In addition to the oversights mentioned by other posters (panels in partial shade, putting panels on the north side where they will never see any sun), it seems that he also neglected to attach a load to the outputs of the cells. This greatly skews the results in favor of the tree arrangement of the cells. If a solar cell does not have a resistive load attached, applying a small amount of light to it quickly raises the voltage across it to a maximum value, and increasing the intensity of the light does not increase the voltage any further. This is visible in the graph of the voltage on his standard design: on most days, the voltage quickly jumps from 0 to nearly maximum voltage and stays constant over the day. If the voltage measured actually described the incoming power, it would show a clear maximum at noon and gradually decrease at earlier and later times as the sunlight becomes less direct. What he has effectively measured is the number of cells being exposed to any sunlight at all. For his "standard" design, only half of the cells are ever in the sun, where for the tree design, it would seem that more than half are in the sun on average, since none of the panels seem to face downward as they would if the orientation were random. I think he would find that, if he would actually measure the power produced, the south-facing panels would produce more, since they face the sun more directly, on average, than somewhat randomly oriented panels.
If the VHF comm was transmitting around 121.19 MHz, the 13th harmonic of this transmission would fall right on the L1 frequency of GPS at 1575.42 MHz ( http://en.wikipedia.org/wiki/GPS_signals ). Given how weak GPS signals are at the surface of the earth, it isn't surprising that even a high harmonic of a multiple Watt signal could interfere with it. But it does seem that the interference only happened because of this overtone. Looking at the GSM frequencies given here ( http://en.wikipedia.org/wiki/GSM_frequency_bands ), it seems there's no integer fraction of either the L1 or L2 frequency of GPS that falls into any of the GSM uplink bands, which would mean that at least GSM phones could not interfere in this manner.
About a month ago, some of my coworkers attended a conference on molecular spectroscopy in the US. One of the scheduled talks there was canceled because the speaker was denied entry to the US. Apparently, when the border control asked him about his profession, he said that he's an "atomic physicist".
I think if this sort of thing continues, more and more conference organizers will simply opt to hold their conferences in countries that are a bit more free.
Normally hard drives require air for the read heads to maintain a proper height above the platters. Additionally, the heads would probably break if they were quickly moved through a viscous medium like oil. As far as I know, hard drives aren't completely air tight. Any ideas why this wasn't a problem?
Despite the theoretical blunder of a few (I find it doubtful that anyone would use Newtonian mechanics to calculate cosmological problems anymore), most people are using GR for their calculations, and this is a real effect. There is an acceleration that, if the data on redshift vs. distance is correct, can only be explained within GR by adding a repulsive term to the equations.
Remember, these publications are peer reviewed. If the mistake were that simple, the reviewers should have caught it.
The short answer is yes, of course it has been tested. No one would accept such a theory, or quantum mechanics in general for that matter, without experimental results that agree with its findings.
This is incorrect. Rotating one of the photons in this pair will cause the two photons to have the same polarization afterward, even though this is undefined. If we have an entangled wave function:
|1V>|2H> - |1H>|2V>
with H and V being horizontal and vertical polarization, and 1 and 2 being the two photons. If we rotate photon one 90 degrees clockwise, V goes to H, and H goes to -V, making the new wave function
|1H>|2H> + |1V>|2V>
This says that the photons must have the same polarization when observed, though it is impossible to know what that polarization will be
This bit of the article has nothing to do with polarizing filters. It's referring to BBO crystals, which are these non-linear optical components which take 2 photons and reemit them into two cones, with two different polarizations. This is useful because these two cones overlap, so that, if a photon emerges from an overlap point, it is impossible to know ahead of time what polarization it will have, but because of various conservation laws, you do know that the other photon will emerge from the other crossing point and have the opposite polarization. These two photons are entangled.
You're misinterpreting the virial theorem. The theorem states that, for the case of inverse square forces, the average kinetic energy is -1/2 of the average potential energy. It is important to note that the potential energy is negative, because it is with reference to infinity. So in the case of going from LEO to ground level, very little of the potential well is traversed. The kinetic energy of LEO (v = 7400 m/s) is 54,760,000 J/kg, but the potential energy between the altitude of LEO (say 300 km) and the ground is only 3,000,000 J/kg.
Okay, normally I wouldn't bother responding, but I feel compelled to correct a number of false statements in this post
1. What is the working principle behind this (mechanism of trapping) ?
They usually trap ions which are charged, and so can be trapped with an electro-magnetic field. A slight subtelty is that you need an oscillating electric-magnetic field which is exactly what the laser provides.
NO, they are not trapping ions. I doubt it is even possible with this scheme. With static fields it is impossible by Earnshaw's theorem, but there's always a possibility with AC fields. In any case, they are not even making use of the AC nature of light, but rather they are creating, using counterpropagating beams, nodes where the electric and magnetic fields are always zero. Away from these points, there are non-zero fields. The atoms they are trapping are neutral, but because they have a non-zero total angular momentum, they have a magnetic dipole which in the presence of a magnetic field, produces a dependence in energy on magnetic field strength, independent of direction. What this means is that, if the atom is a a position where there is no magnetic field, but is immediately surrounded by regions with non-zero field, the atom is going to tend to remain at the lower energy zero-field point.
2. Are these experiments performed at room temperature ?
Hell no, unless you have a holiday house on Triton. They are cooled to almost absolute zero, because otherwise the ions are just moving too quickly to be trapped.
No, the atoms (not ions) themselves are usually at milli- or microKelvin temperatures, but their surroundings rarely need to be cooled. It is fairly straightforward, through laser cooling to cool the atoms, and because this is all done in an ultrahigh vacuum, there is almost no interaction with the room temperature walls, so cooling the macroscopic objects in the experiment does little to improve the setup.
3. How do they ensure they have trapped one "desired" atom and not more atoms and not some other impurity?
A variety of techniques are available to detect individual atoms. One of the most common is to focus a laser tuned to a resonant frequency of the ion at one of the lattice points, the ion will then flouresce and the resulting photons can be detected.
Nevermind that two bosonic atoms in the translational ground state will look exactly the same as one for the purpose of laser-induced fluorescence. In reality, it is very difficult to distinguish 1 atom in a trap from n atoms in a trap. I have yet to see any papers describing how to do so.
4. How is the laser prevented from interfering with lattice (non-desirable interactions) ?
The laser is the lattice - it's an 'optical lattice'.
The optical lattice is produced because, with beams propagating in opposite directions, there will always be fixed points where the field is zero, evenly spaced by half a wavelength. Assuming you meant, why the lasers to not produce undesirable interactions with the atoms they are containing, this is because the lasers are tuned to wavelengths that will not interact with the internal electronic structure of the atom.
Absolutely. It is possible to "route" entangled pairs using quantum repeaters. Such a device would require a photon from two entangled pairs, with each of the other photons going to their final destinations, or to other quantum repeaters. The repeater combines the received photons, and using this, can determine whether the remaining pair will be of the same polarization or of opposite polarizations, but not what the remaining photons will be when measured, which means that the routers do not need to be trusted in order for this to work. Unfortunately, this device requires a CNOT-gate, which although there are no theoretical limitations on its accuracy, the best current experimental examples only work something like 60-70% of the time. Also, any errors introduced in the transmission line are magnified, so generally more pairs need to be transmitted along each link to perform some error corrections before the pair is repeated.
A balloon lifts the exact same amount of weight at every altitude during its ascent. The key is that the amount of gas it contains is constant, which means that the number of gas particles displaced is constant in order to keep pressure and temperature the same on both sides. Therefore, the lift is constant.
Did anyone else catch this line in the article? "He has forgotten more physics than I ever knew..."
At first it seems like a compliment, but on another level, it seems to carry the implication that he's getting a bit senile in his old age...just a thought
I came to a similar conclusion. Also, if the initial energy of the photon were more than twice the rest energy of what is was striking, we would be far past the realm of classical physics and would need to use E^2 = p^2 c^2 + m_0^2 c^4 instead.
Re:Testbed for weather radar in Norman, OK
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Surviving Tornadoes
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Oddly enough, we ran into these people while trying to get in position on a meso near Chickasha. They were out there with a couple of the Doppler on Wheels trucks. Don't know how well it was working though.
For a moment, we'll assume that what Microsoft has said on Palladium thus far is truthful (big assumption I know). From what I've gathered, Palladium is just something that runs in addition to everything else. Linux, MP3s, and anything else that already exists will not be affected, they just won't use the palladium components, just as they don't use palladium components now. Palladium will probably start to be used in some future version of Windows Media Player with some new file format that requires authentication via Palladium. The old, non-Palladium formats will still function as before
Not to say all of this is insignificant. Really, Palladium is just the first step. The next step will be to legislate that only file formats that use Palladium (or the equivalent) are legal to posess. Palladium itself will not provide DRM, it will only give the framework to allow lawmakers to legislate DRM. Using older computers will not help if this is the case, since they will not play the newer formats and the older formats will be illegal. So Palladium still might have the same negative effects, just on a much longer timescales.
Then again, you can always keep the older formats, but it will be just another reason for the feds to come knocking on your door.
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In addition to the oversights mentioned by other posters (panels in partial shade, putting panels on the north side where they will never see any sun), it seems that he also neglected to attach a load to the outputs of the cells. This greatly skews the results in favor of the tree arrangement of the cells. If a solar cell does not have a resistive load attached, applying a small amount of light to it quickly raises the voltage across it to a maximum value, and increasing the intensity of the light does not increase the voltage any further. This is visible in the graph of the voltage on his standard design: on most days, the voltage quickly jumps from 0 to nearly maximum voltage and stays constant over the day. If the voltage measured actually described the incoming power, it would show a clear maximum at noon and gradually decrease at earlier and later times as the sunlight becomes less direct. What he has effectively measured is the number of cells being exposed to any sunlight at all. For his "standard" design, only half of the cells are ever in the sun, where for the tree design, it would seem that more than half are in the sun on average, since none of the panels seem to face downward as they would if the orientation were random. I think he would find that, if he would actually measure the power produced, the south-facing panels would produce more, since they face the sun more directly, on average, than somewhat randomly oriented panels.
If the VHF comm was transmitting around 121.19 MHz, the 13th harmonic of this transmission would fall right on the L1 frequency of GPS at 1575.42 MHz ( http://en.wikipedia.org/wiki/GPS_signals ). Given how weak GPS signals are at the surface of the earth, it isn't surprising that even a high harmonic of a multiple Watt signal could interfere with it. But it does seem that the interference only happened because of this overtone. Looking at the GSM frequencies given here ( http://en.wikipedia.org/wiki/GSM_frequency_bands ), it seems there's no integer fraction of either the L1 or L2 frequency of GPS that falls into any of the GSM uplink bands, which would mean that at least GSM phones could not interfere in this manner.
And a counterfeit warrant wouldn't just have the number of an accomplice on it?
About a month ago, some of my coworkers attended a conference on molecular spectroscopy in the US. One of the scheduled talks there was canceled because the speaker was denied entry to the US. Apparently, when the border control asked him about his profession, he said that he's an "atomic physicist".
I think if this sort of thing continues, more and more conference organizers will simply opt to hold their conferences in countries that are a bit more free.
Normally hard drives require air for the read heads to maintain a proper height above the platters. Additionally, the heads would probably break if they were quickly moved through a viscous medium like oil. As far as I know, hard drives aren't completely air tight. Any ideas why this wasn't a problem?
Despite the theoretical blunder of a few (I find it doubtful that anyone would use Newtonian mechanics to calculate cosmological problems anymore), most people are using GR for their calculations, and this is a real effect. There is an acceleration that, if the data on redshift vs. distance is correct, can only be explained within GR by adding a repulsive term to the equations.
Remember, these publications are peer reviewed. If the mistake were that simple, the reviewers should have caught it.
Quantum computing is also good for solving problems in quantum mechanics. No, really.
Check Wikipedia for "Bell Test Experiments".
The short answer is yes, of course it has been tested. No one would accept such a theory, or quantum mechanics in general for that matter, without experimental results that agree with its findings.
This is incorrect. Rotating one of the photons in this pair will cause the two photons to have the same polarization afterward, even though this is undefined. If we have an entangled wave function:
|1V>|2H> - |1H>|2V>
with H and V being horizontal and vertical polarization, and 1 and 2 being the two photons. If we rotate photon one 90 degrees clockwise, V goes to H, and H goes to -V, making the new wave function
|1H>|2H> + |1V>|2V>
This says that the photons must have the same polarization when observed, though it is impossible to know what that polarization will be
This bit of the article has nothing to do with polarizing filters. It's referring to BBO crystals, which are these non-linear optical components which take 2 photons and reemit them into two cones, with two different polarizations. This is useful because these two cones overlap, so that, if a photon emerges from an overlap point, it is impossible to know ahead of time what polarization it will have, but because of various conservation laws, you do know that the other photon will emerge from the other crossing point and have the opposite polarization. These two photons are entangled.
You're misinterpreting the virial theorem. The theorem states that, for the case of inverse square forces, the average kinetic energy is -1/2 of the average potential energy. It is important to note that the potential energy is negative, because it is with reference to infinity. So in the case of going from LEO to ground level, very little of the potential well is traversed. The kinetic energy of LEO (v = 7400 m/s) is 54,760,000 J/kg, but the potential energy between the altitude of LEO (say 300 km) and the ground is only 3,000,000 J/kg.
Okay, normally I wouldn't bother responding, but I feel compelled to correct a number of false statements in this post
1. What is the working principle behind this (mechanism of trapping) ?
They usually trap ions which are charged, and so can be trapped with an electro-magnetic field. A slight subtelty is that you need an oscillating electric-magnetic field which is exactly what the laser provides.
NO, they are not trapping ions. I doubt it is even possible with this scheme. With static fields it is impossible by Earnshaw's theorem, but there's always a possibility with AC fields. In any case, they are not even making use of the AC nature of light, but rather they are creating, using counterpropagating beams, nodes where the electric and magnetic fields are always zero. Away from these points, there are non-zero fields. The atoms they are trapping are neutral, but because they have a non-zero total angular momentum, they have a magnetic dipole which in the presence of a magnetic field, produces a dependence in energy on magnetic field strength, independent of direction. What this means is that, if the atom is a a position where there is no magnetic field, but is immediately surrounded by regions with non-zero field, the atom is going to tend to remain at the lower energy zero-field point.
2. Are these experiments performed at room temperature ?
Hell no, unless you have a holiday house on Triton. They are cooled to almost absolute zero, because otherwise the ions are just moving too quickly to be trapped.
No, the atoms (not ions) themselves are usually at milli- or microKelvin temperatures, but their surroundings rarely need to be cooled. It is fairly straightforward, through laser cooling to cool the atoms, and because this is all done in an ultrahigh vacuum, there is almost no interaction with the room temperature walls, so cooling the macroscopic objects in the experiment does little to improve the setup.
3. How do they ensure they have trapped one "desired" atom and not more atoms and not some other impurity?
A variety of techniques are available to detect individual atoms. One of the most common is to focus a laser tuned to a resonant frequency of the ion at one of the lattice points, the ion will then flouresce and the resulting photons can be detected.
Nevermind that two bosonic atoms in the translational ground state will look exactly the same as one for the purpose of laser-induced fluorescence. In reality, it is very difficult to distinguish 1 atom in a trap from n atoms in a trap. I have yet to see any papers describing how to do so.
4. How is the laser prevented from interfering with lattice (non-desirable interactions) ?
The laser is the lattice - it's an 'optical lattice'.
The optical lattice is produced because, with beams propagating in opposite directions, there will always be fixed points where the field is zero, evenly spaced by half a wavelength. Assuming you meant, why the lasers to not produce undesirable interactions with the atoms they are containing, this is because the lasers are tuned to wavelengths that will not interact with the internal electronic structure of the atom.
Absolutely. It is possible to "route" entangled pairs using quantum repeaters. Such a device would require a photon from two entangled pairs, with each of the other photons going to their final destinations, or to other quantum repeaters. The repeater combines the received photons, and using this, can determine whether the remaining pair will be of the same polarization or of opposite polarizations, but not what the remaining photons will be when measured, which means that the routers do not need to be trusted in order for this to work. Unfortunately, this device requires a CNOT-gate, which although there are no theoretical limitations on its accuracy, the best current experimental examples only work something like 60-70% of the time. Also, any errors introduced in the transmission line are magnified, so generally more pairs need to be transmitted along each link to perform some error corrections before the pair is repeated.
A balloon lifts the exact same amount of weight at every altitude during its ascent. The key is that the amount of gas it contains is constant, which means that the number of gas particles displaced is constant in order to keep pressure and temperature the same on both sides. Therefore, the lift is constant.
Did anyone else catch this line in the article?
"He has forgotten more physics than I ever knew..."
At first it seems like a compliment, but on another level, it seems to carry the implication that he's getting a bit senile in his old age...just a thought
I came to a similar conclusion. Also, if the initial energy of the photon were more than twice the rest energy of what is was striking, we would be far past the realm of classical physics and would need to use E^2 = p^2 c^2 + m_0^2 c^4 instead.
Oddly enough, we ran into these people while trying to get in position on a meso near Chickasha. They were out there with a couple of the Doppler on Wheels trucks. Don't know how well it was working though.
For a moment, we'll assume that what Microsoft has said on Palladium thus far is truthful (big assumption I know). From what I've gathered, Palladium is just something that runs in addition to everything else. Linux, MP3s, and anything else that already exists will not be affected, they just won't use the palladium components, just as they don't use palladium components now. Palladium will probably start to be used in some future version of Windows Media Player with some new file format that requires authentication via Palladium. The old, non-Palladium formats will still function as before
Not to say all of this is insignificant. Really, Palladium is just the first step. The next step will be to legislate that only file formats that use Palladium (or the equivalent) are legal to posess. Palladium itself will not provide DRM, it will only give the framework to allow lawmakers to legislate DRM. Using older computers will not help if this is the case, since they will not play the newer formats and the older formats will be illegal. So Palladium still might have the same negative effects, just on a much longer timescales.
Then again, you can always keep the older formats, but it will be just another reason for the feds to come knocking on your door.