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I'm going through this at the moment, or actually I've already applied a few weeks ago, but I just did it! One thing I found quite useful was to compare entrance requirements. If I think I'm capable of AAA then I'd want to apply for a university asking for around those grades. As a big generalisation the better the university the better the grades it will ask for, so if I'm an A-student then it would probably be better for me to go to a university offering AAB than one offering CCC. So if I were you then I'd knock a few off if they offer low grades relative to what you think you'll get. Otherwise if you want to post your list then I can look through them and see what I think of them, I've applied for physics, but when a university is good at once technical/science subject it is generally quite good at others. Or you could PM (private message) them to me if you don't want to list all your unis in public, where the uni could see them. Also the Time League Table can be useful. See here: http://www.timesonline.co.uk/section/0,,6734,00.html for a subject specific version of the Times League Table: (non-subject specific) http://www.timesonline.co.uk/section/0,,716,00.html And obviously there's the two main things: 1) Do you like the course? 2) Do you like the university?

In trying to explain the idea of a probability wave I'm going to assume that you know about Young's Double Slit experiment. If you don't then this will not help you. When you think about a light wave going through both slits at the same time there is logic in that one wave can go through two slits, however when you think about it in terms of photons it no longer makes sense. How can a single particle be in two places at once? One way of looking at the situation can be to imagine that the photon is fired, and as soon as it's fired it disappears and is replace by a probability wave. This probability wave goes through both slits. When the system is observed (maybe it's a detecting screen after the double slit, or a detector on one of the slits, whatever it is) the probability wave disappears and the photon reappears somewhere, randomly, but depending on the probability distribution that the probability wave gives. The probability wave explains how probable it is to find the particle (photon in this case) at any point. It is not a physical entity.

Glad to see the problemo is sorted, and I wouldn't have suspected anyone from SFN would ever do something like that, but better to be safe and check. herme3: that type of encryption is fairly safe, however if you were to give me an encrypted password like that I could discover the password via a method known as brute force. As you cannot decode that you basically have to try every single possible combination of letters and numbers until you get it correct. To speed up this process there are big tables listing precalculated passwords/codes. The ultime exaple of this is a 64GB table which can crack any password up to 14 characters long using any possbile characters on a standard keyboard. It would take any one computer years to calculate this, but as all the data is stored in this 64GB table, all a computer has to do is search through the table, which takes a few minutes. Having said all of this I will conclude by saying that md5 is about the safest type of encryption and is used on all Windows systems (well, all the recent ones anyway), and don't worry about people brute forcing your database of passwords.

OK, now I don't know how much you do know about Feynman diagrams, so I'll start at the basics. (excuse my Paint skills in advance!) The following shows a simple Feynman diagram. It shows an electron (e-) and a positron (e+) coming together and annihalating, this produces a photon (the squiggly line). However this high energy photon can have more energy than that of an electron and positron combined. Consequently there is no reason why that photon could not just randomly turn into an electron/positron pair. This pair will then annihalate each other very quickly, as shown in this Feynman diagram: They are known as virtual as they do not exist as an input nor as an output to the annihalation process shown in the Feynman diagram. However who's to say that this process only happens once? In this diagram: the resultant photon splits into an electron/positron pair twice and before the annihalation the electron interacts with itself via a virtual photon. I can't remember what process this was originally noticed with, however initially calculations of some process were quite accurate, however not precise. When the calculations included one loop (a virtual particle or pair) the calculation became more precise. With a 2nd loop it became even more accurate etc.. The calculations are however extremely complex and require supercomputers to compute. This is a good proof that virtual particles to exist, as including them in equations allows us to get answers which agree with experimental data. ===== There is one other experiment that is very relevant, and I think this is one of my favourite experiments. It's called the Casimir effect. Imagine two plates parallel to each other and very close to one another. These are uncharged, in a vacuum and we can ignore gravity, so you would have thought there was no force between the two plates. However there is. It's very small, but noticable. This is known as the Casimir effect. The explanation of this force is that around the two plates you have a 'normal' amount of virtual particles. However between these two plates there is a very little area for virtual particles to exist in. Very simply there is not enough room for 'big' virtual particles to pop into existence between the two plates. As there are less virtual particles between the plates relative to the outside of the plates there is a pressure difference, which means that the plates feel a very small force pushing them together. A great visual of this (found through Google Images, hosted on wikimedia) is this: There's a good analogy of the Casimir effect here: http://en.wikipedia.org/wiki/Casimir_effect#Analogies (the 2nd para, about ships in the ocean)

I had that the other day when the clocks went back 1 hour. I thought it was 1pm on Sunday and that I should go down for lunch, even though I had loads more work to do. Then I suddenly realised that I hadn't changed any of my clocks, so it was actually 12! It was a great feeling, just suddenly gaining an hour in the middle of a work-filled day.

It's a shame they couldn't think of anything more painful, in my humble opinion. It's also seems a waste of time that they took so long coming to that decision. You can see I'm not going to become a lawyer.

The net force is given by: [math]F_{app} - F_{friction} = F_{app} - \mu R[/math] where R is the reaction of the chair on the floor. We know the chair is on a level floor from the question, so R will be equal to mg (weight of the chair), therefore: [math]\mu R = \mu m g[/math] Substituting in the numers give us: [math]335 - 0.330*9.81*m[/math] Now by using F = ma [math]335 - 0.330*9.81*m = ma[/math] and a = 0.722 doing a quick rearrangement (all the terms with mass in them moved to the right): [math]335 = m(0.722 + 0.330*9.81)[/math] and then the final rearrangement to get an expression for mass. [math]m = \frac{335}{0.722 + 0.330*9.81}[/math] therefore m = 84.6kg

Ah, dave, good point. It's points like that I need to pick up before I go laptop shopping in a few months time!

Well that's kinda why I want to read it. I grew up (until say 10yrs old) unreligious, then my family became religious, and so did I. But a year back I started becoming less religious. I didn't believe it, didn't believe in god, it was good socially, meeting new friends etc. but I guess in my mind in any science/religion debate science always win. I do agree with what you said in your quote, and that's why I want to read it. Just to rempasise the point in my own mind. That's not my point. I specifically said I believe it didn't happen. I just said that I thought the argument was a bit weak. You can't say "its more likely you're wrong therefore you are wrong".

There's a double of this over here: http://www.scienceforums.net/showthread.php?p=308934 Igor: please don't double post psynapse: yes, we have smart boards in every room at school! Or every classroom anyway.

Erm, interesting. Try deleting all your cookies and Temporary Internet Files.

Reminds me of a great experiment, it is the quantum version of watching a kettle boil. That is, they excite electrons from one state to a higher one. However if they observe the electrons whilst they are being excited then they cannot change state whilst being observed. Instead of trying to explain the experiment in detail I've scanned in 3 pages from Schrödinger's Kittens and the Search for Reality, by John Gribbin, which gives details of the experiment. First page: http://img.photobucket.com/albums/v601/5614/quantumpot1.png Second and third page: http://img.photobucket.com/albums/v601/5614/quantumpot2.png Incidentally this is an experiment that produces the results it does due the quantum Zeno effect. If you don't understand yet then you may want to understand it before you read through that. Ask here if you have any questions!

That's pretty impressive software. That type of whiteboard is quite common now. Where the whiteboard acts as a touch sensitive screen for a computer. Although it's only touch sensitive to special pens. What's clever about this is not the whiteboard itself, but the software which can tell whether the user wishes to draw a wheel (circle) or attach that wheel to an axel (a smaller circle), or group something (a big circle around it all). After that it's quite simple again. I remember playing puzzle games when I was much younger where you had to move bits of wood etc. so that the balls would end up in the right place. You could even create your own levels and all. The point being that the ability for a program to simulate something freefalling isn't very complex or new. I'd say what's "coolest" (to use their word) about that program is the recognition. You may have noticed that when he was drawing the rectangular planes for the balls to fall down that one of the sides was drawn at a very slight angle. Although the shape still had 4 distinct sides, the very small angle made the computer actually interpretted it as a triangle.

1) Good things, but consider Dell as well. 2) Depends if you're going to use it! I mean when I get a laptop I probably would, because then I can connect it to my phone via bluetooth. I don't have a cable for my phone to connect to the computer, so this would be something useful. Like once every one hundred years. But $30, or £15, when you're spending like, well, how much? >$1500? 3) Didn't know they still made 5400rpm hard drives! They're not that bad and I've never run a comparison to know, but 7200rpm is what everybody who has purchased a computer in the last 5 years has. Except some people, who have 10,000rpm. But that's expensive! 4) Not very upgradable. Sometimes a bit more RAM. You can pull out the current CD drive to replace it with a DVD drive.

I like black, but certainly not on a forum! Keep the forum how it is. And bring back that homepage already!!!

You can disable Adobe Updates. On WinXP: Start Run msconfig Startup tab Oh, Abode Update isn't there for me anymore! In that case for Abode Reader 6 open it up, go to the Edit menu, Preferences, then select Updates. You can then change the updates to manual.

I don't get it why they stop wasting money on the browser itself, take an opensource browser like FF. FF could be used as an advertising point, thus boosting sales of Windows, as well as saving money on the poor IE developers. Et voila, problemo solved.

I've got a similar problem to you, and to be honest I don't know. It makes sense that the graphics card power estimates will be a bit higher than required. Remember that as well as the graphics card the rest of the computer needs power. With a fast processor, a lot of RAM and a powerful graphics card working 305W would probably be ok. But if you have two hard drives, a CD/DVD drive and a sound card all going at the same time, it starts to put a strain on the power supply. In your case, like my case, I think we'd be pushing the limits of the power supply unit (PSU). If this happens then the PSU will get a bit warmer than usual, although not a problem (unless you keep your computer on 24/7), but if the PSU cannot supply enough power to the computer then the performance of the computer will suffer. I have no idea how noticable this would be. Basically it's a bit of a gamble. You could buy it (graphics card) and be fine. Or you could buy it, seem fine, then melt the PSU. Or you could buy it and end up buying a new PSU. My decision was that I wouldn't buy anything and I'd get a brand new laptop in the summer, ready for uni.

Woa, this is a very old thread. Please don't bump threads to say something like that christian. [edit]totally agree with woelen (below)

I saw a friend with that book so asked him if I could borrow it, to which he replied "yes, but you're 101st on the list"! So I'll get it eventually. In the meantime I saw an extract from it earlier. Dealing with what Dawkins would call "mass visions". Extract from The Times review on the book He then goes on to talk about how unlikely it is that 70,000 people all had the same vision, yet he says, it is even less likely that the sun crashed into the Earth and none of the rest of the world noticed. Portugal is not that isolated. I thought this was a bit of a weak argument. He's saying that whilst it's unlikely that 70,000 would all have the same vision, he says it's even less likely that what they "saw" really happened (because none of the rest of the world noticed). With this, he shrugs off the mass visions. He doesn't actually deal with why 70,000 might have seen this. Don't get me wrong, I believe it didn't happen, and I know there is no answer as to what was going through 70,000 people's heads, but I don't like his "well it's even less likely to have happened therefore it didn't". Having said that I can't think of any possible explanation, so I think it's unfair to expect it... but it was just my thought on that one extract. Otherwise what I've seen of the book looks alright.

That is correct. The thing with quantum physics is that it does make sense, but not 'normal sense'. If you look at the everyday world around us then the average object is made from a massive amount of atoms and molecules. The quantum effects, which come into play on a molecular level (and smaller), are simply far too small to see on a more normal scale. Consequently the way we think, with objects of an everyday size, would be considered as thinking 'classically'. Now part of the thing with quantum mechanics (QM) is that it is very non-classical. Whilst objects on an everyday scale behave classically* objects on a molecular scale behave quantum mechanically. If you naturally thought using QM (no one does) then things such as quark confinement seem logical. * technically speaking all objects behave quantum mechanically, it's just that once you get to the size of a few cells it is 'too big' for these effects to be of any significance, and objects seem to behave purely classically. Also once you get up to very high speeds (significant fractions of the speed of light) thing which are 'normally', or classically, logical are no longer true. At high speeds you need to think relativistically. Classically you can always apply a bit more force to go a bit faster and so in theory you could go faster than light (this is impossible), relativity showed that the classical theory is incorrect.

It's not only time that warps around large masses (and obviously small masses, although it warps a lot less in that case), spacetime itself warps around mass. A simple way to see this is to follow the path of a photon (light) around a dense planet. A photon takes the shortest route between any two points. Often referred to as a straight line. However when spacetime itself is bent, the shortest route means following the curvature of spacetime itself. That is, the photon would appear to curve through space, even though it is spacetime which is curving, and not the light. So if you look at a dense planet then you can see light from things behind it. Not a long way behind it, because the effect is small on photons, but things which should be just hidden behind the planet can be seen as the photons 'bend' around the planet.

I believe that trick is done by not tearing up the signed card. You could get a little device which is like two pencils attached via a rod. You trace over the signature with one pen and the other pen (which is attached via a rod) will also move in exactly the same way. Alternatively you could get some slow-drying ink. Meaning that when the signed card and a second card are pressed together some of the ink will transfer.

Acceleration requires a force to act on a body. This force can be detected and so it can be shown who is accelerating. Consequently we know that it is Slim travelling at 120mph and not Jim. "force free" motion is motion where there is no net force on the body. That is, the velocity (speed and direction) is constant. When you have a constant velocity relative to someone else you both think that the other person is moving and you are stationary. Technically you are both correct. Regarding friction: when a car moves along the road there is friction acting against its motion. This friction exerts a force on the car, changing its velocity (slowing its speed). When a car moves at a constant velocity there is a driving force (supplied by the engine), which is equal in magnitude and opposite in direction, to the frictional force. So although there is say 10N backwards due to friction, there is also 10N forward due to the engine. The net force on the car is 0, that is the 10N back and 10N forward cancel, therefore the car continues to move at a constant velocity. This is considered "force free" because the net force on the body is 0.

It works very much like an elastic band. The further apart you pull them the harder they resist. Just as when you find the north pole of a magnet there must be a south pole, so quarks come in twos and threes. There isn't technically a proof for that quantum chromodynamics (physics of the strong force) requires confinement to be true, however it is logical, and agrees with all experimental data, that confinement exists.