Isn't this just an extension of the universal service obligations commonly associated with telephone, electricity etc.?
Having said that, I don't really see the need for 100 Mbps internet access for everyone - it's expensive to provide, and what very important services does it provide that 1 Mbps won't?
Rights are always an imposition on someone else. The right to free speech obliges others to tolerate offensive speech. The right to a fair trial obliges others to provide you with one. The right to bear arms (a popular one with people who advocate arguments such as yours) increases the risks of death from gunshot wounds for other people. The right to own property denies others the use of that property.
The question is whether the rights are worth the imposition.
True, but in all those cases it's trivial to measure and there are even natural feedback mechanisms to stop you overdoing it.
My surprise was that a mere imaging technology could even be capable of delivering radiation levels that would cause tissue damage. For radiotherapy it's to be expected, as the whole point is to cause damage.
Hundreds of mSv is normally considered an enormous dose, well in excess of radiation protection standards in industry.
The high natural background areas deliver the 200 mSv over a period of a year though, not a matter of minutes.
There may be good medical reasons for using such enormous doses, but it still took me by surprise. The average dose of a nuclear worker is only a few mSv/year. Still, I guess a 1 in 40 chance of the radiation causing a fatal cancer isn't so bad if it stops you dying from a stroke in the meantime.
The error went unnoticed for the next 18 months, until this August, when a stroke patient informed the hospital that he had begun losing his hair after a scan.
There's only a factor of 8 difference between a typical scan dose and one large enough to cause hair loss and skin damage? IIRC observable damage doesn't occur until the hundreds of mSv range. I'm pretty astonished that CT scans need such huge doses.
While there can be disagreement as to how practical such a system would be, an economy of abundance where money wasn't the prime motivator for action would be rather appealing. We actually saw very little of the economic system on Earth, since Star Trek focused on the military, so there's rather little to go on.
Regarding the article, using technology as a mere device is entirely sensible, as long as it isn't used for deus ex machina. Stories are about people after all.
What is this miraculous automatic backup scheme? The only options I can think of for genuinely automatic backups are either:
a) Attach an external drive and leave it on b) Online storage
A is vulnerable to common-cause failures (though still better than nothing - it's what I use and it's saved my arse once already) and B is impractical unless you have a small amount of data or an unusually fast internet connection.
It doesn't pop in and out as such - certainly you can't just pluck particle/antiparticle pairs out of empty space without supplying energy. For a quantized field, the vacuum expectation value (crudely, the average value in empty space) for certain quantities can be non-zero, just like atoms in a ground state have a definite non-zero energy.
Even if the energy of a ground state is non-zero, you can't take that energy out - energy must be conserved and there's no lower energy state for free space to fall into.
The energy density of the vacuum is in essence undefined (in quantum theory at least - in general relativity it's a different matter, which is where problems come in). Only energy differences matter.
Well, that's my understanding anyway, but then I was an experimentalist, not a theorist. Perhaps someone will come along and correct me.
Conservation of energy is absolute, as far as we know, not statistical, even in QM. It would be a major revolution in physics if that weren't the case, as conservation is associated with important symmetries, such as the laws of physics not changing from past to future.
Entropy increasing *is* statistical, but no, you can't get around it. See Maxwell's Demon or the Brownian ratchet.
There are existing examples of persisting currents, in superconductors. No way to get energy out without reducing the current, of course, and you have to put energy in to get it back.
Millions of people listen to FM radio. Sheesh, are slashdotters experiences of people really so narrow that that you assume that the geek segment of the population is the only one? Yes, let's get rid of that to add a tiny amount of extra space for people to watch Youtube videos on their mobiles.
There's a better case for re-using the old analogue TV spectrum, but only because it's been replaced with a functionally equivalent but more bandwidth-efficient system. Broadcast radio hasn't.
Yes, but muons are ~200x heavier than electrons, so the total energy at a given relativistic gamma is 200x larger. Since synchrotron radiation is directly dependent on gamma, not energy or mass, the energy achievable is much larger.
This is why LEP was limited by synchrotron radiation at ~ 200 GeV but the LHC can do 14000 GeV and has small synchrotron radiation losses even at that energy - protons are about 1800 times heavier than electrons.
I imagine you could conceivably have an e- e- collider too, but given that a) the need for a higher order electromagnetic process would suppress the production cross sections considerably and b) positrons are easy to get hold of compared to antiprotons, then there isn't much point.
These fancy new e+ e- colliders are all very well anyway, but I love the idea of a muon collider - gets round the pesky synchrotron radiation losses associated with circular electron colliders like LEP. Downside - muons only live for about 2 microseconds in their rest frame. Oh well. With time dilation though, that should be enough to do a fair few laps of the collider.
I've certainly watched presentations by Nobel laureates which were poor in comparison to those by typical scientists, which themselves are often not so clear and polished.
And yet, despite not being as good at communication and convincing people as a salesman or businessman, they still do their job as scientists a lot better than the businessman could do it.
While some communication skills are undoubtedly necessary, demanding that all technical people be excellent at it means you'll reject a lot of perfectly good people. For a scientific or engineering job, "good enough" presentation skills can usually be learned, good enough technical skills rather less so. For management, the reverse may be true, but we're not talking about that.
Electric cars can manage with a single fixed gear due to the flexibility of electric motors compared to petrol engines. The Tesla Roadster does, for example. No need for complicated multiple gear transmissions or CVTs.
Don't forget that petrol is very highly taxed in the UK whereas electricity isn't. IIRC once you compare untaxed prices then electric cars would still be cheaper to run but nowhere near enough to account for the high initial cost.
Well, not until someone comes up with a really cheap battery...
I've never heard of anyone try to explain microwave heating in those terms before, perhaps because it doesn't really explain anything and confuses more than enlightens by bombarding the reader with unintuitive abstractions. There's no current involved for a start, unlike an RC circuit. Impedance here would refer to the ratio between electric and magnetic fields.
The loss mechanism is indeed as Man on Pink Corner described, interaction of polar water molecules with the electric field. The slowdown of microwaves travelling through the medium is due to absorption and re-emission in the medium, but the re-emission has a delay and hence a phase difference. The superposition of waves that results produces a wave pattern equivalent to one travelling at a slower speed.
The basic administrative functions controlled by ICANN are quite comparable to the role that the ITU takes for the telephone network.
The basic technical structure of the internet hasn't changed too much either. We still use IP and DNS, which are the main things that ICANN deal with and are analogous to telephone numbers and standards.
Given that optical fibre capacity is limited by dispersion (different parts of the signal travelling at different speeds, causing adjacent symbols to overlap), it's a reasonable number - both a longer distance and a faster symbol rate make the problem worse. So if this is what's limiting you, you can double the distance by halving the speed, or vice versa. Of course, that's not the only limiting factor, and IIRC some forms of dispersion don't scale proportionally with distance, so it's not the only relevant factor.
UNIVAC is a year older than I am, and nerds were NEVER considered "cool" until normal people started using PCs.
Take off the last six words and I think we're there...
Still, how many careers are "cool"? The best you can realistically get is "respected", though even traditionally respected professions such as doctor, lawyer or engineer seem rather less so these days. The only thing that seems to get respect in current society is money, no matter how obtained. Hence shit-peddling tossers like Alan Sugar get TV programmes and knighthoods.
Indeed, it's known that incompetent people misjudge their own competence to the point that they rate themselves more highly than the genuinely talented.
Slashdot Mirror
Isn't this just an extension of the universal service obligations commonly associated with telephone, electricity etc.?
Having said that, I don't really see the need for 100 Mbps internet access for everyone - it's expensive to provide, and what very important services does it provide that 1 Mbps won't?
Rights are always an imposition on someone else. The right to free speech obliges others to tolerate offensive speech. The right to a fair trial obliges others to provide you with one. The right to bear arms (a popular one with people who advocate arguments such as yours) increases the risks of death from gunshot wounds for other people. The right to own property denies others the use of that property.
The question is whether the rights are worth the imposition.
Thank you, that was a genuinely helpful and informative message, without any sarcasm and abuse, unlike certain other responses.
True, but in all those cases it's trivial to measure and there are even natural feedback mechanisms to stop you overdoing it.
My surprise was that a mere imaging technology could even be capable of delivering radiation levels that would cause tissue damage. For radiotherapy it's to be expected, as the whole point is to cause damage.
Hundreds of mSv is normally considered an enormous dose, well in excess of radiation protection standards in industry.
The high natural background areas deliver the 200 mSv over a period of a year though, not a matter of minutes.
There may be good medical reasons for using such enormous doses, but it still took me by surprise. The average dose of a nuclear worker is only a few mSv/year. Still, I guess a 1 in 40 chance of the radiation causing a fatal cancer isn't so bad if it stops you dying from a stroke in the meantime.
The error went unnoticed for the next 18 months, until this August, when a stroke patient informed the hospital that he had begun losing his hair after a scan.
There's only a factor of 8 difference between a typical scan dose and one large enough to cause hair loss and skin damage? IIRC observable damage doesn't occur until the hundreds of mSv range. I'm pretty astonished that CT scans need such huge doses.
While there can be disagreement as to how practical such a system would be, an economy of abundance where money wasn't the prime motivator for action would be rather appealing. We actually saw very little of the economic system on Earth, since Star Trek focused on the military, so there's rather little to go on.
Regarding the article, using technology as a mere device is entirely sensible, as long as it isn't used for deus ex machina. Stories are about people after all.
What is this miraculous automatic backup scheme? The only options I can think of for genuinely automatic backups are either:
a) Attach an external drive and leave it on
b) Online storage
A is vulnerable to common-cause failures (though still better than nothing - it's what I use and it's saved my arse once already) and B is impractical unless you have a small amount of data or an unusually fast internet connection.
It doesn't pop in and out as such - certainly you can't just pluck particle/antiparticle pairs out of empty space without supplying energy. For a quantized field, the vacuum expectation value (crudely, the average value in empty space) for certain quantities can be non-zero, just like atoms in a ground state have a definite non-zero energy.
Even if the energy of a ground state is non-zero, you can't take that energy out - energy must be conserved and there's no lower energy state for free space to fall into.
The energy density of the vacuum is in essence undefined (in quantum theory at least - in general relativity it's a different matter, which is where problems come in). Only energy differences matter.
Well, that's my understanding anyway, but then I was an experimentalist, not a theorist. Perhaps someone will come along and correct me.
Conservation of energy is absolute, as far as we know, not statistical, even in QM. It would be a major revolution in physics if that weren't the case, as conservation is associated with important symmetries, such as the laws of physics not changing from past to future.
Entropy increasing *is* statistical, but no, you can't get around it. See Maxwell's Demon or the Brownian ratchet.
There are existing examples of persisting currents, in superconductors. No way to get energy out without reducing the current, of course, and you have to put energy in to get it back.
Millions of people listen to FM radio. Sheesh, are slashdotters experiences of people really so narrow that that you assume that the geek segment of the population is the only one? Yes, let's get rid of that to add a tiny amount of extra space for people to watch Youtube videos on their mobiles.
There's a better case for re-using the old analogue TV spectrum, but only because it's been replaced with a functionally equivalent but more bandwidth-efficient system. Broadcast radio hasn't.
Yes, but muons are ~200x heavier than electrons, so the total energy at a given relativistic gamma is 200x larger. Since synchrotron radiation is directly dependent on gamma, not energy or mass, the energy achievable is much larger.
This is why LEP was limited by synchrotron radiation at ~ 200 GeV but the LHC can do 14000 GeV and has small synchrotron radiation losses even at that energy - protons are about 1800 times heavier than electrons.
I imagine you could conceivably have an e- e- collider too, but given that a) the need for a higher order electromagnetic process would suppress the production cross sections considerably and b) positrons are easy to get hold of compared to antiprotons, then there isn't much point.
These fancy new e+ e- colliders are all very well anyway, but I love the idea of a muon collider - gets round the pesky synchrotron radiation losses associated with circular electron colliders like LEP. Downside - muons only live for about 2 microseconds in their rest frame. Oh well. With time dilation though, that should be enough to do a fair few laps of the collider.
I've certainly watched presentations by Nobel laureates which were poor in comparison to those by typical scientists, which themselves are often not so clear and polished.
And yet, despite not being as good at communication and convincing people as a salesman or businessman, they still do their job as scientists a lot better than the businessman could do it.
While some communication skills are undoubtedly necessary, demanding that all technical people be excellent at it means you'll reject a lot of perfectly good people. For a scientific or engineering job, "good enough" presentation skills can usually be learned, good enough technical skills rather less so. For management, the reverse may be true, but we're not talking about that.
I think you're onto a lost cause there.
Still, maybe there's a chance we can save "literally" from the people who use it to mean "not literally".
Electric cars can manage with a single fixed gear due to the flexibility of electric motors compared to petrol engines. The Tesla Roadster does, for example. No need for complicated multiple gear transmissions or CVTs.
Don't forget that petrol is very highly taxed in the UK whereas electricity isn't. IIRC once you compare untaxed prices then electric cars would still be cheaper to run but nowhere near enough to account for the high initial cost.
Well, not until someone comes up with a really cheap battery...
I've never heard of anyone try to explain microwave heating in those terms before, perhaps because it doesn't really explain anything and confuses more than enlightens by bombarding the reader with unintuitive abstractions. There's no current involved for a start, unlike an RC circuit. Impedance here would refer to the ratio between electric and magnetic fields.
The loss mechanism is indeed as Man on Pink Corner described, interaction of polar water molecules with the electric field. The slowdown of microwaves travelling through the medium is due to absorption and re-emission in the medium, but the re-emission has a delay and hence a phase difference. The superposition of waves that results produces a wave pattern equivalent to one travelling at a slower speed.
The basic administrative functions controlled by ICANN are quite comparable to the role that the ITU takes for the telephone network.
The basic technical structure of the internet hasn't changed too much either. We still use IP and DNS, which are the main things that ICANN deal with and are analogous to telephone numbers and standards.
You mean like how the ITU act as censors of the telephone network?
Except they don't.
Given that optical fibre capacity is limited by dispersion (different parts of the signal travelling at different speeds, causing adjacent symbols to overlap), it's a reasonable number - both a longer distance and a faster symbol rate make the problem worse. So if this is what's limiting you, you can double the distance by halving the speed, or vice versa. Of course, that's not the only limiting factor, and IIRC some forms of dispersion don't scale proportionally with distance, so it's not the only relevant factor.
UNIVAC is a year older than I am, and nerds were NEVER considered "cool" until normal people started using PCs.
Take off the last six words and I think we're there...
Still, how many careers are "cool"? The best you can realistically get is "respected", though even traditionally respected professions such as doctor, lawyer or engineer seem rather less so these days. The only thing that seems to get respect in current society is money, no matter how obtained. Hence shit-peddling tossers like Alan Sugar get TV programmes and knighthoods.
Indeed, it's known that incompetent people misjudge their own competence to the point that they rate themselves more highly than the genuinely talented.
Dunning-Kruger effect.
Already there.
That's not exactly low-tech, is it?