Should passes be given for tests, reports, and projects?
We had a high school in our city which introduced a "no zero" policy that no student could even be given a zero in a test. They made the local headlines for firing a physics teacher who refused to not give a zero to students who, after repeated deadline extensions, cajoling etc. still refused to do and hand in assignments.
I got a laugh out of my colleagues in maths for suggesting the perfect solution to this. Don't give them zero, give them an imaginary number as a grade. It's consistent with the letter of the policy, it's an extremely appropriate grade for their imaginary work and, while the students may have learnt nothing else because they have done no work, they will have learnt what imaginary and complex numbers are!
I do not think they would be doing this to manufacture vaporware.
It's not being vaporware that killed all the other "breakthroughs" but rather complications/disadvantages that arose during the path towards large-scale manufacturing. For example, how do these batteries respond to damage and/or age? (rapid discharge can be really bad even without caustic/flammable chemicals) How rapidly do they charge? How rapidly does capacity deplete? etc There are many, many ways in which battery technology can fail.
I'll agree that this does perhaps seem further along that path than most "breakthroughs" but there have been so many failures that I'm not going to believe it until I see it.
No, they were not completely free but they were distributed either at or indeed, below cost which is why they were handed over to for-profit publishers. That was as close as you got 100+ years ago to what we call open access now which can only be made free because the cost of electronic publishing is very close to zero.
Others could see this as a way to reduce the amount of taxes paid by others for corporations abusing welfare.
...which would also apply to both solutions being discussed here. The two policies might not be identical but their effects are very similar as you inadvertently pointed out.
...there is no reason you can't have BOTH pieces of legislation at some point. So no, the two are separate and unrelated.
This is false logic: just because you can implement both policies does not mean they are unrelated. Generally, governments implement policies to solve perceived problems. If you implement one policy and it solves the problem then there is no need to implement the other unless it offers additional benefits or unless the problem is so big it needs multiple policies to fix it.
Or are you really just so wrapped up in politics you are desperately grasping to find a way to reject a proposal you know the other side would support rather than coming together?
What sides? I'm unamerican and was simply making an observation that the proposed policy had some potentially very serious flaws that an alternative, like minimum wage, does not. You are the one who reacted rather extremely to any even vague suggestion about minimum wage. Sorry if I stepped on your political toes by suggesting this but I was being logical, not political and my only motivation was to point out a potential flaw and offer a possibly better alternative - I am a scientist, not a politician so perhaps the different approach caught you off-guard. I have no idea why this would divide people any more than the original proposal since in both cases I am sure some will like it and others will not but then US politics is so screwed up that I utterly fail to understand it.
To suggest that it is this OR a minimum wage is false, logically, neither impacts the other.
I did not suggest this, I simply pointed out that minimum wage is a different way to tackle the same problem which might avoid some of the problems of the other suggestion. Nothing I said excludes someone coming up with other solutions. To say that the minimum wage and this are unrelated is clearly nonsense since both are intended to improve the wage of the lowest earners: one by penalizing corporations if the pay employees poorly and the other by directly preventing them from paying employees poorly.
I do not know how large companies will react to this legislation but if you do believe that this potentially motivates them to make the life of their lowest earners even worse then it would certainy be ethical to oppose it. You might disagee that this is how campies will react - and you might even be right - but just because someone sees the end result differently from you does not mean that they are not acting ethically.
Actually, there is only one way: you HAVE to cut content. The EU currently has 28 member countries and so if each of them has to have 30% local content then the ONLY way you can manage that is to restrict the content available in each country because if all the content you make is available in every country then any one country's share will be a lot less than 30%.
To make matters worse the EU has very strict rules against restricting services between countries so, if you only allow a show to be seen in country X and not in country Y you may well get into trouble. I suppose one way around this would be to have multiple streaming services each of which plays the same local content to make the 30% requirement and then programming from two plus a third other country's content but I can't help getting the idea that someone did not think these new rules through from a simple mathematical perspective...
No, we don't any form of ranking system which bans people from a service based on a highly subjective rating system otherwise we'll end up in the dystopia portrayed in Black Mirror's Nosedive episode.
I applaud the aims but I can't help thinking that it might end up with employees claiming benefits getting fired by the company and the rest ending up getting crap pay and being too afraid to claim any benefits for fear of being fired. Isn't the better way to do this to set a living minimum wage?
as the law is concerned you are a permanent employee and due all the rights of any other permanent employee
Being a permanent employee is nothing like tenure. Tenure grants certain immunities that permanent employees do not have. In particular, I am largely free to share my opinions and knowledge without the concern that I could get fired if this upsets someone. A permanent employee could easily get fired if they vocally disagree with company management or policy - just look at what happened to that Google engineer you refer to in your sig: right or wrong he got fired for speaking his mind which, if he were a tenured academic, would not happen unless his speech was in violation of the law.
Actually all science used to be published in open access journals run by various scientific societies. This is how journals starts: members wrote letters detailing discoveries which were collected and published as a news letter. As the volume of material and the size of the society grew so did the expense of publishing them since printing used to require considerable resources,
As a result, societies spun off their newsletters to publishers who had the resources needed for large circulations and they then charged people for copies to cover their printing costs. However, in the modern world printing is cheap and easy and frankly not even necessary anymore. Hence the original reason for paid journals has gone away and so I think it is very likely that, over time, we are going to end up reverting to the original scientific-society lead model since paid publishing no longer necessary.
Almost certainly. The UK gets a huge slice of the EU research grant budget - far larger than its population would suggest - and the UK government has offered no replacement program yet that will provide the same amount of grants. If Brexit turns out to be a hard one I expect the numbers leaving will increase enormously.
The UK already has some of the lowest academic salaries out there (that was why I ended up leaving since I had a family to support) and they lack tenure - it was replaced by 5-year renewable contracts. Research funding was one of the big draws but if that goes away as well I expect there will be a flood of people leaving.
Most likely because gravity is incredibly weak making measuring its coupling exceedingly hard to do because any gravitational effect can be very easily overshadowed by EM effects. I suspect this leads to many of these experiments underestimating their uncertainties.
Only rest mass is Lorentz invariant. Mass in general is not.
The only mass used in physics is rest mass because it is the only one which has any physical meaning. Relativistic mass has absolutely no physical validity and comes from a fundamental misunderstanding of how relativity works. Einstein warned against using it. The gamma factor in relativistic momentum comes from the relativistic definition of velocity being different to what classically we think of as velocity. This is because relativity mixes space and time between reference frames and velocity depends on both.
If it very easy to see that relativistic mass has no physical meaning if, instead of momentum, you look at the relativistic equivalent of Newton's second law...it is absolutely not "F=gamma*ma"!
Only a small amount of all mass is rest mass
In physics, all mass is rest mass. This is the only definition of mass which makes any physical sense.
Hadrons (including protons and neutrons) seem to have rest mass that is mostly gluons and kinetic energy rather than actual rest mass.
Rest mass is rest mass: it is literally the energy of a particle when it is at rest. What you are discussing are the sources of this rest mass which, in the case of some hadrons, is mainly due to the binding energy of the quarks (the energy of the QCD field between them). This is not the case for all hadrons though - ones including b or even c-quarks can be dominated by the mass of the quarks which itself comes from their coupling to the vacuum's Higgs field.
Trying one more time, the energy in the photons did not used to be matter, but rather used to be kinetic energy.
Well, technically that is still wrong. The kinetic energy is converted into mass-energy by exciting an atom in a collision, converting it into mass-energy. The photons are then emitted from the excited state of an atom transitioning to a less excited state. The mass of an excited state of an atom is slightly greater than that of the unexcited state by the energy of the photon emitted. Normally we do not worry about this mass difference because it is at the eV level while the atom's mass is at the GeV/c^2 level. However, in nuclear reactions where the photons are at the MeV energy region the mass difference is noticeable.
Regarding the original claim gravity couples to 4-momentum and this is something that both photons and matter both have a 4-momentum. So, in that sense, as far as gravity is concerned it is "of the same stuff" if you take 4-momentum to be the "stuff".
Yes, but the pertinent question is whether releasing starfish killing robots is going to be another example of this. Our attempts to fix environmental damage in the past by releasing new organisms to try and kill off some other organism that has got out of control have not exactly been a roaring success. Are we going to kill off the starfish only to find that the reason for their large numbers is that they are eating some other organism that is even more damaging to the reef? Past performance suggests this is certainly possible.
Yes, but the photons of visible light that you can see coming from the matter in the sun have absolutely nothing to do with the production of antimatter.
Matter does not become photons
The original quote was "Photons don't come from matter unless antimatter is involved."...and photons most definitely DO come from matter without any anti-matter being involved. If you heat up atomic matter sufficiently the collisions will promote bound electrons into higher orbitals and cause them to emit photons when they transition back. Hence photons can literally come from matter without any anti-matter being involved whatsoever.
However, when it comes to creating matter from photons without antimatter we know that this process almost certainly does happen but we still do not know exactly how. The matter-antimatter imbalance of the universe requires something like this to exist (from the Sakaharov conditions on the Big Bang).
Only photons at rest have no mass....All photons we know of have energy and thus mass.
You cannot have both! Mass is a Lorentz invariant i.e. it is exactly the same in all inertial reference frames. If a photon at rest has no mass then it must have zero mass at any energy. Just because a particle has energy does not mean it has any mass because the energy can be kinetic energy instead of mass-energy. Mass is literally the energy of the particle when it is a rest and, as you point out, a photon at rest would have no energy and hence no mass.
I have no problem with a grand unified theory. I have a problem with it being based on the electron, which exhibits none of the behaviour you describe.
I never said that a GUT should be based on an electron - although it had better include it along with all the other fundamental particles otherwise it is wrong. What I was pointing out is that your assertion that "If any of these forces could explain gravity, it would be unified by now." is wrong. It is entirely possible (even likely) that there is a unified force which could explain both these forces and gravity that we do yet know about.
Photons do have mass and both cause gravity and are affected by gravity.
Photons do not have a mass. If they did then the EM force would be short range like the weak force (whose bosons do have mass).
Photons don't come from matter unless antimatter is involved.
Have a look up in the sky (provided you are not in the UK or Seattle). See that bright shiny thing there? That's the sun. Notice how it is emitting photons? There is no antimatter involved. It emits photons because it is really hot, just like old incandescent light bulbs (they did not use antimatter either!).
If any of these forces could explain gravity, it would be unified by now.
That is simply not true. Gravity becomes as strong as the other forces are energies of 10^18 GeV (or about 100 million million times higher in energy than the LHC). We have literally no idea what physics goes on at that energy scale and it might well be possible that there is a single, unified force of which gravity is one aspect.
The incredible weakness of gravity (it is MUCH weaker than the weak force) means that we know almost nothing about its fundamental nature at the moment. We don't even have a working, testable theory yet.
Except that this is really a bit of a crap measurement so far. The large discrepancy between the two measured values means that neither can be trusted with much accuracy. If you take the difference between the two values as due to an unknown systematic error, which seems likely, then the uncertainty you get (500 ppm) is MUCH larger than the currently quoted uncertainty on G which is 46 ppm.
While the individual measurements may be very precise the clear systematic difference between the two means that neither is very accurate. Until they identify and fix the source of this systematic difference the measurement is worse than the one we currently have.
Slashdot Mirror
Should passes be given for tests, reports, and projects?
We had a high school in our city which introduced a "no zero" policy that no student could even be given a zero in a test. They made the local headlines for firing a physics teacher who refused to not give a zero to students who, after repeated deadline extensions, cajoling etc. still refused to do and hand in assignments.
I got a laugh out of my colleagues in maths for suggesting the perfect solution to this. Don't give them zero, give them an imaginary number as a grade. It's consistent with the letter of the policy, it's an extremely appropriate grade for their imaginary work and, while the students may have learnt nothing else because they have done no work, they will have learnt what imaginary and complex numbers are!
I'm a professor and I have anxiety about today's educational standards.
Can I just teach you something challenging and useful now?
I do not think they would be doing this to manufacture vaporware.
It's not being vaporware that killed all the other "breakthroughs" but rather complications/disadvantages that arose during the path towards large-scale manufacturing. For example, how do these batteries respond to damage and/or age? (rapid discharge can be really bad even without caustic/flammable chemicals) How rapidly do they charge? How rapidly does capacity deplete? etc There are many, many ways in which battery technology can fail.
I'll agree that this does perhaps seem further along that path than most "breakthroughs" but there have been so many failures that I'm not going to believe it until I see it.
No, they were not completely free but they were distributed either at or indeed, below cost which is why they were handed over to for-profit publishers. That was as close as you got 100+ years ago to what we call open access now which can only be made free because the cost of electronic publishing is very close to zero.
Others could see this as a way to reduce the amount of taxes paid by others for corporations abusing welfare.
...there is no reason you can't have BOTH pieces of legislation at some point. So no, the two are separate and unrelated.
This is false logic: just because you can implement both policies does not mean they are unrelated. Generally, governments implement policies to solve perceived problems. If you implement one policy and it solves the problem then there is no need to implement the other unless it offers additional benefits or unless the problem is so big it needs multiple policies to fix it.
Or are you really just so wrapped up in politics you are desperately grasping to find a way to reject a proposal you know the other side would support rather than coming together?
What sides? I'm unamerican and was simply making an observation that the proposed policy had some potentially very serious flaws that an alternative, like minimum wage, does not. You are the one who reacted rather extremely to any even vague suggestion about minimum wage. Sorry if I stepped on your political toes by suggesting this but I was being logical, not political and my only motivation was to point out a potential flaw and offer a possibly better alternative - I am a scientist, not a politician so perhaps the different approach caught you off-guard. I have no idea why this would divide people any more than the original proposal since in both cases I am sure some will like it and others will not but then US politics is so screwed up that I utterly fail to understand it.
That's what makes it both brilliant and scary.
Are you being dense on purpose?
No, he is just artificial military intelligence.
To turn CO2 into beer. And pay $1 Billion.
Easy, plant some barley and hops, these will grow absorbing CO2 and then use these to make beer. Can I have my $1 billion please?
To suggest that it is this OR a minimum wage is false, logically, neither impacts the other.
I did not suggest this, I simply pointed out that minimum wage is a different way to tackle the same problem which might avoid some of the problems of the other suggestion. Nothing I said excludes someone coming up with other solutions. To say that the minimum wage and this are unrelated is clearly nonsense since both are intended to improve the wage of the lowest earners: one by penalizing corporations if the pay employees poorly and the other by directly preventing them from paying employees poorly.
I do not know how large companies will react to this legislation but if you do believe that this potentially motivates them to make the life of their lowest earners even worse then it would certainy be ethical to oppose it. You might disagee that this is how campies will react - and you might even be right - but just because someone sees the end result differently from you does not mean that they are not acting ethically.
Such quotas can be enforced in two ways
Actually, there is only one way: you HAVE to cut content. The EU currently has 28 member countries and so if each of them has to have 30% local content then the ONLY way you can manage that is to restrict the content available in each country because if all the content you make is available in every country then any one country's share will be a lot less than 30%.
To make matters worse the EU has very strict rules against restricting services between countries so, if you only allow a show to be seen in country X and not in country Y you may well get into trouble. I suppose one way around this would be to have multiple streaming services each of which plays the same local content to make the 30% requirement and then programming from two plus a third other country's content but I can't help getting the idea that someone did not think these new rules through from a simple mathematical perspective...
No, we don't any form of ranking system which bans people from a service based on a highly subjective rating system otherwise we'll end up in the dystopia portrayed in Black Mirror's Nosedive episode.
I applaud the aims but I can't help thinking that it might end up with employees claiming benefits getting fired by the company and the rest ending up getting crap pay and being too afraid to claim any benefits for fear of being fired. Isn't the better way to do this to set a living minimum wage?
as the law is concerned you are a permanent employee and due all the rights of any other permanent employee
Being a permanent employee is nothing like tenure. Tenure grants certain immunities that permanent employees do not have. In particular, I am largely free to share my opinions and knowledge without the concern that I could get fired if this upsets someone. A permanent employee could easily get fired if they vocally disagree with company management or policy - just look at what happened to that Google engineer you refer to in your sig: right or wrong he got fired for speaking his mind which, if he were a tenured academic, would not happen unless his speech was in violation of the law.
Actually all science used to be published in open access journals run by various scientific societies. This is how journals starts: members wrote letters detailing discoveries which were collected and published as a news letter. As the volume of material and the size of the society grew so did the expense of publishing them since printing used to require considerable resources,
As a result, societies spun off their newsletters to publishers who had the resources needed for large circulations and they then charged people for copies to cover their printing costs. However, in the modern world printing is cheap and easy and frankly not even necessary anymore. Hence the original reason for paid journals has gone away and so I think it is very likely that, over time, we are going to end up reverting to the original scientific-society lead model since paid publishing no longer necessary.
I am wondering if this has to do with Brexit.
Almost certainly. The UK gets a huge slice of the EU research grant budget - far larger than its population would suggest - and the UK government has offered no replacement program yet that will provide the same amount of grants. If Brexit turns out to be a hard one I expect the numbers leaving will increase enormously.
The UK already has some of the lowest academic salaries out there (that was why I ended up leaving since I had a family to support) and they lack tenure - it was replaced by 5-year renewable contracts. Research funding was one of the big draws but if that goes away as well I expect there will be a flood of people leaving.
Most likely because gravity is incredibly weak making measuring its coupling exceedingly hard to do because any gravitational effect can be very easily overshadowed by EM effects. I suspect this leads to many of these experiments underestimating their uncertainties.
Only rest mass is Lorentz invariant. Mass in general is not.
The only mass used in physics is rest mass because it is the only one which has any physical meaning. Relativistic mass has absolutely no physical validity and comes from a fundamental misunderstanding of how relativity works. Einstein warned against using it. The gamma factor in relativistic momentum comes from the relativistic definition of velocity being different to what classically we think of as velocity. This is because relativity mixes space and time between reference frames and velocity depends on both.
If it very easy to see that relativistic mass has no physical meaning if, instead of momentum, you look at the relativistic equivalent of Newton's second law...it is absolutely not "F=gamma*ma"!
Only a small amount of all mass is rest mass
In physics, all mass is rest mass. This is the only definition of mass which makes any physical sense.
Hadrons (including protons and neutrons) seem to have rest mass that is mostly gluons and kinetic energy rather than actual rest mass.
Rest mass is rest mass: it is literally the energy of a particle when it is at rest. What you are discussing are the sources of this rest mass which, in the case of some hadrons, is mainly due to the binding energy of the quarks (the energy of the QCD field between them). This is not the case for all hadrons though - ones including b or even c-quarks can be dominated by the mass of the quarks which itself comes from their coupling to the vacuum's Higgs field.
Trying one more time, the energy in the photons did not used to be matter, but rather used to be kinetic energy.
Well, technically that is still wrong. The kinetic energy is converted into mass-energy by exciting an atom in a collision, converting it into mass-energy. The photons are then emitted from the excited state of an atom transitioning to a less excited state. The mass of an excited state of an atom is slightly greater than that of the unexcited state by the energy of the photon emitted. Normally we do not worry about this mass difference because it is at the eV level while the atom's mass is at the GeV/c^2 level. However, in nuclear reactions where the photons are at the MeV energy region the mass difference is noticeable.
Regarding the original claim gravity couples to 4-momentum and this is something that both photons and matter both have a 4-momentum. So, in that sense, as far as gravity is concerned it is "of the same stuff" if you take 4-momentum to be the "stuff".
Humans are fucking up the environment
Yes, but the pertinent question is whether releasing starfish killing robots is going to be another example of this. Our attempts to fix environmental damage in the past by releasing new organisms to try and kill off some other organism that has got out of control have not exactly been a roaring success. Are we going to kill off the starfish only to find that the reason for their large numbers is that they are eating some other organism that is even more damaging to the reef? Past performance suggests this is certainly possible.
The reactions in the sun do release antimatter.
Yes, but the photons of visible light that you can see coming from the matter in the sun have absolutely nothing to do with the production of antimatter.
Matter does not become photons
The original quote was "Photons don't come from matter unless antimatter is involved."...and photons most definitely DO come from matter without any anti-matter being involved. If you heat up atomic matter sufficiently the collisions will promote bound electrons into higher orbitals and cause them to emit photons when they transition back. Hence photons can literally come from matter without any anti-matter being involved whatsoever.
However, when it comes to creating matter from photons without antimatter we know that this process almost certainly does happen but we still do not know exactly how. The matter-antimatter imbalance of the universe requires something like this to exist (from the Sakaharov conditions on the Big Bang).
Only photons at rest have no mass....All photons we know of have energy and thus mass.
You cannot have both! Mass is a Lorentz invariant i.e. it is exactly the same in all inertial reference frames. If a photon at rest has no mass then it must have zero mass at any energy. Just because a particle has energy does not mean it has any mass because the energy can be kinetic energy instead of mass-energy. Mass is literally the energy of the particle when it is a rest and, as you point out, a photon at rest would have no energy and hence no mass.
I have no problem with a grand unified theory. I have a problem with it being based on the electron, which exhibits none of the behaviour you describe.
I never said that a GUT should be based on an electron - although it had better include it along with all the other fundamental particles otherwise it is wrong. What I was pointing out is that your assertion that "If any of these forces could explain gravity, it would be unified by now." is wrong. It is entirely possible (even likely) that there is a unified force which could explain both these forces and gravity that we do yet know about.
Photons do have mass and both cause gravity and are affected by gravity.
Photons do not have a mass. If they did then the EM force would be short range like the weak force (whose bosons do have mass).
Photons don't come from matter unless antimatter is involved.
Have a look up in the sky (provided you are not in the UK or Seattle). See that bright shiny thing there? That's the sun. Notice how it is emitting photons? There is no antimatter involved. It emits photons because it is really hot, just like old incandescent light bulbs (they did not use antimatter either!).
If any of these forces could explain gravity, it would be unified by now.
That is simply not true. Gravity becomes as strong as the other forces are energies of 10^18 GeV (or about 100 million million times higher in energy than the LHC). We have literally no idea what physics goes on at that energy scale and it might well be possible that there is a single, unified force of which gravity is one aspect.
The incredible weakness of gravity (it is MUCH weaker than the weak force) means that we know almost nothing about its fundamental nature at the moment. We don't even have a working, testable theory yet.
Except that this is really a bit of a crap measurement so far. The large discrepancy between the two measured values means that neither can be trusted with much accuracy. If you take the difference between the two values as due to an unknown systematic error, which seems likely, then the uncertainty you get (500 ppm) is MUCH larger than the currently quoted uncertainty on G which is 46 ppm.
While the individual measurements may be very precise the clear systematic difference between the two means that neither is very accurate. Until they identify and fix the source of this systematic difference the measurement is worse than the one we currently have.