More like, more Linux, less busy-work, no company pager calling you into the office at 2 AM to fix all the crashes, etc.
Anything that increases the productivity of a technical person is great. It means that one techie can do even more stuff without breaking a sweat, and the more stuff you can take care of, the more value you create and the more money you can make. Or haven't you noticed that people whose productivity is stagnant, like floor-sweepers, haven't enjoyed the same run-up in income as the tech sector? Remember that.
The off-axis reception does not surprise me; the dish has not been made which doesn't have side-lobes (do the math, it's rather impractical), and even 20 dB of attenuation won't compensate for a nearby source. (You didn't mention the dish size and operating frequency.) Generally you can reduce such problems, if they are problems, by going to a larger antenna or aiming it so that the problem source falls in a null in the pattern.
Says who? You? What's your authority? How much have you studied it?
Microwave would be horrifically hard to implement for something like this. Microwave is directional. So the ISP would have to have a dish pointing at every single customer's house.
PCS uses microwave frequencies (2.4 GHz, I believe). Ever look at a PCS tower? It has no dishes. It has an array of flat-plate antennas, and each one covers a little slice of the horizon. Some towers even have multiple tiers at different angles from the vertical; the lower ones obviously handle nearer connections, and the upper ones (which are angled more toward vertical) handle the farther connections.
Directionality is all a matter of antenna size divided by wavelength; beamwidth in radians is roughly equal to D/lambda (1.3 D/lambda for a circular plane radiator). With the proper antenna design you can be as directional... or not... as you want. As long as you can get enough power from the transmitter to the receiver to satisfy your signal/noise ratio requirements, you're all set.
I'd expect the towers for these babies to look like PCS towers: many tall, skinny rectangles (very narrow vertical beamwidth, much wider horizontal beamwidth) arrayed around a pole. The subscriber dishes only have to point at a server tower. If a server tower starts getting overloaded, it's not that difficult to further subdivide the horizon by using more and wider (smaller horizontal beamwidth) antennas; this lets you distinguish between subscribers separated by smaller and smaller angles. Eventually you have so many connections it pays to put in fiber and use the RF spectrum for land mobile.
but what kind of latency do you expect? 1 or 2 ms like a regular t-1?
And why not? RF in air travels 300 m/microsecond. This is quite a bit faster than light travels in fiber, and there are no bends or kinks in the path. If you are sending to a tower 5 miles (8 km) away, the round-trip time is only 53 microseconds.
That's for the delay in the air. The delay in the equipment for buffering data, creating and checking the Trellis or Viterbi error-correction codes, and whatnot are what eat the time in short-range RF communications. This can all be cut with dedicated hardware; it's not intrinsic to the medium.
Fiber is actually slower; the velocity factor of glass is something like 0.6. On the other hand, a 300 THz carrier has a lot more bandwidth potential than a 2.4 GHz one. Fiber is eventually going to displace RF for point-to-point users, but RF can help build the market for fiber. RF will then recycle the spectrum and go on to serve the mobile market.
wireless, not unlike satellite is plauged with latency issues that will NEVER be resolved. the physical speed and distances limit just how much latency you see on the line. RF is slow.
If that's what you think, go ahead and invest your retirement portfolio accordingly; take these microwave internet stocks and sell them short. Next year, tell us how many years longer you're going to have to work before you can retire.;-)
Just because this is "spread spectrum" does not mean it is at all secure. If it is based on code-division multiple access (CDMA), it is only as secure as the code. To be immune to eavesdropping and spoofing attacks, there has to be another layer of encryption and authentication on top. The one-page PDF file mentions the use of a 64-bit RC4 encryption layer, but I'm not sure this is sufficient in this day and age. The document does not say if the key is unique to a given tower-to-user connection or if it is shared between all connections going to a particular tower, and it mentions nothing about key change intervals.
The fact that US users routinely use 128-bit encryption on browser data going over a phone line, while Gain Wireless only uses 64-bit keys for data going over the air, gives me pause. All in all, I'd like to have more reason to have confidence before I laid out money for anything like this.
Also (and I'm playing devil's advocate here), if you did have things your way and the cops were required to reimburse you for the depreciation of your equipment, would you/we really be better off? It would simply make their job significantly harder.
Only in a police state does the policeman have it easy.
If it takes years to examine your computer equipment for signs of incriminating data, then you need to write some letters to your legislature and the FBI saying, "use more of my tax dollars to streamline and make efficient this process," not, "use more of my tax dollars for reimbursing the innocent."
So what you are saying is that the FBI should continue to conduct "investigations" which are just excuses to sieze and hold computer equipment because there will be no follow-up. You say this is due to a lack of funds. I call it mismanagement. If the FBI were doing its job correctly, it would re-allocate funds from the agents doing the seizing to analysts for evaluating the evidence until they could process everything they grabbed in a reasonable amount of time, say 60 days.
The article says that halite is the mineral that makes up table salt. What on earth is this reporter doing?
Actually being correct about a technical issue.
Halides are ions of the halogen group, which includes chlorine.
Yup. Brush up on your Greek: halo-gen: salt-maker. Halite is salt. From www.m-w.com: Main Entry: halite Pronunciation: 'ha-"lIt, 'hA- Function: noun Date: 1868 : ROCK SALT
On the other hand, Earth has 1/2 of the solar system's known nitrogen (including Jupiter and the like).
If I recall correctly, Venus (about the same size as Earth) has about 2 atmosphere's worth of nitrogen, or about 2.5 times as much as exists in gas form on Earth. Titan apparently has enormous amounts of N2 as well, in a very cold, dense soup of an atmosphere.
Nitrogen makes up 3/4 of the atmosphere
78%, more or less. 21% oxygen, 1% other (including 365 ppm of CO2 or thereabouts).
So far, I haven't heard of a suitable replacement.
Nitrogen is an essential component of amino acids, but the bacteria which fix N2 into nitrate ion would probably do just fine with 7% in the air instead of 78%. Neon would do just fine for the rest, though it's much less common in the universe. People also do quite well breathing helium with their oxygen, but it takes a giant planet to hold onto helium for long.
Sure, they've found water (in solution) inside irradiated salt. This rock became superheated during its trip through the atmosphere.
Contrary to your expectations, many meteorites are so cold they collect frost after landing. This is probably how the "cold iron" legend of nickel-iron meterorites got started; someone observed a meteor fall, and found the rock covered with an unseasonable layer of rime.
Only the outer extremes are heated very much (the "fusion crust", as meteoriticists call it). Just how hot would you expect the bulk of something to become during a 15-second drop from space to the stratosphere? The innards of the rock are going to be right around the 250 K equilibrium temperature of a blackbody near earth, perhaps colder if it fell in through Earth's shadow.
How much more fuel would it actually take to get it going towards the sun? 2x? 10x?
Depends on the fuel, but assuming the use of hypergolics at a specific impulse of around 250 seconds (exhaust velocity roughly 2500 m/sec)...
Orbital velocity is around 8000 meters per second. Boosting to Earth escape velocity (roughly 11,000 m/sec) requires a delta-V of 3000 m/sec. By the rocket equation, the ratio of initial mass to final mass is e to the power of 1.2 (3000/2500), so you would need 3.32-1=2.32 times as much mass of fuel as Mir's mass. You could launch a couple new Mir's for that.
To get to the Sun by the least-energy route requires a flight past Jupiter, which requires roughly as much delta-V as a solar escape burn. Call it a delta-V of about 12,500 meters per second. Using oxygen-hydrogen with an exhaust velocity of 4500 m/sec, the fuel required would be about 15 times the mass of Mir (and a hell of a lot bulkier; liquid hydrogen is about 1/14 the density of water).
If you want to save Mir, I'm sure everybody would be happy to let you pay for this.
... we did it with Skylab, and LLNL proposed a while back that we build an inflatable space station and launch it on a Titan (up in one shot). Total cost, from design to launch, would be a few $billion. Of course, this would not have given enough money to the space contractors,
I think it is a crying shame that Mir is to be abandoned before the USA has any permanently-manned outpost in orbit. The ISS is way behind schedule, over budget, and depends on there not being any more problems with the aging fleet of Space Shuttles. Now, exactly how likely is that?
The real crying shame is that we know how to build a space station that could be launched with one shot into orbit on an existing vehicle; we did it with Skylab, and LLNL proposed a while back that we build an inflatable space be a few $billion. Of course, this would not station and launch it on a Titan (up in one shot). Total cost, from design to launch, would have given enough money to the space contractors, nor would the State Department have been able to use it as a way to funnel money to Russia as a way of doing some foreign policy out of someone else's budget, so that idea went bust. (I tried searching LLNL's site for the "community space suit" paper, but the search engine doesn't seem to know where it is.)
This leaves us in a state where the Senate is trying to kill all of NASA's non-Shuttle, non-ISS programs, keeping the boondoggles and nuking all the science. It's enough to make you sick.
Your memory is awfully short. Mir has had several near-fatal accidents of late, including a fire in one of the backup oxygen generators. IIRC, they've also had leaks in coolant systems and other nasty stuff. Plus they keep having the "navigation" (actually, attitude-stabilization) computer fail, and without any way to maintain attitude the solar panels don't generate power (and they have no way to run the attitude-control system once the batteries run down). Even without a planned shutdown, Mir would soon suffer a loss of power leaving it unrecoverable.
After 10 years in space, Mir is a creaking old hulk; the cosmonauts spend much of their time on maintenance, not science. It wasn't designed to last this long, and if the Russians still had a space program the thing to do would be to launch a new, up-to-date core incorporating the lessons learned from the original, and move over the modules which are still of use. The old core is not worth the fuel required to keep it in orbit. Perhaps it could be useful on the way down, for instance as a test of controlled re-entry using electrodynamic tethers, but in space it's already barely more than a hazard to navigation.
IMHO, law enforcement should be forced to pony up the missing $1800.
Good, but not good enough. Law enforcement should be forced to provide (at their expense) a copying service for all information on the computer's mass-storage devices, copies to be provided to the owner within 5 business days. Then, upon aquittal or past the statute of limitations, they should be forced to pay the original cost of the siezed equipment plus interest at 19.8% per year.
This is the only way that the innocent can be protected from maurauding seizure. If the cops grab your stuff and you haven't done anything, you just buy a new system with your VISA card, plug in the copy of the hard drive and wait for their check to pay off the card.
The really ironic thing about this is that, unlike houses and even cars, computers depreciate so fast they are effectively useless as asset-forfeiture fund-raising material. Yet the cops grab and hold them for ridiculous amounts of time anyway.
...
and the external one hasn't already told the computer that power is out and it should shut down, then destroy all your sensitive material.
Ah, just what the Feds want. After they catch onto the "dual UPS" trick, they'll use the auto-delete list as a roadmap to all of your most incriminating stuff.
You don't mean that. Really, you don't. If some agency is in charge of issuing public keys to citizens, that agency generates (and thus knows) P and Q, which determine M (the RSA modulus). This would implement key-escrow from the very beginning.
Now I'm sure you really didn't mean that, but you should be careful that you truly mean what you say!
One way to make this tax go away is to force the recording companies to be fair about it; if the tax is to be applied to recordable media when purchased, it should be refundable when the media are returned.
Seriously. If a recording is botched and the media are not recoverable, you should be able to get a refund of the tax you paid. In practice the recording industry would be forced to refund the tax on every disk returned. That would sure teach them.
Further consequences of this would be that Parliament would be forced to criminalize the importation of recordable media for refund (fraud, y'know) just as Michigan has criminalized the import of out-of-state soft-drink containers for the ten-cent deposit. Now wouldn't that be fun!
Finally, if you're lucky, you might even get everyone to agree that the whole thing was a rotten idea and that it ought to be scrapped. But you have to force the system into the exercise of the reductio ad absurdum first, so get moving!
For a system that would hold 500 (SSSL) DVD's worth of data this is bad how?
Not necessarily bad, just cumbersome. The capacity/read speed quotient of these things makes mag tapes look like speed demons, and the time to scan a significant portion of the contents is going to be way up there. If you are trying to replace a DVD jukebox with one of these this is not a factor, but if you are trying to do anything like perusing a database using a field which isn't indexed, it's going to be glacial. It would make much more sense to have 100 23 GB drives than 1 2300 GB drive for a great many purposes, and some of those purposes are likely to be yours at one time or another.
A hoax ala' Sokal? Interesting idea. The conclusion from the responses (even those on/.) would have to be "Geeks know opaque bullshit when they see it and avoid stepping in it, whereas post-modernists can't distinguish it from shrimp canapes and stuff themselves with it."
I tried re-loading the paper 4 times and each time it ended in the middle of a sentence with the word-fragment "bet". I obviously did not see anything which supported the author's claims. However, given his fragmented grammar and his nonsensical references to representations of IP numbers in bases other than 2, I doubt very much that his thoughts were sufficiently coherent to arrive at a useful conclusion.
Did you read the article? Access speed of 100 mega-something per second; it was not immediately clear to me if this was bits or bytes. Assuming this is bytes, the 2300 Gb drive would take over 6 HOURS to be read from one end to the other.
The conclusion I draw from this is that such devices are either
Going to require large increases in access speed, such as multiple read/write heads, or
Going to require serious application of database technology with comprehensive indexing
to store things usefully. The days of grepping your hard drive for things you lost will be gone, gone, gone.
Slashdot Mirror
Anything that increases the productivity of a technical person is great. It means that one techie can do even more stuff without breaking a sweat, and the more stuff you can take care of, the more value you create and the more money you can make. Or haven't you noticed that people whose productivity is stagnant, like floor-sweepers, haven't enjoyed the same run-up in income as the tech sector? Remember that.
The off-axis reception does not surprise me; the dish has not been made which doesn't have side-lobes (do the math, it's rather impractical), and even 20 dB of attenuation won't compensate for a nearby source. (You didn't mention the dish size and operating frequency.) Generally you can reduce such problems, if they are problems, by going to a larger antenna or aiming it so that the problem source falls in a null in the pattern.
Directionality is all a matter of antenna size divided by wavelength; beamwidth in radians is roughly equal to D/lambda (1.3 D/lambda for a circular plane radiator). With the proper antenna design you can be as directional... or not... as you want. As long as you can get enough power from the transmitter to the receiver to satisfy your signal/noise ratio requirements, you're all set.
I'd expect the towers for these babies to look like PCS towers: many tall, skinny rectangles (very narrow vertical beamwidth, much wider horizontal beamwidth) arrayed around a pole. The subscriber dishes only have to point at a server tower. If a server tower starts getting overloaded, it's not that difficult to further subdivide the horizon by using more and wider (smaller horizontal beamwidth) antennas; this lets you distinguish between subscribers separated by smaller and smaller angles. Eventually you have so many connections it pays to put in fiber and use the RF spectrum for land mobile.
That's for the delay in the air. The delay in the equipment for buffering data, creating and checking the Trellis or Viterbi error-correction codes, and whatnot are what eat the time in short-range RF communications. This can all be cut with dedicated hardware; it's not intrinsic to the medium.
Fiber is actually slower; the velocity factor of glass is something like 0.6. On the other hand, a 300 THz carrier has a lot more bandwidth potential than a 2.4 GHz one. Fiber is eventually going to displace RF for point-to-point users, but RF can help build the market for fiber. RF will then recycle the spectrum and go on to serve the mobile market.
If that's what you think, go ahead and invest your retirement portfolio accordingly; take these microwave internet stocks and sell them short. Next year, tell us how many years longer you're going to have to work before you can retire.The fact that US users routinely use 128-bit encryption on browser data going over a phone line, while Gain Wireless only uses 64-bit keys for data going over the air, gives me pause. All in all, I'd like to have more reason to have confidence before I laid out money for anything like this.
Only in a police state does the policeman have it easy.
If it takes years to examine your computer equipment for signs of incriminating data, then you need to write some letters to your legislature and the FBI saying, "use more of my tax dollars to streamline and make efficient this process," not, "use more of my tax dollars for reimbursing the innocent."
So what you are saying is that the FBI should continue to conduct "investigations" which are just excuses to sieze and hold computer equipment because there will be no follow-up. You say this is due to a lack of funds. I call it mismanagement. If the FBI were doing its job correctly, it would re-allocate funds from the agents doing the seizing to analysts for evaluating the evidence until they could process everything they grabbed in a reasonable amount of time, say 60 days.
Main Entry: halite
Pronunciation: 'ha-"lIt, 'hA-
Function: noun
Date: 1868
: ROCK SALT
Only the outer extremes are heated very much (the "fusion crust", as meteoriticists call it). Just how hot would you expect the bulk of something to become during a 15-second drop from space to the stratosphere? The innards of the rock are going to be right around the 250 K equilibrium temperature of a blackbody near earth, perhaps colder if it fell in through Earth's shadow.
... it should be called "A hard geek is good to find." ;-)
Orbital velocity is around 8000 meters per second. Boosting to Earth escape velocity (roughly 11,000 m/sec) requires a delta-V of 3000 m/sec. By the rocket equation, the ratio of initial mass to final mass is e to the power of 1.2 (3000/2500), so you would need 3.32-1=2.32 times as much mass of fuel as Mir's mass. You could launch a couple new Mir's for that.
To get to the Sun by the least-energy route requires a flight past Jupiter, which requires roughly as much delta-V as a solar escape burn. Call it a delta-V of about 12,500 meters per second. Using oxygen-hydrogen with an exhaust velocity of 4500 m/sec, the fuel required would be about 15 times the mass of Mir (and a hell of a lot bulkier; liquid hydrogen is about 1/14 the density of water).
If you want to save Mir, I'm sure everybody would be happy to let you pay for this.
The real crying shame is that we know how to build a space station that could be launched with one shot into orbit on an existing vehicle; we did it with Skylab, and LLNL proposed a while back that we build an inflatable space be a few $billion. Of course, this would not station and launch it on a Titan (up in one shot). Total cost, from design to launch, would have given enough money to the space contractors, nor would the State Department have been able to use it as a way to funnel money to Russia as a way of doing some foreign policy out of someone else's budget, so that idea went bust. (I tried searching LLNL's site for the "community space suit" paper, but the search engine doesn't seem to know where it is.)
This leaves us in a state where the Senate is trying to kill all of NASA's non-Shuttle, non-ISS programs, keeping the boondoggles and nuking all the science. It's enough to make you sick.
After 10 years in space, Mir is a creaking old hulk; the cosmonauts spend much of their time on maintenance, not science. It wasn't designed to last this long, and if the Russians still had a space program the thing to do would be to launch a new, up-to-date core incorporating the lessons learned from the original, and move over the modules which are still of use. The old core is not worth the fuel required to keep it in orbit. Perhaps it could be useful on the way down, for instance as a test of controlled re-entry using electrodynamic tethers, but in space it's already barely more than a hazard to navigation.
This is the only way that the innocent can be protected from maurauding seizure. If the cops grab your stuff and you haven't done anything, you just buy a new system with your VISA card, plug in the copy of the hard drive and wait for their check to pay off the card.
The really ironic thing about this is that, unlike houses and even cars, computers depreciate so fast they are effectively useless as asset-forfeiture fund-raising material. Yet the cops grab and hold them for ridiculous amounts of time anyway.
Nice way of shooting yourself in the foot.
Now I'm sure you really didn't mean that, but you should be careful that you truly mean what you say!
Wait, you already are fucked. Never mind.
Seriously. If a recording is botched and the media are not recoverable, you should be able to get a refund of the tax you paid. In practice the recording industry would be forced to refund the tax on every disk returned. That would sure teach them.
Further consequences of this would be that Parliament would be forced to criminalize the importation of recordable media for refund (fraud, y'know) just as Michigan has criminalized the import of out-of-state soft-drink containers for the ten-cent deposit. Now wouldn't that be fun!
Finally, if you're lucky, you might even get everyone to agree that the whole thing was a rotten idea and that it ought to be scrapped. But you have to force the system into the exercise of the reductio ad absurdum first, so get moving!
And I'm sure that he'll always be more buff than you, and get more babes.
A hoax ala' Sokal? Interesting idea. The conclusion from the responses (even those on /.) would have to be "Geeks know opaque bullshit when they see it and avoid stepping in it, whereas post-modernists can't distinguish it from shrimp canapes and stuff themselves with it."
I tried re-loading the paper 4 times and each time it ended in the middle of a sentence with the word-fragment "bet". I obviously did not see anything which supported the author's claims. However, given his fragmented grammar and his nonsensical references to representations of IP numbers in bases other than 2, I doubt very much that his thoughts were sufficiently coherent to arrive at a useful conclusion.
The conclusion I draw from this is that such devices are either
- Going to require large increases in access speed, such as multiple read/write heads, or
- Going to require serious application of database technology with comprehensive indexing
to store things usefully. The days of grepping your hard drive for things you lost will be gone, gone, gone.