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Comment Re:I've never been able to wrap my head around thi (Score 1) 313

Sometime airlines effectively encourage people not to turn up. Example: A few years ago when my wife moved to live with me she needed to book a single ticket (i.e. not a return). She quickly discovered that a return cost less than a single (something which I think is common, but still mystifies me). So, she bought a return ticket and simply didn't turn up for the return flight. So, she was a no-show and it was effectively all the airlines doing.

Comment Re:Wood burning is not clean (Score 1) 111

Did you actually read my comment all the way through? Didn't you notice the bit where I said "...or at least reduce the rate of release to one where society can adapt to the changes"? Of course mankind could exist on an earth with the same climate as the dinosaurs liked, the problem is getting there from here at a price we can afford.

Simple example. Suppose that sea levels were 10m higher than they are today. There would still be enough dry land for mankind (consider that huge areas of the world aren't much occupied) and I am sure we would cope just fine. The problem is that many of our cities have been built on the basis of current sea levels and moving them all 10m uphill is not economically feasible. Now, cities aren't fixed things - the buildings slowly fall down and new ones are built. So, if the sea level goes up slowly enough we can just ensure that we build new building on the higher ground further from the sea and very slowly (with the emphasis on slowly) the city will move uphill. But, we need at least hundreds of years for such a process (the first hundred or so for politicians to agree that something needs to be done) and there is a danger that the sea will go up faster than that.

Comment Re:Wood burning is not clean (Score 2) 111

Back when dinosaurs where stomping about there was a lot more CO2 in the atmosphere than now and the world was a lot hotter (good news for giant reptiles obviously). Over millions of year the carbon from this CO2 ended up in fossil fuels (hence the name) and the average amount in the atmosphere went down and it was in this environment that mankind evolved. The name of the game to fight global warming is to keep this fossil carbon in the ground and not in the atmosphere or at least reduce the rate of release to one where society can adapt to the changes.

Burning 'modern' wood is a different matter. If you leave wood lying around most of it won't turn into coal and anyway not in a useful timescale. It will rot and the bacteria and fungi involved will release the carbon back as CO2 anyway. So you might as well burn it, extract the energy and thereby leave in the ground some fossil carbon which you would otherwise have released.

Comment A VERY rare disease! (Score 1) 133

The University of Edinburgh has a vCJD monitoring unit which records the instances of the disease in the UK. See their latest report. When reading it, it is important to note that it covers all types of CJD, but only the vCJD info is relevant to the mad cow issue (other types of CJD have, for example, genetic causes).

The key take home facts are that (a) the total number of deaths so far in the UK since the disease emerged in 1995 is 178 (128 definite and the rest probable). 28 people died of the disease in 2000 and it has been in decline since then. In the last five years only TWO people have died of it, one in 2013 and one this year. There are ZERO current suspected living cases.

It is of course possible that there could be a second wave of deaths since risk is known to be linked to genetic markers and their could be another genetic group with a much longer incubation period. But with each year with no deaths this seems less and less likely.

Comment Re:so is there a good theory? (Score 1) 470

Honestly, I am making most of this reply up as I go along, since I am not a relativity physicist (or indeed any sort of physicist at all) and Shawyer's entire alleged explanation relies on relativity. Having said that, one can determine one's local velocity without a need for an external reference.

Supposing that you placed the device in empty space. We could call its current speed zero. Clearly it is not zero relative to all the other objects in the universe, some of which are approaching and some of which are receding. If we mount a sensitive accelerometer on the device and then switch it on we will (allegedly) record an acceleration. If we now integrate that acceleration over time we will get a 'local' velocity and I THINK that is the velocity Shawyer is discussing. I very vaguely understand that Einstein's special theory of relativity says that different velocity relative to everything else in the universe doesn't matter and that it all comes out correct when you do all the sums, but that might be completely ignorant rubbish.

The only thing I feel able to say with confidence is that if you want an authoritative answer to your question then you need to (a) read Shawyer's papers with a damp towel wrapped round your head and (b) find a proper physicist who has also read them to discuss it with. Sorry!

Comment Re:Propellantless doesn't mean reactionless (Score 2) 470

Except that according to its inventor (www.emdrive.com) thrust is related to not only power and cavity design, but also velocity. The net effect of this is, he claims, that the device has a terminal velocity of around 30km/s which is well below "free energy" speed. Note: I don't claim this is true, it is just what Shawyer wrote.

Comment Re:so is there a good theory? (Score 3, Interesting) 470

I strongly recommend reading Shawyer's various papers on the drive (most can be found at www.emdrive.com). Now I will admit that I find quite a lot of their contents either incomprehensible or just plain crazy, but he does evolve some equations which relate thrust to input power, velocity (usually zero in these tests) and (vitally) the Q of the cavity.

He claims (and I certainly haven't bothered to verify this) that if you look at the various papers reporting experimental tests and take into account their reported Q values then they all match his equation to within experimental error. So, he claims that the reported thrusts do 'overlap' if you allow for the different Qs being achieved.

Comment Re:so is there a good theory? (Score 1) 470

If you take the time to read Shawyer's own papers on the topic (which may of course be complete drivel) he explicitly states that his drive needs to obey conservation of energy (i.e. no perpetual motion). He then goes on to evolve equations and related explanations which suggest that the drive's thrust drops significantly with increasing acceleration and velocity (basically due to Doppler shifts inside the cavity). I seem to recall that the maximum theoretically possible values are 0.5m/s/s and 30km/s but this does rather depend on precise thruster design.

I am of course unable to say whether his explanations are true, and if the drive doesn't work at all then they are irrelevant, but the papers (mostly available from www.emdrive.com) do at least address the perpetual motion issue.

Comment Confused (Score 3, Interesting) 203

It is very likely that I don't understand enough about Bitcoin!

Question 1: Why would anyone who thought that they might not be paying all their US taxes use an exchange based in the USA? Is it something to do with needing to convert the Bitcoins to Dollars so that you can actually spend them?

Question 2: Given that one of the main selling points of Bitcoin is anonymity, why would someone operating an exchange keep any but the barest records? I appreciate that they can't destroy the information now they have been asked for it, but I am trying to grasp why they would put themselves at risk of being in that position by retaining it in the first place?

Comment Re:Probably under seal (Score 1) 73

Presumably, if he was a Russian citizen then the Russians could - assuming they wanted to - issue him a Diplomatic passport and allow him to travel as an accredited diplomat. Perhaps they could do this even if he wasn't a citizen, I don't know what the rules are there. Clearly, countries could still refuse to allow him and send him back to Russia if they decided too, but I don't see how they could then extradite him somewhere else.

Of course, even if the Russians could do this, there may be no good reason for them actually wanting to.

Comment Re:Odd name for a supermarket (Score 1) 102

When Iceland (the supermarket) first started out, domestic freezers were still a bit of a novelty (at least here in the UK). Iceland was so called because they specialised in this relatively new market. I am just about old enough to remember going there with my mother about 40 years ago when we got our first freezer and Iceland were still quite a new company. I vaguely remember a modest sized (by modern standards) supermarket with rows of big chest freezers.

On the substantive point of the trademark infringement, I had the impression that if you don't defend a trademark then you lose it. Iceland have been displaying their name in huge illuminated signs all over the UK for decades so how the Country can now come along and act shocked I can't imagine.

Comment Re: Old school reflective lcd (Score 1) 294

I got rid of the offending lights some time ago (the problem was mainly from a laptop which I now simply slide under some furniture). My question was one of getting to the bottom of why they bothered her and not me. It appears that I am be the odd one out here in apparently having the ability to snore right through the problem.

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