Wikipedia:Reference desk/Archives/Science/2008 July 6

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July 6

Colorado 14ers

I am curious about Colorado peaks. How many are there over fourteen thousand feet high? I have seen many different numbers, most of them in the fifties. —Preceding unsigned comment added by 75.169.1.13 (talk) 00:28, 6 July 2008 (UTC)

Here's the list of them. See also a WP list. Oded (talk) 01:05, 6 July 2008 (UTC)

Trans Ischemic Attack - same symptoms as stroke in sever cases?

Reading elsewhere, it seems like a transient ischemic attack is only a warning and brain cells don't actually die. Yet, your article speaks of TIAs that can last more than 10 minutes, and seems to say that brain cells do die. So, would the same things as mentioned in stroke apply when it comes to symptoms and treatment, then? In other words, can one experience weakness afterward, maybe periods of aphaxia where one can't talk for a few minutes at a time, etc.? Would rehabilitation be needed even with a TIA or series of them, even if there was no actual stroke that occurred?

Side question - can one be paralyzed on both dies of the body with a TIA/stroke? My hunch is "yes," if in the right place.

I guess it's one of those thigs that will really only be helped once the TIA article grows.209.244.30.221 (talk) 00:35, 6 July 2008 (UTC)

Yes and yes. TIA is code for "Minor stroke." The key is "transient." A stroke is ischemia caused by a thrombus (blood clot) in the brain that often requires thrombolytic therapy to be corrected and may cause permanent brain damage if not treated in time. The difference between a stroke and a TIA is that in a TIA, the thrombus often dislodges itself before serious damage occurs. Sometimes not. A TIA that causes damage is basically a stroke that treated itself, but a little late. Usually if there's any serious damage, they call it a stroke instead of a TIA. --Shaggorama (talk) 02:22, 6 July 2008 (UTC)

The difference between a transient ischemic attack and a stroke is the duration. If the symptoms last less than a day, what happened was a TIA; if longer, it was a stroke. They can't be told apart until the 24 hours passes. By definition, though, if the symptoms have disappeared within 24 hours, then there is no residual deficit after that time. A TIA by definition doesn't need rehabilitation, because the neurologic symptoms have disappeared. - Nunh-huh 02:27, 6 July 2008 (UTC)

This reputable link may help. [1] Richard Avery (talk) 07:39, 6 July 2008 (UTC)

I liked your link so much I edited the article to reflect the info. Thanks Richard, and don't be afraid to be bold. --Shaggorama (talk) 08:32, 6 July 2008 (UTC)

Thanks, all, great article; that really helped. —Preceding unsigned comment added by 209.244.187.155 (talk) 10:50, 6 July 2008 (UTC)

brilliant blue fcf

What is the meaning of fcf in "brilliant blue fcf"? What is fcf stand for in the colouring agents, e.g. in Brilliant Blue FCF, Sunset Yellow FCF. Gcllau (talk) 04:04, 6 July 2008 (UTC)

food coloring something (anon cmt)

FCF doesn't google all that well. I'm going to guess that it's "Food Colouring Formula". Franamax (talk) 05:11, 6 July 2008 (UTC)

Wow there isn't much out there, although I vaguely remember having the same question during a chem lab. All I can find is "Food Contact Formulation" (found at the bottom of here). If you search google for that, one of the summaries lists "fast green food contact formulation", and there is indeed a Fast Green FCF. Hope it helps --Bennybp (talk) 05:52, 6 July 2008 (UTC)

Unexplained Magnetic Phenomenon - Childhood question

Why only, Burnt Matchstick Heads get attracted to a magnet and not unburnt ones. What chemicals are produced after burning that are magnetic in nature and why.
I used to try these scenarios -

1) Matchsticks with heads attached (Wax Paper sticks and Wooden ones).
2) Only Matchstick heads without sticks.
3) Matchstick Heads crushed to fine powder.(To see if weight effects it)

-In all cases only burnt up material got attracted to the magnet.

Regards praneel (talk) 04:19, 6 July 2008 (UTC)

Unable to confirm. My strike-on-box matches seem to be unmagnetic both before and after they are burned. Perhaps you can be more specific as to brand/type and testing procedure? Dragons flight (talk) 04:34, 6 July 2008 (UTC)

I forgot the mention this important thing. You have to let the matchstick burn for a while (up to the middle)and gently remove the burnt head from the Burnt Stick with tweezers. Make sure you do it so gently that no burnt wood is left inside the head. This reduces the weight of the head Otherwise it won't work if you put off the flame just after you lite the match.

I went to the market and bought all available brands and did the experiment. Regardless of brand all burnt heads (removed from the burnt stick)are attracted by the magnet. I think I can shoot this video and give that link here. If you want quick results you can remove the head before burning (easy with wax paper matchsticks) or scrape off the powder in chunks as large as possible without any specs of wood. Then burn them.praneel (talk) 05:33, 6 July 2008 (UTC)

None of the active ingredients in a match head, as listed in our Match article, would become ferromagnetic when burnt, but perhaps your matches contain an impurity such as iron (III) oxide (plain old rust). Iron oxide is not ferromagnetic, so an unlit match containing it would not be attracted to a magnet. However, when a match burns, it releases carbon and carbon monoxide [2], both of which are reducing agents. These would reduce the iron oxide to pure iron, which is ferromagnetic and would be attracted to your magnet. Just a guess. --Heron (talk) 10:51, 6 July 2008 (UTC)

Note that Gamma ferric oxide is indeed ferromagnetic. It what youve got coating your old cassette tapes! —Preceding unsigned comment added by 79.76.248.187 (talk) 19:09, 6 July 2008 (UTC)

Evolution of Evolution

• Can evolution evolve ?
• Can it evolve faster or slower ?
• Can it choose to briefly suspend itself ?
• Can it build on notions of constructivism ?
• Can it sustain bio-diversity and climate change ?
• Can evolution explain the golden number ?

- 69.157.240.224 (talk) 04:24, 6 July 2008 (UTC)

No - no - no - no... All of your questions are based on the terrible (but popular) misconception that evolution has some form of intelligence. Evolution is nothing more than a process. Considering evolution of species, it is a description of how species become different over time primarily based on genetic drift and survival of the fittest. Discussing "evolution of evolution" would require redefining evolution to have some attributes which can evolve. Since evolution doesn't have attributes which evolve, it cannot speed up, pause, or build up any notions. When it comes down to it, your understanding of this will dramatically increase if you look at it from the complete opposite way. Species evolve - even if they are incapable of comprehending what evolution is. The rate at which species evolve is not easy to measure because it happens by chance, not design. Species cannot stop evolving because that would require both a lack of genetic mutation and a perfect fit into the environment that cannot be improved. Species do not evolve on purpose. Giraffes did not get together and vote on how long their necks should be. So, any notion of purpose for evolution is ridiculous. Because species evolve, the total of species changes to better fit the environment. The environment changes, so the species evolve to fit it better. This is ongoing and does not change. The total sum of bio-diversity increases and decreases with environmental changes, but (to my knowledge) has never decreased to one and only one species. Evolution has nothing to do with the golden number. In fact, you can pick any number you like (such as 42) and find that it pops up all over nature. Trying to draw causation from coincidence will lead to nothing but folly. -- kainaw™ 05:04, 6 July 2008 (UTC)

Well, on the "faster or slower" question, it depends what you mean by it. Mutations can spread much more rapidly through a population under some circumstances. For example, if the population is very large and has a lot of diversity, mutations don't spread very quickly—you get regression to the mean. If, however, you end up with a population bottleneck, then suddenly your entire population can end up with a given mutation quite rapidly. The idea that evolutionary change happens in "spurts" rather than just gradually at a constant pace is known as punctuated equilibrium. It's not "faster" in the sense you probably mean though—the popular idea that if you "speed up" evolution you'll get some sort of result. What it means is that traits spread to populations quicker. --98.217.8.46 (talk) 14:49, 6 July 2008 (UTC)

A species can evolve traits that increase or decrease the rate of mutation. It can evolve its preferences for sexual selection. Do those count as evolution evolving? Evolution is required to sustain biodiversity. As for climate change, see Daisyworld. Nothing physical can effect anything mathematical, like the golden ratio. Evolution might be able to explain why people care about the golden ratio, or why it occurs so often in nature, but not the number itself. — DanielLC 15:30, 6 July 2008 (UTC)

• Can evolution evolve ? - Sort of, see the folowing responses.

• Can it evolve faster or slower ? - Yes, both due to changes in the environment and possibly due to changes in the species itself. Sexual reproduction, for example, seems to increase variation in offspring to bring about more rapid adaptation. Some species also appear to have a much high rate of mutation than others. More mutation is better in that it makes for quicker evolution but bad in that more offspring are "defective". Thus, species with many offspring are able to benefit from higher mutation rates without losing a critical number of offspring.

• Can it choose to briefly suspend itself ? - No.

• Can it build on notions of constructivism ? - No, although you may have to explain what you mean better here.

• Can it sustain bio-diversity and climate change ? - If you mean does evolution lead to bio-diversity and species which can survive climate change, then the answer is yes.

• Can evolution explain the golden number ? - I doubt it. StuRat (talk) 19:03, 6 July 2008 (UTC)

If the rate at which evolution occurs can change, "Evolution" doesn't consciously change that rate. That's a bit like saying that "Rain" consciously decides whether to rain more heavily or not.

I blame the creators of Heroes and X men (and the like) for giving children a false impression of what evolution is. I wouldn't mind if creators of fiction were banned from using the word "evolution" unless they used it to describe Biological Evolution as explained in that article. Zain Ebrahim (talk) 12:42, 7 July 2008 (UTC)

That is why I said "no, no, no..." Evolution is nothing more than a word used to describe a process. It is not a living, thinking, planning thing. It has no speed. It has no purpose. This question is no different than asking "Does the Dewey decimal system speed up or slow down?" The only way to provide an answer is to redefine evolution as having some sort of speed or attribute of evolution itself. Once you redefine evolution, you are no longer talking about evolution. -- kainaw™ 12:59, 7 July 2008 (UTC)

I don't quite follow when you say that evolution has no speed. The rate at which mutations occur and genes diverge from the starting point is certainly both measurable and variable. I take it you aren't calling those items by the name "evolution", then ? StuRat (talk) 03:20, 8 July 2008 (UTC)

A mutation is a mutation. It is not evolution. Three mutations is just three mutations. It is not evolution. Evolution is a process by which some mutations (not all of them and not in any specific frequency) help a species better fit into an environment. It isn't based on a lot of mutations or very few mutations. Claiming that it is going faster or slower indicates that evolution is in control of the mutations - perhaps with a purpose in mind. Evolution is not in control of anything. It is an abstract term used to define the relationship between beneficial mutations and how well a species fits into the environment - including divergence of species. The biggest hurdle in explaining evolution is trying to break people of the habit of saying things like "evolution made that bird have a pointy beak so it could get ants out of holes in the rocks." Evolution did not make the bird have a pointy beak. Mutations did that. Evolution did not have a goal of getting ants out of holes in the rocks. As the beaks got pointier, some birds just found it easier to stick their beaks into the holes. Had their beaks got wider, they would have used them for some other purpose. As I stated, trying to give it speed requires redefining evolution to be "the rate at which mutations change a species" - which is not a proper definition. -- kainaw™ 13:50, 8 July 2008 (UTC)

It's just a manner of speaking, like saying "the Sun rose" instead of "the Earth rotated into a position such that from my location on the Earth's surface, the Sun became visible above for horizon". It's also easier, although less precise, to say "evolution changed reptiles into birds", than to say "a number of mutations occured in reptiles, some of which were beneficial and thus were retained into subsequent generations, eventually leading to the development of birds". StuRat (talk) 04:43, 10 July 2008 (UTC)

Unleaded fuel

How can the effects of using leaded fuel or LRP in a car that is supposed to use unleaded fuel be overcome —Preceding unsigned comment added by Razzmetazz (talk • contribs) 05:34, 6 July 2008 (UTC)

Feel free to ignore this if you want but may I ask why? According to Tetra-ethyl lead "and the only countries in which leaded gasoline is extensively used are Yemen, Afghanistan and North Korea[citation needed]." I presume if you are living in Yemen, Afghanistan or North Korea, you probably have a car which is not designed to use leaded fuel. In any case Catalytic converter doesn't mention any methods to prevent fouling with lead. My gut feeling is it's difficult if possible. More likely you'd have to use a significantly different catalytic converter which is pointless since you might as well just switch to unleaded fuel and if you can't, e.g. because your Afghanistan your vehicles are probably already so polluting that equiping them with catalytic converters is somewhat pointless, there's more effective things to do first (e.g. switch to unleaded fuel). Presuming you've made the mistake of using leaded fuel in a car with a catalytic converter, our article mentions "Depending on the contaminant, catalyst poisoning can sometimes be reversed by running the engine under a very heavy load for an extended period of time. The increased exhaust temperature can sometimes liquefy or sublime the catalytic contaminant, removing it from the catalytic surface. However, removal of lead deposits in this manner is usually not possible due to lead's high boiling point. In particularly bad cases of catalytic lead poisoning, the catalytic converter may actually become completely plugged with lead residue". My suggestion would be to just replace the catalytic converter... Nil Einne (talk) 17:21, 6 July 2008 (UTC)

If you're going to burn fuel with lead in it, you might as well replace the catalytic converter with a piece of regular exhaust pipe too. But would there be additional concerns with fouling of the various mass-flow sensors in the engine-management system? Franamax (talk) 18:03, 6 July 2008 (UTC)

I'm going to make an educated guess here that you may have based your question on incorrect info. Many years ago gasoline grades in the US were called "Regular", "Unleaded", and "Premium". At that time the "Regular" and "Premium" both meant leaded gasoline. However, at some point it became illegal to sell leaded gasoline in the US, at which point the grades were called "Regular", "Plus", and "Premium" (the names vary slightly from brand to brand). The "Regular" and "Premium" now have a different meaning, as they, along with "Plus", refer to unleaded gasoline only. However, I could certainly see how someone might think that, since the grade called "Unleaded" had disappeared, that this meant that unleaded gasoline was no longer sold. StuRat (talk) 18:51, 6 July 2008 (UTC)

It is possible that the questioner is making a false assumption based on good knowledge. If you have a car that is designed to run on leaded gasoline, using unleaded gasoline will reduce the effective octane level a tiny bit (about 85 instead of 87 octane). It isn't enough to really notice. Now, if you assume this applies in reverse, you will think that you can take a car designed for unleaded gasoline, put leaded gasoline in it, and get an effective boost in the octane level. Sorry, but that isn't true. All you will do is throw off the engine's timing (effectively lowering the octane level) and increase lead pollution in the air. The key is understanding that the engine is timed for the specific type of gasoline it is intended to use. If you use a different type of gasoline, the timing will be off. You won't use the combustion of the gasoline to its full potential and, in the end, run at what could be effectively be referred to as a lower octane level. The gas doesn't actually lose octane. The engine just doesn't use it properly. -- kainaw™ 00:05, 7 July 2008 (UTC)

The reason for asking the question is that we will be touring Africa and most reports we get from fellow travellers is that unleaded fuel is not available most of the time. Iam not sure if the term unleaded is still used and if not that may be the cause for the confusion. I was trying to establish if any precautions could be taken should the situation arise and we are forced to use leaded petrol —Preceding unsigned comment added by Razzmetazz (talk • contribs) 06:52, 8 July 2008 (UTC)

Well, leaded fuel will ruin the catalytic converter. Other than that, there won't be much noticeable damage. Extended use can cause buildup in the catalytic converter, leading to exhaust problems and (worse case very rare scenario) blowing out the exhaust system. If you just plan to replace your catalytic converter when you return, you should be fine. Personally, I'd flush the gas tank upon return also. Not only is unleaded gas difficult to find in some places, regulated gas is even harder to find. You will have no way to know what was in the "gas" that you purchased (especially in areas where you aren't allowed to watch them pump it): water, apple juice, ping pong balls... -- kainaw™ 18:05, 8 July 2008 (UTC)

Courage

What is the most coragious felin? And the most coragious animal? Francesco —Preceding unsigned comment added by 87.20.213.78 (talk) 08:25, 6 July 2008 (UTC)

That's difficult to answer - how do you distinguish bravery and stupidity? There are plenty of animals that wouldn't be scared of something dangerous simply because it's not something they would ever encounter in their natural environment, and have never encountered before. That's not bravery, it's just ignorance. --Tango (talk) 13:19, 6 July 2008 (UTC)

Most courageous animal? Must be deers. When faced with several tons of steel running toward them at 70 mph, most deers would choose to stand their ground instead of running. Never have I seen another species display such gallantry so consistently :) --71.175.20.73 (talk) 13:48, 6 July 2008 (UTC)

Same with several hundred tonnes at 100 mph. An antler charge on an intercity train... that was brave (and messy). --BozMo talk 14:43, 6 July 2008 (UTC)

In general, many female animals with young display incredible bravery when threatened. Courage is probably related to fighting skill, I'd nominate polar bears and especially wolverines, which even bears don't mess with. Franamax (talk) 17:59, 6 July 2008 (UTC)

I'd disagree , surely courage is measured in part by the odds against you, meaning that flys/ants etc are extremely brave (and with a life expectency to match...)87.102.86.73 (talk) 19:40, 6 July 2008 (UTC)

Yes, there was a case of a house cat which rescued it's kittens from a burning building, one at a time, and burned both of it's ears off in the process. That's quite the act of bravery. StuRat (talk) 18:43, 6 July 2008 (UTC)

Personally, I'm not sure I'd ascribe "courage" to most animals at all. I tend to think of courage as a willingness to face danger/pain/struggle, but that presupposes an awareness and anticipation of the danger/pain/etc. If an animal acts on instinct, without awareness of the potential consequences of its actions, then for me those actions don't seem courageous. I'm sure there are exceptions for some actions by some more intellectually capable animals, but to the degree that much of animal behavior is instinct devoid of foresight or planning, then I'd see those actions shouldn't be interpreted as courageous at all. Dragons flight (talk) 18:54, 6 July 2008 (UTC)

Yes, we are antropomorphizing here. Blame it on that documentary about the penguins. However sometimes what we call courage could also be interpreted as stupidity, a lot of courageous acts are performed by humans acting on what you could call instinct, i.e. insufficient assessment of the risks. It seems to me that at least some of the people who rescue someone from a smashed-up car in a pool of gasoline must reflect later and think "what the hell was I doing?". Franamax (talk) 19:56, 6 July 2008 (UTC)

And, instinct or not, a mother facing down a predator to protect her young satisfies your criterion of "willingness to face danger" with "awareness...of the danger". Franamax (talk) 19:59, 6 July 2008 (UTC)

I don't feel that an animal standing it's ground, like a deer as described above, is *necessarily* brave. Some animals become paralysed with fear. This fear may be misconstrued as bravery or courage.

As for the most courageous animal, the well-bred German Shepherd dog. But then, I'm a bit biased.

I think most people tend to give animals human emotions. A silly practice if you ask me.

Ruairí Óg the Rogue (talk) 05:13, 7 July 2008 (UTC)

Animals don't defend their young because of bravery; they do so because it increases the possibility of their genes being passed down. The behaviour is due to instinct, not conscious choice, and the mother may not even feel fear while defending their children. --Bowlhover (talk) 04:43, 10 July 2008 (UTC)

Depends on the species. Humans are considered animals, are they not? You wouldn't say the same thing about us. 70.212.230.44 (talk) 07:45, 10 July 2008 (UTC)

Oh, but I would. Even humans usually think irrationally during emergencies and act on instinct, so I doubt other primates would reason out the advantages of disadvantages of different courses of action during an emergency. -Bowlhover (talk) 04:36, 11 July 2008 (UTC)

Life in free-fall

Hi, how would menstruation work in free-fall? At first I thought tampons might work, but then you can't reach the uterine wall with a tampon.

Also, does gravity play a roll in how a fetus is attached to the uterine walls? Any help would be much appreciated. Thanks. --Kjoonlee 14:23, 6 July 2008 (UTC)

According to various google hits ([3]), gravity is not required for menstruation, so it happens with no difficulty in space. I have no idea how it works, though. [4] says that pregnancy in space appears to be possible. --Tango (talk) 15:46, 6 July 2008 (UTC)

First, tampons aren't inserted into the uterus, just the vagina. They would have no problem reaching the vaginal wall since they expand when wet, and this works fine without gravity. The only concern is that gravity may be important in removing the menstrual fluid quickly, before it starts to decompose. I imagine bedridden women have faced this issue before, however. Menstruation obviously still "works" in zero-g, but it may be a bit less efficient, meaning women need to be extra careful not to do other things which might make the situation worse, like leaving the same tampon in too long. They may be more susceptible to toxic shock syndrome in zero-g than normal gravity, if they aren't careful. StuRat (talk) 18:36, 6 July 2008 (UTC)

Menstruation is probably less problematic in space than when bed-ridden because women in space can move around. This is important if period pains are to be avoided. Itsmejudith (talk) 20:59, 6 July 2008 (UTC)

Iron lattice

The lattice spacing of iron given at [5] is 286.66 pm. Can this be calculated? How? Thanks, *Max* (talk) 18:26, 6 July 2008 (UTC).

Typically experimentally by X-ray crystallography

Alternatively: knowing the density of the solid, the atomic mass, and the number of atoms per mole, and assuming a crystal structure you can make a good estimate with out using x-rays..

Please ask if you require further information on either method.87.102.86.73 (talk) 19:38, 6 July 2008 (UTC)

I wanted to know how it could be calculated from the electromagnetic forces between the atoms. Is this possible? *Max* (talk) 03:26, 7 July 2008 (UTC).

You can certainly do molecular modeling calculations to minimize the energy for a collection of iron atoms. For your purposes, you would want some sort of ab initio quantum chemistry methods, as any of the simple molecular mechanics or Semi-empirical quantum chemistry method approaches would likely be based on observed interatomic distances, so you wouldn't really be calculating them. DMacks (talk) 04:09, 7 July 2008 (UTC)

You could try to get an estimate this way.. even using classical inverse square electric field. - but a computer would help a lot - simply place the charged iron nuclei in the desired lattice and add the electrons randomly to the lattice.. then let the electrons and nuclei move under the resultant forces (do this stepwise) until some sort of equilibrium is found... NOTE you need to introduce a arbitrary barrier around the nucleus to prevent the electrons falling into the nucleus (ie a bounding spherical shell within which the electrons are not allowed to go)..

You can repeat this experiment with smaller and smaller bounding spherical shell and maybe even calculate the limit as the shell radius tend to zero. (you can also replace electrons with N pseudo-electrons of charge e/N to get a better approximation to electron density) This I suspect would work quite well...

I can't think of a method that you could easily do on paper though.. not without resorting to heavy maths or a heavyily simplified model.87.102.86.73 (talk) 13:17, 7 July 2008 (UTC)

What potentials would there be between the atoms if I used molecular mechanics? *Max* (talk) 19:32, 7 July 2008 (UTC).

Van der waals and electrostatic. VdW is probably the major one if you're doing simple molecular mechanics and considering atoms as point-masses that include their valence electrons...would have parameters (Lennard-Jones potential constants, for example) for the idealized interatomic spacing. Which is based on experimental determination of those parameters:) DMacks (talk) 02:29, 8 July 2008 (UTC)

Wouldn't molecular mechanics be not much use in terms of calculating Fe interatomic distance since the models used need force/distance formula and an estimate of interatomic distance to work: which was what was supposed to be being calculated.87.102.86.73 (talk) 06:22, 8 July 2008 (UTC)

Flashes from Zen Vision W

The flashes from my Zen Vision W, which I told you about earlier, are real, not my imagination. I've just seen one while looking directly at the device. The screen flashed a solid light gray for about a tenth of a second, while the device was turned off. What is the cause of this? JIP | Talk 17:33, 5 July 2008 (UTC)

So the backlight turned on by itself? --antilived^{T | C | G} 23:43, 5 July 2008 (UTC)

Seems like that, yes. And it turned off by itself immediately afterwards. JIP | Talk 18:18, 6 July 2008 (UTC)

Redirected from Wikipedia:Reference desk/Miscellaneous#Flashes from Zen Vision W87.102.86.73 (talk) 19:33, 6 July 2008 (UTC)

For the record the previous question was here Wikipedia:Reference_desk/Miscellaneous#Weird_flashes_from_Zen_Vision_W, it seems the light is real, and not imagined.. what causes this.?87.102.86.73 (talk) 19:33, 6 July 2008 (UTC)

I'm not sure about Zen Vision W, but most media players feature only a soft-off power switch. This means that even when the device is in a power-off state, the internal circuitry is still on, but consumes only a very small amount of electricity. So, these flashes could be caused by a faulty component, broken connection, or even a firmware bug. You should first check whether these flashes still happen with the battery removed. —Preceding unsigned comment added by 85.222.93.28 (talk) 00:27, 7 July 2008 (UTC)

I doubt the battery is removable (without voiding the warranty, that is). Secondly, what would that prove? I think I can pretty much guarantee that if you remove the battery, it's not going to do any flashing -- no power, no light, surely? -- Captain Disdain (talk) 11:51, 7 July 2008 (UTC)

What about somesort of residual charge in the light driver (note I don't actually know if its fluorescent source or Electro-luminesencent..)

I also think I've seen a similar effect say ~15mins? after a electronic fluorescent light has been switched off (see linked original question), additionally I vaguely remember a similar effect from old black and white TV's after they had been switched off.. I suggested some sort of cascade process... but where would the residual voltage come from?? and what would cause the electron cascade to start: cosmic rays? 87.102.86.73 (talk) 13:09, 7 July 2008 (UTC)

Never exclude the possibility of a firmware bug activating the backlight when you wouldn't expect it.

Atlant (talk) 17:40, 8 July 2008 (UTC)

The battery isn't removable, but it is detachable. The Zen Vision W has a user-usable (for want of a better word) switch at the bottom that severs the connection between the battery and the device. It can be reattached immediately afterwards. I find this a very useful way of doing a hard reset, and it avoids the possibility of losing the battery. I have not tried whether the flashes happen with the battery detached. JIP | Talk 18:01, 8 July 2008 (UTC)

Citing

Hello. I am making a registry of the most commonly cited sources that I use. When citing in APA style, must I include the author's title (i.e., Dr.) as part of the first name initial? For example, would the following be correct?

Jenkins, Dr F., Van Kessel, H., Davies, L., Lantz, Dr O., Thomas, P., & Tompkins, D. (2002). Chemistry 11. Canada: Nelson Thomson Canada Limited.

Thanks in advance. --Mayfare (talk) 20:07, 6 July 2008 (UTC)

Almost certainly not, I can't recall ever seeing a 'Dr.' title in a citation..87.102.86.73 (talk) 20:13, 6 July 2008 (UTC)

No, you don't use titles at all, much less professional ones. --98.217.8.46 (talk) 20:15, 6 July 2008 (UTC)

Note that the page APA style is actually a very good resource. --Several Times (talk) 20:14, 7 July 2008 (UTC)

Breeding spiders

My jumping spider, (I think Dendryphantinae) has spun a nest, and laid her eggs. The spiderlings have hatched but are still in the nest (they can't/don't come out). When raising spiderlings should they be taken out of the nest or left on their own until they come out themselves? (Maybe someone who has raised Tarantulas can tell me what is done in that case). Pro bug catcher (talk • contribs). 21:41, 6 July 2008 (UTC)

I'm not a spider expert but it seems unlikely to me that human intervention would be helpful in this situation. The spiders aren't waiting for you. They are probably only marginally aware of your existence. --98.217.8.46 (talk) 21:46, 6 July 2008 (UTC)

There are many (too many) spiders that make my yard their home. I often see nests teeming with tiny legged specks moving all around. After a while, they come out, sling out a little sting of web, and float off. Then, I have dozens of them trying to make a new home on my car. -- kainaw™ 23:57, 6 July 2008 (UTC)