You eyes focus on a 40 inch screen 3-4m away, however you brain thinks you are looking in the distance because the image is converging at a different point (not 3m away).
The way the brain processes stereo vision has little connection with the focussing of the eyes and the angle between your left and right eye.
I once attended a demonstration where we, wearing red/green glasses, were shown a stereoscopic image that appeared to be floating somewhere in front of us. The room was completely darkened to remove other depth cues and we were asked to estimate the distance. I remember that I was convinced that the object was floating at an arm's length in front of me, something that should have been pretty obvious from the focus of my eye and the angle between left and right eye. When the lights were switched on, it turned out that it was more like 3 meters away.
The nice thing about this is that 3D movies work both for people sitting in the front row and those in the back row of the cinema. Think about it.
As far as I understand, the EU sets fines proportional to the sales over the duration of the sales, with a proportionality constant dependent on how much the infringement hurt the market. Although not many details are published on the EU website so far (EU case on DRAM), the EU has published the guidelines for the fine calculation (Guidelines on the method of setting fines). More details on the settlement decision will follow.
Unless there are clear indications of the opposite, I would assume that the 330m euro was in proportion with the amount of extra profit that the companies made thanks to the cartel; without the cartel, the profits or losses of the companies would probably have been similar.
You're talking at least 10 watts per square meter, much more during the daytime.
I am reading this 10 W/m2 all the time in this discussion. It might be a reasonable estimate if the idea is that you visible illuminate the surface. However, with a clear sky, such a light source would look like someone was shining a laser pointer into your eye (e.g. 1 mW laser beam through your 0.25 cm2 pupil = 40 W/m2). You need much less power to make a very noticeable blinking star on the sky in the middle of the day, e.g. 10 mW/m2. Of course, if you flash that light with a 1:10 duty cycle over a 10x1000 km area, yous still need a couple of megawatts of power, but at least it is less infeasible than it may have seemed at first.
Of course, it won't help against tsunamis during a clouded sky.
5) Touch input. (...) Now put it upright like a computer screen and tell me how convenient, comfortable or accurate it is.
The cash registers in our company restaurant all use upright(-ish) touch screens. One of the cashiers told me that she tends to stick her fingers into her computer screen at home while web surfing. Here in Netherlands, most pubs and restaurants use computers with touch screens as well for keeping track of orders, although that is not continuous use.
That's funny, because two of them are designed to be visible regardless of color vision.;-)
This color-blind label does not mean we cannot tell the different between the two colors in real life.
There are actually four types of red-green color blindness, varying from missing either the red or green receptors to having mutated spectral response curves for either er dor green. According to Wikipedia, the most common type of color blindness (6% of the males) is one with a mutated green receptor, where there is only a problem in distinguishing subtle hue differences in red-yellow-green colors. Since you are able to read resistor color codes, you probably have this. Your personal observations are not necessarily representative of what people with other types of color blindness see. For example, I know people who can hardly see the red dot of a laser pointer (during a beamer presentation) due to a missing receptor for red.
I imagine there may even be some upside to fair complexions in cold weather
It's vitamin D production in the skin during exposure to sunlight. In climates with relatively little sun during the winter, a dark skin could lead to vitamin D deficiency.
There's a Volkswagen (Polo) they sell in Europe at the moment that in BlueMotion diesel tune will get 70, yes, 70 miles per gallon.... Also, despite the fact that Toyota claims 48 mpg in EPA testing, no respectable publication has come even close to that in real-world testing.
That's funny, because that webpage that you refer to states 39 mpg average up to 54 mpg for certain types of use for the Prius and 36 mpg average up to 39 mpg for the Polo.
It assumes that your mobile phone costs should be 0 when your usage is not 0.
I was recently in Norway and had to get a temporary phone due to problems with my own phone. I can attest that I got a plan that would let me call for free to other customers of the same operator. Of course, phone calls to landlines and other operators were not for free. I think I ended up paying €60 for a prepaid phone including an hour's worth of international calls within Europe.
(s= table height, let's say 0.8m)=4m/s to zero in about - well, let's say 1mm as this stuff gets rigid very quickly. This makes it face a deceleration of 8000g. Hell, let's say 5mm and it's still 1600g.
You are mixing g units (9.8 m/s^2) with SI units (m/s^2). The number of g's during deceleration is simply the ratio of fall height to deceleration distance. For 0.005 m, you get 0.8 m/0.005 = 160 g, which is something that a parked hard disk should be able to handle.
They're also super aggressive at that time of year and can sting repeatedly.
A yellowjacket will sting if provoked, for example if they are caught in your clothes or if you try to hit them. What usually makes me nervous is if someone starts to frantically wavie their arms in the air to chase them away. Staying calm never got me a sting. I did get stung when I badly disturbed a nest, but that is a different story.
picture going to work in a big city, in a high rise. Ride your bike to the building. Then, ride it inside, through the lobby, among the crowd. Ride it into the elevator, and then out of it again, down the hall and to your office.
That's exactly what people do with small folding bikes like the Brompton and the Strida...
Luminous efficiencies are indeed in that ball park, but it is a silly measure, since 100% is only possible with monochromatic green light. The theoretical maximum luminous efficiency of a white light source that covers the entire red-yellow-green-blue range of the spectrum is closer to 50%. That should really be the benchmark for indoor lighting, which means that you would have to multiply the luminous efficiencies by about a factor 2. If you want the light source to give the warm yellow color temperature of an incandescent light bulb rather than the hard white of LED lights, then the theoretical maximum luminous effciency is going to be even lower.
When the Ctrl keys are on the bottom row, because they're on the corners, I tend to hit them with my palms instead of my fingers so I don't have to move my hands so much.
I used to do that. It gave me a pretty bad RSI (fingers and arms hurting day and night, even after quitting keyboarding for a week) when I switched from single-tasking DOS to multi-tasking Linux. I then switched caps and control and moved to Dvorak layout, which did improve things for me.
thus the strength of the signal goes weaker as you increase the sphere from which it diffuse to.
Moreover, you would receive the combined signals of all radio and tv transmitters that use overlapping frequencies. Even if an alien could detect the signals, they wouldn't be able to demodulate them. At most, they would notice that there is a lot of RF noise in particular frequency bands coming from that particular planet.
As for the grandparent: all the example "men" jobs require a lot of physical strength, which is simply not so common among women.
As for the electronics assembly lines: I can think of two things: (1) women are less likely to make mistakes, and (2) small fingers are convenient when you have to handle small electronics parts. I think I have read both reasons somewhere, a long time ago.
Unfortunately, producing the massive amounts of white paint needed to paint all these surfaces and maintain them produces about as much CO2 as was saved by starting this excellent project.
You need about 100 g of paint to cover a square meter. Suppose that the paint costs 1 kg worth of fuel to manufacture. The amount of sunlight it reflects over 10 years in a sunny climate is on the order of 50 gigajoules, or about 1000 kg of fuel to burn. Even if only 10% of the heat has to be cooled away by airconditioning, it is a good deal: invest 1 kg of fuel; save 100 kg in fuel for the airconditioning. (I assume that the inefficiency of a power plant compensates the efficiency of a heat pump)
I'm not sure how making the pavement lighter will reduce CO2 emissions. It would reduce the greenhouse effect a bit due to less infared radiation being trapped - increasing the world's albedo by 1% or so would have a quite significant impact on the climate, but it is difficult to translate than into an absolute amount of CO2 emission.
Taxing profits does not mean labor reduction. [...] What REALLY happens is these companies are forced to cut dividends
Not necessarily. A book profit means that the balance (difference between assets and depts) increased. That could mean that the assets have increased because new equipment was bought from the cash income. Taxing profits means that young companies grow less. Profits are only paid out as dividends for mature companies that are not expanding anymore.
Elsevier is a major scientific publisher;... and university libraries will look more closely at the subscription package deals which is where the journal publishers make most of their money.
Well, ask any librarian who has to deal with Elsevier Science about their opinion. Elsevier is the Microsoft of the scientific press. Elsevier charges subscribers as much as they can afford, completely unrelated to the costs related to producing the journal. Typically, they will start a new journal, get some reputable professors to participate in the editorial board. If the journal has enough papers that are being cited, Elsevier increases the subscription price, knowing that a university that does research in the particular niche that the journal covers must have a subscription regardless of the price.
A while ago, I did a price comparison of a couple of journals. The (non-profit) American Physical Society publishes the reputable Physical Review journals (A-E and Letters). An institutional subscription (up to 500 people or so) costs about €0,10 per page IIRC. (There are quite a few pages per year, though) Science and Nature, published by for-profit companies, charge significantly more, I think around €0,60 per page. One of the more reputable Elsevier journals, Chemical Physics Letters, costs €2 per page! That means that a journal that has 5000 pages per year sets you back by 10 k per year. And those prices for Elsevier tend to increase every year.
It doesn't surprise me in the least that Elsevier would do something unethical that makes them money. If you're a scientist and considering to publish papers, avoid citing papers published in Elsevier journals and don't publish there yourself.
So if we want a cable capable of transmitting information at 1tbps, the cable will need a bandwidth of roughly 1000 GHz. That means that it would be impossible to carry that amount of information using even microwaves. We're talking about at minimum infrared light.
As others already pointed out, with a better S/N ratio you can lower the frequency bandwidth, although impedance mismatches become more of a problem. If you try to send a 250 GHz signal through the cable, the wavelength is about 1 mm, which means that an impedance fluctuation over roughly 0.5 mm is enough to create a significant reflection. That could happen if the distance between the two wires in the twisted pair varies a bit, if the cable is bent, etcetera.
Another problem is that a lot of materials tend to absorb radiation at that kind of frequencies, which means that the insulation around the wire will be heated by the signal that travels through the copper wire. It might be hard to get useful signals after more than a few meters of cable.
How hard would it be for a computer program to derive 3D information from a stereogram and make sense out of it?
Converting the stereogram into a depth map: not very hard I think; at least, easier than for most humans. You look for repeating patterns along horizontal lines. Depending on whether the pattern repeats itself squeezed or stretched, it corresponds to negative or positive depth changes. The next problem is interpreting the depth map as an image to answer the captcha challenge (Q: what do you see here? A: shark), but it would be much more user-friendly to present the depth map directly to the user. I once read about the idea generate pictures from 3-dimensional models with arbitrary angles of view ("mother with child viewed from above"). The brain is much better at recognizing such pictures than computer vision software. A problem is that the web server needs to judge whether the answer given by the visitor is correct with a close-to-zero chance of guessing correct.
I suppose that they did investigate the matter, but I wonder how this works. It's clear that there are a lot of watts being dissipated in the datacenter, but the problem is that they are dissipated against room temperature air. In order to heat houses with that, you have to use a heat pump which converts a heat flow at room temperature into a 65 C water that can easily be transported over large distances.
Normally, an airconditioning works as a heat pump that absorbs the heat by evaporating refrigerant slightly below room temperature (say 10 C), then compressing it so that it can condense and release the heat in an outdoor radiator at 40 C (ambient temperature up to 35 C). An ideal heat engine would be able to do this with an efficiency of 313 K/(40 C-10 C) = 10, which means that in order to displace 10 W of heat, you need to put in 1 W of mechanical work. I believe that a practical air-conditioning heat pump has an efficiency of 4 or so. Now in order to release the heat against 65 C (condensor temperature 75 C) instead of 35 C, the efficiency would halve. The work that you have to put into this heat engine comes from a power plant which itself has only 35% efficiency. So the balance would be:
Standard datacenter:
Server heat production: P
A/C electricity consumption: 0.25*P
Heat from burning fuel in power plant: 3.75*P
Datacenter with residential heating:
Server heat production: P
Heat pump electricity consumption: 0.6*P
Heat output to homes: 1.6*P (gain: 1.6*P)
Heat in power plant: 4.8*P (extra cost: 1.05*P)
Net gain: 0.55*P. For that you have to do all the infrastructure of big insulated hot-water pipes to residential areas and special heat pumps. It's not clear to me that this will pay off (in money and in environmental cost).
Shouldn't there be extra salt added at some point to the PIN before final hash is created?
The idea of a salt is that the salt is not very secret, but makes it infeasible to construct a dictionary of hashed keys. You don't need to construct a dictionary of hashes for PIN numbers since they are only 14 bits; trying the hash function for the whole key space with the known salt takes only a fraction of a second. If you want to keep the salt secret, then it isn't really a salt anymore but rather a private encryption key and you have to design a way to securely distribute those private keys from all possible bank systems to all the ATMs over the world. There are ways to do that, but you can't really call it a salt anymore.
Slashdot Mirror
The way the brain processes stereo vision has little connection with the focussing of the eyes and the angle between your left and right eye.
I once attended a demonstration where we, wearing red/green glasses, were shown a stereoscopic image that appeared to be floating somewhere in front of us. The room was completely darkened to remove other depth cues and we were asked to estimate the distance. I remember that I was convinced that the object was floating at an arm's length in front of me, something that should have been pretty obvious from the focus of my eye and the angle between left and right eye. When the lights were switched on, it turned out that it was more like 3 meters away.
The nice thing about this is that 3D movies work both for people sitting in the front row and those in the back row of the cinema. Think about it.
Well, the proportionality constant may be larger than 1. The upper limit is 30% of the sales value, which is usually much more than the profit.
As far as I understand, the EU sets fines proportional to the sales over the duration of the sales, with a proportionality constant dependent on how much the infringement hurt the market. Although not many details are published on the EU website so far (EU case on DRAM), the EU has published the guidelines for the fine calculation (Guidelines on the method of setting fines). More details on the settlement decision will follow.
Unless there are clear indications of the opposite, I would assume that the 330m euro was in proportion with the amount of extra profit that the companies made thanks to the cartel; without the cartel, the profits or losses of the companies would probably have been similar.
Not even so unrealistic if the US dollar starts to hyperinflate a due to the national debt. ;-)
I am reading this 10 W/m2 all the time in this discussion. It might be a reasonable estimate if the idea is that you visible illuminate the surface. However, with a clear sky, such a light source would look like someone was shining a laser pointer into your eye (e.g. 1 mW laser beam through your 0.25 cm2 pupil = 40 W/m2). You need much less power to make a very noticeable blinking star on the sky in the middle of the day, e.g. 10 mW/m2. Of course, if you flash that light with a 1:10 duty cycle over a 10x1000 km area, yous still need a couple of megawatts of power, but at least it is less infeasible than it may have seemed at first.
Of course, it won't help against tsunamis during a clouded sky.
The cash registers in our company restaurant all use upright(-ish) touch screens. One of the cashiers told me that she tends to stick her fingers into her computer screen at home while web surfing. Here in Netherlands, most pubs and restaurants use computers with touch screens as well for keeping track of orders, although that is not continuous use.
That's funny, because two of them are designed to be visible regardless of color vision. ;-)
There are actually four types of red-green color blindness, varying from missing either the red or green receptors to having mutated spectral response curves for either er dor green. According to Wikipedia, the most common type of color blindness (6% of the males) is one with a mutated green receptor, where there is only a problem in distinguishing subtle hue differences in red-yellow-green colors. Since you are able to read resistor color codes, you probably have this. Your personal observations are not necessarily representative of what people with other types of color blindness see. For example, I know people who can hardly see the red dot of a laser pointer (during a beamer presentation) due to a missing receptor for red.
It's vitamin D production in the skin during exposure to sunlight. In climates with relatively little sun during the winter, a dark skin could lead to vitamin D deficiency.
That's funny, because that webpage that you refer to states 39 mpg average up to 54 mpg for certain types of use for the Prius and 36 mpg average up to 39 mpg for the Polo.
I was recently in Norway and had to get a temporary phone due to problems with my own phone. I can attest that I got a plan that would let me call for free to other customers of the same operator. Of course, phone calls to landlines and other operators were not for free. I think I ended up paying €60 for a prepaid phone including an hour's worth of international calls within Europe.
You are mixing g units (9.8 m/s^2) with SI units (m/s^2). The number of g's during deceleration is simply the ratio of fall height to deceleration distance. For 0.005 m, you get 0.8 m/0.005 = 160 g, which is something that a parked hard disk should be able to handle.
A yellowjacket will sting if provoked, for example if they are caught in your clothes or if you try to hit them. What usually makes me nervous is if someone starts to frantically wavie their arms in the air to chase them away. Staying calm never got me a sting. I did get stung when I badly disturbed a nest, but that is a different story.
That's exactly what people do with small folding bikes like the Brompton and the Strida...
Luminous efficiencies are indeed in that ball park, but it is a silly measure, since 100% is only possible with monochromatic green light. The theoretical maximum luminous efficiency of a white light source that covers the entire red-yellow-green-blue range of the spectrum is closer to 50%. That should really be the benchmark for indoor lighting, which means that you would have to multiply the luminous efficiencies by about a factor 2. If you want the light source to give the warm yellow color temperature of an incandescent light bulb rather than the hard white of LED lights, then the theoretical maximum luminous effciency is going to be even lower.
I used to do that. It gave me a pretty bad RSI (fingers and arms hurting day and night, even after quitting keyboarding for a week) when I switched from single-tasking DOS to multi-tasking Linux. I then switched caps and control and moved to Dvorak layout, which did improve things for me.
Moreover, you would receive the combined signals of all radio and tv transmitters that use overlapping frequencies. Even if an alien could detect the signals, they wouldn't be able to demodulate them. At most, they would notice that there is a lot of RF noise in particular frequency bands coming from that particular planet.
As for the electronics assembly lines: I can think of two things: (1) women are less likely to make mistakes, and (2) small fingers are convenient when you have to handle small electronics parts. I think I have read both reasons somewhere, a long time ago.
You need about 100 g of paint to cover a square meter. Suppose that the paint costs 1 kg worth of fuel to manufacture. The amount of sunlight it reflects over 10 years in a sunny climate is on the order of 50 gigajoules, or about 1000 kg of fuel to burn. Even if only 10% of the heat has to be cooled away by airconditioning, it is a good deal: invest 1 kg of fuel; save 100 kg in fuel for the airconditioning. (I assume that the inefficiency of a power plant compensates the efficiency of a heat pump)
I'm not sure how making the pavement lighter will reduce CO2 emissions. It would reduce the greenhouse effect a bit due to less infared radiation being trapped - increasing the world's albedo by 1% or so would have a quite significant impact on the climate, but it is difficult to translate than into an absolute amount of CO2 emission.
And what happens to the connection of the other guy who had that IP address assigned to him?
By the way, wouldn't the mac address be sufficient? With DHCP you would get the rest of the settings, isn't it?
Not necessarily. A book profit means that the balance (difference between assets and depts) increased. That could mean that the assets have increased because new equipment was bought from the cash income. Taxing profits means that young companies grow less. Profits are only paid out as dividends for mature companies that are not expanding anymore.
Well, ask any librarian who has to deal with Elsevier Science about their opinion. Elsevier is the Microsoft of the scientific press. Elsevier charges subscribers as much as they can afford, completely unrelated to the costs related to producing the journal. Typically, they will start a new journal, get some reputable professors to participate in the editorial board. If the journal has enough papers that are being cited, Elsevier increases the subscription price, knowing that a university that does research in the particular niche that the journal covers must have a subscription regardless of the price.
A while ago, I did a price comparison of a couple of journals. The (non-profit) American Physical Society publishes the reputable Physical Review journals (A-E and Letters). An institutional subscription (up to 500 people or so) costs about €0,10 per page IIRC. (There are quite a few pages per year, though) Science and Nature, published by for-profit companies, charge significantly more, I think around €0,60 per page. One of the more reputable Elsevier journals, Chemical Physics Letters, costs €2 per page! That means that a journal that has 5000 pages per year sets you back by 10 k per year. And those prices for Elsevier tend to increase every year.
It doesn't surprise me in the least that Elsevier would do something unethical that makes them money. If you're a scientist and considering to publish papers, avoid citing papers published in Elsevier journals and don't publish there yourself.
As others already pointed out, with a better S/N ratio you can lower the frequency bandwidth, although impedance mismatches become more of a problem. If you try to send a 250 GHz signal through the cable, the wavelength is about 1 mm, which means that an impedance fluctuation over roughly 0.5 mm is enough to create a significant reflection. That could happen if the distance between the two wires in the twisted pair varies a bit, if the cable is bent, etcetera.
Another problem is that a lot of materials tend to absorb radiation at that kind of frequencies, which means that the insulation around the wire will be heated by the signal that travels through the copper wire. It might be hard to get useful signals after more than a few meters of cable.
Converting the stereogram into a depth map: not very hard I think; at least, easier than for most humans. You look for repeating patterns along horizontal lines. Depending on whether the pattern repeats itself squeezed or stretched, it corresponds to negative or positive depth changes. The next problem is interpreting the depth map as an image to answer the captcha challenge (Q: what do you see here? A: shark), but it would be much more user-friendly to present the depth map directly to the user. I once read about the idea generate pictures from 3-dimensional models with arbitrary angles of view ("mother with child viewed from above"). The brain is much better at recognizing such pictures than computer vision software. A problem is that the web server needs to judge whether the answer given by the visitor is correct with a close-to-zero chance of guessing correct.
I suppose that they did investigate the matter, but I wonder how this works. It's clear that there are a lot of watts being dissipated in the datacenter, but the problem is that they are dissipated against room temperature air. In order to heat houses with that, you have to use a heat pump which converts a heat flow at room temperature into a 65 C water that can easily be transported over large distances.
Normally, an airconditioning works as a heat pump that absorbs the heat by evaporating refrigerant slightly below room temperature (say 10 C), then compressing it so that it can condense and release the heat in an outdoor radiator at 40 C (ambient temperature up to 35 C). An ideal heat engine would be able to do this with an efficiency of 313 K/(40 C-10 C) = 10, which means that in order to displace 10 W of heat, you need to put in 1 W of mechanical work. I believe that a practical air-conditioning heat pump has an efficiency of 4 or so. Now in order to release the heat against 65 C (condensor temperature 75 C) instead of 35 C, the efficiency would halve. The work that you have to put into this heat engine comes from a power plant which itself has only 35% efficiency. So the balance would be:
Standard datacenter:
Server heat production: P
A/C electricity consumption: 0.25*P
Heat from burning fuel in power plant: 3.75*P
Datacenter with residential heating:
Server heat production: P
Heat pump electricity consumption: 0.6*P
Heat output to homes: 1.6*P
(gain: 1.6*P) Heat in power plant: 4.8*P (extra cost: 1.05*P)
Net gain: 0.55*P. For that you have to do all the infrastructure of big insulated hot-water pipes to residential areas and special heat pumps. It's not clear to me that this will pay off (in money and in environmental cost).
The idea of a salt is that the salt is not very secret, but makes it infeasible to construct a dictionary of hashed keys. You don't need to construct a dictionary of hashes for PIN numbers since they are only 14 bits; trying the hash function for the whole key space with the known salt takes only a fraction of a second. If you want to keep the salt secret, then it isn't really a salt anymore but rather a private encryption key and you have to design a way to securely distribute those private keys from all possible bank systems to all the ATMs over the world. There are ways to do that, but you can't really call it a salt anymore.