC)

I realise I wouldn't have much trouble getting a hold of people who can help me identify things, but I really want to learn to identify things myself, so that I can make quick identifications in the field and help others identify things. These people must have learned somewhere, right? Dcoetzee 20:49, 27 July 2009 (UTC)

If you aren't going to undertake formal education or training, then I presume that most people learn by experience. Just by using the forums I have learned more about plants, hopefully in a manner that will stick with me. Other than that, I don't know what to suggest, apart from approaching a gardener or a botanist and requesting introductory lessons or guidance. You could also try to approach the families of plants in a logical manner and begin by studying overall characteristics, before narrowing down to genus or species. That would allow you to use your identification books more effectively. Maedin\^talk 20:57, 27 July 2009 (UTC)

I wouldn't mind formal education or training, I just don't know what background is pertinent. I'm pretty sure I need some basic anatomy and taxonomy, not so sure about genetics and genomics or cell biology or microbial plants. I'll be attending UC Berkeley but they don't appear to have specific classes in plant anatomy or identification (see plant biology classes). In any case I've mailed the department's advisor and I'll see if they can help with this. Dcoetzee 21:21, 27 July 2009 (UTC)

I think you are looking more for something like Botany and Horticulture. This link says Berkeley lumps that in with plant biology [6]. Maybe you could do something in the extracurricular area. This looks promising [7]. From your catalog the plant morphology classes have a different focus, but may still get you the information you seek C107 + C107L. This book is quite old, but may still be a good place to start. [8] There seem to be various versions about. [9] I'm not sure whether the online download is the same as the full 6 volume book. This seems to indicate only 3 of the 6 volumes can be downloaded if I'm reading it right [10]. See if your library has a copy for comparison. This site may also be a useful resource [11]. This is a lot to check, but may help [12] Hope this helps. 71.236.26.74 (talk) 01:21, 28 July 2009 (UTC)

Thank you for your help! Dcoetzee 19:57, 28 July 2009 (UTC)

A good first step is to learn the characteristics of at least the common plant families. You could start with a website like [13]. It is very satisfying to look at a plant and be able to tell, without looking anything up, what family it belongs to. The links at the bottom of that site are also useful - especially the bottom one on botanical Latin, try looking up some names that you see in plant labels in botanic gardens - they are a lot easier to remember if you know what they mean. Finally, if you get into some of the more technical literature some sort of glossary would be very useful, as the description of plants - phytography - is a whole new language. I'm sure good online ones exist but a quick and dirty google search only brought up books such as this one [14]. 84.12.138.49 (talk) 21:45, 29 July 2009 (UTC)

P.S. One book I just found seems just about perfect for what you want. It covers North temperate regions (I assume this includes Seattle), concentrates on flowering plants, and includes cultivated plants. —Preceding unsigned comment added by 84.12.138.49 (talk) 21:51, 29 July 2009 (UTC)

which vein is involved in echymosis over mastoid process in battles sign

which vein is involved in echymosis over mastoid process in battles sign —Preceding unsigned comment added by Ashupg (talk • contribs) 19:01, 27 July 2009 (UTC)

Is "echymosis" a typo of ecchymosis? Dogposter (talk) 20:55, 27 July 2009 (UTC)

We do have an article on Battle's sign, but it unfortunately doesn't say which vein is involved. Red Act (talk) 21:00, 27 July 2009 (UTC)

According to this, Battle’s sign results from the extravasation of blood along the path of the posterior auricular artery. Red Act (talk) 21:22, 27 July 2009 (UTC)

I have updated the Battle's sign article to include this information. Red Act (talk) 21:53, 27 July 2009 (UTC)

Butterfly effect - Changing the evolution of species with time travel

There have been lots of instances of the Butterfly effect in films and TV programmes (including the Simpsons) where somebody has travelled back in time, has killed some plant or animal, and has significantly changed the evolution of species. I wonder if there has been any serious scientific work done on the issue of how much impact the killing of a single individual can realistically have on the evolution of the species, and of other species. I would imagine that if all of the evironmental pressures remained the same, then the killing of an individual would actually have a minimal effect on the evolution of a species, because any mutation that individual had would no doubt be acquired my another individual soon enough - but soon, enough every individual would be slightly different. Perhaps treading on a rodent 100 million years ago might mean that Barack Obama would be Susan Stout instead, but would not make him a 20 foot lizard. But, has there been any serious research or publications that are relevant to this. Would really appreciate any help. Thanks Squashed Star (talk) 19:55, 27 July 2009 (UTC)

There are too many variables and hypotheticals to take into account. It might have no effect, it might have a large effect. Individuals sometimes don't matter, individuals sometimes do matter. I'm not sure there is any very scientific way to approach the question, given the magnitude of the uncertainties involved. --98.217.14.211 (talk) 20:14, 27 July 2009 (UTC)

It's not hard to imagine a situation in which killing an individual could have a significant impact. If the population in a region has been temporarily reduced to a level at which it can barely sustain itself, the death of an individual could have a dramatic effect. And just as an individual human touches many people in their lives, an animal modifies the behaviour of virtually every other animal it comes into contact with, and it's difficult to predict the long term effect of this. Dcoetzee 20:20, 27 July 2009 (UTC)

But if a population is big enough, and "real, text book evolution" is taking place, killing one individual should have no effect. That one that you kill can't be a special one, because evolution does not work by macro-mutants. The pressures are still the same so at least a similar solution should be found. Aaadddaaammm (talk) 20:48, 27 July 2009 (UTC)

Yeah, but consider this hypothetical scenario: you kill a prey animal which, if it had lived, would have distracted a group of predators from pursuing a harder-to-catch prey, who would have led the predator to its nest and caused its entire colony to be eradicated, which happens to be the only one remaining in the region. The point of the butterfly effect is that small things can lead to larger effects in a chain reaction. Dcoetzee 20:57, 27 July 2009 (UTC)

"If a population is big enough" is certainly a subset of the original question. However, there have been times in researchable history where populations dwindled to a few survivors only to roar back into prominence some time later. The most recent article was about wild cats in Africa, if I recall. In such a case, going back and "selecting against" one of the few surviving members could have a dramatic effect on the future size (or extinction) of the population. --66.195.232.121 (talk) 21:05, 27 July 2009 (UTC)

The main problem with research in this field is that, absent time travel devices, and absent access to parallel, almost-identical universes in which alternate events occur, there is no control available so we can compare what would have happened otherwise. Because of this, it's all speculation, so it's OK to stick with Homer Simpson. Tempshill (talk) 21:16, 27 July 2009 (UTC)

Jacques Hadamard just thinking aloud about the butterfly effect has had repercussions in literature, chaos theory and ripples of the event persist over a century later here in Wikipedia. The consequences of a hypothesis that travelling back in time is possible (if true) would be at least as great a perturbation to the way things are, and to actually do anything when one arrives in the past would cause an even greater upset. The OP's question, which I cannot answer, boils down to whether the upset would decay over time and whether the residual effect today would bother us. I think we could tolerate a US president named Susan. Cuddlyable3 (talk) 21:54, 27 July 2009 (UTC)

The very idea of 'time travel' is patently preposterous and denotes a serious misunderstanding of the nature of things. So anything predicated on 'travelling back through time' cannot be spoken of sensibly. Napoleon Dynamite got it right when the uncle tried to return to his high school days and just ended up electrocuting his testicles. Vranak (talk) 22:21, 27 July 2009 (UTC)

That's a rather rigid response. It's true that at our current level of scientific understanding and technology level we cannot conceive a realistic method of time travel, however that's not to say we couldn't at some point in the future do so. Exxolon (talk) 22:44, 27 July 2009 (UTC)

The trouble with that kind of thinking is that it prevents you from ruling out anything whatever - this makes doing science impossible. You'd be unable to do even the most mundane activities or come to the most basic conclusions without having to worry that some future development would utterly overturn it. We have to say that occam's razor says "NO!" to time travel until/unless some spectacular new science comes along. Meanwhile - the only rational and sane way to proceed is to make the strong assumption that it cannot exist. SteveBaker (talk) 23:29, 27 July 2009 (UTC)

Well, there are different levels of "ruling out". If someone walks up to you on the street and says he's from the future, doesn't have any 2009 money to make stock picks with, but if you'll give him yours he'll make you rich — yes, we can rule that out. On the other hand, if a respectable physicist wants to study a theory that might imply time travel in principle — if it looks vaguely plausible to other experts, fund it. You never know. --Trovatore (talk) 01:55, 29 July 2009 (UTC)

Certainly the butterfly effect exists. Changing any small thing today could potentially have a deep and profound effect on what happens in the future. That has nothing to do with time travel - it's more a function of Chaos theory. Chaotic systems (which many systems here on Earth are) can amplify small changes into big changes. Of course, there is no way to plan for that - and equally, no way to know whether some other small change wouldn't cancel out some of the effects of the first one. But there are plenty of cases in history where a very small change would have made a lot of difference. On 28 June 1914, three police officers got into the wrong car by mistake. Had they gotten into the right car - neither you nor I nor anyone else here would exist! Because...as a result of them getting into the wrong car, Archduke Franz Ferdinand didn't have sufficient protection in some parade or other - so he got assassinated - which started the first World War. Most of us are either 'baby-boomers' or descendants of baby boomers - the baby boom only happened because of soldiers returning from the second world war - which would undoubtedly have played out very differently if the first world war hadn't happened - our parents would have met different spouses - our genetic makeup would be different - and so would be that of Jimmy Wales - so no Wikipedia. It's pretty safe to say that everyone reading this thread would not exist...or at least not precisely as we are now. So three cops get into the RIGHT car - and all of us pop out of existance! But if three cops in a sleepy little village in (say) Argentina had gotten into a different car than they actually did - would the effect have been so profound? It's hard to say. Chaos theory says that the consequences could easily be just as severe - but it's really impossible to know specifically. I suspect that ANY change 100 years ago would produce effects that would be just as dramatic. SteveBaker (talk) 23:29, 27 July 2009 (UTC)

Sure, that's one extreme view of the butterfly effect. The other is that events take place more like a river flowing downstream. If you throw a rock into the water at 8:00AM rather than 9:00AM, the individual water molecules disrupted by your rock throwing will all be different; but the ripples look about the same, and from the viewpoint of a bystander along the river, it doesn't make a shade of difference. Anyway, to go back to the OP's question, you will notice that beyond this kind of speculation, nobody has cited any "serious scientific work" on the butterfly effect, let alone your related evolution question, which is what you had asked about. Tempshill (talk) 00:09, 28 July 2009 (UTC)

But who's a bystander in the History of Planet Earth? If cats instead of primates occupied our spot on the food-chain, I suppose the rest of the solar system would be pretty much the same. But it would make a big difference to the hypothetical time traveler returning from the Cretaceous to modern day after stepping on a butterfly. APL (talk) 00:45, 28 July 2009 (UTC)

@Tempshill: This is the RD - we don't have to cite serious scientific work - we have merely to link to appropriate articles - which in turn cite the serious scientific work. Hence, I linked to Chaos theory - which has 50+ references, 50 more citations in the scientific literature and about a dozen other useful web links for our OP to follow. Chaos theory is a solid mathematical field - it shows that the kinds of systems that have a sensitive dependence on initial conditions do not settle down after a small disturbance - instead, they magnify it. The mathematics also shows how to identify such chaotic systems - and indeed the entire field was discovered as a result of weather prediction studies in which it was discovered that the earth's weather conditions are indeed 'Chaotic' in the mathematical sense of the word.

If the weather were the only chaotic system on earth, we'd still have a situation where a tiny change sufficiently long ago would cause huge changes down the line...but it's not. Chaotic systems are everywhere. Our entire society is one gigantic chaos engine. One kid films himself playing with a toy light sabre in his garage - and a few weeks later, half the people on the planet have seen the video. Monty Python do one sketch that makes 'Watney's Red Barrel' beer seem un-cool, the company that makes it goes bust within a year - the entire British brewing industry flips over to "Real Ale" - pubs become more family friendly and the whole dynamic of how "guys" go off down to the pub leaving their wives behind is erased in just a few years. One guy comes up with the concept of a "wiki-wiki-web" and six years later almost all of human knowledge is encapsulated in one - millions of people rely on it.

Animal populations undergo boom/bust cycles for reasons that are far too obscure to ever decypher - because they are chaotic. Financial markets...chaos. Traffic speeds down a freeway...chaos. It's everywhere. If you look at the underlying mathematics - it's plain to see that the big picture is NOT one where these kinds of ripples 'die down' over time - they magnify enormously from small beginnings.

The problem is that we never really know what would have happened if any particular ripple hadn't started - all we know is that there are a tens of thousands of examples where the tiniest of nudges changed everything that followed.

SteveBaker (talk) 01:21, 28 July 2009 (UTC)

It seems unlikely that Barack Obama could become a murdered female caucasian graduate student in psychology, born long before he was, for whom a library was named: [15]. Edison (talk) 05:26, 28 July 2009 (UTC)

It's difficult to frame this question in a way that even makes sense. In order to say that some event had an effect you have to suppose that there was an alternative (if it had not happened then the future would have been different). But in order to attribute the whole future course of history to that fateful moment, you have to suppose that everything after that was a necessary consequence of what came before. That rarely makes sense. In the case of the "butterfly effect" you could argue that the butterfly had the choice to not flap its wings but the air didn't have any choice in how to respond (though I'm not sure I believe that—they're both quantum systems of similar complexity), but there are other butterflies, and other animals, and people, and how do you distribute the blame? It's not a linear system. And there's no way you can do that kind of thing in the case of an assassination. If the assassin could have not pulled the trigger then everyone else could have chosen to not react in the way that they did.

Also, though you can formalize what it means for a system to be chaotic, I don't think there was ever any mathematics or physics behind the butterfly effect specifically, i.e. the claimed influence of butterfly flight on weather patterns. The fact that the weather is hard to predict doesn't imply that it's unstable under perturbations of that particular form, and I'm not sure it actually is. -- BenRG (talk) 16:19, 28 July 2009 (UTC)

When I was a child I recall reading a short story at school about someone who went back in time and accidently trod on a butterfly. When they came back, the world had changed a lot. I read it long before the butterfly effect had become a common phrase. Perhaps that short story was its origin. Anyone know what short story it was? 78.146.235.174 (talk) 11:45, 31 July 2009 (UTC)

"A Sound of Thunder" by Ray Bradbury. 98.234.126.251 (talk) 05:18, 1 August 2009 (UTC)

What are these creatures/objects?

Hi, everyone, as I was uploading images of South Korea, especially Andong areas in the east southern part of Korean peninsula, I found them, but don't know what they are. Thus, the photo names are incorrectly named because of my ignorance, but I want to fix them. The photographer is a foreigner and inactive for a while, so I stumble here to seek a help from those who are knowledge of biology...If you could answer my questions, I would appreciate your input. Thanks.--Caspian blue 21:18, 27 July 2009 (UTC)

• 
  1. What is the name of the bug?
• 
  2. What function do these rocks have?
• 
  3. Mushroom?
• 
  4. Mushroom?
• 
  5. What mushroom species?
• 
  6. Bird nest?
• 
  7. What berry?
• 
  8. Pumpkin or gourd?

1. Probably a swallowtail butterfly larva. Check Old World Swallowtail which is found in Korea. Here is a taxonomy sheet with pictures which may be helpful [16] Sifaka ^talk 21:39, 27 July 2009 (UTC)

2. This is a kind of ancient burial called Dolmen. In Korea, they call it 고인돌. Elkellogg54 (talk) 21:46, 27 July 2009 (UTC)

also see Megalith#Asian_megaliths83.100.250.79 (talk) 23:54, 27 July 2009 (UTC)

3 Likely a mushroom (pretty sure it's not a lichen), probably the same species as #4. Sifaka ^talk 21:50, 27 July 2009 (UTC)

4 Definitely a mushroom of the bracket variety. These are going to be hard to identify by look and geographic location alone, but the family is probably Polyporaceae. Sifaka ^talk 21:50, 27 July 2009 (UTC)

Maybe Genus trametes [17]? Sjschen (talk) 18:52, 28 July 2009 (UTC)

5 I'm not sure it can be definitely IDed without a shot of the underside and a spore print. Those flecks on the cap make me think genus Amanita, but that's a real tenuous guess. Sifaka ^talk 22:05, 27 July 2009 (UTC)

6 Almost certainly a bird nest. No guesses yet as to what kind of bird. Sifaka ^talk 22:12, 27 July 2009 (UTC)

7 Maybe a cherry? Sifaka ^talk 22:12, 27 July 2009 (UTC)

I'm almost certain it's some kind of crabapple, if you look at the base of the fruit you'll see where the flower used to be. Sjschen (talk) 18:52, 28 July 2009 (UTC)

8 (Almost) definitely a pumpkin. FWiW 98.234.126.251 (talk) 23:09, 27 July 2009 (UTC)

But it really really looks like a gourd[18][19]. I'm also not sure pumpkins are grown on trellises? Sjschen (talk) 19:28, 28 July 2009 (UTC)

Thank you for the answers everyone. I really appreciate your help. --Caspian blue 03:31, 29 July 2009 (UTC)

day and night on gas giants

Do Saturn, Uranus, and Neptune have daytime or it is always nighttime? The differ between gas ginats and rocky planets is thye rotate faster on axis and the day/night is less than 18 hours. And they have so little sunlight penetrating through if they have a solid surface, then they would be always nighttime. —Preceding unsigned comment added by 69.228.145.50 (talk) 22:16, 27 July 2009 (UTC)

Daytime and nighttime isn't caused by penetration of light through the planet, as I guess you've noticed by observing our own planet. The speed of rotation doesn't effect the existence of daytime and nighttime, it only shortens or extends the respective durations of each. So yes, they would have a daytime (the side facing the sun) and a nighttime (the side being blocked by the other). I struggled reading your question, so if I misunderstood please do clarify. Regards, --—Cyclonenim | Chat  22:46, 27 July 2009 (UTC)

Well, there wouldn't be much light coming from the sun right down at the "surface" (to the extent that gas giants have something like a "surface" under all that metallic hydrogen and stuff)...but there would be some teeny-tiny number of photons making it down that deep - and there would be more of those on the side of the planet facing the sun than on the side pointing away from it - so technically, even down on the surface of the rocky core, there would be "day" and "night". But to human eyes, it would pretty much look black all the time. But higher up in the atmosphere day/night cycles are just like on earth. The question of how long day and night lasts is a little tricky since different parts of the atmosphere are rotating at different rates. SteveBaker (talk) 23:04, 27 July 2009 (UTC)

OKay, I got the point.--69.228.145.50 (talk) 23:42, 27 July 2009 (UTC)

Shotgun backfiring

What is the sequence of events involved in a semi-auto (not pump-action or double-barrel) shotgun backfiring? I know that the breech gets forced open somehow or other, but how exactly does it happen? Also, if a shotgun backfires, what kinds of eye/face injuries can you expect? Would those injuries be readily reparable by surgical means? (No, I'm not looking for medical advice, I need to know these things for a short story that I'm writing.) Thanks in advance! 98.234.126.251 (talk) 23:18, 27 July 2009 (UTC)

As far as the second part of your question goes, it's hard to say -- much depends on how close to your face the weapon is when it backfires, and how the backfire actually takes place. In a worst case scenario, you could undoubtedly be killed; people have ended up death from firing blanks, for example. You could definitely lose an eye or get badly scarred. Cosmetic surgery is pretty good, these days, so it's possible that the damage could be repaired, but it's impossible to generalize. It all depends on how the force from the backfire is directed, how close the shooter's face is to the backfire, what kind of a shell the shooter is firing, the model of the weapon, etc.

Suffice to say that you can get hurt really badly, but if you don't get hurt too badly, they can patch you up well enough to keep you from being horribly disfigured, even if there's a bit of scarring. -- Captain Disdain (talk) 09:08, 29 July 2009 (UTC)

Well, the problem is, although I'm pretty well versed in the mechanics of semi-automatic firearms, I don't really know the exact sequence of events that leads up to the breech being forced open, so I can't really say exactly how the backfire actually takes place, straight to the rear through the breech, or sideways through the ejection port. As for how close to the face, let's assume that the shooter has the shotgun braced against his shoulder but is using the point-and-shoot technique and is not using the sights to aim. The weapon in my scenario is a gas-operated, rotating-bolt semi-automatic hunting shotgun (say a Remington 1100 or similar), and the shell is a 3-inch, 12-gauge plastic-cased buckshot shell with, say, number-four shot. How dangerous would a backfire be in this scenario? Thanks! 98.234.126.251 (talk) 05:01, 30 July 2009 (UTC)

Honestly, it's impossible to say how dangerous it would be, especially as I'm not familiar enough with the weapon in question. In any case, you might as well be wondering something like, oh, "a guy fall off a motorcycle while doing 50 km/h, and he's not wearing a helmet, how badly is he going to get hurt?". And you can't answer that question, because a lot of it depends on how the guy falls down, whether he hits anything, etc. I mean, you can say he'll probably get hurt, but it's impossible to predict the exact result.

On a hunch, though, I'd say that the risk of injury in your situation would be considerable, but injuries like this aren't necessarily predictable -- it all depends on how much stuff there is flying through the air, how fast and at what angle it impacts with the shooter's face, what the exact position of the gun is at the moment of firing, etc. Let me put it this way: if a 12-gauge shotgun shell exploded next to my face, I'd expect to get pretty badly hurt. The gun itself is going to direct and shape that blast, though, so a lot of it depends on how it does that: if the blast is directed away from the face, there might not be any injury at all. Or maybe you're liable to lose an eye. I guess the only way to find out anything concrete would be to conduct a series of experiments where the weapon is forced to backfire, and see what kind of damage it does to things around them -- a ballistic gel dummy would be the classic "shooter" of choice for something like this, I guess. -- Captain Disdain (talk) 10:26, 31 July 2009 (UTC)

Ok, that's what I was hoping for. (For the record, I want my character to get hurt real bad, but not so bad that a good surgeon can't fix it.) I'll try to do some more research for the exact kinds of injuries to be expected. Thanks a lot, and clear skies to you! 98.234.126.251 (talk) 05:23, 1 August 2009 (UTC)