Royston

Same...I want a fried shrimp T-shirt. Exactly, I wasn't being sarcastic. It's deliberately crap (though I wouldn't class it as such), the film is a comedy, it's a blatant parody. I admit, I was a bit tentative about posting it on here, though I knew some of you would 'get it.' I made sure to mention, it wasn't to everybodies taste.

I'd personally be careful with 'gravitantionally bound', think of galaxies undergoing a dynamic slingshot type of effect. It depends on the velocity of the galaxies, and their trajectory. True, but Andromeda is a simple (observable) case, now try applying the same principle, to less obvious cases.

Not a fan of fried shrimp...fair enough.

If you havn't seen this trailer already, for 'Robogeisha' (though not to everybodies taste) click on the link below. The narration does for it me. It's a tad graphic in places

Well, how do you think super clusters were formed, that will give you a hint. AFAIK, it's quite hard to determine whether some clusters are truly isolated from superclusters, i.e expansion isn't necessarily between all (10 million or so) superclusters. I'm pretty certain there are a number of isolated examples. Maybe someone knows better. Merged post follows: Consecutive posts merged Oops, should read 'all expansion isn't necessarily between superclusters (AFAIK).'

I'd go with the latter, it's all a matter of perspective, blah blah blah. However, as much as I love the subject (physics that is) and it was my choice to study it, for all I know, I could be happier raising llamas on a small farm. I simply don't know or will ever know. Well, I'd know with that particular example, (llamas all the way), but you get the idea. Just to add, since when has anybody been too old to study a subject ? I wouldn't class myself as old per se, but reasonably ripe at 32.

That's true, I wasn't really picking holes in the analogy itself, more, it could have been misconstrued by somebody new to the subject. Still, that was a nice afterthought / elaboration, on your part.

Unfortunately, it remains a mystery, my friend studies the subject, and has been fossil hunting for some years. I haven't received any further feedback. Part of me quite likes the idea of owning a curiosity, but it would be nice to put a name to a face, albeit it has no face, or even a head for that matter.

I think that's rather misleading, because it implies collisions based on likelihood rather than distance, and forces et.c buzzinfinity, I'm sure you know the electrostatic force is stronger than gravity. So, when you rub a balloon against your head and stick it to the ceiling of a room, you can see that the electrostatic force overcomes the gravitational force of the Earth. However, if you repeated the same experiment, and held the ballon a metre away from the ceiling, it would fall to Earth, because it's too great a distance from the ceiling, i.e gravity then governs the direction of the balloon. Now just apply that to two galaxies, if they're close enough, they're gravitational forces bring them together, too far apart, and dark energy overcomes the gravitational force (as it's too weak at large distances) and they are then subject to the expansion of space between them instead.

This has (since studying physics) bugged me, it's a stochastic process. If I assumed an ideal system where I could get a series of measurements, i.e a number of eigenstates over a period of time, I could trace back a history of those events, so they appear determined. However, the next event I wish to measure, to add to this series, is subject to probability. It's bugged me, because it sticks the act of measurement, in a position of central importance, but the laws of physics play out without observation. Which, I thought recently, that the first paragraph, is more a mathematical consequence, over an observed phenomena. But I'm not sure.

I might possibly, be barking up the wrong tree, but for a given set of vectors...[math]q_1\bold{v}_1+q_2\bold{v}_2+q_3\bold{v}_3 = \bold{0}[/math] The set is linearly independent if (trivially) [math]q=0[/math]. So, surely you'd need to define the interval of [math]x[/math], for the set of those two functions ? EDIT: I misread, you're asking for a definition. I'm a bit confused by this (possibly beyond my scope), plus, why are you asking ? Is this a brain teaser of some sort, or are you expecting somebody to do your work ?

It's more than likely that Robins Williams can't pull off an English (whatever region) accent, and that American twang made him sound Scottish. In any case, what sounds distinct if you live in the country, is almost undetectable if you don't. For instance, I can differentiate between a Kiwi and an Oz accent, but when it comes to regional accents of the two countries, I'd have no idea. I'm sure that would sound incredibly silly to somebody who lives in either Australia or New Zealand, but I find it equally silly that somebody can't tell the difference between a Yorkshire and a Birmingham accent. As a side note, if you're used to hearing an actor with a certain accent, and then they try to adopt a foreign accent, you instantly look for flaws. As an example, Andrew Sachs who was famous for his role in Fawlty Towers, sounded bizarre when he started narrating nature documentaries, because he has a very refined English accent in reality. By the same token, Hugh Laurie who plays House, sounded grating when I watched the first few episodes, because I was so used to hearing him with a bumbling toff accent. Out of interest, which State does House sound like he comes from (compared to where he's supposed to come from), and does he do a good job ? I always thought he sounded a little generic. Practically everyone who I've met from the States, who tries to pull off an English accent, sounds like Dick Van Dyke in Mary Poppins.

For anybody who hasn't already signed, or is even aware of the BCA libel case against Simon Singh, please click on the link below... http://www.senseaboutscience.org.uk/index.php/site/project/333/ Thankfully the debate has reached the House of Commons, but any extra support, in giving freedom of speech within the scientific community and beyond, is a petition worth signing for. The full story is available through the link above.

Thanks for the suggestions Mokele, but I still can't find any similar examples. There's a couple of paleontology websites I've come across where you can submit photographs for identification, so I'll give that a go. My housemate posted this is on our Uni forums, and one suggestion was a Hamite, but all the Hamites I've looked at have a threaded (like a screw) shell, and even if flattened, the symmetry of the ridges wouldn't be straight line segments. If I get any feedback, I'll be sure to post it. EDIT: well my housemate has just shown me a Hamite that has symmetrical ridges (as opposed to a screw thread) but it doesn't explain the central divide, running along the length of the fossil, or the possible third segment that may have broken off (or if it does indeed curl round.)

I recently went fossil hunting with my housemate in Folkestone (Kent, south coast of England), and I was wondering if anyone could help in identifying this find. The period is Cretaceous, mid possibly lower Albian, and the fossil is embedded in gault clay. At first glance it appears to be a fern, but the white coating is the same material as shell fragments found in the same slab, so calcite or possibly calcium phosphate. Note how the lower end curls round, and a series of smaller decreasing ridges can be seen on the right side, going back up. I've scoured a number of websites, but I can't find anything remotely similar. So, any ideas ?

Thanks DH, and sorry grandpa....I literally just walked out of a 3 hour physics exam, so being quite brash. I've only just got my head round solving partial differential equations, so sorry about that.

Not very convincing grandpa, you've regurgitated something you've read, without understanding it. Classically, rotation can be described with polar co-ordinates (personal preference), so your first statement is flawed i.e it doesn't require 'pairs of axes'. No mention of quaternions (at this level), how come ? You can 'describe' rotation in any way you choose, be it a differential equation, a matrix, whatever...I'm getting the strong feeling you're just arguing for the sake of it.

Well perhaps you could run us through it then granpa, AFAICS the question has been answered, but for some strange (troll like reason) you beg to differ. So, for the viewers at home, explain how a hypersphere rotates.

I took the plunge myself, and like you buttacup, I was programming BASIC at a very young age. So, due to a recent redundancy package, I decided to buy an all singing, all dancing PC...this thing is sick, it has two 1 gig graphics cards, so I could run a PS3 Emu if I felt like it, a heavy quad core processor (equivalent of 14 Ghz) and a 22" TFT monitor. It's indulgent, I know, and I feel slightly guilty for buying it...my programming ability is null, but I can't wait to run maple through it, and my current PC will be dedicated to running Cubase and an OS (and that's it). The former is mainly for games, when I'm bored, but a math platform, with those graphics capabilities, will be very useful.

Even if you were referring to an n-sphere, your answer still makes no sense.

In reality, of course it can, but it entirely depends on inertia i.e how the mass is distributed, so you're constricted in some sense (i.e an ideal sphere will be limited), but spin a ball, then kick it, so it's spinning in one direction, and another. Due to inertia, the axes of rotation are different. Mathematically, a sphere can have as many axes of rotation as you wish. That makes absolutely no sense whatsoever, a sphere is two dimensional for a start.

As an example of something I covered a while ago on my current course, and this was basic population modelling was using the Lotka Volterra equations, which are very straightforward, but you need to understand vector fields, how to solve partial differential equations, systems of differential equations, and be familiar with matrices (the Jacobian in this instance.) I'm not sure if any of that sounds a little scary (it's not that bad), but it just illustrates how many different methods are required even with something that basic. So a sound grasp of a number of techniques would definitely be beneficial, and give you a much deeper understanding of a given model.

What a strange question, the point of a Lorentz transformation is it's frame dependent, so although Galilean addition works at small velocities (as I'm sure you know) they're not frame dependent, so that's an indirect answer to your question. But anyway...explicitly, no.

I was replying to a completely different forum and question, not sure how that happened....sorry about that.

My initial idea was use the chain rule, have you tried solving it with a matrix ? Try separating it with a matrix, you should end up with two differential equations.