I wanted to make a cool graphic to show the relative sizes of the IPv4 and IPv6 address spaces. You know, where I’d show the IPv6 address space as a big box and the IPv4 address space as a tiny one. The problem is that the IPv6 address space is so much larger than the IPv4 space that there is no way to show it to scale! To make this diagram to scale, imagine the IPv4 address space is the 1.6-inch square above. In that case, the IPv6 address space would be represented by a square the size of the solar system.
Blowing up children in Yemen would stand out as a bad way to spend that kind of money. vs. being put to productive use in the US economy.
As economic stimulus goes, I think I'd rather have bridges that don't fall down and railways that work than 1 Gbps to my home.
If the USG weren't trying to take defacto control of the majority of the Middle East, you could have both.
Quite so. Of course, end-of-war savings (peace dividends) rarely seem to materialize. Still, spending is good for the economy -- even if you only pay people to dig holes in the ground and fill them up. Of course it's still better if they fix bridges and highways and avoid shooting people.
Yes, but the Iraq war benefits the bankers, globalists, and components of the military-industrial-media complex. Nationwide gigabit fiber would chiefly benefit the citizenry and small businesses. So, the Legislators simply can't vote for such a thing!
There's no bad way to spend $140 B (or more). A lot goes into the pockets of workers who dig trenches and string fiber. (We really need those jobs.) Some goes to electronics manufacturers, but it all stimulates the economy -- and serves somebody's interests. The problem is if AT&T, Verizon, et. al. are locked out, especially if it's a government investment.
As economic stimulus goes, I think I'd rather have bridges that don't fall down and railways that work than 1 Gbps to my home. A mere 100 Mbs should keep me happy for the next 5 years, I'm thinking. I making do with 18 at the moment.
Why exactly is a fluid necessary? I don't think there is a fluid.
Heat pipes work by evaporating a liquid at the hot end and condensing it at the cold end.. The fancy wicking stuff is to persuade the liquid to move back to the hot place to get evaporated again. See http://en.wikipedia.org/wiki/Heat_pipe .
It's not a revolutionary invention, but it should be very helpful if they can cut the peak and the average power draw on the power grid by a substantial amount. There's an energy cost saving and also transmission grid saving. You don't need such a heavy connection between the train system to the general power grid.
a 10-car subway train in New York's system requires a jolt of three to four megawatts of power for 30 seconds to get up to cruising speed — that's enough energy to power 1,300 average U.S. homes."
For how long?
For 30 seconds, more or less, if a home is ~ 2-3 kW.
Not a flame war for me, anyway. But it does seem like a lot of the pro-Mac anti-Windows comments are aimed at Win XP or even Win 98. I'm a Linux guy, but I do see Win 7 as pretty respectable in terms of GUI quality, stability, security, etc. A resource hog, sure, but that's what we have cheap RAM and CPU cycles for.
Mac OS X and Mac hardware are fine, too. For me, they're worth a premium, but not 2X compared to Linux-friendly laptops.
I'm retired and willing to spend time doing some system stuff on Linux. If your time is at a premium, that would tilt the scales. My grad student daughter just upgraded her Mac, so there you are. (If was a grad student again, I'd be wary of spending time on/. or games, though.)
A few more simple rules: Don't buy the cheapest, and don't buy the most expensive. The best value is usually somewhere in the middle. If I buy a laptop, it's generally in the $500-700 range, and it might be last year's model on close-out. Oh, and don't buy Apple... unless "cool" is worth a ~100% tax to you.
You have to read the instructions carefully. The current wants to flow in the proper direction. Don't hook it up backwards, or the warranty is void! I wonder how many/. readers have their 1000bT cables reversed?
You might also want to look into the pre-charged dielectric cable. It needs a (premium - of course) DC supply to be sure the dielectric is operating in the linear range.
These things really do work. Just ask the users who spend $K on their system wiring!
There are many ways to look at a university. It's about research, it's about federal funding, it's about raising money from alumni, it's about patent licensing and athletics, it's about recruiting faculty, promoting faculty, about running a big physical plant, internet pipes, etc. etc. Oh, and there are students, too. Teaching is just one of many things that happen there, not the most visible - even at places that claim to emphasize the student experience. Students do get to pay up to around $200K for the privilege of becoming alumni and then being asked to contribute cash. But a big research university actually loses money on every student. They'd be better off financially if they stopped admitting.
Universities, most of them, are non-profit corporations. You're right they aren't charities in the moral sense, but the US tax laws treat them as if they were. Pity the legislator who suggests repealing the their charitable tax deduction.
Or simply run Linux off a live CD -- Ubuntu, Knoppix, etc. Slow to boot, but reasonably fast to run. Fair chance it will be more responsive in limited RAM.
Meant to say you can concentrate megawatts into less than 1 Hz of bandwidth and then multiply the power by using a very high gain antenna. The big problem in SETI is not knowing where to look or where to tune your receiver.
What I've also wondered is how big of an antenna would we need to detect a communication from a near star, say 50ly. And how much power would it take to send a message that far?
If we can't even see planets, how can SETI expect to receive a transmission from one?
I've asked some astronomy majors about this and received only blank stares. Do they teach this kind of thing in astronomy? What are the calculations?
It's a fair question. Fortunately, an intentional transmitter can be much brighter than the star or planet -- in a narrow bandwidth and pointing straight at you. (And stars aren't very bright at microwave frequencies.) There's no problem communicating to nearby space if you know each other's frequency and direction. You can concentrate megawatts of power into
Interferometry (increasing the spatial resolution of the receiving antenna) actually doesn't help you much, except to discriminate against the diffuse galactic background. You need all the collecting area you can afford, but that's not the same thing.
48 kW period. (Physics: A Watt is a unit of power. A Watt-hour is a unit of energy. A Watt per hour is a rate of increase of power.)
You won't be getting a "quick charge" at home without an expensive service upgrade. Overnight probably means up to 12 hours for a charge. That gets you about 288 kW-hr of energy if you draw 100 A on a 240 V circuit. In very rough terms, you can think of a kilowatt as a horsepower (1.3 actually). So you could run your high performance car at full power for 1 hr on an overnight charge. Your typical commute needs a lot less energy, but YMMV.
There's another reason that switching batteries is good. If a 62 kW supply is required to charge a battery in 30 minutes, you would need 360 kW+ to charge it in 5 minutes. That's a phenomenal power level. If your charging efficiency is 90%, that means you will be dissipating 36 kW in your car as heat while charging. That's pretty close to explosive.
The service station and the power utility would have an interest in leveling their load, so charging an inventory of batteries relatively slowly is a good thing. Even so, each recharging station might need a flywheel energy storage unit (or comparable) to even their load on the utility.
Not really. It depends on the current drawn through the wire. For power P (constant for the computer, more or less) required at a voltage V, you need I=P/V amps. You're not going to distribute 3 V or 5 V, which is what your ICs want, I hope! You could distribute 120 V DC with the same size wiring you use for the usual AC connection. You could send around 1,200 V (DC or AC) and use 1/100 the copper. (Power lost to heating goes as I**2.) The high voltage limit is set by safety and cost of DC-DC converters.
The system is arguably less secure. You have 50 systems depending on one AC-DC converter (or a small number of them), and that introduces a single point of failure.
When our data center installed a nice shiny big UPS system to help us solve some problems about unreliable AC supply, I (correctly) predicted the next data center outage would be from the UPS.
Slashdot Mirror
Who needs software? Print lots of $100 bills, put into suitcases, put suitcases on pallets, and ship to Commanding Officers around the world.
Morse is the orginal digital system, being sent with the fingers.
I prefer this visualisation;
I wanted to make a cool graphic to show the relative sizes of the IPv4 and IPv6 address spaces. You know, where I’d show the IPv6 address space as a big box and the IPv4 address space as a tiny one. The problem is that the IPv6 address space is so much larger than the IPv4 space that there is no way to show it to scale! To make this diagram to scale, imagine the IPv4 address space is the 1.6-inch square above. In that case, the IPv6 address space would be represented by a square the size of the solar system.
I think this is why logarithms were invented.
There's no bad way to spend $140 B (or more).
Blowing up children in Yemen would stand out as a bad way to spend that kind of money. vs. being put to productive use in the US economy.
As economic stimulus goes, I think I'd rather have bridges that don't fall down and railways that work than 1 Gbps to my home.
If the USG weren't trying to take defacto control of the majority of the Middle East, you could have both.
Quite so. Of course, end-of-war savings (peace dividends) rarely seem to materialize. Still, spending is good for the economy -- even if you only pay people to dig holes in the ground and fill them up. Of course it's still better if they fix bridges and highways and avoid shooting people.
Yes, but the Iraq war benefits the bankers, globalists, and components of the military-industrial-media complex. Nationwide gigabit fiber would chiefly benefit the citizenry and small businesses. So, the Legislators simply can't vote for such a thing!
There's no bad way to spend $140 B (or more). A lot goes into the pockets of workers who dig trenches and string fiber. (We really need those jobs.) Some goes to electronics manufacturers, but it all stimulates the economy -- and serves somebody's interests. The problem is if AT&T, Verizon, et. al. are locked out, especially if it's a government investment.
As economic stimulus goes, I think I'd rather have bridges that don't fall down and railways that work than 1 Gbps to my home. A mere 100 Mbs should keep me happy for the next 5 years, I'm thinking. I making do with 18 at the moment.
I've never heard of Occam's Razor. What is it? I'm imagining some kind of 7 legged, supersonic, invisible shoe.
It's an Olde English Cellphone.
Technically this is called aristocracy
Nope. Plutocracy. Aristocrats are aristocrats because their parents were aristocrats.
It's a British thing. Queen's English. What what.
Why exactly is a fluid necessary? I don't think there is a fluid.
Heat pipes work by evaporating a liquid at the hot end and condensing it at the cold end.. The fancy wicking stuff is to persuade the liquid to move back to the hot place to get evaporated again. See http://en.wikipedia.org/wiki/Heat_pipe .
There's a working fluid there somewhere, it must have come out, and it might be toxic. Or it might give you a high. The review is silent on this.
It's not a revolutionary invention, but it should be very helpful if they can cut the peak and the average power draw on the power grid by a substantial amount. There's an energy cost saving and also transmission grid saving. You don't need such a heavy connection between the train system to the general power grid.
a 10-car subway train in New York's system requires a jolt of three to four megawatts of power for 30 seconds to get up to cruising speed — that's enough energy to power 1,300 average U.S. homes."
For how long?
For 30 seconds, more or less, if a home is ~ 2-3 kW.
This isn't the place!
You could try http://krugman.blogs.nytimes.com/
Not a flame war for me, anyway. But it does seem like a lot of the pro-Mac anti-Windows comments are aimed at Win XP or even Win 98. I'm a Linux guy, but I do see Win 7 as pretty respectable in terms of GUI quality, stability, security, etc. A resource hog, sure, but that's what we have cheap RAM and CPU cycles for.
Mac OS X and Mac hardware are fine, too. For me, they're worth a premium, but not 2X compared to Linux-friendly laptops.
I'm retired and willing to spend time doing some system stuff on Linux. If your time is at a premium, that would tilt the scales. My grad student daughter just upgraded her Mac, so there you are. (If was a grad student again, I'd be wary of spending time on /. or games, though.)
A few more simple rules: Don't buy the cheapest, and don't buy the most expensive. The best value is usually somewhere in the middle. If I buy a laptop, it's generally in the $500-700 range, and it might be last year's model on close-out. Oh, and don't buy Apple... unless "cool" is worth a ~100% tax to you.
You have to read the instructions carefully. The current wants to flow in the proper direction. Don't hook it up backwards, or the warranty is void! I wonder how many /. readers have their 1000bT cables reversed?
You might also want to look into the pre-charged dielectric cable. It needs a (premium - of course) DC supply to be sure the dielectric is operating in the linear range.
These things really do work. Just ask the users who spend $K on their system wiring!
There are many ways to look at a university. It's about research, it's about federal funding, it's about raising money from alumni, it's about patent licensing and athletics, it's about recruiting faculty, promoting faculty, about running a big physical plant, internet pipes, etc. etc. Oh, and there are students, too. Teaching is just one of many things that happen there, not the most visible - even at places that claim to emphasize the student experience. Students do get to pay up to around $200K for the privilege of becoming alumni and then being asked to contribute cash. But a big research university actually loses money on every student. They'd be better off financially if they stopped admitting.
Universities, most of them, are non-profit corporations. You're right they aren't charities in the moral sense, but the US tax laws treat them as if they were. Pity the legislator who suggests repealing the their charitable tax deduction.
Or simply run Linux off a live CD -- Ubuntu, Knoppix, etc. Slow to boot, but reasonably fast to run. Fair chance it will be more responsive in limited RAM.
Meant to say you can concentrate megawatts into less than 1 Hz of bandwidth and then multiply the power by using a very high gain antenna. The big problem in SETI is not knowing where to look or where to tune your receiver.
What I've also wondered is how big of an antenna would we need to detect a communication from a near star, say 50ly. And how much power would it take to send a message that far? If we can't even see planets, how can SETI expect to receive a transmission from one? I've asked some astronomy majors about this and received only blank stares. Do they teach this kind of thing in astronomy? What are the calculations?
It's a fair question. Fortunately, an intentional transmitter can be much brighter than the star or planet -- in a narrow bandwidth and pointing straight at you. (And stars aren't very bright at microwave frequencies.) There's no problem communicating to nearby space if you know each other's frequency and direction. You can concentrate megawatts of power into
Interferometry (increasing the spatial resolution of the receiving antenna) actually doesn't help you much, except to discriminate against the diffuse galactic background. You need all the collecting area you can afford, but that's not the same thing.
...dedicated output power of 48KW per hour.
48 kW period. (Physics: A Watt is a unit of power. A Watt-hour is a unit of energy. A Watt per hour is a rate of increase of power.)
You won't be getting a "quick charge" at home without an expensive service upgrade. Overnight probably means up to 12 hours for a charge. That gets you about 288 kW-hr of energy if you draw 100 A on a 240 V circuit. In very rough terms, you can think of a kilowatt as a horsepower (1.3 actually). So you could run your high performance car at full power for 1 hr on an overnight charge. Your typical commute needs a lot less energy, but YMMV.
There's another reason that switching batteries is good. If a 62 kW supply is required to charge a battery in 30 minutes, you would need 360 kW+ to charge it in 5 minutes. That's a phenomenal power level. If your charging efficiency is 90%, that means you will be dissipating 36 kW in your car as heat while charging. That's pretty close to explosive.
The service station and the power utility would have an interest in leveling their load, so charging an inventory of batteries relatively slowly is a good thing. Even so, each recharging station might need a flywheel energy storage unit (or comparable) to even their load on the utility.
Not really. It depends on the current drawn through the wire. For power P (constant for the computer, more or less) required at a voltage V, you need I=P/V amps. You're not going to distribute 3 V or 5 V, which is what your ICs want, I hope! You could distribute 120 V DC with the same size wiring you use for the usual AC connection. You could send around 1,200 V (DC or AC) and use 1/100 the copper. (Power lost to heating goes as I**2.) The high voltage limit is set by safety and cost of DC-DC converters.
The system is arguably less secure. You have 50 systems depending on one AC-DC converter (or a small number of them), and that introduces a single point of failure.
When our data center installed a nice shiny big UPS system to help us solve some problems about unreliable AC supply, I (correctly) predicted the next data center outage would be from the UPS.
Another crack at this:
15 Mb/s is 162 GB/day or about 5000 GB/month
So at 250 GB cap is 5% of theoretical maximum transfer.
Or you could say the (inverse) cap is 4 months / TB - the time it would take to fill up my hard drive.