Right, so I downloaded the source and took out the artificial degrading, which took 5 minutes, and the data is still crap. 2 hits within a block of my house. Most of the hits were in a nearby downtown area or along major highways. Maybe it is logging the locations of cell towers.
Two ways to end the war: (1) Kill all terrorists. (2) Convert to Islam. Unfortunately, diplomacy is not a part of either
You post a long defense of Christianity and Christian love (entitled "Mindblowing stupidity"), and then end it with this scary sig? How about what Christ said here:
"But I tell you who hear me: Love your enemies, do good to those who hate you, bless those who curse you, pray for those who mistreat you. If someone strikes you on one cheek, turn to him the other also. If someone takes your cloak, do not stop him from taking your tunic. Give to everyone who asks you, and if anyone takes what belongs to you, do not demand it back. Do to others as you would have them do to you." Luke 6:27-31
it doesn't even give me a chance to enter the host. Right after I enter the first line of the request, it returns 302 and then closes the connection. Try it.
The wavelength is always much larger than the skin depth for any realistic case (at least for copper). The skin depth for copper at 100 khz is.066 mm, which is much less than the wavelength of 300 m, but I assure you that copper antennas can pick up 100 khz frequencies. The current flow on the surface of the antenna is enough to drive the receiver. If there were no receiver connected to the antenna, the antenna would reflect most of the radiation and dissipate the rest as heat.
I'm not saying it's going to work, I'm just picking nits. Anyway part of the problem with this guy's patent is that the whole analysis probably is not correct for optical frequencies. So I'm not even sure the skin depth formula is valid here.
I think he's multiplying the field strength by the wavelength because the length of the antenna must be on the order of a wavelength. The length of the antenna times the field strength equals the voltage across the antenna. (?)
Anyway, I agree that we can't expect this to work like an ordinary macroscopic antenna, because light has such a high frequency. For example, copper is a conductor at low frequencies and so we would expect it to reflect all EM radiation. But, it is not as good of a conductor at certain ranges of optical frequencies, which is why copper looks copper-colored. Light is powerful enough to knock individual electrons into higher states, so using simple low-frequency models of conductors probably will not work in this case.
My personal belief is that if this goes unchecked it will be the death of western civilization (assuming our contempt for our own environment doesn't get us first, except that is really part and parcel of the same phenomenon.)
You lost me here. If oligopolies are not challenged, it would certainly be bad.. But oligopolies and monopolies wanting to control everything are certainly nothing new, and western civilization has survived them OK for a long time. Trust-busting in the US is only about a century old, after all; at the time, most of western civilization was controlled by monarchies who didn't want openness or change.
The picture quality of Tivo is better than a VCR, and you don't have to wait forever to rewind or fast forward to find the show you want. You just select it from a menu and it comes up right away. You can also pause and go backwards with live TV, which we do a lot. And you can skip over commercials much more quickly and easily than with a VCR.
As several people have mentioned, photons have momentum and do exert pressure (called radiation pressure).
Looking at it classically, though, electromagnetic waves are made up of electric fields and magnetic fields. Electric fields exert a force on charged particles. So if you point a radio wave at an object that reflects waves, then the wave's electric field will push the electrons in the object back and forth. The moving charged particles then interact with the wave's magnetic field, pushing them in the direction the wave was traveling.. Which is the same thing we could have predicted from conservation of momentum. (Warning: IANAP.)
yes, Forrest Gump lost money on paper. the screenwriter and the guy who wrote the novel both got screwed because they were supposed to get a percentage of the profits. More on that here, including details on how the accounting was rigged.
fill a mason jar with pure oxygen, light a piece of steel wool (which will have a very feeble red glow where you lit it, if anything) and then put it in the pure oxygen. It lights up real good.
fill a mason jar with pure hydrogen and then open the jar and light it up. It just makes a big bang if memory serves.
(there are probably safety considerations with the last two which I'm forgetting.)
Someone already mentioned the gas can filled with boiling water which you seal and then cool it down to cause the gas can to be crushed by atmospheric pressure. That was another good one, from high school chemistry.
Also in high school chemistry we had an "acid tasting experiment" which I don't recommend you try.:) We tasted successively stronger acids until we got to hydrocloric acid, as I recall. I just got a slight whiff of that one, not a real good taste.
There are a lot of good little science toys, I mean demonstrations, at Scientifics Online. The van de graaf generator is cool, of course. There is also a magnetic levitator which is very cool, but its scientific value is unclear.:)
get a length of copper tube from home depot, the thicker the better. I got a length of tube and then some repair coupling to put over it, to make the tube thicker. then drop a strong magnet down the tube. It will float slowly down instead of falling at a normal rate. here's a page describing a simmilar experiment.. you can get great magnets from wondermagnet. (the spherical ones work best.)
Another fun thing: get two linear polarizers and then show that they are transparent when lined up but opaque when crossed. This is pretty cool if you haven't seen it before. You can get nice big ones from edmund optics.
Also you can get 1/2 wave retarder film from this same place; put the retarder film between the crossed polarizers, and it opens up a little "window" which allows you to see through the otherwise opaque polarizers.
Other stuff you can do with polarizers: look at a window and observe that the glare on the window is dimmer when you turn the polarizer the right way. Also cross two polarizers and put a piece of clear plastic (like a CD case) between them, and you can see all sorts of pretty colors. Also you can take a clear plastic bag and stretch it and put it between the two polarizers, and the colors will indicate the stresses in the bag.
Cute, but the article doesn't answer my question. Please quote the line in the article which answers the question. The article just gives some non-technical handwaving about electricity dissipating like ripples in a pond.
clue me in please... why is the resistance such a problem, if the third rail is how they are powering the trains in the first place? Why does the braking energy from the trains get wasted, but the energy from the systems that are powering the third rail does not?
People don't seem to realize that the reason there's so little investment in alternatives to oil, for example, is that oil is too cheap. There are lots of renewable alternatives to fossil fuels; it's just that they are more expensive, so nobody uses them. When oil starts to run out, it will become more expensive, and people will start to use alternative fuels, invest more in finding new ones, and/or conserve more, by simple economics.
Yeah forgot about that. But that experiment can't be done with paper and a light source like the original poster said. You need a photomultiplier tube, etc.
The existence of photons, by itself, overthrows classical wave mechanics. The photoelectric effect was the basis for that.
This had nothing to do with quantum mechanics. Young's double slit experiment was done way back in 1800 and classical electrodynamics explains it just fine. All you need is the wave theory of light.
In 1961, a similar two-slit experiment was done with electrons, with similar results; that's what you might be thinking of. But it was a more complicated experiment because the wavelength of electrons is so small. (Anyway, diffraction of electrons had been done years before that using a crystal.)
The most important experiments establishing the need for quantum mechanics were the photoelectric effect and Plack's analysis of blackbody radiation.
Home Planet does a good job, and has an orrery display as well as a sky view.
you'll also want the orbital elements, which can be put into the cometnew.csv file so you know where all the latest comets are (including Ikeya-Zhang)
how are you going to assess a duty on software? Are you going to ask companies to report how many hours it took to develop the software and make them pay some per-hour tax? Or some percentage of the software sales? What if you're not selling the software, but developing it in-house? What if it's only partially developed overseas?
And how are you going to catch people doing offshore development, or phone support or sales, etc.? With the internet, there's no way to block software from coming across the border.
It's globalization.. It causes change, which is scary, but trying to block it only makes things worse. If we start putting up trade barriers, than other countries will retaliate.
How about free software.. That's even worse, since nobody can compete with people working for free. I don't see anyone complaining to their representatives about THAT.
Slashdot Mirror
Right, so I downloaded the source and took out the artificial degrading, which took 5 minutes, and the data is still crap. 2 hits within a block of my house. Most of the hits were in a nearby downtown area or along major highways. Maybe it is logging the locations of cell towers.
Two ways to end the war: (1) Kill all terrorists. (2) Convert to Islam. Unfortunately, diplomacy is not a part of either
You post a long defense of Christianity and Christian love (entitled "Mindblowing stupidity"), and then end it with this scary sig? How about what Christ said here:
"But I tell you who hear me: Love your enemies, do good to those who hate you, bless those who curse you, pray for those who mistreat you. If someone strikes you on one cheek, turn to him the other also. If someone takes your cloak, do not stop him from taking your tunic. Give to everyone who asks you, and if anyone takes what belongs to you, do not demand it back. Do to others as you would have them do to you." Luke 6:27-31
it doesn't even give me a chance to enter the host. Right after I enter the first line of the request, it returns 302 and then closes the connection. Try it.
Tim Berners-Lee invented the web, not the internet.
Yeah, in fact, most kids these days couldn't catch the spelling error in your subject line.
The wavelength is always much larger than the skin depth for any realistic case (at least for copper). The skin depth for copper at 100 khz is .066 mm, which is much less than the wavelength of 300 m, but I assure you that copper antennas can pick up 100 khz frequencies. The current flow on the surface of the antenna is enough to drive the receiver. If there were no receiver connected to the antenna, the antenna would reflect most of the radiation and dissipate the rest as heat.
I'm not saying it's going to work, I'm just picking nits. Anyway part of the problem with this guy's patent is that the whole analysis probably is not correct for optical frequencies. So I'm not even sure the skin depth formula is valid here.
I think he's multiplying the field strength by the wavelength because the length of the antenna must be on the order of a wavelength. The length of the antenna times the field strength equals the voltage across the antenna. (?)
Anyway, I agree that we can't expect this to work like an ordinary macroscopic antenna, because light has such a high frequency. For example, copper is a conductor at low frequencies and so we would expect it to reflect all EM radiation. But, it is not as good of a conductor at certain ranges of optical frequencies, which is why copper looks copper-colored. Light is powerful enough to knock individual electrons into higher states, so using simple low-frequency models of conductors probably will not work in this case.
You lost me here. If oligopolies are not challenged, it would certainly be bad.. But oligopolies and monopolies wanting to control everything are certainly nothing new, and western civilization has survived them OK for a long time. Trust-busting in the US is only about a century old, after all; at the time, most of western civilization was controlled by monarchies who didn't want openness or change.
The picture quality of Tivo is better than a VCR, and you don't have to wait forever to rewind or fast forward to find the show you want. You just select it from a menu and it comes up right away. You can also pause and go backwards with live TV, which we do a lot. And you can skip over commercials much more quickly and easily than with a VCR.
As several people have mentioned, photons have momentum and do exert pressure (called radiation pressure).
Looking at it classically, though, electromagnetic waves are made up of electric fields and magnetic fields. Electric fields exert a force on charged particles. So if you point a radio wave at an object that reflects waves, then the wave's electric field will push the electrons in the object back and forth. The moving charged particles then interact with the wave's magnetic field, pushing them in the direction the wave was traveling.. Which is the same thing we could have predicted from conservation of momentum. (Warning: IANAP.)
yes, Forrest Gump lost money on paper. the screenwriter and the guy who wrote the novel both got screwed because they were supposed to get a percentage of the profits. More on that here, including details on how the accounting was rigged.
other memorable demonstrations from 9th grade science class:
:) We tasted successively stronger acids until we got to hydrocloric acid, as I recall. I just got a slight whiff of that one, not a real good taste.
:)
put a feather in a vacuum chamber and watch it fall as fast as a rock.
fill a mason jar with pure oxygen, light a piece of steel wool (which will have a very feeble red glow where you lit it, if anything) and then put it in the pure oxygen. It lights up real good.
fill a mason jar with pure hydrogen and then open the jar and light it up. It just makes a big bang if memory serves.
(there are probably safety considerations with the last two which I'm forgetting.)
Someone already mentioned the gas can filled with boiling water which you seal and then cool it down to cause the gas can to be crushed by atmospheric pressure. That was another good one, from high school chemistry.
Also in high school chemistry we had an "acid tasting experiment" which I don't recommend you try.
There are a lot of good little science toys, I mean demonstrations, at Scientifics Online. The van de graaf generator is cool, of course. There is also a magnetic levitator which is very cool, but its scientific value is unclear.
get a length of copper tube from home depot, the thicker the better. I got a length of tube and then some repair coupling to put over it, to make the tube thicker. then drop a strong magnet down the tube. It will float slowly down instead of falling at a normal rate. here's a page describing a simmilar experiment.. you can get great magnets from wondermagnet. (the spherical ones work best.)
Another fun thing: get two linear polarizers and then show that they are transparent when lined up but opaque when crossed. This is pretty cool if you haven't seen it before. You can get nice big ones from edmund optics.
Also you can get 1/2 wave retarder film from this same place; put the retarder film between the crossed polarizers, and it opens up a little "window" which allows you to see through the otherwise opaque polarizers.
Other stuff you can do with polarizers: look at a window and observe that the glare on the window is dimmer when you turn the polarizer the right way. Also cross two polarizers and put a piece of clear plastic (like a CD case) between them, and you can see all sorts of pretty colors. Also you can take a clear plastic bag and stretch it and put it between the two polarizers, and the colors will indicate the stresses in the bag.
Cute, but the article doesn't answer my question. Please quote the line in the article which answers the question. The article just gives some non-technical handwaving about electricity dissipating like ripples in a pond.
clue me in please... why is the resistance such a problem, if the third rail is how they are powering the trains in the first place? Why does the braking energy from the trains get wasted, but the energy from the systems that are powering the third rail does not?
bravo!
People don't seem to realize that the reason there's so little investment in alternatives to oil, for example, is that oil is too cheap. There are lots of renewable alternatives to fossil fuels; it's just that they are more expensive, so nobody uses them. When oil starts to run out, it will become more expensive, and people will start to use alternative fuels, invest more in finding new ones, and/or conserve more, by simple economics.
Yeah forgot about that. But that experiment can't be done with paper and a light source like the original poster said. You need a photomultiplier tube, etc.
The existence of photons, by itself, overthrows classical wave mechanics. The photoelectric effect was the basis for that.
This had nothing to do with quantum mechanics. Young's double slit experiment was done way back in 1800 and classical electrodynamics explains it just fine. All you need is the wave theory of light.
In 1961, a similar two-slit experiment was done with electrons, with similar results; that's what you might be thinking of. But it was a more complicated experiment because the wavelength of electrons is so small. (Anyway, diffraction of electrons had been done years before that using a crystal.)
The most important experiments establishing the need for quantum mechanics were the photoelectric effect and Plack's analysis of blackbody radiation.
Home Planet does a good job, and has an orrery display as well as a sky view. you'll also want the orbital elements, which can be put into the cometnew.csv file so you know where all the latest comets are (including Ikeya-Zhang)
how are you going to assess a duty on software? Are you going to ask companies to report how many hours it took to develop the software and make them pay some per-hour tax? Or some percentage of the software sales? What if you're not selling the software, but developing it in-house? What if it's only partially developed overseas?
And how are you going to catch people doing offshore development, or phone support or sales, etc.? With the internet, there's no way to block software from coming across the border.
It's globalization.. It causes change, which is scary, but trying to block it only makes things worse. If we start putting up trade barriers, than other countries will retaliate.
How about free software.. That's even worse, since nobody can compete with people working for free. I don't see anyone complaining to their representatives about THAT.
check again.. it's seventh largest, smaller than India.