You still have restricted timing windows if you want to return to the Earth, but that's the case with feasible rocket-powered orbital returns anyway.
Leaving aside that I already pointed out that you can use gravity in the manner you suggest there is one complication with a light sail: you have no control over the direction of thrust. As you point out you already have limited windows for returns with rockets, with a light sail you have this additional restriction which is likely to make things even more restrictive resulting in longer stays and/or journeys so what you save in fuel you may make up for in supplies....but you would have to do the maths to know for certain.
The complication is that, unlike a rocket, the only direction you can thrust is either away from the Earth (if laser based) or away from the sun (if solar based). This will make the orbital maneuvering a lot harder.
Sailing into the wind relies on the keel to resist any sideways motion of the hull so that the only component of force remaining is one which points into the wind. You cannot do that in space. The only way I can think to do anything close to that in space is to use a gravitational field which will be very different to wind-based sailing.
For example no tacking is required: if you want to move closer to the sun use your solar sail to slow your orbital velocity and then just retract the sails and fall. However if you are powered by a laser bank then getting bank to Earth will be a lot trickier since there is no gravitational field to pull you in at inter-planetary distances. You will likely need good timing and rely heavily on complex orbital maneuvers in which case it is hard to see how it is better than a rocket.
you might conclude that you had travelled at a speed well in excess of the speed of light. So Newtonian mechanics discarded a possibility that General Relativity allowed, and General Relativity discarded a possibility that Newtonian mechanics disallowed
You would not conclude that because of length contraction: you would conclude that Andromeda was a lot closer. Newtonian mechanics also predates relativity. Therefore when relativity was discovered it replaced Newtonian mechanics which essentially became the low energy approximation to relativity. So in no sense did Newtonian mechanics "discard" a possibility allowed by relativity: once relativity was confirmed Newtonian mechanics was relegated to a low energy approximation of relativity and was no longer regarded as a fundamental description of the universe.
This last part is a key point in physics. The data supporting relativity are overwhelming: special relativity is the most accurately tested theory science has ever come up with. Any replacement of relativity by something new will almost certainly mean that the new theory can only significantly differ under situations we have never tested relativity under. As such it is very unlikely to introduce possibilities which we have already discarded and far more likely to introduce possibilities we have never even thought of. In fact you example is a good case in point: Andromeda was classed a nebula before relativity was discovered and our modern understanding of an expanding universe filled with galaxies requires relativity to describe it. Hence we would never have even conceived of a trip to a distant galaxy without relativity.
Do the presidential candidates know what encryption is and how technology commonly uses it? Don't set the bar too high - you are dealing with politicians, although one of them apparently ran her own email server so you would hope that she at least knows the value of encryption!
We need to be careful here:. The argument should be that it doesn't matter whether or not they used encryption. We should not destroy our ability to communicate privately since this is fundamental to a free society and worse, it would give the terrorists a government mandated backdoor they might get hold of. While it is tempting to just point out that this call is based on a lie (and if I were more cynical I might suspect that this is the reason for making such an obvious lie) one day it probably won't be so we need to make sure the real argument against mandated back doors is out there too.
However, if the punishment is so toothless as to encourage corporations to, in turn, encourage their employees to continue to break the rules
If this is true then one way to fix it might be to turn the tables on the corporations: report their content and have it removed so they can see first hand how one sided the rules are. With any luck they may go crying to their lobbyists and the law will be changed to include some penalty for abuse of the system.
Yes - someone standing for a non-political office should be required to not be a member of any political party. If you have elections which are thought to be more important than the one which actually counts then that's a problem with your electoral system which also needs to be fixed. Using one problem as an excuse not to fix another serious problem is illogical.
What exactly do you have in mind when you want 'apolitical'?
Simple: no publicly known affiliation with a political party. The moment a judge is associated with a political party their rulings are viewed as a political, rather than legal, decision. This completely undermines any confidence that the US justice system is impartial and fair whenever a case has political ramifications.
Why should the inheritance of intangible property be treated any differently?
You are making the wrong comparison. Intangible "property" is not property in the real world in which we live, it is simply an artificial legal construct which society created so that artists can make money from their work. If we started thinking about it as a way to reward for work instead of as property we would have a far better system.
m is taken to be the relativistic mass rather than the rest mass.
Relativistic mass is a misleading and wrong concept which even Einstein himself cautioned against. Mass is something called a Lorentz invariant which means that it never changes no matter which inertial frame you look at it in. The gamma factor in things like momentum, p=gamma*mv, comes from the mixing of space and time which means that the relativistic concept of velocity (the rate of change of position with respect to time) in relativity is not quite what we think of in our everyday world as velocity. Hence the gamma factor has nothing to do with the mass and everything to do with the velocity.
An easy way to see this is to try to use it with forces and accelerations: you cannot get away with 'F=gamma*ma' for relativistic forces.
Also let us state it correctly. Einstein did not say E= m c^2. He proved it.
Yes lets state it correctly: it is E^2=p^2c^2+m^2c^4. Only when you are stationary, and so have zero momentum, does E=mc^2. Also Einstein did not prove it. He was doing physics, not maths. What he showed was that given his postulates for special relativity it followed that E^2=p^2c^2+m^2c^4. He was then proven to be correct by experiments not by the maths alone because until those experiments were done his theory might have been nothing more than an exercise in abstract maths.
This makes complete sense. The point of copyright is to make artists confident that they or their immediate heirs will be able to benefit from their works for a limited time.
This does not make any sense at all. Why should the heirs of the artist be allowed to benefit from the artist's work? No other job provides benefits for heirs after the death of the worker unless that worker has saved some of their income and put it into a suitable savings vehicle.
Artists should be recompensed under the same set of ideals. Copyright should be a fixed length regardless of the life of the author. This should be long enough that the creator will gain adequate recompense for the work but the current system is ridicuous. Why should a work created by an artist who dies immediately after creating it earn less than a similar work created by an artist who lives for 50 years after creating it?
With fixed term copyright if the artist dies before the copyright expiration then, and only then, should the heirs inherit the copyright for the remaining term. If the copyright expires before the creator then either they can create more works or they can live off their savings. This is what everyone else has to do so why can't artists work under the same system?
I mean the mass density of a typical nucleus. "Neutron densities", particularly when plural, would generally refer to the number of neutrons per unit volume.
To create significant gravitational waves you need to accelerate extremely compact objects which have nuclear densities up to large fractions of the speed of light. If you can do that you already have a far more powerful weapon than any gravitational waves you might be able to get them to emit.
StartsWithABang must think Forbes is a popular science magazine.
Well it would be nice if he got his science right then. The first astrophysical neutrinos detected came from the sun and were detected by the Homestake Experiment in the late 1960s for which a Nobel Prize was awarded. Those from SN1987a were the first neutrinos detected from a source outside the solar system.
One of the notorious characteristics of supposed cold fusion is that it does not produce neutrons.
Actually I understood that the way they "detected" that a nuclear reaction was taking place was by the production of neutrons. Indeed without neutrons how can you possibly say that fusion has occurred because then all you have is an unexplained heat gain which could be due to one of any number of things.
Neutron detection is hard to get right at these low energies and I understood that this was the explanation why so many people were fooled into thinking that fusion had occurred. This was certainly the reason behind the originally wrong discovery claim.
As for military involvement in (let's say it) cold fusion, that does not exactly inspire confidence.
I completely agree that there is absolutely nothing of substance in any of the so-called evidence of LENR/cold fusion presented so-far. However I actually don't think it is a bad idea for the military to be involved in checking out the claims because the security implications are enormous. Any fusion reaction will produce neutrons and if these are moderated and then incident on uranium you can produce plutonium. This is essentially how a fast breeder reactor works.
Plutonium can be chemically separated from uranium for more easily than separating two isotopes of uranium. So having the military know that cold fusion is impossible is a good thing otherwise they might take terrorists claiming to have used cold fusion to build a nuclear device seriously.
So if I link to a pdf of some slides claiming an observation of flying pigs does that mean that pigs can fly? Show me a peer reviewed article in a _respected_ journal and I'll be interested.
The trouble with LENR is we can see it work,
If that were the case then we would have a working way to extract energy from it by now. The problem is that only some, "special" people can see it work and nobody else can. The most likely explanation for this is that those "special" people are not doing their experiment correctly especially since there has been a long history of this in this field.
This slowdown in economic activity causes a recession...until once again their price goes up
If you were talking about a normal 'fiat' currency then yes I would agree. However if you have an absolutely fixed supply of currency then deflation is not an abnormal condition but the steady state. In such a condition I'm not sure that your argument holds because there is no point in holding off for when prices start to rise because they will not, at least not be any significant amount.
Even if you are right and steady-state deflation encourages people to hold off on purchases until they really need something perhaps this is not a bad thing. Reducing consumption is a good thing to do given the limited resources of the planet. As for the stability of the economy look at the UK recessions. The US is a relatively new country which had a rapidly developing and changing economy over the period you give also the measure used changes with different periods in the article you linked. If you look at the UK list then, except for the great depression, there is no real difference in the depth of the recessions but there may be some indication that there were fewer, but longer, recessions before 1931 when the UK came off the gold standard. So I don't see the evidence to support your assertions.
Free speech means that you are free to say whatever you want. But it does not place any entity, private or public, under any obligation to offer you a platform.
That depends where you are. In Europe if you offer a public service to people then generally you are not allowed to refuse service for a variety of reasons one of which is usually the political views you hold. Unfortunately though most European countries ban certain times of speech outright.
What we need is a hybrid system: the American rules on what we are allowed to say and the European rules to protect our ability to say where others can hear it if they choose to.
If you browse through the FCC database and read the objections to date, what you'll find is mainly a bunch of "OMG! Electromagnetic radiation will poison us! Stop Project Loon!"
If you are going to name the project 'loon' why would you be surprised that the responses you get are loony?
Slashdot Mirror
You still have restricted timing windows if you want to return to the Earth, but that's the case with feasible rocket-powered orbital returns anyway.
Leaving aside that I already pointed out that you can use gravity in the manner you suggest there is one complication with a light sail: you have no control over the direction of thrust. As you point out you already have limited windows for returns with rockets, with a light sail you have this additional restriction which is likely to make things even more restrictive resulting in longer stays and/or journeys so what you save in fuel you may make up for in supplies....but you would have to do the maths to know for certain.
The complication is that, unlike a rocket, the only direction you can thrust is either away from the Earth (if laser based) or away from the sun (if solar based). This will make the orbital maneuvering a lot harder.
Sailing into the wind relies on the keel to resist any sideways motion of the hull so that the only component of force remaining is one which points into the wind. You cannot do that in space. The only way I can think to do anything close to that in space is to use a gravitational field which will be very different to wind-based sailing.
For example no tacking is required: if you want to move closer to the sun use your solar sail to slow your orbital velocity and then just retract the sails and fall. However if you are powered by a laser bank then getting bank to Earth will be a lot trickier since there is no gravitational field to pull you in at inter-planetary distances. You will likely need good timing and rely heavily on complex orbital maneuvers in which case it is hard to see how it is better than a rocket.
you might conclude that you had travelled at a speed well in excess of the speed of light. So Newtonian mechanics discarded a possibility that General Relativity allowed, and General Relativity discarded a possibility that Newtonian mechanics disallowed
You would not conclude that because of length contraction: you would conclude that Andromeda was a lot closer. Newtonian mechanics also predates relativity. Therefore when relativity was discovered it replaced Newtonian mechanics which essentially became the low energy approximation to relativity. So in no sense did Newtonian mechanics "discard" a possibility allowed by relativity: once relativity was confirmed Newtonian mechanics was relegated to a low energy approximation of relativity and was no longer regarded as a fundamental description of the universe.
This last part is a key point in physics. The data supporting relativity are overwhelming: special relativity is the most accurately tested theory science has ever come up with. Any replacement of relativity by something new will almost certainly mean that the new theory can only significantly differ under situations we have never tested relativity under. As such it is very unlikely to introduce possibilities which we have already discarded and far more likely to introduce possibilities we have never even thought of. In fact you example is a good case in point: Andromeda was classed a nebula before relativity was discovered and our modern understanding of an expanding universe filled with galaxies requires relativity to describe it. Hence we would never have even conceived of a trip to a distant galaxy without relativity.
Do the presidential candidates know what encryption is and how technology commonly uses it? Don't set the bar too high - you are dealing with politicians, although one of them apparently ran her own email server so you would hope that she at least knows the value of encryption!
We need to be careful here:. The argument should be that it doesn't matter whether or not they used encryption. We should not destroy our ability to communicate privately since this is fundamental to a free society and worse, it would give the terrorists a government mandated backdoor they might get hold of. While it is tempting to just point out that this call is based on a lie (and if I were more cynical I might suspect that this is the reason for making such an obvious lie) one day it probably won't be so we need to make sure the real argument against mandated back doors is out there too.
However, if the punishment is so toothless as to encourage corporations to, in turn, encourage their employees to continue to break the rules
If this is true then one way to fix it might be to turn the tables on the corporations: report their content and have it removed so they can see first hand how one sided the rules are. With any luck they may go crying to their lobbyists and the law will be changed to include some penalty for abuse of the system.
If only it looked something like the Hindenburg instead of a 21st century Robin Reliant.
Yes - someone standing for a non-political office should be required to not be a member of any political party. If you have elections which are thought to be more important than the one which actually counts then that's a problem with your electoral system which also needs to be fixed. Using one problem as an excuse not to fix another serious problem is illogical.
Then they came for our laser pointers, but I did not complain, because they had the only guns and knives.
This means we still have our laser guided, air to surface missiles. If so perhaps there is a simple solution to this problem...
What exactly do you have in mind when you want 'apolitical'?
Simple: no publicly known affiliation with a political party. The moment a judge is associated with a political party their rulings are viewed as a political, rather than legal, decision. This completely undermines any confidence that the US justice system is impartial and fair whenever a case has political ramifications.
Why should the inheritance of intangible property be treated any differently?
You are making the wrong comparison. Intangible "property" is not property in the real world in which we live, it is simply an artificial legal construct which society created so that artists can make money from their work. If we started thinking about it as a way to reward for work instead of as property we would have a far better system.
m is taken to be the relativistic mass rather than the rest mass.
Relativistic mass is a misleading and wrong concept which even Einstein himself cautioned against. Mass is something called a Lorentz invariant which means that it never changes no matter which inertial frame you look at it in. The gamma factor in things like momentum, p=gamma*mv, comes from the mixing of space and time which means that the relativistic concept of velocity (the rate of change of position with respect to time) in relativity is not quite what we think of in our everyday world as velocity. Hence the gamma factor has nothing to do with the mass and everything to do with the velocity.
An easy way to see this is to try to use it with forces and accelerations: you cannot get away with 'F=gamma*ma' for relativistic forces.
Also let us state it correctly. Einstein did not say E= m c^2. He proved it.
Yes lets state it correctly: it is E^2=p^2c^2+m^2c^4. Only when you are stationary, and so have zero momentum, does E=mc^2. Also Einstein did not prove it. He was doing physics, not maths. What he showed was that given his postulates for special relativity it followed that E^2=p^2c^2+m^2c^4. He was then proven to be correct by experiments not by the maths alone because until those experiments were done his theory might have been nothing more than an exercise in abstract maths.
This makes complete sense. The point of copyright is to make artists confident that they or their immediate heirs will be able to benefit from their works for a limited time.
This does not make any sense at all. Why should the heirs of the artist be allowed to benefit from the artist's work? No other job provides benefits for heirs after the death of the worker unless that worker has saved some of their income and put it into a suitable savings vehicle.
Artists should be recompensed under the same set of ideals. Copyright should be a fixed length regardless of the life of the author. This should be long enough that the creator will gain adequate recompense for the work but the current system is ridicuous. Why should a work created by an artist who dies immediately after creating it earn less than a similar work created by an artist who lives for 50 years after creating it?
With fixed term copyright if the artist dies before the copyright expiration then, and only then, should the heirs inherit the copyright for the remaining term. If the copyright expires before the creator then either they can create more works or they can live off their savings. This is what everyone else has to do so why can't artists work under the same system?
I mean the mass density of a typical nucleus. "Neutron densities", particularly when plural, would generally refer to the number of neutrons per unit volume.
To create significant gravitational waves you need to accelerate extremely compact objects which have nuclear densities up to large fractions of the speed of light. If you can do that you already have a far more powerful weapon than any gravitational waves you might be able to get them to emit.
Since they passed through the entire planet you did, on the 14th September last year. Hope you enjoyed it.
StartsWithABang must think Forbes is a popular science magazine.
Well it would be nice if he got his science right then. The first astrophysical neutrinos detected came from the sun and were detected by the Homestake Experiment in the late 1960s for which a Nobel Prize was awarded. Those from SN1987a were the first neutrinos detected from a source outside the solar system.
One of the notorious characteristics of supposed cold fusion is that it does not produce neutrons.
Actually I understood that the way they "detected" that a nuclear reaction was taking place was by the production of neutrons. Indeed without neutrons how can you possibly say that fusion has occurred because then all you have is an unexplained heat gain which could be due to one of any number of things.
Neutron detection is hard to get right at these low energies and I understood that this was the explanation why so many people were fooled into thinking that fusion had occurred. This was certainly the reason behind the originally wrong discovery claim.
As for military involvement in (let's say it) cold fusion, that does not exactly inspire confidence.
I completely agree that there is absolutely nothing of substance in any of the so-called evidence of LENR/cold fusion presented so-far. However I actually don't think it is a bad idea for the military to be involved in checking out the claims because the security implications are enormous. Any fusion reaction will produce neutrons and if these are moderated and then incident on uranium you can produce plutonium. This is essentially how a fast breeder reactor works.
Plutonium can be chemically separated from uranium for more easily than separating two isotopes of uranium. So having the military know that cold fusion is impossible is a good thing otherwise they might take terrorists claiming to have used cold fusion to build a nuclear device seriously.
(And for those of you who think LENR is a myth: https://www.lenr-forum.com/for... )
So if I link to a pdf of some slides claiming an observation of flying pigs does that mean that pigs can fly? Show me a peer reviewed article in a _respected_ journal and I'll be interested.
The trouble with LENR is we can see it work,
If that were the case then we would have a working way to extract energy from it by now. The problem is that only some, "special" people can see it work and nobody else can. The most likely explanation for this is that those "special" people are not doing their experiment correctly especially since there has been a long history of this in this field.
This slowdown in economic activity causes a recession...until once again their price goes up
If you were talking about a normal 'fiat' currency then yes I would agree. However if you have an absolutely fixed supply of currency then deflation is not an abnormal condition but the steady state. In such a condition I'm not sure that your argument holds because there is no point in holding off for when prices start to rise because they will not, at least not be any significant amount.
Even if you are right and steady-state deflation encourages people to hold off on purchases until they really need something perhaps this is not a bad thing. Reducing consumption is a good thing to do given the limited resources of the planet. As for the stability of the economy look at the UK recessions. The US is a relatively new country which had a rapidly developing and changing economy over the period you give also the measure used changes with different periods in the article you linked. If you look at the UK list then, except for the great depression, there is no real difference in the depth of the recessions but there may be some indication that there were fewer, but longer, recessions before 1931 when the UK came off the gold standard. So I don't see the evidence to support your assertions.
Free speech means that you are free to say whatever you want. But it does not place any entity, private or public, under any obligation to offer you a platform.
That depends where you are. In Europe if you offer a public service to people then generally you are not allowed to refuse service for a variety of reasons one of which is usually the political views you hold. Unfortunately though most European countries ban certain times of speech outright.
What we need is a hybrid system: the American rules on what we are allowed to say and the European rules to protect our ability to say where others can hear it if they choose to.
If you browse through the FCC database and read the objections to date, what you'll find is mainly a bunch of "OMG! Electromagnetic radiation will poison us! Stop Project Loon!"
If you are going to name the project 'loon' why would you be surprised that the responses you get are loony?