Nor are alcohol, tobacco and weapons - society could do without their side effects. I was arguing against the grandparent's point that all illegal substances are useless and only harm, not that weed was harmless.
Another thing - as for it being harmful to society, as you say that is a side effect. In no way does the sale of marijuana impinge on a person's rights.
As for your snide crack about my employment, I've actually never smoked in my life - weed nor tobacco. I know plenty that do and I've been offered, but I enjoy the ability to breathe and exercise without wheezing like an old geezer. Nevertheless, I'd like to see weed legal, so as to remove those side effects that you just listed - if you can get your hit from the local grocery store, why kill someone for it?
Marijuana? Illegal, but possibly medicinal in small doses (glaucoma, for instance).
The issue is that you're not depriving them of anything, but are in fact providing them with something that they want but will most likely be harmful. It is always (at least in the beginning) the user's choice.
Dude, screw it's usefulness. This guy built a walker in his garage. No matter how weak it is, that still gives me the shivers when I consider what's coming...
You really think he built this because he thought it would be BETTER than a car?
In what sense? I just watched the movie and, although it's clear that the feet are sliding and probably have wheels under them, do you really think there are any motors attached to them? Unless he's really trying to trick everyone, it's more likely there are only brakes - lock one foot, the other has to slide.
Of course it is possible that the legs are not actually driven and are only made to look like they're the source of motive power, but that would be quite sad...
The strength of your death ray relies on the number of photons you can focus onto one point. This, of course, depends on the size of your first lens or mirror, whose size determines how much light is captured.
A telescope is generally large enough to capture sufficient photons to start a fire, whereas a microscope is simply too small, regardless of the level of magnification. The magnification of the lenses will only influence the focal length and angle of incidence, not the light strength itself.
A quick proof: get a microscope with a broad range of magnifications and compare the smallest to the largest - you will notice a significant difference in the brightness of the image.
DRM is perfectly acceptable on rentals, totally unacceptable on purchased goods. When I rent something, there is an expectation that it's only for me and that I will return it within a number of days - I am paying for a short-term license. When I purchase something, I am explicitly paying for the right to a single instance, and shoud therefore be allowed to do with it whatever I want within current legal bounds.
Also expect some law suits from Americans about the product you guys sell as "beer".
Right. And when you Americans force the same agreement on us Europeans, we'll have a few remarks about your "beer":)
You don't know what beer is until you've been among the Germanic people. Hell, my own country of Belgium isn't much bigger than Massachusetts, but we've got somewhere in the 300 different beers coming from over a hundred breweries. No idea what the Germans themselves have, but I expect it's significantly more.
But what happens to the rest of the window. Is it made invisible? Then you may as well use the 'behind' metaphore. Is it moved elsewhere? Then you're detaching the widget from its window and breaking the 'sheet of paper' metaphore. Either way it is no longer a 'desktop', but a new concept that people would have to learn to relate to.
Anyone with a messy desk is quite familliar with the concept of documents on top of others and the current environment becomes quite familliar. I'd say ideally you'd use the computer desktop as a clean desk - any document you're not working with is 'put away' in the task bar (or nearest equivalent) and your current working documents are laid nicely next to eachother. Problem is, the resolution of computers today is insufficient to nicely tile two documents, much less more, without becoming excessively cluttered. This is, in my opinion, the reason we still use the messy desk metaphore.
You can have my overlapping windows when you pry them from my cold dead fingers.
Honestly, I can't tell you how often I've had two or three windows open, needing info from all three but not neccessarily from the whole window of each. To be restricted to an arbitrary tiling mechanism of the windows manager would be only slightly better than no tiling at all, but it still means I have to look at the whole window when all I needed was a little chunk.
Attributing physical traits to non-physical entities is useful in that it gives us a degree of familiarity and allows us to interact more intuitively with said objects.
Elemental chlorine is significantly heavier, but chlorine gas is not very dense at all, meaning that a bit of wind or convection will stir it up quite nicely in a standard atmosphere.
That's fine - cut the current in half. 100A is still sufficient to melt most wires and to overload the battery itself. There's a reason you can't recharge batteries fast - it's an inefficient process that generates much waste heat. 100A, 20V -> 2000W which will lead to far more heat than a battery can safely dissipate while it's recharging.
Thing is, your hairdryer runs on 10X the voltage. Take a 2200W hair dryer: it's gonna draw 20A in operation (P=I*V). To recharge a 10.8V battery applying the full 2200W while recharging, you need to provide 200A. Considering most laptop batteries are in the range of 22Wh, your battery would be recharged in about 36 seconds assuming it survived.
It's quite simple: a 10V battery of 30Wh (my laptop battery) requires 300mA to recharege in 10h, 3A to recharge in 1H, and 30A to recharge in (1/10)h.
Anyone have some more details on the charging system?
I believe that one of the problems with this is that you cannot read the signal from individual neurons, but only from large regions of the brain. This would be nowhere near exact enough to control the motion of fingers, for example.
They are not quite taking electricity in the manner you think of. For one, when a neuron fires it generates an electric field by pumping ions out of its cell body, creating a voltage. Tapping this would only reduce the voltage of that one neuron (although if done too much, it might prevent the activation of the next one in the chain). The connection between that one and the next neuron is chemical, however, so you're only draining power from one neuron.
Secondly, there exist a number of electrical components that can amplify a voltage signal without drawing any power from the source. A mosfet, for instance, can easily give you an amplification of 5-10x while drawing almost no current from the source. This means you could put your probe next to a nerve and measure the signal with only a negligible influence on the signal itself.
Actually, it was. Guess which signal they measured the doppler shift of - it was the data signal for this very experiment. The issue was that Cassini forgot to relay it, so they had to rely on the weak signal from Huygens itself.
Check out some of the other comments to this effect...
Well, the pebble bed works on a similar principle I believe. The idea is that if it gets too hot, the graphite casing around the fuel will begin to expand and increase the distance between fuel pellets, thus dampening the reaction...
I always find it ironic that nuclear waste is used as an anti-nuke argument.
Consider this: A nuke plant generates a ton or two of pure radioactive waste a month. The 7 trains of coal the power plant next door burns a month contain a roughly equal ammount of radioactive waste, most of it going into the atmosphere.
Personally, I'd rather have it concentrated where I can deal with it than in the air I'm breathing.
Well, whatever it is, turns out I'm wrong about it being a problem for cables. The skin effect is not significant enough in most decently-sized cables at audio frequencies to have any audible effect.
I left a link in another post in this thread somewhere with a pretty good explanation.
I looked it up and you are indeed correct that the effects are negligible around audio frequencies. At 25KHz there is a drop of approximately.02dB and a propagation delay of -50nsec (high frequencies arrive before low frequencies), which are probably too subtle to be heard by humans.
Another interesting fact - due to the fact that braided wire still conducts between the braids, it is, for all practical purposes, equivalent to a solid wire with a slightly reduced cross section. Wire where each braid is insulated gives the most neutral characteristics, but again probably not audible.
Actually, as Webmoth pointed out, the correct term is impedance. This refers to a resistance that has a real (resistor) and an imaginary (cap/coil) component.
True, reactance is the name for a purely imaginary resistance. Howerver, a cable will always have a real resistance, and thus we speak of impedance.
As for the skin effect only being relevant at high frequencies, that was exactly my point. Take the average sound system, where you have a number of mid-range speakers that handle the majority of frequencies in the music. The low-frequency end of this range will travel through the whole cable almost as though it was DC. The high end, however, will begin to migrate to the edges, reducing the effective cross-section of the cable and thus increasing the actual resistance (and this time it is resistance, not impedance).
Well, any cable's fine as long as it has negligible inductance and capacitance. A bit of resistance is ok - it'll just reduce the ammount of power reaching your speakers, but as long as your amp can handle a variety of load resistances it shouldn't be a problem.
Distortion due to cables mainly arises when the cable resistance becomes frequency dependent. At that point it will damp some tones more than others, and everything falls apart. I suppose you could fix it by playing with the equalizer, but that is far from a good solution.
Prognosis: use a braided cable (many small strands, not one solid) with decent quality copper to keep the resistance down and your music should sound fine. The braids will reduce the increase in resistance due to the skin effect (where high-frequency current migrates to the surface of the conductor, reducing the effective cross-section of your cable).
Slashdot Mirror
...which leads to it being exactly the same size - QED.
Jw
Pot isnt harmless
Nor are alcohol, tobacco and weapons - society could do without their side effects. I was arguing against the grandparent's point that all illegal substances are useless and only harm, not that weed was harmless.
Another thing - as for it being harmful to society, as you say that is a side effect. In no way does the sale of marijuana impinge on a person's rights.
As for your snide crack about my employment, I've actually never smoked in my life - weed nor tobacco. I know plenty that do and I've been offered, but I enjoy the ability to breathe and exercise without wheezing like an old geezer. Nevertheless, I'd like to see weed legal, so as to remove those side effects that you just listed - if you can get your hit from the local grocery store, why kill someone for it?
Jw
Marijuana?
Illegal, but possibly medicinal in small doses (glaucoma, for instance).
The issue is that you're not depriving them of anything, but are in fact providing them with something that they want but will most likely be harmful. It is always (at least in the beginning) the user's choice.
Jw
Dude, screw it's usefulness. This guy built a walker in his garage. No matter how weak it is, that still gives me the shivers when I consider what's coming...
You really think he built this because he thought it would be BETTER than a car?
Jw
In what sense? I just watched the movie and, although it's clear that the feet are sliding and probably have wheels under them, do you really think there are any motors attached to them? Unless he's really trying to trick everyone, it's more likely there are only brakes - lock one foot, the other has to slide.
Of course it is possible that the legs are not actually driven and are only made to look like they're the source of motive power, but that would be quite sad...
Jw
The strength of your death ray relies on the number of photons you can focus onto one point. This, of course, depends on the size of your first lens or mirror, whose size determines how much light is captured.
A telescope is generally large enough to capture sufficient photons to start a fire, whereas a microscope is simply too small, regardless of the level of magnification. The magnification of the lenses will only influence the focal length and angle of incidence, not the light strength itself.
A quick proof: get a microscope with a broad range of magnifications and compare the smallest to the largest - you will notice a significant difference in the brightness of the image.
Jw
DRM is perfectly acceptable on rentals, totally unacceptable on purchased goods. When I rent something, there is an expectation that it's only for me and that I will return it within a number of days - I am paying for a short-term license. When I purchase something, I am explicitly paying for the right to a single instance, and shoud therefore be allowed to do with it whatever I want within current legal bounds.
Jw
Also expect some law suits from Americans about the product you guys sell as "beer".
:)
Right. And when you Americans force the same agreement on us Europeans, we'll have a few remarks about your "beer"
You don't know what beer is until you've been among the Germanic people. Hell, my own country of Belgium isn't much bigger than Massachusetts, but we've got somewhere in the 300 different beers coming from over a hundred breweries. No idea what the Germans themselves have, but I expect it's significantly more.
Jw
But what happens to the rest of the window. Is it made invisible? Then you may as well use the 'behind' metaphore. Is it moved elsewhere? Then you're detaching the widget from its window and breaking the 'sheet of paper' metaphore. Either way it is no longer a 'desktop', but a new concept that people would have to learn to relate to.
Anyone with a messy desk is quite familliar with the concept of documents on top of others and the current environment becomes quite familliar. I'd say ideally you'd use the computer desktop as a clean desk - any document you're not working with is 'put away' in the task bar (or nearest equivalent) and your current working documents are laid nicely next to eachother. Problem is, the resolution of computers today is insufficient to nicely tile two documents, much less more, without becoming excessively cluttered. This is, in my opinion, the reason we still use the messy desk metaphore.
Jw
You can have my overlapping windows when you pry them from my cold dead fingers.
Honestly, I can't tell you how often I've had two or three windows open, needing info from all three but not neccessarily from the whole window of each. To be restricted to an arbitrary tiling mechanism of the windows manager would be only slightly better than no tiling at all, but it still means I have to look at the whole window when all I needed was a little chunk.
Attributing physical traits to non-physical entities is useful in that it gives us a degree of familiarity and allows us to interact more intuitively with said objects.
Jw
Elemental chlorine is significantly heavier, but chlorine gas is not very dense at all, meaning that a bit of wind or convection will stir it up quite nicely in a standard atmosphere.
Jw
That's fine - cut the current in half. 100A is still sufficient to melt most wires and to overload the battery itself.
There's a reason you can't recharge batteries fast - it's an inefficient process that generates much waste heat. 100A, 20V -> 2000W which will lead to far more heat than a battery can safely dissipate while it's recharging.
Thing is, your hairdryer runs on 10X the voltage. Take a 2200W hair dryer: it's gonna draw 20A in operation (P=I*V). To recharge a 10.8V battery applying the full 2200W while recharging, you need to provide 200A. Considering most laptop batteries are in the range of 22Wh, your battery would be recharged in about 36 seconds assuming it survived.
It's quite simple: a 10V battery of 30Wh (my laptop battery) requires 300mA to recharege in 10h, 3A to recharge in 1H, and 30A to recharge in (1/10)h.
Anyone have some more details on the charging system?
Jw
I believe that one of the problems with this is that you cannot read the signal from individual neurons, but only from large regions of the brain. This would be nowhere near exact enough to control the motion of fingers, for example.
Jw
They are not quite taking electricity in the manner you think of. For one, when a neuron fires it generates an electric field by pumping ions out of its cell body, creating a voltage. Tapping this would only reduce the voltage of that one neuron (although if done too much, it might prevent the activation of the next one in the chain). The connection between that one and the next neuron is chemical, however, so you're only draining power from one neuron.
Secondly, there exist a number of electrical components that can amplify a voltage signal without drawing any power from the source. A mosfet, for instance, can easily give you an amplification of 5-10x while drawing almost no current from the source. This means you could put your probe next to a nerve and measure the signal with only a negligible influence on the signal itself.
Jw
Actually, it was. Guess which signal they measured the doppler shift of - it was the data signal for this very experiment. The issue was that Cassini forgot to relay it, so they had to rely on the weak signal from Huygens itself.
Check out some of the other comments to this effect...
Jw
Well, the pebble bed works on a similar principle I believe. The idea is that if it gets too hot, the graphite casing around the fuel will begin to expand and increase the distance between fuel pellets, thus dampening the reaction...
Jw
I always find it ironic that nuclear waste is used as an anti-nuke argument.
Consider this: A nuke plant generates a ton or two of pure radioactive waste a month. The 7 trains of coal the power plant next door burns a month contain a roughly equal ammount of radioactive waste, most of it going into the atmosphere.
Personally, I'd rather have it concentrated where I can deal with it than in the air I'm breathing.
Jw
Well, whatever it is, turns out I'm wrong about it being a problem for cables. The skin effect is not significant enough in most decently-sized cables at audio frequencies to have any audible effect.
I left a link in another post in this thread somewhere with a pretty good explanation.
Jw
I looked it up and you are indeed correct that the effects are negligible around audio frequencies. At 25KHz there is a drop of approximately .02dB and a propagation delay of -50nsec (high frequencies arrive before low frequencies), which are probably too subtle to be heard by humans.
u dio/skineffect/page1.html
Another interesting fact - due to the fact that braided wire still conducts between the braids, it is, for all practical purposes, equivalent to a solid wire with a slightly reduced cross section. Wire where each braid is insulated gives the most neutral characteristics, but again probably not audible.
A good explanation, as far as I can tell: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/a
Jw
Actually, as Webmoth pointed out, the correct term is impedance. This refers to a resistance that has a real (resistor) and an imaginary (cap/coil) component.
True, reactance is the name for a purely imaginary resistance. Howerver, a cable will always have a real resistance, and thus we speak of impedance.
Jw
Incorrect. The skin effect is not caused by electrostatic repulsion.
http://en.wikipedia.org/wiki/Skin_effect
There is no skin effect for DC current.
Jw
You could be correct - I'll admit I don't remember how to calculate the depth.
.01dB
the difference between 10kHz and 25kHz is on the order of
What do you mean by this? The difference in the skin depth? The difference in the resulting power loss due to skin effect? I don't quite follow...
Jw
Indeed, impedance it is. My mistake.
As for the skin effect only being relevant at high frequencies, that was exactly my point.
Take the average sound system, where you have a number of mid-range speakers that handle the majority of frequencies in the music. The low-frequency end of this range will travel through the whole cable almost as though it was DC. The high end, however, will begin to migrate to the edges, reducing the effective cross-section of the cable and thus increasing the actual resistance (and this time it is resistance, not impedance).
Jw
Well, any cable's fine as long as it has negligible inductance and capacitance. A bit of resistance is ok - it'll just reduce the ammount of power reaching your speakers, but as long as your amp can handle a variety of load resistances it shouldn't be a problem.
Distortion due to cables mainly arises when the cable resistance becomes frequency dependent. At that point it will damp some tones more than others, and everything falls apart. I suppose you could fix it by playing with the equalizer, but that is far from a good solution.
Prognosis: use a braided cable (many small strands, not one solid) with decent quality copper to keep the resistance down and your music should sound fine. The braids will reduce the increase in resistance due to the skin effect (where high-frequency current migrates to the surface of the conductor, reducing the effective cross-section of your cable).
Jw