He also assumes the military will always be on the side of the government. We have a hard enough time getting people to volunteer to shoot foreigners. Try convincing them to shoot Americans.
If this stands? It hasn't even occurred yet. It's simply conjecture at this point. We have no idea what evidence they have that useful data is contained in the encrypted drive, what evidence they have that the subject does or does not remember the password, or what the judge will do about it.
All they have to say is "We believe this file is encrypted using stenography, give us the password"
In theory. In practice, the judge, prosecutor, and investigator on the case are unlikely to keep their jobs long once the defendant's lawyer plays up the case in the media.
"The defendant has truecrypt in his possession and we believe he has a hidden volume, give us the password'
They'd also need to produce a file that is likely to be a TrueCrypt container -- sufficiently large and high-entropy. Evidence that the TrueCrypt software was also used instead of just installed would help.
It depends. If you have reason to believe that you will be arrested and it will be seized as evidence, then "maybe". If you're simply cleaning up your drives, then "probably not". Where of course "you have reason to believe" is really "your lawyer is able to convince a judge that you had reason to believe". As far as I know, spoliation charges are usually only pursued in cases where they could demonstrate that the suspect was blatantly and knowingly destroying evidence.
The legal system is not as mathematically-driven as you'd like it to be.
Let's say you have a bunch of files of different sizes on your disk that appear to contain random data. Okay, do you have TrueCrypt on your system? Do Windows registry entries suggest you've mounted TrueCrypt disks before? Does the investigator have information that suggests that you have some cache of hidden data that contains evidence relevant to the case?
If there's evidence that you've accessed files on a TrueCrypt volume, you have TrueCrypt installed, you have large random-seeming data files on your hard drive, and the investigator believes that case-relevant data is in an encrypted volume, they're probably going to try to make you decrypt the volumes.
If there is no such evidence, you don't have TrueCrypt on your system, and you claim that you created large random data files on your hard drive just to annoy future investigators, they probably aren't going to try to make you decrypt the volumes.
Right. The public offering is $5B in shares. The market cap of the preexisting shares is not a part of the public offering. It's often the number bandied about during an IPO, but it is not the actual size of the IPO.
The problem they discovered in Germany (using microwave scanners) is actually the opposite: the false positive rate is too high. This isn't something you'd normally associate with "doesn't work", but is a legitimate concern.
The radiation you get from airplane travel is full-body and full-spectrum, consisting of X-Rays, Gamma rays, radio waves, and everything in between.
This is why such things are all converted into rem, which is an adjustment for the type and energy of radiation and what part of the body is being irradiated. So that they can be compared more or less directly.
The radiation you get from the terahertz scanners deposits all of its energy into your skin, in a small band of frequencies. That makes it potentially more likely to cause skin cancer than the broadband, full body radiation you get from air travel.
For one, the broad-spectrum radiation from the Sun is deposited at a variety of depths. It's not strictly full-body. For example, the THz radiation from the Sun is deposited in the skin with the exact same depth profile as the THz radiation from a scanner. While I don't know the specific details, most of the energy from the Sun will also be deposited at the skin layer. Penetration depth increases as energy increases and, as a black-body radiator, the Sun's energy is weighted toward lower-energy radiation. (You shouldn't be surprised that this is the case -- the sort of cancer you frequently get from exposure to the Sun is skin cancer.)
For another, THz radiation is below the ionization threshold, so it's enormously less likely to give you skin cancer than radiation from the Sun. By "enormously less likely", I mean that there is no mechanism that we have discovered that would cause sub-ionizing radiation to cause cancer. It's radiation in the same sense that your WiFi antenna and your incandescent lightbulb produce radiation.
It's just "Stasi" -- it's not an acronym. (It's short for Staatssicherheit, which in turn is short for Ministerium für Staatssicherheit, which roughly translates to National Security Agency -- well, Ministry of State Security.)
People have already answered, but there's no ads in Netflix streaming. To be fair, Netflix didn't put the ads in their discs, either. They don't make the discs, they just rent them out.
I had almost forgotten that DVDs had ads or unskippable material, thanks to playing everything with mplayer.
It cannot, it can only be used to make it more difficult. If your computer is one of the endpoints for an SSL connection, you have access to the cryptographic material necessary to decrypt the communication. (Obviously, since both the endpoint and the monitor are software running on your computer.) It's just tricky, but some traffic-capture software will decrypt SSL connections using just such techniques.
Of course, for a Web browser it's a lot easier. Take an open-source web browser and hack it to record the SSL traffic. Obviously your browser need to be able to decrypt the SSL, and you're able to modify your browser. The reason people don't bother with this is that tricking your browser into thinking that the bank is telling you "yes, you totally have a million dollars" doesn't do anything. It just displays text on your screen.
Intercepting the DRM communications, on the other hand, is more useful. Unless critical game data is provided to you during this online exchange, though, it would be easier to hack the game to not bother contacting the server in the first place.
Yeah, I also buy the 160 T. 1/10 is an interesting figure. Of course the capacity of the oceans is enormous compared to the atmosphere; the controlling factor there will be how rapidly heat can actually flow into the oceans.
Yep. The hydrogen fusion reaction doesn't produce much light at visible wavelengths. Just like with anything in space, the sun only loses energy through radiation (and particle loss), so it heats up until its radiation balances the energy production (to be fair, this only gets you the surface temperature of the sun). More or less.
You can easily get lost in the "large objects produce larger numbers than you would have guessed, human" game. For example, figure out how much force solar radiation exerts (just in the form of light, since light carries momentum) on the Earth.
Yes, the Earth subtends a ridiculously small area, so the Sun is belting out an enormous quantity of energy -- so much that it's a lot of mass just in energy.
This is actually a decent way of working out the Sun-Earth thermal equilibrium, since from the color of the sun you can guess its temperature (very roughly) and thus its black-body radiation (which is more or less what solar radiation is), which lets you work out without measurement how much energy the Earth receives from the Sun.
Incidentally, your posts are starting at Score: 2. If you look at the comment overview on your page, though, the karma bonus is not included. (As a result, if you hit the cap of 5, which includes the karma bonus, it will show up on that page as capped at a score of 4.)
Not necessarily. I certainly don't buy numbers just because a scientician was quoted in a BBC article. But the point is that 160 tons is not an unreasonable quantity of heat.
Who says adding heat to matter doesn't increase its weight? Although it's not reasonable to talk about the "weight" of things that are that large, it's better to speak of mass.
It seems clear to me that the temperature of the earth is going to be vary wildly depending on albedo/reemission, which life on earth affects by varying the composition of the atmosphere and surface reflection.
Albedo and emissivity are basically what controls the temperature of the Earth. You do have to remember, though, that both the enormous thermal mass of the Earth and weird feedback effects can make this progress differently. (For example, CO2 in the atmosphere increases the albedo-emissivity gap, which increases the temperature of the earth. A higher temperature causes more CO2 to be dissolved into ocean water, which decreases the amount of CO2 in the atmosphere -- though not by nearly as much as what was added initially. Feedbacks get much more complicated, though.)
Fortunately, albedo and emissivity don't change a huge amount, so the Earth stays vaguely in thermal equilibrium (by radiating away heat via black-body radiation).
They are calculating the warming of the entire planet, including the core.
Where's it say that?
Also, I gave figures for warming the air only, no water or land. It's a back-of-the-envelope calculation to see if you're within a few orders of magnitude. If you're within 3 or 4 orders of magnitude, you need to work out whether your estimate is accurate enough, and mine isn't, by a long shot.
The better way to approach this is probably to look at the difference between solar insolation and thermal radiative losses to space, since those are easier to measure than what mass of the Earth is heating up how much. I didn't have radiative-loss estimates on hand, though.
It would take thousands to millions of years for a one degree average surface temperature change to work it's way through the entire planet.
Who said this had to be the case? Can you get 160 tons (in energy) of heat by heating only the atmosphere? Atmosphere plus surface water and land? What does it take?
Without data, you're just making shit up based on a guess.
Solar energy, however, does increase Earth's mass via energy, and a byproduct of that energy is global warming
That's what man-made global warming is. (The term "anthropogenic" is better here to imply that it's man-caused and not man-made.) We do things that increase the fraction of the heat from solar radiation that remains on Earth*. The Sun then causes Earth's temperature to increase.
* Specifically, since Earth is more or less in a vacuum, its entire thermodynamic exchange consists of radiation: (a) the Sun irradiating the Earth, adding energy and (b) Earth radiating out into space. Factor (a) is basically a constant (solar irradiation * Earth cross-sectional area) times some things that are variable: like reflectivity. Factor (b) is roughly black-body radiation: Stefan-Boltzmann constant * emissivity * T^4, where emissivity is the thing that is annoyingly complicated. The average temperature of the Earth is the value of T such that (a) = (b); that is, the Earth is in thermal equilibrium.
This estimate would be vaguely correct if you used the Earth's surface area. However, the Earth's cross-sectional area is area of the 2D disc that is formed by a meridian. The area of solar radiation it absorbs is exactly its cross-sectional area. (What part of the surface that happens to be changes as time passes and a unit of sunlight is spread over a larger surface around the edges, but the total area is constant and is simply the cross-sectional area.)
You'd have to heat 10^19 kg of air (air only) by 1 K to increase its mass by 160 ton. [ (160 ton * c^2) / (N_A * k_B * 1 K) * (29 g/mol) = 4.6 * 10^19 kg ] The mass of Earth's atmosphere is 10^18 kg (5 * 10^18 kg). So it's well within the realm of "you'd need to analyze this more carefully".
And warming the earth doesn't make it more massive.
It does if the energy comes from an outside source (the Sun). Mass and energy are the same. Increasing the energy of something increases its mass. Temperature is just an abstraction of kinetic energy of particles, so increasing the temperature of a collection of particles is the same as increasing their kinetic energies. Thus, increasing the temperature of something increases its mass.
So now burning (hint, just a chemical action) some dead dinosaur is releasing the energy equivilent of 160 TONNES? Eh?
No. Burning is mass-neutral. Not only is it chemical, as you point out, but the energy released during burning is still in Earth, so by mass-energy-conservation, the total mass of the Earth is unchanged.
It's the increasing average temperature of the Earth that causes the increase in mass. That temperature increase is not energy released from burning fuel, but rather additional energy captured from solar radiation (as a result of increased atmospheric CO2). So ultimately all the additional mass is coming from solar radiation.
160 tons of mass ~= 10^22 J Solar irradiance over the surface of the Earth ~= 10^17 W ~= 10^24 J/yr
Math people, try it sometime.
I see that you didn't take your own advice. I see no math in your post whatsoever, despite the fact that 1 kg of mass in energy is easy to compute and the total energy used by civilization has been estimated before.
IF one assumes AGW the mass of heating the crust and atmosphere of the earth a tiny fraction of a degree per year isn't going to give tons either.
Slashdot Mirror
He also assumes the military will always be on the side of the government. We have a hard enough time getting people to volunteer to shoot foreigners. Try convincing them to shoot Americans.
If this stands? It hasn't even occurred yet. It's simply conjecture at this point. We have no idea what evidence they have that useful data is contained in the encrypted drive, what evidence they have that the subject does or does not remember the password, or what the judge will do about it.
All they have to say is "We believe this file is encrypted using stenography, give us the password"
In theory. In practice, the judge, prosecutor, and investigator on the case are unlikely to keep their jobs long once the defendant's lawyer plays up the case in the media.
"The defendant has truecrypt in his possession and we believe he has a hidden volume, give us the password'
They'd also need to produce a file that is likely to be a TrueCrypt container -- sufficiently large and high-entropy. Evidence that the TrueCrypt software was also used instead of just installed would help.
It depends. If you have reason to believe that you will be arrested and it will be seized as evidence, then "maybe". If you're simply cleaning up your drives, then "probably not". Where of course "you have reason to believe" is really "your lawyer is able to convince a judge that you had reason to believe". As far as I know, spoliation charges are usually only pursued in cases where they could demonstrate that the suspect was blatantly and knowingly destroying evidence.
The legal system is not as mathematically-driven as you'd like it to be.
Let's say you have a bunch of files of different sizes on your disk that appear to contain random data. Okay, do you have TrueCrypt on your system? Do Windows registry entries suggest you've mounted TrueCrypt disks before? Does the investigator have information that suggests that you have some cache of hidden data that contains evidence relevant to the case?
If there's evidence that you've accessed files on a TrueCrypt volume, you have TrueCrypt installed, you have large random-seeming data files on your hard drive, and the investigator believes that case-relevant data is in an encrypted volume, they're probably going to try to make you decrypt the volumes.
If there is no such evidence, you don't have TrueCrypt on your system, and you claim that you created large random data files on your hard drive just to annoy future investigators, they probably aren't going to try to make you decrypt the volumes.
Sinogenic.
Right. The public offering is $5B in shares. The market cap of the preexisting shares is not a part of the public offering. It's often the number bandied about during an IPO, but it is not the actual size of the IPO.
The problem they discovered in Germany (using microwave scanners) is actually the opposite: the false positive rate is too high. This isn't something you'd normally associate with "doesn't work", but is a legitimate concern.
The radiation you get from airplane travel is full-body and full-spectrum, consisting of X-Rays, Gamma rays, radio waves, and everything in between.
This is why such things are all converted into rem, which is an adjustment for the type and energy of radiation and what part of the body is being irradiated. So that they can be compared more or less directly.
The radiation you get from the terahertz scanners deposits all of its energy into your skin, in a small band of frequencies. That makes it potentially more likely to cause skin cancer than the broadband, full body radiation you get from air travel.
For one, the broad-spectrum radiation from the Sun is deposited at a variety of depths. It's not strictly full-body. For example, the THz radiation from the Sun is deposited in the skin with the exact same depth profile as the THz radiation from a scanner. While I don't know the specific details, most of the energy from the Sun will also be deposited at the skin layer. Penetration depth increases as energy increases and, as a black-body radiator, the Sun's energy is weighted toward lower-energy radiation. (You shouldn't be surprised that this is the case -- the sort of cancer you frequently get from exposure to the Sun is skin cancer.)
For another, THz radiation is below the ionization threshold, so it's enormously less likely to give you skin cancer than radiation from the Sun. By "enormously less likely", I mean that there is no mechanism that we have discovered that would cause sub-ionizing radiation to cause cancer. It's radiation in the same sense that your WiFi antenna and your incandescent lightbulb produce radiation.
Nominally, yes. It depends on how each is implemented.
It's just "Stasi" -- it's not an acronym. (It's short for Staatssicherheit, which in turn is short for Ministerium für Staatssicherheit, which roughly translates to National Security Agency -- well, Ministry of State Security.)
People have already answered, but there's no ads in Netflix streaming. To be fair, Netflix didn't put the ads in their discs, either. They don't make the discs, they just rent them out.
I had almost forgotten that DVDs had ads or unskippable material, thanks to playing everything with mplayer.
It cannot, it can only be used to make it more difficult. If your computer is one of the endpoints for an SSL connection, you have access to the cryptographic material necessary to decrypt the communication. (Obviously, since both the endpoint and the monitor are software running on your computer.) It's just tricky, but some traffic-capture software will decrypt SSL connections using just such techniques.
Of course, for a Web browser it's a lot easier. Take an open-source web browser and hack it to record the SSL traffic. Obviously your browser need to be able to decrypt the SSL, and you're able to modify your browser. The reason people don't bother with this is that tricking your browser into thinking that the bank is telling you "yes, you totally have a million dollars" doesn't do anything. It just displays text on your screen.
Intercepting the DRM communications, on the other hand, is more useful. Unless critical game data is provided to you during this online exchange, though, it would be easier to hack the game to not bother contacting the server in the first place.
Yeah, I also buy the 160 T. 1/10 is an interesting figure. Of course the capacity of the oceans is enormous compared to the atmosphere; the controlling factor there will be how rapidly heat can actually flow into the oceans.
Yep. The hydrogen fusion reaction doesn't produce much light at visible wavelengths. Just like with anything in space, the sun only loses energy through radiation (and particle loss), so it heats up until its radiation balances the energy production (to be fair, this only gets you the surface temperature of the sun). More or less.
You can easily get lost in the "large objects produce larger numbers than you would have guessed, human" game. For example, figure out how much force solar radiation exerts (just in the form of light, since light carries momentum) on the Earth.
Yes, the Earth subtends a ridiculously small area, so the Sun is belting out an enormous quantity of energy -- so much that it's a lot of mass just in energy.
This is actually a decent way of working out the Sun-Earth thermal equilibrium, since from the color of the sun you can guess its temperature (very roughly) and thus its black-body radiation (which is more or less what solar radiation is), which lets you work out without measurement how much energy the Earth receives from the Sun.
Incidentally, your posts are starting at Score: 2. If you look at the comment overview on your page, though, the karma bonus is not included. (As a result, if you hit the cap of 5, which includes the karma bonus, it will show up on that page as capped at a score of 4.)
Not necessarily. I certainly don't buy numbers just because a scientician was quoted in a BBC article. But the point is that 160 tons is not an unreasonable quantity of heat.
Who says adding heat to matter doesn't increase its weight? Although it's not reasonable to talk about the "weight" of things that are that large, it's better to speak of mass.
It seems clear to me that the temperature of the earth is going to be vary wildly depending on albedo/reemission, which life on earth affects by varying the composition of the atmosphere and surface reflection.
Albedo and emissivity are basically what controls the temperature of the Earth. You do have to remember, though, that both the enormous thermal mass of the Earth and weird feedback effects can make this progress differently. (For example, CO2 in the atmosphere increases the albedo-emissivity gap, which increases the temperature of the earth. A higher temperature causes more CO2 to be dissolved into ocean water, which decreases the amount of CO2 in the atmosphere -- though not by nearly as much as what was added initially. Feedbacks get much more complicated, though.)
Fortunately, albedo and emissivity don't change a huge amount, so the Earth stays vaguely in thermal equilibrium (by radiating away heat via black-body radiation).
They are calculating the warming of the entire planet, including the core.
Where's it say that?
Also, I gave figures for warming the air only, no water or land. It's a back-of-the-envelope calculation to see if you're within a few orders of magnitude. If you're within 3 or 4 orders of magnitude, you need to work out whether your estimate is accurate enough, and mine isn't, by a long shot.
The better way to approach this is probably to look at the difference between solar insolation and thermal radiative losses to space, since those are easier to measure than what mass of the Earth is heating up how much. I didn't have radiative-loss estimates on hand, though.
Without working it out, how do you know?
It would take thousands to millions of years for a one degree average surface temperature change to work it's way through the entire planet.
Who said this had to be the case? Can you get 160 tons (in energy) of heat by heating only the atmosphere? Atmosphere plus surface water and land? What does it take?
Without data, you're just making shit up based on a guess.
Solar energy, however, does increase Earth's mass via energy, and a byproduct of that energy is global warming
That's what man-made global warming is. (The term "anthropogenic" is better here to imply that it's man-caused and not man-made.) We do things that increase the fraction of the heat from solar radiation that remains on Earth*. The Sun then causes Earth's temperature to increase.
* Specifically, since Earth is more or less in a vacuum, its entire thermodynamic exchange consists of radiation: (a) the Sun irradiating the Earth, adding energy and (b) Earth radiating out into space. Factor (a) is basically a constant (solar irradiation * Earth cross-sectional area) times some things that are variable: like reflectivity. Factor (b) is roughly black-body radiation: Stefan-Boltzmann constant * emissivity * T^4, where emissivity is the thing that is annoyingly complicated. The average temperature of the Earth is the value of T such that (a) = (b); that is, the Earth is in thermal equilibrium.
This estimate would be vaguely correct if you used the Earth's surface area. However, the Earth's cross-sectional area is area of the 2D disc that is formed by a meridian. The area of solar radiation it absorbs is exactly its cross-sectional area. (What part of the surface that happens to be changes as time passes and a unit of sunlight is spread over a larger surface around the edges, but the total area is constant and is simply the cross-sectional area.)
To add more math:
You'd have to heat 10^19 kg of air (air only) by 1 K to increase its mass by 160 ton. [ (160 ton * c^2) / (N_A * k_B * 1 K) * (29 g/mol) = 4.6 * 10^19 kg ] The mass of Earth's atmosphere is 10^18 kg (5 * 10^18 kg). So it's well within the realm of "you'd need to analyze this more carefully".
And warming the earth doesn't make it more massive.
It does if the energy comes from an outside source (the Sun). Mass and energy are the same. Increasing the energy of something increases its mass. Temperature is just an abstraction of kinetic energy of particles, so increasing the temperature of a collection of particles is the same as increasing their kinetic energies. Thus, increasing the temperature of something increases its mass.
So now burning (hint, just a chemical action) some dead dinosaur is releasing the energy equivilent of 160 TONNES? Eh?
No. Burning is mass-neutral. Not only is it chemical, as you point out, but the energy released during burning is still in Earth, so by mass-energy-conservation, the total mass of the Earth is unchanged.
It's the increasing average temperature of the Earth that causes the increase in mass. That temperature increase is not energy released from burning fuel, but rather additional energy captured from solar radiation (as a result of increased atmospheric CO2). So ultimately all the additional mass is coming from solar radiation.
160 tons of mass ~= 10^22 J
Solar irradiance over the surface of the Earth ~= 10^17 W ~= 10^24 J/yr
Math people, try it sometime.
I see that you didn't take your own advice. I see no math in your post whatsoever, despite the fact that 1 kg of mass in energy is easy to compute and the total energy used by civilization has been estimated before.
IF one assumes AGW the mass of heating the crust and atmosphere of the earth a tiny fraction of a degree per year isn't going to give tons either.
See, here math would have been useful.