I used loop-aes for encryption on a Linux server. Once I thought why not
give the automatic update (SWUP) a try? A few weeks later I rebooted the
machine and found my harddisks inaccessable. The reason was that SWUP
updated the MOUNT command and thus removed support for loop-aes partitions.
Debian lets you set a package to a 'hold' state - it won't upgrade it from then on unless you specifically ask it to. So after you compile and install your custom-patched mount package, you would set it to hold, and breathe easy.
Other distributions almost certainly have something similar.
Ekranoplans are surface effect craft or "Wing In Ground".
Pilots usually refer to "surface effect" as "ground effect". While a wing is within half a wingspan of a surface (such as the ground or water) it can produce much more lift with less induced drag.
The only problem is that ground and water aren't exactly flat. While a ground effect craft can temporarily climb above an obstacle, this requires a lot of pilot skill. In addition, ocean rogue waves can be upwards of twice the height of surrounding swells and can appear and disappear in seconds (they're waves of constructive interference). With this in mind, a ground-effect craft would need to be very large (at least 747 large) to fly high enough to be safe. The noise from such a large vehicle operating so closely to the ground would limit such a craft to oversea routes.
In my opinion, we could find limited use for a ground-effect craft if we had to, but we wouldn't like it.
Meaning that the phone will need to send a stronger signal (to reach the tower, but also to reach your head) with an internal antenna? Have you measured the attenuation from your hand? It isn't much.
and secondly the internal antennas are usually a small coil of wire.
It's usually a dipole either way. Especially at 2.4ghz where a dipole is only 6cm long (as opposed to 900mhz for which a 16cm dipole would be optimal)
A 4" whip
antanna stickout out the top of the phone has a considerably different efficiency and radiation pattern to a 4" whip a few millimeters away from the metal shields around the innards of the phone.
What is this "efficiency" you speak of? Do you think they would have noticably different standing wave ratios? As for radiation patterns, they'd both be mostly omnidirectional. The sidelobes caused by the guts of the phone might be a dB or two, but nothing so dramatic that a phone user would be able to note the difference in signal strength.
Giving away their shnazzy algorithm that's three times as fast as any other technique is just dumb
Algorithms? Techniques? Sheesh. Look at the average C header file or a reference document for some trivial microprocessor some day. It's mostly enumerations of functions and constants, with explanations for each one. That's the level of information we need, and historically, vendors who care about their customers give it to them for the asking.
It's as much "moving this bit over there" as posting this comment to slashdot is "moving this bit over there" - but we wouldn't be having this discussion right now if TCP/IP, HTTP, and HTML were undocumented and released as some binary-only implementation.
Who cares about their optimizations? We're smart, we can figure that out ourselves.
If Intel's choices boil down to "release a binary driver or ignore Linux", which realistically, they do
No. Full stop, no.
Knowing how to drive a car does not mean I, myself, can build another just like it.
Knowing how to replace a light bulb does not mean I can make one myself.
Knowing how to read a map does not mean I am a cartographer.
Knowing how to drive the roads does not mean I can repave Rome in a day.
On the contrary, all of those examples show how I am more likely to use and buy a product if I know how to use it.
If I could look at a product's manuals, and from that, figure out how to copy the product, then you can be quite certain I knew 99% of what I needed to know to make such a product beforehand.
For example, if I hand you a black box that takes two numbers as input and outputs a third, and you deduce that it's a multiplication box, you knew everything you needed to know to make a multiplication box before I even handed it to you.
On top of this, if you simply copy a competitor, you're a year behind them and dead meat anyway.
If you're not careful, you'll put yourself in a position where you could be sued without even realizing you'd done so
It's called "head first", it's very true that you didn't realize you'd done so, and your mom actually did most of the work. Be sure to thank her come Mother's Day.
You can sue anyone at any time for any reason (or lack of it). Of course, the case may be thrown out and you may be countersued...
This is borderline unrelated, but any long-haul fiber cable (that would need repeaters) will have power running through it - usually at a very high voltage.
Do you have any idea how expensive this is? Doing this can easily quadruple the cost of a building.
Wire mesh of the appropriate size (you want holes no larger than 1/10th the wavelength of the highest frequency you need to block - 1/4" mesh is good up to at least a few GHz) is quite cheap. The windows and doors require some attention to detail, but metal-screen double-pane windows and metal doors with metallized weatherstripping are already used all over the place. Chances are there won't be that many windows in such a building anyway.
Expensive to retrofit, yes, but almost certainly cheaper than, say, the insulation, to put in in the first place.
It's the drag that slows it down and causes it to drift back to earth.
There are two kinds of drag - parasitic drag and induced drag. Parasitic drag is drag that does not contribute lift. It increases with the square of airspeed. Induced drag is due to the fact that wings do not lift straight up - they lift slightly aft as well (well, that's the simplified explanation). The larger the lift coefficient, the more pronounced this aftward lift is.
In this design, you can be sure that almost all of the drag is induced drag.
The more weight, the larger the lift coefficient has to be for a given wing area. This increased induced drag means more potential energy must be expended (altitude or fuel cell capacity) to maintain airspeed.
For a given signal-to-noise ratio, double the bitrate still requires double the bandwidth. Improvement in modulation techniques can only serve to more closely approximate the theoretical.
I figure if you can build a HV system that generates 15KV to 50KV, and enough continuous power to produce 2.5 or more watts per gram, you could build a completely self-sustained lifter.
Given that gasoline has an energy density of 12.3 watt hours per gram, and gasoline can be readily converted to electricity at 40% efficiency, it should be very easy for you to make a VTOL flying car with a 3-to-1 fuel-to-structure weight ratio that would hover in the air for an hour or two.
Let us know when you've built it and flown it from place to place - Slashdot would be sure to post it on the front page.
Or, alternatively, succumb to the NASA spiel in this post's sibling.
I'll probably use a single board computer running embedded linux and a 2.5" hard drive.
You may find the OpenBrick to be a good starting point. They take 2.5" drives and run off 5V. Build a DC->DC convertor circuit using something like a MAX787, or (if you have more heatsinks than time) a 7805, and you should be able to run it off a lead-acid battery a very very long time.
4000 miles is 6437376 meters. Assume a non-ethernet signal is run over this 4000-mile cat5 cable at 1mhz. Attenuation per 100 meters is 2.0dB, or 128746dB for the whole thing. Thus, you would need an input voltage 2^42915 times more powerful than your receiver can distinguish.
The significance of such a voltage would, I am afraid, be comprehendable only by slashdot's lameness filter.
We'll be able to patch probably two thirds of the components without shutting the system down. That's an area where the Unix guys are ahead of us, because of the way they do redirection -- they can patch a file and then change the symbolic link. That's an area where we've got a problem, and we'll fix it in the near future when possible.
You can patch a file in use on UNIX without shutting down because you can delete an open file and the applications will still be able to map/read/write to that inode, which will magically disappear when the last application closes it.
Example:
Application starts using libc.so.
Admin runs mv libc.so-new libc.so.
Application continues to use the old libc.so, which now has no filename.
Application exits.
Kernel marks the inode that the old libc.so was using as free.
Symlinks are cool, and it would have been nice if Microsoft implemented Shortcuts at the file system level, but they aren't what save us from rebooting.
The politicians couldn't tack riders onto bills either a) completely unrelated to the bill itself, and b) designed to submarine a bill by being completely ludicrous?
This could be accomplished by having representatives use an ordinal voting system such as Condorcet to vote on bills.
The bill with pork could be on the ballot right next to the bill without pork, and representatives would be able to pass the bill whether or not they felt the pork was worthwhile.
This would obviously require a constitutional amendment.
Slashdot Mirror
Debian lets you set a package to a 'hold' state - it won't upgrade it from then on unless you specifically ask it to. So after you compile and install your custom-patched mount package, you would set it to hold, and breathe easy.
Other distributions almost certainly have something similar.
Pilots usually refer to "surface effect" as "ground effect". While a wing is within half a wingspan of a surface (such as the ground or water) it can produce much more lift with less induced drag.
The only problem is that ground and water aren't exactly flat. While a ground effect craft can temporarily climb above an obstacle, this requires a lot of pilot skill. In addition, ocean rogue waves can be upwards of twice the height of surrounding swells and can appear and disappear in seconds (they're waves of constructive interference). With this in mind, a ground-effect craft would need to be very large (at least 747 large) to fly high enough to be safe. The noise from such a large vehicle operating so closely to the ground would limit such a craft to oversea routes.
In my opinion, we could find limited use for a ground-effect craft if we had to, but we wouldn't like it.
It's bound by the same laws of physics as fiber or air, and the answer is a definite "well, that depends". Read up on Shannon's Law.
Meaning that the phone will need to send a stronger signal (to reach the tower, but also to reach your head) with an internal antenna? Have you measured the attenuation from your hand? It isn't much.
and secondly the internal antennas are usually a small coil of wire.
It's usually a dipole either way. Especially at 2.4ghz where a dipole is only 6cm long (as opposed to 900mhz for which a 16cm dipole would be optimal)
A 4" whip antanna stickout out the top of the phone has a considerably different efficiency and radiation pattern to a 4" whip a few millimeters away from the metal shields around the innards of the phone.
What is this "efficiency" you speak of? Do you think they would have noticably different standing wave ratios? As for radiation patterns, they'd both be mostly omnidirectional. The sidelobes caused by the guts of the phone might be a dB or two, but nothing so dramatic that a phone user would be able to note the difference in signal strength.
Algorithms? Techniques? Sheesh. Look at the average C header file or a reference document for some trivial microprocessor some day. It's mostly enumerations of functions and constants, with explanations for each one. That's the level of information we need, and historically, vendors who care about their customers give it to them for the asking.
It's as much "moving this bit over there" as posting this comment to slashdot is "moving this bit over there" - but we wouldn't be having this discussion right now if TCP/IP, HTTP, and HTML were undocumented and released as some binary-only implementation.
Who cares about their optimizations? We're smart, we can figure that out ourselves.
No. Full stop, no.
On the contrary, all of those examples show how I am more likely to use and buy a product if I know how to use it.
If I could look at a product's manuals, and from that, figure out how to copy the product, then you can be quite certain I knew 99% of what I needed to know to make such a product beforehand.
For example, if I hand you a black box that takes two numbers as input and outputs a third, and you deduce that it's a multiplication box, you knew everything you needed to know to make a multiplication box before I even handed it to you.
On top of this, if you simply copy a competitor, you're a year behind them and dead meat anyway.
It's called "head first", it's very true that you didn't realize you'd done so, and your mom actually did most of the work. Be sure to thank her come Mother's Day.
You can sue anyone at any time for any reason (or lack of it). Of course, the case may be thrown out and you may be countersued...
The new opposite of 'oll korrect'?
$ units
2084 units, 71 prefixes, 32 nonlinear units
You have: 30 kilometers
You want: light seconds
* 0.00010006923
/ 9993.0819
0.1ms is a heck of a lot better than the average T1.
This is borderline unrelated, but any long-haul fiber cable (that would need repeaters) will have power running through it - usually at a very high voltage.
Hmmm. Half the stupid people are below average intelligence. Ergo, everyone on earth is stupid.
I think you're on to something there.
Wire mesh of the appropriate size (you want holes no larger than 1/10th the wavelength of the highest frequency you need to block - 1/4" mesh is good up to at least a few GHz) is quite cheap. The windows and doors require some attention to detail, but metal-screen double-pane windows and metal doors with metallized weatherstripping are already used all over the place. Chances are there won't be that many windows in such a building anyway.
Expensive to retrofit, yes, but almost certainly cheaper than, say, the insulation, to put in in the first place.
Well, peril does come from the same root word as experience.
There are two kinds of drag - parasitic drag and induced drag. Parasitic drag is drag that does not contribute lift. It increases with the square of airspeed. Induced drag is due to the fact that wings do not lift straight up - they lift slightly aft as well (well, that's the simplified explanation). The larger the lift coefficient, the more pronounced this aftward lift is.
In this design, you can be sure that almost all of the drag is induced drag.
The more weight, the larger the lift coefficient has to be for a given wing area. This increased induced drag means more potential energy must be expended (altitude or fuel cell capacity) to maintain airspeed.
They consume 5 watts each. A bookshelf with 40 of them would only consume 200 watts, evenly distributed over several square feet.
You'd have much better luck starting a fire with a string of miniature christmas lights, or Athlons, or something.
No, it can't.
For a given signal-to-noise ratio, double the bitrate still requires double the bandwidth. Improvement in modulation techniques can only serve to more closely approximate the theoretical.
Given that gasoline has an energy density of 12.3 watt hours per gram, and gasoline can be readily converted to electricity at 40% efficiency, it should be very easy for you to make a VTOL flying car with a 3-to-1 fuel-to-structure weight ratio that would hover in the air for an hour or two.
Let us know when you've built it and flown it from place to place - Slashdot would be sure to post it on the front page.
Or, alternatively, succumb to the NASA spiel in this post's sibling.
You may find the OpenBrick to be a good starting point. They take 2.5" drives and run off 5V. Build a DC->DC convertor circuit using something like a MAX787, or (if you have more heatsinks than time) a 7805, and you should be able to run it off a lead-acid battery a very very long time.
I have no association with them.
Congress would be powerless to enact copyright law without Article I, Section 8.
Look at the part that starts with "To promote the progress of science and useful arts..." Note specifically the "limited times" clause.
The significance of such a voltage would, I am afraid, be comprehendable only by slashdot's lameness filter.
Ergo, the repeater/digipeater.
It happens.
We'll be able to patch probably two thirds of the components without shutting the system down. That's an area where the Unix guys are ahead of us, because of the way they do redirection -- they can patch a file and then change the symbolic link. That's an area where we've got a problem, and we'll fix it in the near future when possible.
You can patch a file in use on UNIX without shutting down because you can delete an open file and the applications will still be able to map/read/write to that inode, which will magically disappear when the last application closes it.
Example:
Symlinks are cool, and it would have been nice if Microsoft implemented Shortcuts at the file system level, but they aren't what save us from rebooting.
There are lots of things in this world that are hard but straightforward.
This could be accomplished by having representatives use an ordinal voting system such as Condorcet to vote on bills.
The bill with pork could be on the ballot right next to the bill without pork, and representatives would be able to pass the bill whether or not they felt the pork was worthwhile.
This would obviously require a constitutional amendment.