Wikipedia:Reference desk/Archives/Science/2009 February 10

= February 10 =

How come this image says that the galaxy is impossible?
http://img87.imageshack.us/img87/6498/univerrrrsehg9jy8.jpg

In the bottom right frame, what does it mean when it says the galaxy is too large to exist according to current theories? —Preceding unsigned comment added by 70.171.234.117 (talk) 01:33, 10 February 2009 (UTC)


 * I'm not sure but if I had to guess, I'd say they mean we don't currently have a theory for how galaxies that large could form. --Tango (talk) 01:49, 10 February 2009 (UTC)


 * Those images are from the Hubble Ultra Deep Field. This webpage comments on the exact same galaxy you pointed to.


 * That galaxy--the one to the lower right of this image--is only 800 million years older ("younger" B00P) than the universe itself. That's quite surprising because for a long time after the Big Bang, no galaxies formed; even after all the hydrogen and helium cooled enough for stars to become a possibility, gravity still needs to bring the sparse gas clouds together to form stars.  The first star probably formed 100 million years after the Big Bang--a significant fraction of this galaxy's age.  Then enough stars had to form to organize themselves into large, gravitationally-bound galaxies.  For this reason you'd expect the first galaxies to be small, because only after more stars form and those small galaxies combine are large galaxies possible.  But the one in the photo is not only big, it has already stopped forming new stars!  Exactly how the scientists know that I admit I can't tell, but it certainly doesn't seem young, which can't (yet) be easily explained by current theories.  --Bowlhover (talk) 03:25, 10 February 2009 (UTC)


 * My bullshit meter is going off-scale here.


 * Our galaxy has 2x1011 stars. Eight times that many would be 1.6x1012.  Our article "Galaxy" says: "Typical galaxies range from dwarfs with as few as ten million (107) stars up to giants with one trillion (1012) stars,".   Well if 1012 is "typical" for a giant galaxy then I really very much doubt that 1.6 times more than that is "impossible".  So I strongly suspect the language of that image is just over-hyped.  Sure, it's a big galaxy...but I very much doubt "impossible" - or even particularly surprising.  People are very fond of telling us that science regards such-and-such things as "impossible"  (the flight of bees and the speed that dolphins swim are common examples) - perhaps because they think it's exciting for their readers.  But that's rarely, if ever, actually true.  Science just doesn't work like that.  If the current theory of galaxy size says that there is a hard upper limit - then we find a galaxy that's 1.6 times bigger, we don't say "That Galaxy Is Impossible!!!" - we say "Our theory of maximum galaxy size is incorrect", then we start looking for a better theory.   Hence it may be true to say that we have no good explanation for the sizes of some large galaxies - but it's certainly not true that science says it's impossible.   But my best guess is that the author of that slide has one or more facts just plain wrong.  This article  says that there are galaxies 100 times more massive than our own - so a mere 8 times heavier is nothing.  We actually have an article about Abell 2029 - a galaxy that's 80 times bigger than the Milky Way.


 * SteveBaker (talk) 03:39, 10 February 2009 (UTC)


 * Did you read my post? That galaxy grew to eight times the size of the Milky Way within the first 800 million years of the universe's existence.  For comparison, stars didn't even begin forming until 100 million years after the Big Bang.  --Bowlhover (talk) 04:25, 10 February 2009 (UTC)
 * We had a little edit-conflict...so no, I didn't. OK - so the age of the galaxy is surprising given it's size - but it's size (in general) is not particularly amazing. SteveBaker (talk) 04:38, 10 February 2009 (UTC)


 * It just arises from the fact that the person who wrote the fact that something is impossible according to science doesn't understand science at all. Science would never say that something which is plainly observable is impossible.  One of two things is going on: 1) The observation is flawed; for example that there is something distorting our image of the galaxy making it appear either older, farther away, or larger than it actually is (for example, some exotic sort of Gravitational lensing) OR 2) our current theories are flawed, at which point the current theories need to be tweaked.  Science, thankfully, is flexible enough to deal with both of these situations.  If the galaxy REALLY is that big, then it isn't impossible.  That which actually exists is never impossible.  --Jayron32. talk . contribs  05:24, 10 February 2009 (UTC)


 * I just gotta meet this Science character. Really smart AND flexible.  Cool.  --Scray (talk) 05:32, 10 February 2009 (UTC)
 * When a group of people are engaged in similar endeavors and who use the same general set of methods and principles, we use words like "Society", "Economy", "Education", "Government" and "Academia" to describe them as a group. It's really nothing to panic about. cf: "The Wikipedia Reference Desk doesn't answer homework questions".  WP:RD would also be a cool dude to meet. SteveBaker (talk) 14:51, 10 February 2009 (UTC)
 * "Really smart AND flexible." I'd prefer Science as a girl. Zain Ebrahim (talk) 16:19, 10 February 2009 (UTC)
 * Would she have a really low-cut lab-coat? ...and could she say: "Is that a slide-rule in your pocket - or are you just glad to see me?"...then after you'd nod speechlessly she'd maybe say something like "You meet me behind the centrifuge and we we'll square some really BIG numbers...".  That would be COOL...um - in a professional kind of way of course. SteveBaker (talk) 00:02, 11 February 2009 (UTC)
 * It is worth noting that some scientists have no qualms using the phrase "impossible" while discussing plainly observed phenomena in reputable journal publications:
 * In Science (journal) - Generation of impossible cross-peaks..., "have been experimentally produced and detected, although such coherences are inconceivable in the normal theoretical framework";
 * In Evolutionary Anthropology - The impossible coincidence. A single-species model for the origins of modern human behavior in Europe, ..."We are probably on safe ground in assuming that symbolic behavior and expression of this level of complexity would be inconceivable in the absence of highly structured language systems and brains closely similar, if not identical to, our own."
 * International Symposium on Directions in General Relativity, Impossible measurements on quantum fields. "It is shown that the attempt to extend the notion of ideal measurement to quantum field theory leads to a conflict with locality, because (for most observables) the state vector reduction associated with an ideal measurement acts to transmit information faster than light.  Two examples of such information-transfer are given..."
 * I am not judging whether these things are impossible, or if the empirical observations are flawed; I am merely noting that this omniscient Science character doesn't seem to mind using some sensational language every now and then to attract a few extra readers. Personally, I think it's pretty horrible that this "impossible" word-choice was used, and it's worse that it got past the reviewing committee.  In regards to the original question, it's quite possible (probable, even) that some scientist actually used the term "impossible" while describing these galaxy observations.  This Science character possibly has a few flaws every now and then... Nimur (talk) 06:53, 10 February 2009 (UTC)


 * The text on that poster has another significant over-simplification. It says "On September 3rd, 2003 the Hubble Space Telescope began pointing its camera at a small area in the night sky ... Hubble kept its camera pointing there for over 4 months, taking in all the light it could ...". From the 2003 date given, this is indeedreferring to the Hubble Ultra Deep Field, where data which was collected over 4 months between September 2003 and January 2004. However, the observations were not continuous, as the author implies - the HUDF was not even in Hubble's "continuous viewing zone". As our article explains, observations were made twice per orbit over two periods of about four weeks and six weeks respectively, and the total exposure time was about 1 million seconds or 11.5 days. As the author can't present this basic information accurately, I wouldn't take anything else they say on the poster too seriously. Gandalf61 (talk) 10:19, 10 February 2009 (UTC)

why are branched hydrocarbons more thermodynamically stable than unbranched ones?
I can't find a readable explanation anywhere. 199.111.188.173 (talk) 06:47, 10 February 2009 (UTC)


 * A C–H bond at a primary carbon (methyl group) is energetically different than at a secondary carbon (CH2 group along a chain), and a tertiary (CH at a branch-point) is also different. In addition, there are steric differences (crowding of lots of atoms near each other) if you are branched vs being straight-chain. Seemsl like alkane or isomer might have info, but I haven't read them lately. DMacks (talk) 18:34, 10 February 2009 (UTC)

Genetic Modification potato
Which plants have genes that are suitable for GM potatos that are high yield and low energy waste?(more starch is present in edible areas than flowers etc.) I also need genes that require less water and fertiliser for growth. Tks. I need the info ASAP. tks —Preceding unsigned comment added by Invisiblebug590 (talk • contribs) 07:13, 10 February 2009 (UTC)
 * This sounds to me a lot like a homework question, forgive me if I am mistaken. If it is, next time, don't leave your homework to the last minute. And don't bother asking somewhere where we don't answer homework questions Nil Einne (talk) 12:15, 10 February 2009 (UTC)

SteveBaker (talk) 14:44, 10 February 2009 (UTC)


 * It sounds like a farmer asking for help, to me. StuRat (talk) 17:29, 10 February 2009 (UTC)


 * Except that for some reason, the OP needs the answer "ASAP". Anyone who is seriously contemplating genetic engineering should have plenty of time to be patient and make the right choices.  In any event, perhaps the Genetically modified food article would be helpful to the OP?  Simply Googling "transgenic potato"  also retrieves several potentially useful links.  The starch article is a good place to start looking for plants that might have the desired characteristics.  Drought tolerance discusses plants that adapted to arid conditions, and might be useful sources of "genes that require less water" (what you mean is "genes that allow the plant to utilize less water"). --- Medical geneticist (talk) 21:05, 10 February 2009 (UTC)


 * Yes - exactly. Farmers don't to genetic engineering.  Seed potato producers might - but they know that the plural of potato is potatoes - and they most certainly don't decide what genes to splice on the basis of some geeks on Wikipedia!  The 'ASAP' bit is also a bit strange for any kind of professional inquiry about something that would take years to get from laboratory to field.  Hence,  . SteveBaker (talk) 23:55, 10 February 2009 (UTC)

Curious shadow over Moon - cloud, or not?
Good day, RefDeskers. Today I have a query that's totally out of this world. Namely, last night I had a brief spur of photographing our own Moon because it was almost full, and the sky was quite clear. I just had a few minutes, but I managed to take among others, two photographs (at right) which show a curious shadow over the surface of our celestial companion. The span between both photos is eighteen seconds. They are unmodified and uncut of course. No tripod used, just put it down on a convenient staircase in my house. These are the only photos on which the shadow appears.

So, for the question that unavoidably poses itself (at least in my curious mind) - what is it? My mind refuses to accept a priori that it could be an Earthly cloud that got in the way.

Ideas, explanations, will be very much welcome. Feast your minds, and cheers! --Ouro (blah blah) 07:55, 10 February 2009 (UTC)


 * Could it be the February 2009 lunar eclipse? Pfly (talk) 08:45, 10 February 2009 (UTC)
 * Perhaps. I live in Gdańsk, Poland, so that could have _just_ been it. Yeah, that could be it (checked this image), maybe. --Ouro (blah blah) 08:51, 10 February 2009 (UTC)
 * Ah, I was on a long drive through the smoke haze from the 2009 Victorian bushfires, here in South-Eastern Australia. After sunset a dark orange full moon was rising directly ahead. I looked hard, because there did seem to be some unusual shading. That rather good diagram at Ouro's link confirms it as an eclipse, as I thought it might be at the time. Thanks!
 * – ⊥ ¡ɐɔıʇǝo N oetica! T– 09:21, 10 February 2009 (UTC)


 * A whisp of cloud? You should definately reject the notion that it could possibly be something so common and ordinary. I say you should claim you've photographed herds of wild chupacabras on their annual migration from Mare Imbrium to Mare Nubium, and sell the pictures to some supermarket tabloid. That's real science - and some money in your pocket. You could even start a cult. B00P (talk) 21:09, 10 February 2009 (UTC)


 * Can we add these images to the article's photo gallery? It says "NONE" and that should be fixed. ~ A H  1 (TCU) 02:32, 11 February 2009 (UTC)
 * They are contributed under CCA-SA3 - so yes! I think they could use some fairly drastic cropping first though.  The location from which they were taken should be added to the image info so that the time stamp from the camera in the image Metadata can be corrected to UT. SteveBaker (talk) 03:13, 11 February 2009 (UTC)
 * Convince me that they are pictures of the eclipse. When I open them in two tabs in IE, blow them up full size, and switch between them, I see a blurry shape smaller than the lunar diameter move across from NE to SW in the upper part of the face. --Milkbreath (talk) 03:34, 11 February 2009 (UTC)


 * I'm doubtful on this too. Eclipses develop over much longer periods than 18 seconds and the shadow advances uniformly over the entire face. Also, depending on how accurate the clock on the camera is, Poland is at UT+0100 so the images were taken 22 minutes after the P4 point, i.e. the eclipse was already over by then. My money's on the chupacabras. Franamax (talk) 07:21, 11 February 2009 (UTC)
 * You can crop them any way you wish, guys. I don't think these are Chupacabras or Greys or anything on their daily stampede. Gonna get breakfast now... --Ouro (blah blah) 08:02, 11 February 2009 (UTC)
 * Can you check the clock on your camera to see how accurate it is? Franamax (talk) 08:27, 11 February 2009 (UTC)
 * I don't think it matters much whether the camera clock is accurate. According to at Gdańsk, the sunrise is at 07:19 and sunset is at 16:41 on February 9th. Given the difference of UTC+1, this means 06:19 UTC and 15:41 UTC. The eclipse P1 was at 12:36:50 UTC and P4 was at 16:39:39 UTC. In other words it was before sunset for a big part of the eclipse. It's true that the end of the eclipse was after sunset but I doubt you would have seen much, remember it was a penumbral eclipse and even if it 90% at the greatest, that was over 1 hour before sunset. The image is cleaarly after sunset. Edit: Note according to  on February 9th the moonrise was at 16:45 i.e. 15:45 UTC so it must have been after then. Nil Einne (talk) 09:43, 11 February 2009 (UTC)
 * It's two minutes and eight seconds behind if you omit time zone difference. --Ouro (blah blah) 08:53, 11 February 2009 (UTC)
 * That pins it down then, it was 20 minutes after the eclipse ended. Maybe some bizarre atmospheric refraction effect, but I've never heard of such a thing. A wisp of cloud or plastic bag blowing past seem most likely. Sure is strange though. Franamax (talk) 17:22, 11 February 2009 (UTC)
 * I'd love to get to the bottom of this. Maybe it's the shadow of another planet or something that could have been between the Sun and the Moon at that time? I doubt it'd be a plastic bag blowing past, and I think that a cloud would have looked differently... --Ouro (blah blah) 17:49, 11 February 2009 (UTC)
 * Sure doesn't look like a cloud to me. I'm looking forward to looking at this photo in high-res when I get home.  -Pete5x5 (talk) 18:14, 11 February 2009 (UTC)
 * It looks pretty cloud like to me. --Tango (talk) 18:27, 11 February 2009 (UTC)
 * Comparing the pictures on a better monitor, it looks like the shadow of a cloud. It moved quite a bit in 18 seconds!  -Pete5x5 (talk) 21:23, 11 February 2009 (UTC)
 * Thing is, it's doubtful to me that it'd be a cloud, they usually move straight horizontally, and this shadow seems to have moved diagonally. That's my impression, at least. And, I believe that a cloud located straight in line between the camera and the Moon would have been illuminated by the light reflected by the Moon coming in the direction of the lens... and this does not seem to be the case here. --Ouro (blah blah) 21:44, 11 February 2009 (UTC)
 * Interestingly, the diagonal movement appears to be precisely opposite to the shadow track shown in, which I interpret as meaning that the penumbra moved from W/SW towards the NE. Is there such a thing as an atmospheric refraction effect? Seems to me that might move in the opposite direction to the penumbra. Franamax (talk) 22:19, 11 February 2009 (UTC)
 * How about simulating that moment using Celestia or similar software? Could that yield any results? --Ouro (blah blah) 07:05, 13 February 2009 (UTC)
 * If it is the shadow of a cloud, it wouldn't seem strange to me for it to move 30 arcminutes in 18 seconds. I've seen clouds move 1 degree (that's 60 arcminutes) in ONE second! ~ A H  1 (TCU) 00:20, 14 February 2009 (UTC)
 * I don't doubt it that clouds can be fast, but I'm more and more convinced that this isn't one. Unfortunately I haven't got the time to simulate the mechanics of the heavens accurately now, sadly. --Ouro (blah blah) 07:06, 16 February 2009 (UTC)

Medically qualified people with main contribution in physics\mathematics
David Alter comes to mind!As does William Gilbert.But do we have a comprehensive list of those who were medically qualified but made seminal contribution in physics or mathematics?(Ramanathan) —Preceding unsigned comment added by 212.247.70.129 (talk) 13:50, 10 February 2009 (UTC)


 * I don't think we have that kind of list, but one could use overlapping biography categories or clever googling to find them I think. The only one which comes to mind is James Lind whose medical experimental design in 1747 contained much of what is now standard experimental design in statistics and other sciences.
 * I think the other way round is much more common. For instance Adrian Kantrowitz, Joseph Rotblat and Thomas Rockwell Mackie all had an education in physics or math and went on to make contributions in medicine. EverGreg (talk) 14:08, 10 February 2009 (UTC)


 * Abū 'l-Walīd Muḥammad ibn Aḥmad ibn Rushd and Abu Ali Sina Balkhi both come to mind, but they are from such a distant era that the distinctions between "physics", "math", "chemistry", and "medicine" are all kind of blurry. The scholars of that era are all just some kind of scientist... Ibn Rushd described the retina, immune response, and defined kinetic energy 400 years before Isaac Newton.  Abu Ali wrote over 100 medical treatises, and made contributions to thermodynamics, pre-Newtonian mechanics, and geology.  Nimur (talk) 17:27, 10 February 2009 (UTC)


 * I was aware of this name when I asked the question but for the very reasons you adumbrate did not feel it right to consider him.Even a more striking example is Nasiruddin Tusi!And I remember reading that Pythagoras was a physician as well as was Galileo(Ramanathan) —Preceding unsigned comment added by 212.247.70.129 (talk) 12:03, 11 February 2009 (UTC)

Why is the death toll so high in the 2009 Victorian bushfires ?
California frequently has massive bushfires, but with lower death tolls. So, why the diff ? StuRat (talk) 19:27, 10 February 2009 (UTC)


 * It wasn't the size of the fires that caused the deaths, it was the unexpectedly high speed at which they travelled. Some described it as like a tsunami of fire.    D b f i r s   19:36, 10 February 2009 (UTC)


 * And what caused that ? High winds ? StuRat (talk) 19:39, 10 February 2009 (UTC)


 * High winds blew embers about, these embers started new fires ahead of the main fire front. There was also a record heatwave, producing more dry fuel for the fire, and I believe that it had been unusually wet a few months ago, leading to lots of new growth which, once dried out by the heatwave, contributed more fuel. DuncanHill (talk) 19:50, 10 February 2009 (UTC)


 * Is the vegetation in Australia (Eucalyptus?) more flammable than that in California? Do weather forecasters and public safety officials give less advance warning of fire danger? Are people less prone to heed warnings and wait until the last minute to attempt to flee? Are there fewer evacuation routes? Edison (talk) 20:12, 10 February 2009 (UTC)
 * Yes: Eucalyptus is extremely flammable and can explode. Extreme droughts prior to the fires, then winds of 120kmh: . Marysville, for example, was destroyed in a few minutes: .  Official fire plans are to evacuate early or stay and defend.  A number of deaths occurred when people fled at the last minute: perhaps changing their mind due to the ferocity of the blaze? Not a totally bad idea (a number of people saved their houses) but it seems the policy which will be reassessed. Various other contributing factors, also: .  Gwinva (talk) 20:31, 10 February 2009 (UTC)
 * There's tons of eucalyptus in coastal California. (Well, strictly speaking tons is a vast underestimate, of course.)  Technically I suppose it's an invasive species; it was brought here I think a little over a century ago.  But by now people like it and don't want to get rid of it, even if it were feasible. --Trovatore (talk) 22:41, 10 February 2009 (UTC)
 * There were reports that a number of the affected areas hit all-time highs before the fire started, including one area that hit 117 F (47 C), which is really scary hot. Most of the areas in California that are prone to fires never get quite that high.  Dragons flight (talk) 20:59, 10 February 2009 (UTC)


 * Death Valley, California is, of course, one of the hottest places on Earth, but you're right that nothing much grows there so there's nothing much to burn. StuRat (talk) 21:11, 10 February 2009 (UTC)
 * Also, but more minorly, the fires hit populated areas a little more than usual - there were extentions of the fires in New South Wales and South Australia, but very few people live in the affected parts. - Jarry1250 (t, c) 22:12, 10 February 2009 (UTC)

When talking about temperatures, remember that official temperatures are always shade temperatures. The actual temperature outside, in the sun, was more like 60+ C (= 140+ F). (Hell, it was 50 C outside my place, and fortunately I'm well away from the nearest fire; not that we haven't been significantly affected by it, but I'm not complaining). Add that to hurricane-strength winds and incredibly dry vegetation and you've got a major problem. There's been a lot of speculation about why, understandably. That's why there's going to be a Royal Commission, to put all the facts on the table and make sure this can be avoided in future. The irony is that the confluence of extreme factors on Saturday may never happen again. -- JackofOz (talk) 22:40, 10 February 2009 (UTC)
 * You have to be careful when talking about temperatures in the sun — it's not always so clear what is meant. It's difficult to measure the air temperature in a sunny place, because the sunlight warms the thermometer, but I doubt that the actual air is that much hotter than it is in the shade.
 * Certainly you get hotter in the sun, because the sun also warms your body, but how much it warms it depends a lot on what you're wearing, and is not well captured by a single temperature number. --Trovatore (talk) 23:39, 10 February 2009 (UTC)


 * The dryer the vegetation you burn the better the chances of getting a firestorm from a fire.76.97.245.5 (talk) 03:50, 11 February 2009 (UTC)

One factor that certainly contributed to the death toll was that it happened on a Saturday, when people were at home. Had they been at work (in Melbourne for example, unless they worked close by), they'd have been safe. -- JackofOz (talk) 00:59, 13 February 2009 (UTC)

Be a good egg and answer this Q...
On Quincy, M.E. I saw them using chicken eggs as a bacteria culture medium. Are eggs still used for this ? If not, when did they stop using them ? I would think eggs would be less than ideal due to variations from egg to egg and them not being guaranteed to be sterile. StuRat (talk) 19:42, 10 February 2009 (UTC)


 * Eggs are still used as a cost-effective growth medium for certain cultures that need to be mass produced. The most common is probably in the manufacture of influenza vaccine (which is a virus not a bacteria, but you get the point).  I would expect that eggs themselves would be unlikely to be used in first-world hospitals or labs these days, though there are a variety of culture growth media that are partially derived from processed and sterilized egg products.  Dragons flight (talk) 20:17, 10 February 2009 (UTC)
 * Although not extremely detailed, Egg (biology) and Ernest William Goodpasture may be of some interest. cheers, 10draftsdeep (talk) 21:14, 10 February 2009 (UTC)
 * Following on Dragon flight's comment, this page has interesting details. --Scray (talk) 22:34, 10 February 2009 (UTC)


 * Yes - eggs are used in vast numbers on industrial scales for doing this. They are used for virus vaccine production because a virus needs a living cell's DNA/RNA in order to reproduce - they can't do it by themselves.  On the other hand, bacteria can be produced in non-living material like agar (which is made from seaweed) because they can reproduce by themselves if they just have enough nutrients.  I presume eggs are better than other living animals because they don't have to be fed or anything and they are easier to keep sterile.  SteveBaker (talk) 23:49, 10 February 2009 (UTC)

do French and United Kingdom has same watts plugs?
Dear Sir/Madam,

Do I need only to the convert plug bceause French and United Kingdom has the same watts ??

In the wait for your response, —Preceding unsigned comment added by 82.120.236.246 (talk) 22:42, 10 February 2009 (UTC)


 * Do you mean volts? If so, yes, the whole of Europe (or maybe just EU) is 230V (+/- 10%) now. Watts depends on what current is being drawn - the maximum you can draw from a standard UK mains circuit is 13A (so 230*13=2990W), I expect France is similar, if not the same. --Tango (talk) 23:02, 10 February 2009 (UTC)


 * Volts and Hertz are mostly what matters - but you'll be OK in the UK and France. The plugs are different shapes but that's really all.  The amount of power you can pull from the socket varies from outlet to outlet.  In the UK, most house circuits are setup with thick enough wires and big enough fuses to allow you to pull 13 Amps (which - as Tango points out - is 2990 Watts).  I doubt that France is the same - but it may vary depending on the age of the house.  Basically - unless you're planning on running something HUGE like a refrigerator or washing machine - you'll be OK with nothing more than a converter plug.   The worst that could happen would be that you'd blow a fuse in the house circuit. SteveBaker (talk) 23:38, 10 February 2009 (UTC)
 * Forgive me: there is not much use answering a tentatively phrased question with mention of Hertz (applicable to alternating current power sources) if you don't explain what that means. It is also a good idea to provide links.
 * For the basics concerning electricity, see Electricity. For power-supply characteristics in various countries, including voltage and frequency (for alternating current), see Mains power systems. For types of plugs in use, see AC power plugs and sockets, which covers most supplies. For DC plugs, see DC connector.
 * – ⊥ ¡ɐɔıʇǝo N oetica! T– 05:13, 11 February 2009 (UTC)
 * From this side of the pond, it seems surprising that France and the UK would have any consistencies. Has the Common Market been that effective? Edison (talk) 06:13, 11 February 2009 (UTC)
 * I don't think it has much to do with the common market. Most of the world outside of the Americas, Japan, Taiwan and evidentally a few Arab/African countries, has been for a very long time 220-240V with 50Hz (see this map File:WorldMap Voltage&Frequency.png). The EU has harmonised it to 230V with a big enough error to allow 240V but for most devices, the difference in voltage provided the voltage didn't vary too much from 220-240V was never a big problem AFAIK. Plugs have been more variable File:WorldMap PlugTypeInUse.png but the difference often isn't significant since you can use a passive converter in most instances. As mentioned by SB, the plugs used in the UK, as well as a number of Commonwealth countries are capable of providing 13 amps, as should the sockets, this is the only difference likely to be of significance since most other plugs don't support that high a current (the ones in NZ & Australia for example only support 10 amps) Nil Einne (talk) 08:31, 11 February 2009 (UTC)


 * Questioner, amongst all this learned stuff the answer is YES!. You only need to adapt the plug. I say this as someone who has travelled to France and used my English electrical equipment with no problems after using a plug adaptor. Richard Avery (talk) 08:47, 11 February 2009 (UTC)
 * Didn't we already say that? :-P Nil Einne (talk) 09:55, 11 February 2009 (UTC)