imatfaal

Yes - in that gift-wrapping stops being a chore which preludes the fun of giving and becomes a pleasure in and of itself. I think so - the obvious effort that has been expended is always appreciated. And if I stop now... It is not that easy to get apart without ripping. But you can judge the closeness in genetic heritage by the amount of care taken. I use cheap paper so there is no point in being careful to reuse. For wedding presents I use Elephant Hide type paper which once the obvious bits are tugged will open up almost automatically - this takes a lot of effort but is worth it. I re-wrapped one wedding present box with all the cards and greetings for the Bride and Groom inside - they sent me a photo of them in tears rereading these on their fifth wedding anniversary; it has since been re-re-wrapped I did once use glue when a nephew swore that he had learnt the process and was going to unwrap completely and then re-wrap. But the idea of covering a present with expensive paper and then covering said expensive paper with sellotape is anathema. I think the whole tapeless thang comes from my parents' reluctance to rip any paper - their formative years were during the rationing accompanying the second world war and waste was just impossible then

Each part is (a+(n-1)k+1/2(n-2)(n-1)m)^n so the sum is Sum from 1 to i of (a+(n-1)k+1/2(n-2)(n-1)m)^n I assume the pattern continues e = d + k4 etc and k5=k4+m [latex]\sum_{n=1}^{i} \left(a+(n-1)\cdot k+\frac{(n-2)(n-1)}{2}\cdot m\right)^n[/latex] [latex]\sum_{n=1}^{i} \left(a+(n-1)\cdot k+\frac{(n-2)(n-1)}{2}\cdot m\right)^n[/latex]

I never use tape - that's for amateurs. Just use a bit* more paper, buy fairly regular-shaped presents, and tuck the paper into itself. I have had requests for empty boxes to be re-wrapped once the goodies from inside have been removed - "just cos it is so cool that you cannot see the joins and there's no sticky-tape" I blame William Gibson... *OK - about twice to thrice the amount for normal wrapping

not sure I agree with the idea But x^2+y^2 = constant will lose both dimensions r=constant +constant*(theta) will lose neither - but I am not sure it can be easily expressed in rectangular coordinates

Sorry - but just no. If AB=BC=AC then it MUST be an equilateral triangle. And 60 degrees does NOT equal 1 radian - it is almost 5% out. That is not close enough.

Phi you might be interested in the legal niceties of excuse and justification. These act as defences against conviction and seem the same at first glance; an excuse is a judicial acceptance that whilst the act was committed there existed circumstances which mean that the accused should be excused whereas a justification means that no morally/legally culpable act was actually committed as the actions were justified. For example in the case of a homicide - a mental disorder might provide an excuse whereas legitimate self-defence would provide a justification. The rule of thumb is that society would grundingly accept the commission of an excusable act but would almost encourage the commission of a justifiable act

To define something in the way that you have requested requires a lower level of agreed axiomata - physics does not really have this. Time is what clocks measure - we do not define it in terms of anything more fundamental as physics does not recognise/understand anything much more fundamental. As an analogy I would say that you are asking about what is the number 2; in maths we have created very low-level axiomata (the peano) which can answer this and thus describe numbers, operations, logic etc in terms of simpler (?) ideas. In physics we do not have that group of simpler ideas because there needs to be an empirical evidential link - and at present we have nothing that we can measure which is more fundamental than time (or distance)

Red Mercury is a hoax / confidence trick https://en.wikipedia.org/wiki/Red_mercury This is a new story - Red Mercury has an E-number E251 and is used to maintain the pink colour of bacon and sausages; and now to part fools from their money by making mercury red

Post punk- not punk. You can see what Ian Curtis was like in film biopics "24 hour Party People" and "Control"

Been stuck in one of those since 1993!

No thanks - would almost certainly be above my head. Thanks anyway

Ignorance is never an offence, but acting in a manner proscribed by law in a state of ignorance can sometimes (almost always) be an offence. Some laws in some jurisdictions will use a reasonability test, others will look at could not know versus did not know, yet other have a criminal code which is presumed to be known, and yet others make it up on a case by case basis. On the whole, as swansonT said - it is presumed that there is knowledge of the law. The code based law countries use the ancient maxim that ignorance of the law is harmful; ie that individuals are taking risks by acting without knowledge of the law. The presumption in common law countries that people are aware of a correctly promulgated law is normally irrebuttable. If you know you are innocent - then you must have considered that there is a guilt-innocence calculus in play; therefore most courts would have expected a reasonable person to have checked before acting. Ignorance is often only considered mitigation in sentencing when it can be shown that there was lack of knowledge/understanding that the action was the subject of legislation in any form or even of societal disapproval. Ignorance can also be a factor for mitigation if this ignorance was non-culpable

Glad my old memories have helped. From a physical view (ie more physics as the science than anatomy) you could also think about the relationship mathematically between angular velocity and net torque. I would avoid getting too tied up in the vector notation etc but getting your head around angular velocity, and importantly the link between change in angular velocity (ie angular acceleration) and net torque would be very useful. But a word of warning - analysing any biological systems movement in terms of classical mechanics requires a big dose of simplification and even then it is complex

When you are talking muscles acting within larger groups I think eccentric and concentric are used as follows -Concentric: when a joint is flexing and the muscles in question are shortening (ie agonists to the flexion) or when a joint is extending and the muscles are extending (I would hazard an example as biceps and lifting a weight by flexing the elbow for concentric flexion, and triceps (some of it) in extension -Eccentric: when a joint is flexing and the muscles in question are lengthening (ie antagonists to the flexion) or the joint is extending and the muscles are shortening (this is less usual and harder to grasp - it only comes about with other muscles or forces involved. The best example is the squat - your hips and your knees are both flexing but both Glut Max for hips and Quadriceps for knees are working against this motion (ie they are antagonists); the motion is caused mainly by gravity - GlutMax and Quadriceps are controlling and slowing motion. This is much more complicated in the running pace - but the same idea applies. You have to consider what is happening to the knee joint (ie its rate of rotation) - and why at every moment; is it moving because of muscle action, because of inertia (of both the lower leg and/or the body), through action of gravity, or a combination of all the above. Function will stroll by soon and set me right To explain the graph - the dotted line is the angular velocity which is in radians per second (ie the change in angle over time). When the line is below the axis the knee is flexing - ie the foot is moving clockwise with respect to the knee. When the line is above the axis the knee is extending - the foot is moving anticlockwise wrto the knee And my guest for my next meeting have arrived and I have to leave it there

Mordred - you know these data far better than I do; didn't Planck allow for flat or +ly curved within the margin of error?

1. Would have all been energy - matter formation was later. Total mass/energy would not have changed (I think) 2. 10^53kg of normal matter

! Moderator Note OK - I am close to calling a halt to this thread. Assertions like the above have no place in a physics discussion; if you have any form of proof that the electron is not fundamental then post it - if you do not (and this is almost certainly the case) then do not use such an assertion in your argument. The reason for this rule is that any argument can be made and supported if members are just allowed to make stuff up as they fancy it. So from now on please ensure that statements are backed up, or at least capable of being backed up; if you find this impossible then it is a fair hint that your position in this thread is untenable. Do not respond to this moderation within the thread.

I think you are crossing the line into philosophy. Free will is not agreed upon, either existentially or definitionally, by most disputants in this area.

I can dig out my old copies of Last and Snell and give you some Anatomy pop-quizzes if you are that nostalgic

! Moderator Note branch on dark matter planets split off to its own thread

Not that I have heard - neither mirror matter, antimatter, or even normal matter has that characteristic. Anti and Normal will annihilate. Mirror and Normal will interact only gravitationally as neither the strong, nor weak nor the electromagnetic will have any effect transmitted by the mirror gauge bosons - gravity / the graviton is its own mirror boson and thus will have effect Not that I can tell - I don't think there has been a great deal of progress on finding the DM particle*. If it is weakly interacting massive particle that would be hard enough - but mirror matter would be even harder to find. * note the last paper suggesting this listed by wiki is 1995 - so maybe unfashionable rather than disproved I think the idea is that they would be invisible to US and would only affect US gravitationally - to themselves everything would be normal

! Moderator Note Sorry - but that many links is going to put off members. There is a tutorial here to allow you to post the images http://www.scienceforums.net/topic/73369-uploading-images/ And - we do not do homework for you, we help you with your study. Put down your ideas and members will aid you

Lovely lateral thinking. We might as well do one pointing straight up as well - although as SwansonT mentioned that we have already commpared switching from vertical to horizontal slits I guess we have already tried slits perpendicular to the earth's surface

It is highly unlikely for dark matter to clump together.* It is gravitationally attracted to itself - so like normal matter, it will tend to draw in but, and whilst this seems a minor quibble it is important, it has no easy way to lose its kinetic energy, momentum, and angular momentum. Normal matter is able to dissipate energy by way of heat and radiation after an interaction involving the electromagnetic force; two things bump into each other, release a photon or a more, move away from each other more sluggishly; lots of things bounce about and get hot giving off infrared; etc. Dark matter does not interact in this manner (if it did we would be able to see it glow and we wouldn't have called it dark) and thus it forms lose ever-moving filaments, halos, and clouds rather than the more solid stuff required for planetary formation. Very simplistically, DM has no obvious way fo slowing down; so whilst it may be attracted to other bits of DM it will not be able to get together with them - but will end up in an orbit with them. * But as we don't know too much about dark matter any notion in this area is pretty speculative If you wish to continue this line of investigation - we will split this off to a new thread (pm me and I will do so)

You are right it cannot - but it is closely related. The gravitational wave is, in effect, a change in gravity (g); we can look at this as the difference in gravitational attraction (g') between two test objects as time changes. This difference in gravity is, of course, also an acceleration; if we integrate this acceleration twice with respect to time we get the strain (h) - which is what we actually observe and is the amplitude in most of the wave equations regarding gravitational waves. [latex] h=2 * \iint g' \cdot dt^2 = 2 * \frac{change\ in\ displacement}{displacement} [/latex]