If you go to https://facebook.com/ you do view an encrypted home page. But all of the links to everything are just non-encrypted http. Unless you copy each link, paste it into the address bar, and prepend 'https://' to it (or write a browser script to do the same) then most of your facebook session will not be secured.
Water has a pretty high thermal mass so I don't think variable temperatures are anything to worry about
Sure water has a high thermal mass, but solar power irradiates the earth to the tune of ~1kW/m^2. That's why you can use a solar pool cover (essentially heavy duty bubble wrap - allows radiation in, limits convection out) to heat an 8 foot deep pool to over 105F on a hot summer day (in my experience). Most bio-reactors must have actively controlled temperatures to optimize production. The reality is it heavily depends on the volume to solar-incident surface area ratio they choose and the temperature sensitivity of the cyanobacteria they have engineered, details which will determine the presence/cost of cooling system.
Biocontamination can be dealt with fairly easily, by sequestration and redundancy.
This makes scaling much more difficult, since instead of increasing the size of each bioreactor you are instead proposing to build a lot of little ones, each of which must be separately monitored and maintained.
Waste product removal is a halfway interesting problem, but I'd bet Kevin Costner is working on it as we speak.
It's more than halfway interesting, it's a key factor in the viability of the system. If they can't remove the hydrocarbons and other waste products efficiently, then this scheme just won't work at all.
more of a political stunt, as it has always been the case with these "space missions".
Funding agencies are risk-averse. It may seem like a waste of time and money to conduct such a test, but now when the Russian space agency asks for money for a Mars mission from their government, they can point to this study as addressing one of the risk factors of this mission.
The government gave them the money to perform this study because the study itself is low-risk and will give them a much better idea how a large 6-person crew will perform under the simulated conditions.
It's all about taking small steps so that eventually mankind can take a giant leap.
Yeah, it's a trip to Mars - minus the lack of gravity, minus the cosmic radiation, minus the occasional pebble whizzing by at thousands of miles per hour, minus the constant knowledge that a few millimeters of metal alloy separates you from pretty much instant death at all times.
Surprisingly enough death isn't actually very quick in the vacuum of space (ref). You would maintain consciousness for about 15 seconds and be able to take actions which may save your life, and even after unconsciousness you would most likely survive without significant injury if returned to an atmospheric environment within about 90 seconds.
Apple effectively has 4 products. iPods, iPhones, iPads, and laptop/desktops.
You forgot about iTunes, which is estimated to have generated a revenue of $1.8 Billion in 2009. Sure the total revenue may not be as large as total hardware revenue, but it's not chump change either.
My big question is what is the payout rules? Do they deposit the money in my checking account automatically? Or do you have to have a minimum sales amount before they'll cut a check?
Having sold some textbooks through Amazon Marketplace they automatically transfer your funds every 14 days, and you can also have your funds transferred as fast as once per day. Here is how Amazon describes it.
This app marketplace might be run differently, but this is probably a good guideline for how they will disburse funds.
You're right, I apologize, all of my CNN money numbers are 1 year off because the numbers are posted in 2010 for 2009 by CNN money, and I didn't notice initially that they organize by posting year, not earning year.
I couldn't find a definitive number for Exxon's 2010 profit, but it looks like it is on track for about $26 billion profit. Much like previous years, still larger than Apple but at a lower profit margin.
Thinking longer term I don't think Apple's growth will reflect the growing markets of China and India, but Exxon Mobil will certainly continue to benefit from the increased oil consumption.
Granted Apple has done quite well in the MP3 player market, and with its excellent profit margin it is certainly an extremely successful company. But let's compare Apple (market cap $296 billion) to Exxon Mobil (market cap $377 billion).
Furthermore, surgeries are scheduled by days of the week - you will have (e.g.) one room on Mondays, two rooms on Tuesdays, and one room on Friday afternoons. Regardless of what night you're on call, that's when you can operate. Since surgeons only make money when they operate, there is an enormous incentive not to miss an operative day.
This sounds like the crux of the problem: inflexible scheduling is forcing surgeons to choose between losing money and inconveniencing patients or operating while sleep deprived. I know that schedules often need to shift around, but it seems to me like they could simply schedule on-call around the surgery schedule, which is probably easier than the reverse. For example, if you're operating on Monday and Tuesday morning then someone else is on call on Sunday and Monday nights, then that guy operates on Wednesday and Thursday after a guaranteed night of sleep, when it's you who is on call.
I have no particular knowledge of the hospital industry, but would this not work? Or are surgeons operating on too many days of the week to make this possible?
I'm pretty sure that machines were used in Europe, the Luddites were not successful. Although they had the right intentions: machinery lowered the pay and job security of the workers for the benefit of the mill owners.
You left out the part about the dramatic rise in living standards thanks to this industrialization. Peasants/the proletariat/minimum wage workers have always been abused by those with more power and industrialization didn't change this fact. Unions rose up to fight for the factory workers, and then things got better for them, and progress marched forwards.
What I'm wondering, is why Americans on Internet forums are so unknowledgeable about the things they talk about. It seems the less they know about a topic, the more passionately they talk about it.
This sweeping generalization pegs you as just as ignorant and arrogant as the stereotype you seem to hold of Americans. Don't blame the level of discourse on the internet just on the Americans, because there are stupid people all over the world.
Replying to undo moderation, I marked you "informative" but I meant to mark "funny".
P.S., does anybody know how to undo moderation in the current system? In the old one I had to press the moderation button. Now the moderation is immediate once I select from the pop-down menu and I don't see a way to undo it...
Is it also your humble opinion that textbooks can be photocopied for free for in-class use? Exactly where you draw the line on fair use is a tricky thing. Suppose a teacher buys one copy of a sheet music book and photocopies it for 30 students. Maybe that's okay. Now maybe a school buys one copy of the book and photocopies it for 5 classes of 30 students each. Next maybe the school district buys one copy and photocopies it for dozens of schools, ending up with hundreds or thousands of photocopies of the original.
I don't think there is any question that a line must be drawn between fair use and infringement in these cases. Is there a specific number of copies that you would draw it at? One copy, one class's worth of copies, 50, 100?
For a book of sheet music of children's songs, schools may comprise a big portion of their customer base. The money from sale of the book must go to many people/entities after the retailer makes their cut: composer, arranger, editor, graphic designer, book layout, and ultimately a cut to the publisher as their profit for licensing the work and hiring the necessary people and managing them to a finished product. Maybe in this day and age it could be made more efficient with artists selling their sheet music online, but if you buy a book then you are taking the work of all those people I mentioned, and those people deserve compensation for their work. If you don't want to compensate them just don't use their work, use somebody else's.
I know that in the USA there are some fair-use copyright exemptions specifically for academic use, this seems like it can be solved in one of two ways: the German government can enact a specific law governing how fair use applies to this situation, such as purchasing one song book per class of up to 40 students which the teacher can then copy up to 40 times per year; Or the publishers can sell an edition of their songbooks which may cost more and is specifically licensed to be copied for classroom usage. I know that some teacher's editions of textbooks, solution manuals, and the like typically contain some language about what constitutes fair-use copying.
Same accelerator concept though. Maybe what they have built is flexible enough to handle both roles.
No, they're not the same concept, and the electromagnetic plane launcher that they are building here cannot readily be re-purposed as a railgun.
The EMALS (electromagnetic air launch system) is a Linear Induction Motor which works just like a standard AC motor except it has been laid out flat instead of in a circle. The launch carriage has a set of alternating magnetic poles (the stator) and it is driven by a series of series of coils which are driven with the appropriate AC waveform as the carriage passes overhead.
A Railgun contains no permanent magnets, it uses a current through the projectile (or through a projectile carrier) to create a Lorentz force with the current in the rails which propels the projectile.
In principle one could attempt to design a linear induction motor as a weapon, but since the point of a railgun is to achieve extremely high exit velocity (current Navy efforts have achieved on the order of 2.5km/s, shooting for 5km/s) it will be very challenging to achieve the appropriate rise/fall times in the driving coils. The need for permanent magnets in the projectile are also a problem, and I imagine there would be issues with magnetic fields saturating the projectile unless the magnitudes are limited, meaning the weapon must be longer.
I could see a role for LIM directly as a weapon only if there were some application where you need to launch a relatively very heavy projectile at relatively small exit velocity.
The square cube law is always the elephant in the room when people start talking about 3D circuits. It is certainly a problem, but the field is still open to improvements. For example, the "through silicon via" process presumably means they etch a via entirely through a silicon wafer and plate it with a metal. These could also be used as heatsinking aids and not just ways to transfer signals through vertically stacked chips, and though some surface area is consumed it may be more than made up for by the vertical stacking. There are researchers working on micro-/nano-scale structures which have greatly enhanced thermal conductivities which can be useful for 3D integration.
I assume it is not thermal noise which needs to be overcome, it is probably thermally-induced leakage current which requires the use of higher voltage to increase the difference between a "1" and a "0", because at higher temperatures more electrons have enough energy to jump the barrier of an off-state transistor, making the 0 more of a 0.5 for example. Although both result from thermal processes, they are significantly different effects. (disclaimer: I am not a VLSI engineer).
The last photonics researcher I talked to was of the opinion that photonic transistors are still a pipe dream... but many researchers and big companies are making steady process to replacing off-chip interconnects with photonic modules.
Disclaimer: I'm not a power engineer but I am an electrical engineer, so while the principles I state are probably correct there is some guesswork as I apply it to power transmission.
However, wires have capacitance.
Yes, all wires have a certain capacitance and inductance per length. Given the very wide separation between the power line and ground the capacitance per length should be very small, since it is inversely proportional per distance. Given the wide area the current encloses, the inductance will conversely be large. Therefore I would guess that the inductance of the transmission line is more important than its capacitance, and that it can be modeled primarily as a resistance in series with an inductance.
Overcoming that capacitance requires energy, which is an inefficiency.
Correct, though I'd like to add to that. An ideal capacitor is a lossless device (if you bring up the "two capacitor problem" note that by definition the capacitors or the wires connecting them cannot be lossless or it would never reach steady state). However in any AC transmission there will be conductor loss due to the resistance of the wire, possibly increased by skin effect, and dielectric loss due to the changing polarization of polar molecules in the dielectric surrounding the wire. Air is a virtually lossless dielectric. The wire's insulation is not going to be lossless, but since dielectric loss is usually proportional to frequency and 60Hz is very low frequency, and the insulator is small, I would guess that conductor loss dominates. And since frequency is very low skin effect may be negligible and we can just use the DC resistance.
One more note is that most loads are inductive (ballasts for flourescent lights, motors for air conditioners, motors for industrial equipment, transformers, etc) and this is probably going to dominate the power factor of power transmission much more than the reactance of the power transmission lines themselves. That's why most load compensation is in the form of added shunt capacitance.
Of course there are still many advantages of DC transmission, but for power lines on poles I wouldn't be convinced of frequency-dependent loss playing a large role unless I saw a full analysis.
Im surprised the defense hasnt considered a "substantial non-infringing uses" defense. For instance playing backup disks and homebrew. The well known issue of scratched disks, and the desire for interoperability with non-microsoft approved software. This is separate from "fair use" in that the illegality of the mod chip itself is challenged.
It's such a good idea that the defendant was already planning to use it in his defense:
The judge on Wednesday even backtracked on an earlier ruling that had prohibited Crippen, 28, from raising a “fair use” defense at trial.
Crippen was hoping to argue to jurors that it was legal to hack the consoles because the modification had non-infringing purposes, like allowing the machines to run homebrew software, or permitting limited fair use of copyright material such as backup copies of video games.
The metal connections are certainly fast enough, after all the signals on the metal lines will travel at a fraction of the speed of light divided by the index of refraction of the surrounding dielectric medium, same as an optical waveguide.
But there are two important problems which this does not address: loss and crosstalk.
Because the conductor loss is very significant for metal interconnects, much more power is consumed in long interconnects. This power consumption only increases with transistor density as wires get narrower, and minimizing power dissipation is one of the major challenges in continuing to scale chips smaller and smaller. The resistance also introduces an RC charging time constant when driving the gate capacitance of the receiving transistor.
Each wire/transmission line on a chip also has an associated electric/magnetic field around it, and closely spaced lines suffer from crosstalk. Take for example the LGA1366 socket that the i7 uses: there are 1366 pins very tightly packed on the chip package, and even more tightly packed on chip itself. Eventually we cannot pack them any tighter because the crosstalk will kill the signal to noise ratio.
Optical systems are better because the loss is much smaller, so less power is required to transmit each bit a certain distance, much more bandwidth is available per optical channel, and you can multiplex multiple color channels, and crosstalk is less of a problem for optical waveguides (both because fields are better confined and because you need fewer waveguides).
Most of this I got from a talk by John Bowers who leads one of the many research groups working in this area.
And I have a phone on my desk that has a 5 line LCD screen which tells me what number I've dialed in, what number is calling me, and it has a directory of all the phone numbers at our company to boot. I can click on a contact whose phone number I have in my Outlook address book and have my phone dial the number. I'm sure there are even more bells and whistles that somebody who uses their phone a lot would know about.
Are any of these features necessary? Of course not, but they sure are convenient:)
No, your tuition isn't for the network. The network is a benefit of being a student (in most cases).
No, your tuition isn't for the classes. The classes are a benefit of being a student (in most cases).
FTFY. You see, aside from outside support like grants, governmental support, and donations, the tuition and fees of students do actually pay for all of the college's services. Grants will be spent on highly specific projects, much of the government and donation money often goes to buildings and salaries. The residential network is most likely paid for out of student housing fees (i.e. rent).
It does depend on situation. If I am on a school computer in a school lab, although my tuition and fees have probably paid for the machine and its internet connection, it is within their rights to prohibit usage of P2P software on it because they maintain the machine. However I suspect that this case is about the college's residential network users on their personal machines. In this situation it is far more like an ISP than a "benefit of being a student". It is likely that the students had to agree to a restrictive AUP (I know I did) which they have no choice but to accept if they wish to live in campus housing. But even if this harsh P2P rule is in the AUP it doesn't mean that it should be.
Oh please, the US is the country that forces its security theater on the flights of foreign nations that land in the US. It's not the other countries who want to force their security requirements on us. I think it's a reasonable expectation to place on these flights that they have the same security as domestically originating flights, though I happen to think that the security for a domestic flights is largely a farce.
In a tit-for-tat move, Brazil now fingerprints visiting US citizens (only US citizens mind you) because this is what the US does to visiting Brazilians.
The US is one of the most paranoid countries in the world when it comes to flight security, though not all of the security measures increase security in a meaningful way.
I think that proofs are great, because I think it's useful to learn the processes used to find results, instead of just being given a result. Teaching to fish versus being given a fish.
That' my big complaint with the way my high school physics class was taught: calculus was not a prerequisite so much of the class was just being given a formula and applying it without seeing the underlying simplicity of the relationship between position, velocity, and acceleration, for example. Proving the quadratic theorem may not seem a useful exercise to you, but the process is useful for those who continue in some of the technical fields. Sure we can use Mathematica to simplify equations for us, but you frequently lose insight to the original problem when you just put computers to work on numbers, plus there are problems that it cannot solve.
I do agree with your point on statistics. I think it should be a requirement in high school (it wasn't for me) and a requirement for most college fields. Knowing how to analyze the validity and significance of your data, whether it's a questionnaire survey of people for economics/psychology/politics/etc or a measurement instrument readout is an incredibly important skill.
You must be a terrible physicist. As an electrical engineer, I need literary analysis every time I read a technical paper, and I needed composition skills last time I submitted one for publication.
I guess when you were learning electrical engineering, composition, and literary analysis you didn't have time to learn how to not make childish insults.
I'd agree with you on composition skills, although parent poster said nothing about composition.
But literary analysis is a completely different field from technical reading. Literary analysis has to do with analyzing literature for things like themes, motives, symbols, etc. You probably learned this in high school, like most people. Reading a technical paper is about understanding new theories, models, or ideas and finding out what results some people have achieved in a field. There may be search for hidden meanings like the drawbacks of an approach that the paper's authors don't come out and say, but I think you learn to spot this through experience in academia and your field, and not from having studied literature.
Slashdot Mirror
If you go to https://facebook.com/ you do view an encrypted home page. But all of the links to everything are just non-encrypted http. Unless you copy each link, paste it into the address bar, and prepend 'https://' to it (or write a browser script to do the same) then most of your facebook session will not be secured.
Sure water has a high thermal mass, but solar power irradiates the earth to the tune of ~1kW/m^2. That's why you can use a solar pool cover (essentially heavy duty bubble wrap - allows radiation in, limits convection out) to heat an 8 foot deep pool to over 105F on a hot summer day (in my experience). Most bio-reactors must have actively controlled temperatures to optimize production. The reality is it heavily depends on the volume to solar-incident surface area ratio they choose and the temperature sensitivity of the cyanobacteria they have engineered, details which will determine the presence/cost of cooling system.
This makes scaling much more difficult, since instead of increasing the size of each bioreactor you are instead proposing to build a lot of little ones, each of which must be separately monitored and maintained.
It's more than halfway interesting, it's a key factor in the viability of the system. If they can't remove the hydrocarbons and other waste products efficiently, then this scheme just won't work at all.
Funding agencies are risk-averse. It may seem like a waste of time and money to conduct such a test, but now when the Russian space agency asks for money for a Mars mission from their government, they can point to this study as addressing one of the risk factors of this mission.
The government gave them the money to perform this study because the study itself is low-risk and will give them a much better idea how a large 6-person crew will perform under the simulated conditions.
It's all about taking small steps so that eventually mankind can take a giant leap.
Surprisingly enough death isn't actually very quick in the vacuum of space (ref). You would maintain consciousness for about 15 seconds and be able to take actions which may save your life, and even after unconsciousness you would most likely survive without significant injury if returned to an atmospheric environment within about 90 seconds.
You forgot about iTunes, which is estimated to have generated a revenue of $1.8 Billion in 2009. Sure the total revenue may not be as large as total hardware revenue, but it's not chump change either.
Having sold some textbooks through Amazon Marketplace they automatically transfer your funds every 14 days, and you can also have your funds transferred as fast as once per day. Here is how Amazon describes it.
This app marketplace might be run differently, but this is probably a good guideline for how they will disburse funds.
You're right, I apologize, all of my CNN money numbers are 1 year off because the numbers are posted in 2010 for 2009 by CNN money, and I didn't notice initially that they organize by posting year, not earning year.
I couldn't find a definitive number for Exxon's 2010 profit, but it looks like it is on track for about $26 billion profit. Much like previous years, still larger than Apple but at a lower profit margin.
Thinking longer term I don't think Apple's growth will reflect the growing markets of China and India, but Exxon Mobil will certainly continue to benefit from the increased oil consumption.
At least in 2009 (I haven't looked up 2010)
The Blackberry phones outsold iPhones (revenue and units sold) and as usual, Nokia dwarfs them all (in market share).
Granted Apple has done quite well in the MP3 player market, and with its excellent profit margin it is certainly an extremely successful company. But let's compare Apple (market cap $296 billion) to Exxon Mobil (market cap $377 billion).
Exxon Mobil's 2010 profits of $19 Billion on $285 Billion in revenue completely dwarf Apple's 2010 profit of $6 billion on $36 billion in revenue. Granted Apple has a higher profit margin than Exxon Mobil, but in 2009 Exxon Mobil's profits were greater than Apple's revenue.
Both companies are certainly successful, but I suspect Apple's stock price has more to do with its image than its value.
This sounds like the crux of the problem: inflexible scheduling is forcing surgeons to choose between losing money and inconveniencing patients or operating while sleep deprived. I know that schedules often need to shift around, but it seems to me like they could simply schedule on-call around the surgery schedule, which is probably easier than the reverse. For example, if you're operating on Monday and Tuesday morning then someone else is on call on Sunday and Monday nights, then that guy operates on Wednesday and Thursday after a guaranteed night of sleep, when it's you who is on call.
I have no particular knowledge of the hospital industry, but would this not work? Or are surgeons operating on too many days of the week to make this possible?
You left out the part about the dramatic rise in living standards thanks to this industrialization. Peasants/the proletariat/minimum wage workers have always been abused by those with more power and industrialization didn't change this fact. Unions rose up to fight for the factory workers, and then things got better for them, and progress marched forwards.
This sweeping generalization pegs you as just as ignorant and arrogant as the stereotype you seem to hold of Americans. Don't blame the level of discourse on the internet just on the Americans, because there are stupid people all over the world.
Replying to undo moderation, I marked you "informative" but I meant to mark "funny".
P.S., does anybody know how to undo moderation in the current system? In the old one I had to press the moderation button. Now the moderation is immediate once I select from the pop-down menu and I don't see a way to undo it...
Is it also your humble opinion that textbooks can be photocopied for free for in-class use? Exactly where you draw the line on fair use is a tricky thing. Suppose a teacher buys one copy of a sheet music book and photocopies it for 30 students. Maybe that's okay. Now maybe a school buys one copy of the book and photocopies it for 5 classes of 30 students each. Next maybe the school district buys one copy and photocopies it for dozens of schools, ending up with hundreds or thousands of photocopies of the original.
I don't think there is any question that a line must be drawn between fair use and infringement in these cases. Is there a specific number of copies that you would draw it at? One copy, one class's worth of copies, 50, 100?
For a book of sheet music of children's songs, schools may comprise a big portion of their customer base. The money from sale of the book must go to many people/entities after the retailer makes their cut: composer, arranger, editor, graphic designer, book layout, and ultimately a cut to the publisher as their profit for licensing the work and hiring the necessary people and managing them to a finished product. Maybe in this day and age it could be made more efficient with artists selling their sheet music online, but if you buy a book then you are taking the work of all those people I mentioned, and those people deserve compensation for their work. If you don't want to compensate them just don't use their work, use somebody else's.
I know that in the USA there are some fair-use copyright exemptions specifically for academic use, this seems like it can be solved in one of two ways: the German government can enact a specific law governing how fair use applies to this situation, such as purchasing one song book per class of up to 40 students which the teacher can then copy up to 40 times per year; Or the publishers can sell an edition of their songbooks which may cost more and is specifically licensed to be copied for classroom usage. I know that some teacher's editions of textbooks, solution manuals, and the like typically contain some language about what constitutes fair-use copying.
Hmm... that would make compasses more entertaining than they are now!
Actually, putting your poles on the right half of the s-plane gives you instability :)
(Reference)
Right you are, thanks for the correction. A linear induction motor would actually be closer to a railgun, although still not quite there.
No, they're not the same concept, and the electromagnetic plane launcher that they are building here cannot readily be re-purposed as a railgun.
The EMALS (electromagnetic air launch system) is a Linear Induction Motor which works just like a standard AC motor except it has been laid out flat instead of in a circle. The launch carriage has a set of alternating magnetic poles (the stator) and it is driven by a series of series of coils which are driven with the appropriate AC waveform as the carriage passes overhead.
A Railgun contains no permanent magnets, it uses a current through the projectile (or through a projectile carrier) to create a Lorentz force with the current in the rails which propels the projectile.
In principle one could attempt to design a linear induction motor as a weapon, but since the point of a railgun is to achieve extremely high exit velocity (current Navy efforts have achieved on the order of 2.5km/s, shooting for 5km/s) it will be very challenging to achieve the appropriate rise/fall times in the driving coils. The need for permanent magnets in the projectile are also a problem, and I imagine there would be issues with magnetic fields saturating the projectile unless the magnitudes are limited, meaning the weapon must be longer.
I could see a role for LIM directly as a weapon only if there were some application where you need to launch a relatively very heavy projectile at relatively small exit velocity.
The square cube law is always the elephant in the room when people start talking about 3D circuits. It is certainly a problem, but the field is still open to improvements. For example, the "through silicon via" process presumably means they etch a via entirely through a silicon wafer and plate it with a metal. These could also be used as heatsinking aids and not just ways to transfer signals through vertically stacked chips, and though some surface area is consumed it may be more than made up for by the vertical stacking. There are researchers working on micro-/nano-scale structures which have greatly enhanced thermal conductivities which can be useful for 3D integration.
I assume it is not thermal noise which needs to be overcome, it is probably thermally-induced leakage current which requires the use of higher voltage to increase the difference between a "1" and a "0", because at higher temperatures more electrons have enough energy to jump the barrier of an off-state transistor, making the 0 more of a 0.5 for example. Although both result from thermal processes, they are significantly different effects. (disclaimer: I am not a VLSI engineer).
The last photonics researcher I talked to was of the opinion that photonic transistors are still a pipe dream... but many researchers and big companies are making steady process to replacing off-chip interconnects with photonic modules.
Disclaimer: I'm not a power engineer but I am an electrical engineer, so while the principles I state are probably correct there is some guesswork as I apply it to power transmission.
However, wires have capacitance.
Yes, all wires have a certain capacitance and inductance per length. Given the very wide separation between the power line and ground the capacitance per length should be very small, since it is inversely proportional per distance. Given the wide area the current encloses, the inductance will conversely be large. Therefore I would guess that the inductance of the transmission line is more important than its capacitance, and that it can be modeled primarily as a resistance in series with an inductance.
Overcoming that capacitance requires energy, which is an inefficiency.
Correct, though I'd like to add to that. An ideal capacitor is a lossless device (if you bring up the "two capacitor problem" note that by definition the capacitors or the wires connecting them cannot be lossless or it would never reach steady state). However in any AC transmission there will be conductor loss due to the resistance of the wire, possibly increased by skin effect, and dielectric loss due to the changing polarization of polar molecules in the dielectric surrounding the wire. Air is a virtually lossless dielectric. The wire's insulation is not going to be lossless, but since dielectric loss is usually proportional to frequency and 60Hz is very low frequency, and the insulator is small, I would guess that conductor loss dominates. And since frequency is very low skin effect may be negligible and we can just use the DC resistance.
One more note is that most loads are inductive (ballasts for flourescent lights, motors for air conditioners, motors for industrial equipment, transformers, etc) and this is probably going to dominate the power factor of power transmission much more than the reactance of the power transmission lines themselves. That's why most load compensation is in the form of added shunt capacitance.
Of course there are still many advantages of DC transmission, but for power lines on poles I wouldn't be convinced of frequency-dependent loss playing a large role unless I saw a full analysis.
Im surprised the defense hasnt considered a "substantial non-infringing uses" defense. For instance playing backup disks and homebrew. The well known issue of scratched disks, and the desire for interoperability with non-microsoft approved software. This is separate from "fair use" in that the illegality of the mod chip itself is challenged.
It's such a good idea that the defendant was already planning to use it in his defense:
The judge on Wednesday even backtracked on an earlier ruling that had prohibited Crippen, 28, from raising a “fair use” defense at trial.
Crippen was hoping to argue to jurors that it was legal to hack the consoles because the modification had non-infringing purposes, like allowing the machines to run homebrew software, or permitting limited fair use of copyright material such as backup copies of video games.
The metal connections are certainly fast enough, after all the signals on the metal lines will travel at a fraction of the speed of light divided by the index of refraction of the surrounding dielectric medium, same as an optical waveguide.
But there are two important problems which this does not address: loss and crosstalk.
Because the conductor loss is very significant for metal interconnects, much more power is consumed in long interconnects. This power consumption only increases with transistor density as wires get narrower, and minimizing power dissipation is one of the major challenges in continuing to scale chips smaller and smaller. The resistance also introduces an RC charging time constant when driving the gate capacitance of the receiving transistor.
Each wire/transmission line on a chip also has an associated electric/magnetic field around it, and closely spaced lines suffer from crosstalk. Take for example the LGA1366 socket that the i7 uses: there are 1366 pins very tightly packed on the chip package, and even more tightly packed on chip itself. Eventually we cannot pack them any tighter because the crosstalk will kill the signal to noise ratio.
Optical systems are better because the loss is much smaller, so less power is required to transmit each bit a certain distance, much more bandwidth is available per optical channel, and you can multiplex multiple color channels, and crosstalk is less of a problem for optical waveguides (both because fields are better confined and because you need fewer waveguides).
Most of this I got from a talk by John Bowers who leads one of the many research groups working in this area.
And I have a phone on my desk that has a 5 line LCD screen which tells me what number I've dialed in, what number is calling me, and it has a directory of all the phone numbers at our company to boot. I can click on a contact whose phone number I have in my Outlook address book and have my phone dial the number. I'm sure there are even more bells and whistles that somebody who uses their phone a lot would know about.
Are any of these features necessary? Of course not, but they sure are convenient :)
FTFY. You see, aside from outside support like grants, governmental support, and donations, the tuition and fees of students do actually pay for all of the college's services. Grants will be spent on highly specific projects, much of the government and donation money often goes to buildings and salaries. The residential network is most likely paid for out of student housing fees (i.e. rent).
It does depend on situation. If I am on a school computer in a school lab, although my tuition and fees have probably paid for the machine and its internet connection, it is within their rights to prohibit usage of P2P software on it because they maintain the machine. However I suspect that this case is about the college's residential network users on their personal machines. In this situation it is far more like an ISP than a "benefit of being a student". It is likely that the students had to agree to a restrictive AUP (I know I did) which they have no choice but to accept if they wish to live in campus housing. But even if this harsh P2P rule is in the AUP it doesn't mean that it should be.
Oh please, the US is the country that forces its security theater on the flights of foreign nations that land in the US. It's not the other countries who want to force their security requirements on us. I think it's a reasonable expectation to place on these flights that they have the same security as domestically originating flights, though I happen to think that the security for a domestic flights is largely a farce.
In a tit-for-tat move, Brazil now fingerprints visiting US citizens (only US citizens mind you) because this is what the US does to visiting Brazilians.
The US is one of the most paranoid countries in the world when it comes to flight security, though not all of the security measures increase security in a meaningful way.
I think that proofs are great, because I think it's useful to learn the processes used to find results, instead of just being given a result. Teaching to fish versus being given a fish.
That' my big complaint with the way my high school physics class was taught: calculus was not a prerequisite so much of the class was just being given a formula and applying it without seeing the underlying simplicity of the relationship between position, velocity, and acceleration, for example. Proving the quadratic theorem may not seem a useful exercise to you, but the process is useful for those who continue in some of the technical fields. Sure we can use Mathematica to simplify equations for us, but you frequently lose insight to the original problem when you just put computers to work on numbers, plus there are problems that it cannot solve.
I do agree with your point on statistics. I think it should be a requirement in high school (it wasn't for me) and a requirement for most college fields. Knowing how to analyze the validity and significance of your data, whether it's a questionnaire survey of people for economics/psychology/politics/etc or a measurement instrument readout is an incredibly important skill.
I guess when you were learning electrical engineering, composition, and literary analysis you didn't have time to learn how to not make childish insults.
I'd agree with you on composition skills, although parent poster said nothing about composition.
But literary analysis is a completely different field from technical reading. Literary analysis has to do with analyzing literature for things like themes, motives, symbols, etc. You probably learned this in high school, like most people. Reading a technical paper is about understanding new theories, models, or ideas and finding out what results some people have achieved in a field. There may be search for hidden meanings like the drawbacks of an approach that the paper's authors don't come out and say, but I think you learn to spot this through experience in academia and your field, and not from having studied literature.