Second, everyone that does speculate about it agrees that to probe the existence of this discretization would require particle collisions with energy around the Planck energy, about 10^28 eV.
That's a rather strong statement considering that there are groups on ATLAS and CMS looking for evidence of Large Extra Dimensions which would reduce the energy scale for this to a few tens of TeV. Personally I don't think they will find anything but certainly they are clearly speculating about it at far lower energy scales.
To think that some lame tabletop experiment using only classical electrodynamics, running at most at 80 watts, somehow magically found a way to probe phenomena from an energy scale 15 orders of magnitude larger than the LHC scale, just shows a complete lack of knowledge of all the science involved.
Unfortunately again this is not really a correct thing to say because there are such experiments hunting for axion models of Dark Matter. The LHC is one way to get at high energy physics that is almost guaranteed to find new physics in our energy reach so it is worth the huge cost. However this does not rule out others trying lower budget approaches which can afford to be riskier and to only probe certain models. It is worth remembering that only a few years ago the Nobel prize was awarded to a group which essentially used scotch tape to separate graphite layers something which far more expensive approaches had failed to do.
Newtons second law (F=m*a) was rewritten by Einstein as F = (m*a / ((1-v2)/c2)^(2/3)) where m is rest mass.
You are missing part of the formula for relativistic acceleration plus you have a bracket in the wrong place and the fractional power inverted. The full formula is:
F = gamma^3*m*a(parallel) + gamma*m*a(perp)
where gamma=1/sqrt(1-v^2/c^2) and parallel/perp refer to the acceleration components parallel and perpendicular to the velocity.
My understanding is that the Laws of Motion still apply at large scales, but that mass also increases with velocity (whereas Newton would have assumed that mass was constant). It's only Newton's Law of Gravity that was superseded by relativity. Correct me if I'm wrong.
Challenge accepted. Newton's laws of motion are an approximation which work at everyday scales and energies. Special Relativity replaces Newton's Laws of motion at high energies and at really large scales (cosmological) you need General Relativity to explain the bending of space-time which is what replaces Newton's Law of Gravity.
Lastly mass does not increase with velocity, even in relativity it is constant because it is something called a 'Lorentz invariant'. The concept of 'relativistic mass' results from a misunderstanding of relativity which Einstein himself cautioned against. It arises from the fact that in relativity the momentum of a particle with a mass m and velocity v is no longer just 'mv' but 'gamma*mv' where gamma is a factor which depends on the particle's speed.
This unfortunately makes it appear that it is like Newton's momentum but just using 'gamma*m' for the mass. However the gamma factor comes from the velocity because in relativity space and time change with the observer. It is easier to see if we think of Newton's second law which in relativity is NOT 'F=gamma*m*a' because we have acceleration and the difference between relativistic and newtonian acceleration is more complex than a single 'gamma' term.
No, it really does. Conservation of momentum is a principle very deeply baked into physics and has had a vast amount of testing. It's reached the point where anyone claiming otherwise is quire reasonably considered a crackpot unless they have some quite amazingly compelling evidence.
...so science is not settled because it can always be overturned by compelling evidence. Relativity and QM are two examples of overturning basic, fundamental principles which had been held for ~300 years so it is possible but the EM drive has got a long way to go before it even gets vaguely compelling and even then it will need a theoretical explanation which can be tested.
Here in Europe (specifically Germany) we always say a photon has mass because E=mc^2 but its rest mass is 0
No we do not say this in Europe and none of the Germans I have worked with at CERN have ever said this either because it is provably wrong. Photons have momentum but no mass. Either you had a really bad physics teacher or you did not understand what you were being taught. For a photon E=pc where 'p' is the momentum.
If it turns out that this does work, I think it's much more likely that, rather than being a violation of Newton's 2nd law, it's due to production of some hard-to-detect particle such as neutrinos.
Newton's second law was violated just over 110 years ago when Einstein discovered relativity because the very concept we have for acceleration is not actually how the universe works (although it works fine for everyday speeds). The problem with this drive not that it violates Newton's second law but that it violates a far, far more important principle: conservation of momentum.
In physics all conservation laws are tied to symmetries (due to a beautiful piece of maths called Neother's theorem) and the symmetry in this case is that the laws of physics are the same everywhere in the space. So for this drive to work either the laws of physics are different in different parts of space or there is some other explanation. However creating and emitting some new particle cannot be it because this would still follow conservation of momentum.
One idea which could possibly work and keep conservation of momentum intact would be interacting with Dark Matter. If the drive somehow gives the energy to DM particles which are believed to exist everywhere so they come shooting out of the end then this might work. Since it oes not involve creating new particles but only interacting with particles which are already there the momentum calculation is different. However if it was this easy to interact with DM via EM forces it is hard to see how we could not have already detected DM so there are still serious flaws even with this idea.
However a far more likely explanation is that the drive shoots out electrons or other charged particles and, while on earth, there is a mechanism to return the charge imbalance to the drive via interaction with the environment. In space this will not be possible and the charge will build up until the drive stops working. So until this is ruled out this seems by far the most likely explanation: it preserves conservation of momentum and only needs particles we already know about to behave in ways we already understand. So please lets rule simple explanations like this out before looking for the crazy stuff.
The history of Apple is replete with pundits who say, 'If Apple doesn't change what it's doing, then it will go out of business.'
However this only seems to hold true when Jobs was the CEO. During the brief period when he was not they very nearly did go out of business...and sadly it seems to be happening again.
The Mac Pro is the same way. (Some) People think "Oh look it is so small, and sleek, how cool!"
Really? The first thing I think of when I look at it is "Oh look it is almost old enough to belong in a computer museum why the heck are they trying to pass off a 3 year old machine as new".
Apple's famed reality distortion field seems to be suffering from severe feedback. Rather than us being affected it seems to now be affecting them which would explain why they think a their new laptops and desktops (3 year old MacPro, 2-core mini) will sell, at least after the Apple fan boys have purchased the initial production.
If you have British citizenship you should have the right to vote. That is what democracy means otherwise why not have an intelligence test? or how about requiring a certain amount of money to be invested in the UK? etc. Excluding citizens from voting is just wrong and undemocratic. If you don't want certain people to vote don't give them British citizenship.
The Government is to announce on Friday that it will scrap the 15-year limit after which more than three million Britons living overseas lose their right to vote.
Clearly suggests that 3 million Brits are affected because the have ben aborad for more than 15 years because the total number of brits abroad is well over 4 million.
Except the treaty we signed back then is totally different to the situation now.
I was merely pointing out that the majority back then was huge and at the level you would expect for a major, life changing decision. Barely squeaking over 50% is not the sort of majority which most countries will accept for major sweeping and irrevocable changes. Yes things have changed since then and there are some serious problems with the EU but that does not change the point which is to do with ANY huge changes to a country. You need to make sure that you have a very clear majority onboard before doing things like this otherwise you risk breaking the country especially where there was a very strong counter vote in some regions.
According to the Telegraph, which being a strongly Tory paper is hardly pro-EU, their estimate as of a month ago was that the vote exclusion affects 3 million Brits. So my apologies for getting it wrong, it should be 3 million but I'll admit that I expect this has a large margin of error but not large enough to drop it to 700k and almost certainly enough to call into question the referendum result.
So if the story I linked is true and they do scrap the exclusion how about a rematch after we all get to vote? If it is only 700k of us who are affected and support for Brexit has remained constant since the referendum what have you got to lose?
I don't know what was required for entry but the 1975 referendum on EEC membership (which became the EU) had a 67.23% 'yes' vote which is over a two thirds majority in favour of joining that is typical for major changes.
Actually it *is* OK to "ignore what they say" since in the UK parliament is sovereign and not bound to any referendum's outcome.
That is not actually correct...but in a way which supports the decision of the court even more strongly. Parliament can choose whether or not to make the result of a referendum binding. The proportional vote referendum was indeed binding because parliament passed it that way.
This means that parliament deliberately chose NOT to make the EU referendum binding which implies that they wanted a chance to deliberate on the outcome and not blindly charge into Article 50. Hence the court's decision is absolutely correct: parliament made a deliberate choice to ensure that whatever the result the final decision on how to deal with the referendum rested with them.
So you'll accept the result of the vote.... just as long as you win.
To put it in a US election context would you accept the results of the US election if 10 million US citizens in a demographic group who were very likely to vote in support of your favourite candidate were excluded from having a vote and the victory margin of the winner was 6 million votes? (although I know the actual number of votes is not actually relevant in the US system).
This is exactly what happen with the referendum: 2 million British citizens (which if you scale the from a population of 60M to 300M is equivalent to 10 million US citizens) were denied a vote because they live abroad. Many of them live in the EU enjoying the benefits of membership and so were extremely likely to vote remain.
If 10 million US republicans (or 10M democrats) were denied a vote would you happily sit by and accept the results of the election? I very much doubt it so why should we accept it in the UK? It might have been legal but it was certainly not democratic.
I'm not presuming to talk for everybody, but personally, if that's what the constitution demands, then yes.
We do not have a constitution in the UK just laws and tradition. Since we entered the EU by parliament passing laws it takes parliament to repeal those same laws. It is just common sense. The reason the brexiteers are so paniced by this is because the majority for brexit was very slim and they are worried that any other referendum or vote will show that people have changed their mind.
This is why major changes to the fabric of a country are usually required to pass a far higher hurdle than merely 50% of the voters. You need a convincing margin to persuade those voting for the status quo to accept that the will of the people really has changed and that this is not a statistical blip fed by lies. Nobody is at all convinced that a second referendum, even at 50/50, would yield the same result now that the horrendous lies the leave campaign made have been exposed for what they were which happened within hours of the win.
Even worse was the fact that 2 million British citizens living abroad were excluded from the vote and many of them were enjoying the benefits of EU membership and so extremely likely to vote for remain. So the first vote was not even democratic since it excluded many of the citizens who are most directly affected by the results of the decision and since the victory margin was only 1.4 million this could easily have reversed the decision.
If the precise model they need isn't available now it will be in a month or two so what, we wait another 18 months for them to update the line by which time it will be hopelessly out of date? If you only release new models once every 12-18 months you have to make sure that there is not going to be a significant spec bump just after, or in the case of the GPU months before, you release it.
I don't care that much about it but it is just one thing in a long list of stupid things they did wrong. The biggest for me are the lack of any USB-A, the crap CPU+GPU and the insanely high price and these, coupled with the utter lack of any reasonable desktop, is why I am switching.
You are missing the point: it is bad design to make a system where everyone has to carry around a bag of dongles in order to use it. If this were not the case then why, in its hey day, did Apple ship laptops with ethernet, USB and Firewire ports? They could easily have just used nothing but Firewire and sold dongles for everything else. Apple hardware used to be sleek, elegant and functional. Now it is just sleek and elegant and that is not acceptable for a laptop at the prices they want to charge.
Slashdot Mirror
Second, everyone that does speculate about it agrees that to probe the existence of this discretization would require particle collisions with energy around the Planck energy, about 10^28 eV.
That's a rather strong statement considering that there are groups on ATLAS and CMS looking for evidence of Large Extra Dimensions which would reduce the energy scale for this to a few tens of TeV. Personally I don't think they will find anything but certainly they are clearly speculating about it at far lower energy scales.
To think that some lame tabletop experiment using only classical electrodynamics, running at most at 80 watts, somehow magically found a way to probe phenomena from an energy scale 15 orders of magnitude larger than the LHC scale, just shows a complete lack of knowledge of all the science involved.
Unfortunately again this is not really a correct thing to say because there are such experiments hunting for axion models of Dark Matter. The LHC is one way to get at high energy physics that is almost guaranteed to find new physics in our energy reach so it is worth the huge cost. However this does not rule out others trying lower budget approaches which can afford to be riskier and to only probe certain models. It is worth remembering that only a few years ago the Nobel prize was awarded to a group which essentially used scotch tape to separate graphite layers something which far more expensive approaches had failed to do.
Newtons second law (F=m*a) was rewritten by Einstein as F = (m*a / ((1-v2)/c2)^(2/3)) where m is rest mass.
You are missing part of the formula for relativistic acceleration plus you have a bracket in the wrong place and the fractional power inverted. The full formula is:
F = gamma^3*m*a(parallel) + gamma*m*a(perp)
where gamma=1/sqrt(1-v^2/c^2) and parallel/perp refer to the acceleration components parallel and perpendicular to the velocity.
My understanding is that the Laws of Motion still apply at large scales, but that mass also increases with velocity (whereas Newton would have assumed that mass was constant). It's only Newton's Law of Gravity that was superseded by relativity. Correct me if I'm wrong.
Challenge accepted. Newton's laws of motion are an approximation which work at everyday scales and energies. Special Relativity replaces Newton's Laws of motion at high energies and at really large scales (cosmological) you need General Relativity to explain the bending of space-time which is what replaces Newton's Law of Gravity.
Lastly mass does not increase with velocity, even in relativity it is constant because it is something called a 'Lorentz invariant'. The concept of 'relativistic mass' results from a misunderstanding of relativity which Einstein himself cautioned against. It arises from the fact that in relativity the momentum of a particle with a mass m and velocity v is no longer just 'mv' but 'gamma*mv' where gamma is a factor which depends on the particle's speed.
This unfortunately makes it appear that it is like Newton's momentum but just using 'gamma*m' for the mass. However the gamma factor comes from the velocity because in relativity space and time change with the observer. It is easier to see if we think of Newton's second law which in relativity is NOT 'F=gamma*m*a' because we have acceleration and the difference between relativistic and newtonian acceleration is more complex than a single 'gamma' term.
No, it really does. Conservation of momentum is a principle very deeply baked into physics and has had a vast amount of testing. It's reached the point where anyone claiming otherwise is quire reasonably considered a crackpot unless they have some quite amazingly compelling evidence.
Here in Europe (specifically Germany) we always say a photon has mass because E=mc^2 but its rest mass is 0
No we do not say this in Europe and none of the Germans I have worked with at CERN have ever said this either because it is provably wrong. Photons have momentum but no mass. Either you had a really bad physics teacher or you did not understand what you were being taught. For a photon E=pc where 'p' is the momentum.
If it turns out that this does work, I think it's much more likely that, rather than being a violation of Newton's 2nd law, it's due to production of some hard-to-detect particle such as neutrinos.
Newton's second law was violated just over 110 years ago when Einstein discovered relativity because the very concept we have for acceleration is not actually how the universe works (although it works fine for everyday speeds). The problem with this drive not that it violates Newton's second law but that it violates a far, far more important principle: conservation of momentum.
In physics all conservation laws are tied to symmetries (due to a beautiful piece of maths called Neother's theorem) and the symmetry in this case is that the laws of physics are the same everywhere in the space. So for this drive to work either the laws of physics are different in different parts of space or there is some other explanation. However creating and emitting some new particle cannot be it because this would still follow conservation of momentum.
One idea which could possibly work and keep conservation of momentum intact would be interacting with Dark Matter. If the drive somehow gives the energy to DM particles which are believed to exist everywhere so they come shooting out of the end then this might work. Since it oes not involve creating new particles but only interacting with particles which are already there the momentum calculation is different. However if it was this easy to interact with DM via EM forces it is hard to see how we could not have already detected DM so there are still serious flaws even with this idea.
However a far more likely explanation is that the drive shoots out electrons or other charged particles and, while on earth, there is a mechanism to return the charge imbalance to the drive via interaction with the environment. In space this will not be possible and the charge will build up until the drive stops working. So until this is ruled out this seems by far the most likely explanation: it preserves conservation of momentum and only needs particles we already know about to behave in ways we already understand. So please lets rule simple explanations like this out before looking for the crazy stuff.
Want to trust your company's secrets to the tender loving care of the Chinese judicial system? Or the creaking Indian system?
There may be some differences but I expect they are just like the US system: with enough money you can pretty much get the result you want.
a 'current account' is like a checking account in the US
Apparently not the ones at Tesco Bank where it seems there is clearly no where near enough checking going on.
by not being sold.
Don't worry - Apple seems to have been hard at work fixing that problem.
The history of Apple is replete with pundits who say, 'If Apple doesn't change what it's doing, then it will go out of business.'
However this only seems to hold true when Jobs was the CEO. During the brief period when he was not they very nearly did go out of business...and sadly it seems to be happening again.
It's like asking Hannibal Lecter for cooking tips.
I'm not so sure: Hannibal Lecter at least seemed to know something about cooking.
The Mac Pro is the same way. (Some) People think "Oh look it is so small, and sleek, how cool!"
Really? The first thing I think of when I look at it is "Oh look it is almost old enough to belong in a computer museum why the heck are they trying to pass off a 3 year old machine as new".
Apple's famed reality distortion field seems to be suffering from severe feedback. Rather than us being affected it seems to now be affecting them which would explain why they think a their new laptops and desktops (3 year old MacPro, 2-core mini) will sell, at least after the Apple fan boys have purchased the initial production.
If you have British citizenship you should have the right to vote. That is what democracy means otherwise why not have an intelligence test? or how about requiring a certain amount of money to be invested in the UK? etc. Excluding citizens from voting is just wrong and undemocratic. If you don't want certain people to vote don't give them British citizenship.
In five years, USB-C will be ubiquitous.
Great so this is the laptop to own in 5 years time.
The Government is to announce on Friday that it will scrap the 15-year limit after which more than three million Britons living overseas lose their right to vote.
Clearly suggests that 3 million Brits are affected because the have ben aborad for more than 15 years because the total number of brits abroad is well over 4 million.
Except the treaty we signed back then is totally different to the situation now.
I was merely pointing out that the majority back then was huge and at the level you would expect for a major, life changing decision. Barely squeaking over 50% is not the sort of majority which most countries will accept for major sweeping and irrevocable changes. Yes things have changed since then and there are some serious problems with the EU but that does not change the point which is to do with ANY huge changes to a country. You need to make sure that you have a very clear majority onboard before doing things like this otherwise you risk breaking the country especially where there was a very strong counter vote in some regions.
According to the Telegraph, which being a strongly Tory paper is hardly pro-EU, their estimate as of a month ago was that the vote exclusion affects 3 million Brits. So my apologies for getting it wrong, it should be 3 million but I'll admit that I expect this has a large margin of error but not large enough to drop it to 700k and almost certainly enough to call into question the referendum result.
So if the story I linked is true and they do scrap the exclusion how about a rematch after we all get to vote? If it is only 700k of us who are affected and support for Brexit has remained constant since the referendum what have you got to lose?
I don't know what was required for entry but the 1975 referendum on EEC membership (which became the EU) had a 67.23% 'yes' vote which is over a two thirds majority in favour of joining that is typical for major changes.
Actually it *is* OK to "ignore what they say" since in the UK parliament is sovereign and not bound to any referendum's outcome.
That is not actually correct...but in a way which supports the decision of the court even more strongly. Parliament can choose whether or not to make the result of a referendum binding. The proportional vote referendum was indeed binding because parliament passed it that way.
This means that parliament deliberately chose NOT to make the EU referendum binding which implies that they wanted a chance to deliberate on the outcome and not blindly charge into Article 50. Hence the court's decision is absolutely correct: parliament made a deliberate choice to ensure that whatever the result the final decision on how to deal with the referendum rested with them.
So you'll accept the result of the vote.... just as long as you win.
To put it in a US election context would you accept the results of the US election if 10 million US citizens in a demographic group who were very likely to vote in support of your favourite candidate were excluded from having a vote and the victory margin of the winner was 6 million votes? (although I know the actual number of votes is not actually relevant in the US system).
This is exactly what happen with the referendum: 2 million British citizens (which if you scale the from a population of 60M to 300M is equivalent to 10 million US citizens) were denied a vote because they live abroad. Many of them live in the EU enjoying the benefits of membership and so were extremely likely to vote remain.
If 10 million US republicans (or 10M democrats) were denied a vote would you happily sit by and accept the results of the election? I very much doubt it so why should we accept it in the UK? It might have been legal but it was certainly not democratic.
I'm not presuming to talk for everybody, but personally, if that's what the constitution demands, then yes.
We do not have a constitution in the UK just laws and tradition. Since we entered the EU by parliament passing laws it takes parliament to repeal those same laws. It is just common sense. The reason the brexiteers are so paniced by this is because the majority for brexit was very slim and they are worried that any other referendum or vote will show that people have changed their mind.
This is why major changes to the fabric of a country are usually required to pass a far higher hurdle than merely 50% of the voters. You need a convincing margin to persuade those voting for the status quo to accept that the will of the people really has changed and that this is not a statistical blip fed by lies. Nobody is at all convinced that a second referendum, even at 50/50, would yield the same result now that the horrendous lies the leave campaign made have been exposed for what they were which happened within hours of the win.
Even worse was the fact that 2 million British citizens living abroad were excluded from the vote and many of them were enjoying the benefits of EU membership and so extremely likely to vote for remain. So the first vote was not even democratic since it excluded many of the citizens who are most directly affected by the results of the decision and since the victory margin was only 1.4 million this could easily have reversed the decision.
If the precise model they need isn't available now it will be in a month or two so what, we wait another 18 months for them to update the line by which time it will be hopelessly out of date? If you only release new models once every 12-18 months you have to make sure that there is not going to be a significant spec bump just after, or in the case of the GPU months before, you release it.
I don't care that much about it but it is just one thing in a long list of stupid things they did wrong. The biggest for me are the lack of any USB-A, the crap CPU+GPU and the insanely high price and these, coupled with the utter lack of any reasonable desktop, is why I am switching.
You are missing the point: it is bad design to make a system where everyone has to carry around a bag of dongles in order to use it. If this were not the case then why, in its hey day, did Apple ship laptops with ethernet, USB and Firewire ports? They could easily have just used nothing but Firewire and sold dongles for everything else. Apple hardware used to be sleek, elegant and functional. Now it is just sleek and elegant and that is not acceptable for a laptop at the prices they want to charge.
One thing I've always admired was how polished the macbook line hardware
Agreed but with the new macbooks it is worth remembering that a polished turd is still a turd.