Ollie

No, commonly people say "respiration" when they mean "breathing" but respiration is the process by which an organism obtains energy. Sunflowers can't grow that fast, though I'm not sure of the mechanism by which they turn, but there are other example. Venus fly traps snap shut when triggered, some trees will turn leaves to avoid/follow direct sunlight. Some curl up when touched, or even approached.

Respiration doesnt have to result in oxygen, and in fact many plants reverse photosynthesis and burn oxygen while producing CO2 at night. And plants can move too. The french for sunflower is (I believe) tournasol as they will move their heads to follow the sun through the day.

In the UK, the answer to that question, as taught up to A-level (I don't know what they say there, or even if they ask the question, as I didn't take it) is generally something along the lines of the GRIMREF, MR GREEN or MRS GREN acronymns. Using GRIMREF, all living things should: Grow Reproduce Irritate (have senses) Move Respire Excrete Food (eat) That's probably not a conclusive list, but it's a fairly good starting point.

I've just found another one: http://maps.google.com/maps?q=33409&ll=26.803894,-80.130072&spn=0.032530,0.042658&t=k&hl=en Shouldnt be. Any water should evaporate off, and any optical enclosure would probably be kept at a vacuum too.

Eh gads! They're multiplying!

Area 51 No UFO's though

All the free electrons in a wire are bumping around at high speeds anyway. By applying a voltage to the wire a slight force is applied to them, causing them to tend to go in one direction slightly more. The sum of this effect is called their drift velocity, and is generally on the order of 10^(-4) ms^(-1). It just seems near-instantaneous because the driving voltage propogates at the speed of light.

They don't fuzz the google images. The White-house is just blocked out, and area 51 is left totally alone. At this level of zoom it would have to be a veryveryvery small thing on the camera, and the fact that it's lit casts large doubt on that for me (why would there be a light in a high-resolution camera? It would only introduce noise). It would have top be a huge balloon, as there have been blimps caught that are smaller. Dunno if anyone else has noticed, but there appears to be a small dent on the top-right of it.

Wouldnt he have published it in a journal?

This kinda reminds me of a current balance experiment I performed a couple of months ago. Two magnetic fields (generated by coils) at right-angles to each other. One is fixed to one end of an arm of length l with a mass at the other end, you get: I^2=mgl(2a1)/{(mu0)(n1)(n2)(A2)} where I is the current flowing through both coils (they're connected), a1 is the radius of the larger coil (it was oriented with its direction vector pointing off to one side in our experiment, or maybe "forward", I forget), n1 and n2 are the numbers of turns on the coils and A2 is the area of the smaller coil. By adding mass, the smaller coil is forced to rotate in one direction, but the opposing magnetic fields generated by the current resist this motion. By tweaking the current until the arm was horizontal again we could check the current predicted by the above formula with that oberved. Typically the current we observed was in the rage of 1 to 4 Amps. While this set-up itself is not quite what you're looking for, it's something to consider.

Phew, panic over. He really shouldnt run around scaring people like that.

I saw this the other day: April, 2002. Attacks some arguments I'd never seen before. Quite an interesting watch, as Sky at Night always is.

What about Hidden Faces in a Stack of Squares or Pythagorean Triples? Both of them can easily stretch to 25 pages.

8. puffball?

Dredging from my memory, could this be the "Twisted Light" article that New Scientist ran a while ago? Not sure at all though.

http://www.hackaday.com might provide inspiration. Of particular note are the IR webcam, solar death ray and (more recently) the hamster powered MIDI sequencer. While they're not all directly physics, chemistry or biology related, they are things to do on a rainy day.

I think I saw in New Scientist some time in the last couple of years someones made a small combustion engine. I doubt it was quite nano-scale, but surely a step in the right direction.

They aren't dimensions like various sci-fi shows would have you believe. The easiest way to think of them is as extra degrees of freedom. Everyday experience of a dimension can be summed up by, for instance, making a delivery to to Room 218, Big Building, Townsville. An address tells us a rooms position in 3 dimensions. If you wanted to send lots of packages, but didn't want them to all arrive at once (swamping the confused receiver), you would send each one with a different delivery time (spacing them out in a fourth dimension). If you still needed to send more parcels, you could attach properties such as "colour", "smell", "taste", "texture", "monkiness" etc to them, so that no 2 parcels with the same colour, smell, taste, texture and monkiness can be delivered to teh same place at the same time, but an entire spectrum of parcels, or a 4-course meal of them, could be received. The 11-dimensions (actually, they include our everyday 4, so there are fewer) are so small that they cant really have any meaning attatched to them, other than as mathematical properties that allow strings to oscillate in the variety of complex ways they need to in order to create the physics we observe.

Howdy all. Firstly, apologies if this is in the wrong sub-forum. Now, On with the question! I've recently been reading through Marcus du Sautoys "Music Of The Primes". It's a great book, I thoroughly reccommend it to anyone wanting a book to read. I've been keeping up with what the maths ok so far (precious little that there has been), but one thing's bothered me. There's a chapter about Srinivasa Ramanujan, where it says that in his first letter to Hardy and Littlewood he wrote the line 1 + 2 + 3 + .... + n = -1/12 where n is infinity. Yes, I know it looks crazy. Apparently it took H&L an evening or two to work out that he really meant: 1 + 1/(2^-1) + 1/(3^-1) + ... + 1/(n^-1) = -1/12 According to du Sautoy, this makes perfect sense. Now, I'm the first to admit that sums of series have never been my strong point, but this can't be right, can it? Surely the two lines mean the same thing, and the answer is wrong? Apparently this is a solution for zeta(-1), but no matter how I look at it, I always get infinity. What am I missing? On a related (I think) note, would anyone be able to tell me what the evaluation of x^i is? My blind faith that there is a proper answer to that (which is somehow negative) is all that keeps me thinking I understand the Riemann hypothesis (even just a little). If not, then I've got to go back to the drawing board Many thanks from a newbie, Ollie