imatfaal

http://www.bbc.co.uk/news/science-environment-36917174 It seems from early indications that the UK govts initiative to force larger retailers to charge for plastic bags (5p - ie GBP0.05) has had amazing results. First surveys seem to show that UK bag consumption will fall by around 7 billion - ie by an order of magnitude - from 7.7 billion to .7 billion. Hopefully this result is borne out by future checks and the trend continues. http://www.bbc.co.uk/news/magazine-36882799 We get through 2.5 billion disposable coffee cups a year - this seems ripe for a similar measure. Someone reading (especially if of a certain age) will be thinking beer/pop bottles and the deposits you could collect on them as a good supplement to pocket money - this is unfo a nogo due to European competition law (vide Danish Bottles). And all you Brexiteers before you start - it was the UK govt that forced the case and, to all extents and purposes, stopped beer bottle deposits being legal

Surely we were talking about 2d representations of the donut or teapot - therefore you cannot reach out and check. The 3d representation is invariant whereas the 2d depend on the angle of the viewer. Our simple measurements of length and time are analogous to the 2d representations, whereas the invariant space-time interval is analogous to the 3d. To extend the metaphor perhaps too much - there is no hole in the middle of a picture of a donut. ceci n'est pas un pipe

Well at least the metric kangaroo system makes a bit of sense and has common multiples - the mad New Zealand Geologists are still using Imperial Kiwi Units - three Kakapo to the Kiwi, twelve Kiwi to the lamb,1760 lambs to the Rugby Pitch

Turns out my NYC office has a membership of the Botanical Gardens (what sort of office ...?) and quite a few managed to get across to see it - "dreadful, but wouldn't have missed it for the world" http://www.bbc.co.uk/news/video_and_audio/headlines/36929332 worth watching for the little girl with the shades and her description

! Moderator Note Last Chance. Gravitational Waves and the Aether.

http://www.nybg.org/exhibitions/2016/corpse-flower.php#diva Live streaming of the opening of the New York Botanical Gardens Corpse flower. First time they have had one bloom for 80 years - takes at least 10 years to bloom and lasts a day or so

Exactly - but to add the point that the separation distances are hugely under represented on that diagram; to the extent that I don't think the human eye could discern hit or miss. The sun is c.360 times further away than the moon and c.400 times larger - these almost balance so that apparent disc size from earth varies between 31-32 arc minutes for the sun and 29-33 arc minutes for the moon

"To me, reality is what it is in its own frame. It is not a convention, it corresponds to an origin point in a diagram. You put the origin at the intersection of all viewers, and the intersection is at the event of the observed object." From the frame of the muon the Burj al Khalifa is 160m high - I will give you a 200 metre rope and you can try abseiling down it. It is 160m and it is 820m. Length is dependent on relative velocity - the longest you will measure is in the objects rest-frame; there is no datum concrete reality and observational artefact - there is a firm mathematical relationship "For C, which is observed the same in all frames, there is no issue of ambiguity, there is no need to be in the photon's frame. Anyways all observers agree, no matter the frame." inertial observers - those in accelerated frames will not

But it is wrong. As numerous people have been telling you. Just because you cannot conceptualize it does not mean that it is not true - this is the argument from incredulity; and in this case it is almost justified. Once you get your head around what Einstein was say it is pretty amazing, it goes against most of what we have been taught, and it is contrary to common sense - you clearly have knowledge of what SR entails but are rejecting it because it does not fit into your worldview. How does the muon hit the earth's surface if it is all an observational artefact? - because they do. The muon has a half life in the order of 2 microseconds and a speed of .98c The distance they must travel from the point of creation in the atmosphere to the earth is c. 10km The simple maths shows that about 3 in 10 million will make it. The observation is that 500,000 out of 10 million will make it.

and to round off the most excellent comic interlude some good news for Stringjunky - dietary cholesterol seems to have little to no effect on plasma cholesterol; check out the latest FDA dietary advice

Frankly it just made me realise why they pay John Williams so much. It was pretty formulaic - not impressed; what were you looking for in it?

Now you know what scientists think when posters start quoting pop-science as the height of learning and treating michio kaku as if he is handing down tablets of wisdom. It is exactly the same in my field - or my erstwhile field now I suppose - jurisprudence, critical legal studies, and criminology. I much prefer to read books deliberately pitched at a lay audience and written by professional communicators rather than dumbed down and embarrassing nonsense by academics looking to leverage their position into a little hard cash through mass market publication. Some real geniuses manage to cross over and do both; you will know H L A Hart and John Rawls - a more modern example is Michael Sandel at Harvard Law School and now on the BBC. I do not know enough science to properly judge in that arena but Chad Orzel strikes me as both a superb communicator to the lay-reader and a steadfast refusnik when it comes to the elision of the truth through the desire for mass-market appeal

Even if there were an eclipse it would be very unlikely to see it. From the amount of turn we see (about a quarter) then I would estimate that was about 6 hours, in 20 frames, so a frame shot ever 18 minutes. The longest you can get totality is about 7 minutes. The disc you can see of the earth is about 12500km - the size of the umbra is around 150-250 km wide. And as the sun is almost directly behind us - then the eclipse would be covered from view by the moon anyway BTW - great find; that really is an epic video

! Moderator Note Mike - either we get back to a SCIENTIFIC discussion of "gravitational waves and the aether" (with possible off-shoots into your claims for the need for a medium in all waves - if kept short and to the point) or I will lock this thread. This is not your blog - stop posting meaningless meanderings accompanied by dodgy snapshots. If you wish to open a blog then do so - it is pretty easy to do and you can wax lyrical to your heart's content; but this is the physics forum and we insist on science here. Do not respond to this moderation within the thread.

Not sure quite what you are getting at but it sounds as if you are claiming that everything is merely in the eye of the beholder. This is not the case - length contraction and time dilation are real phenomena not an artefact of observation. In the LHC we take lead ions and speed them up - the ion streams smash into each other at fantastic speeds. We then compare the results to the models we have drawn up regarding such energetic collisions - to get results that are even close to the hot quark gluon plasma which we observe we must model the ions as discs highly flattened in the direction of travel. There is also the muon decay observation that was mentioned earlier in which the reciprocity of time dilation (from our perspective) and length contraction (from the muons 'perspective') are complementary over the two frames to show how muons with a short life time can travel much further than we would expect

Not sure which is more unusual the Compressorhead version with robots actually playing - or Lemmy singing softly

Let's not gdwnze the thread with a discussion of nazi atrocities. I wrote to him asked for him to consider a trip to the UK - we need a decent Prime Minister, we are long overdue a person of colour in the top job, we would love to have the coolest CEO on the planet, and he could get away from all the shit like Fox news. Now I realise my mistake - we should have gone double bubble - Barack for PM and head of government, Michelle for Queen and head of state.

! Moderator Note Professional Strawman - stop trolling. You are clearly here to provoke a disagreement and to insult the membership - and not for a substantive discussion of the physics. If you feel the level of interaction is beneath you then the answer is to look elsewhere not to attempt to belittle the level of discourse here. Do not respond to this moderation within the thread. This post may be reported if there are concerns with this moderation note. And everyone else DFtT

on the topic of women's names At the wrong speed - so unusual

! Moderator Note Last chance - post some physics or the thread gets locked

"One can transform any distance in light-seconds, or light-years." This sounds as if you think the light-second or light-year are measurements of time - they are not, they are measurements of distance. At light speed there are massive connexions - but they are not the same "Hubble's law can be translated in an increase of speed by time." Not really unless you want to confuse yourself even more. Right now the gaps between any two galactic cluster size objects that are not gravitationally bound are increasing at c. 71km/s/Mpc - it is not necessary to tie this into one of the objects observing the other - or even being observed by a third party. You could - this is needless complication - take the geocentric idea of only thinking about objects receding from earth at this moment and then divide the distances by the speed of light to get a calculation with respect to the time past since the light was emitted by the object; but why? And acceleration is the second derivation with respect to time not with respect to distance; whichever way you want to look at it.

To provide details - the two most deadly mass attacks of this sort were the Aum Shinriko Sarin Attacks in 1995 and these stabbings claiming 12 and 19 lives respectively. These horrific crimes happen 'only' about once a decade in Japan - although by my reckoning 4 since/including 1995 Sarin Subway Attack

Not kidding - and distance only means time in things like Planck Units (and even then it is not exact).

No - Newton would not have done so. The thing we are looking at (in non-accelerated expansion) is increase in speed is per unit of distance - Newton used increase in speed per unit of time (this was what he tied into a relationship with Force and mass). They are not the same. What we have with accelerated expansion is increase in speed per unit of distance - which itself is increasing over time

Further to Strange's answer. Expansion is technically quantified in units of s-1 per second but that is a little confusing really the most common units are (km/s)/Mpc (kilometres per second) per Megaparsec. That is a speed for the gap between two objects to open per unit distance - ie the further away two object are the quicker the gap between them is enlarging. The factor of expansion in (km/s)/Mpc is about 71 - what we mean by accelerating expansion is that this scale factor is not constant over time it is increasing. In simplistic terms the gap between two objects a megaparsec apart will be increasing at 71km/s at present - in the future the gap between two other objects also a megaparsec apart will be increasing by more than 71km/s