"surround the construct by 10-20m of black concrete or gravel". Right! It is a solar energy collector. And a bad one at that.
A normal solar collector will work whenever there is sun. This thing will only work if there is sun AND the atmosphere is unstable. In that case it might be able to "amplify" the solar energy by about a factor of two. If it becomes more than a factor of two, then "shutting down the base" which the inventor claims to shut the thing down, won't be effective anymore. And your vortex might escape.
This depends on the weather. i.e. is inherently unpredictable.
could two (or more) SATA1 drives on a SATA2 bus exceed 150 MB/s in total? I would think not, in which case SATA2 is a big advantage if you want multiple drives on a bus.
Well...... I'd vote against two drives on one bus. SATA is point to point. Max one drive per connection.
So the article, and the WDC website claim 300MB per second transfer rate. That's THEORETICAL buffer-to-host. Apparently someone measured that at 170 Mbyte per second.
Platter to buffer is an impressive 748 Mbit per second. That's an impressive 93.5 Mbyte per second!!!!! Read on and "sustained max" is 65 Mbyte per second. Duh. That's pretty normal for a 2005 drive. Nothing out of the ordinary.
Now about the advantage of SATA2 (300MB/s) versus SATA1 (150MB/s).
You get to use the extra bandwidth if you let the disk buffer (16 MB) fill with data from the platter (65Mb/sec) -> about 250 ms. And then suddenly you decide that you need all that data in the computer's main memory.
If this happens just once, you win some 200ms. That's hardly noticable. It would matter if it happens lots of times in a row. But it is a very very funny traffic pattern where your disk is able to cache 250 ms worth of data into its buffer while the computer doesn't "see it coming", and has to take full advantage of the much smarter drive. Right! Nah.
The buffer should be large enough that if you're streaming say 200Mbyte per second off 4 drives in striping RAID, the drive should "stay ahead", and while you're handling the other three drives, the buffer shouldn't overflow. So the RAID block size should not exceed about 10 mbyte. Well, that's outrageous. The buffer is QUITE large enough.
At 7200 RPM, or 120 rotations per second, and 65 Mbyte per second. we can calculate the data density to be about 0.5 Mbyte per track. So with a buffer of more than two tracks (one megabyte), you quickly approach the theoretical throughput.
Really, there is nothing special about this drive.
The wavelenght of say 10Hz sound, or about 30m is too large to fit in ahouse. So the only way to experience 10Hz "sounds" inside a house is to pressurise/depressurise the whole house in the right rhythm.
So the claimed configuration: in the attic, with the back of the device into the attic, and the front into the rest of the house is one of the rare configurations that CAN work.
Opening a window will spoil the effect quite a bit: Lots of pressure will escape at 10Hz through an open window.
Wether or not the device will produce irritating overtones in the audible range remains to be seen....
We have the Altera Stratix development kit. It's a PCI card with a Stratix on it among lots of other goodies. Leave off the goodies, and you're in business, right? Well, there is the issue of cost. The stratix we have costs around $600, clean. i.e. no board, no peripherals. That is one expensive chip. The computing power you can get from a $600 CPU is quite a lot higher than what you get from the stratix.
Of course, there are a bunch of things that the Stratix is good at.
So what do you do if you KNOW that the system will work poorly in sub-zero? Don't test it? Test it in sub-zero and conclude it failed?
what do you do if the system MIGHT not work flawlessly in sub-zero? It is the FIRST test, remember?
It is a proof-of-concept situation. And if there is a problem with cold temperatures, that can be fixed.
IIRC, diesel engines also have a problem getting started if their temperature is low. The engineers have been working on that problem for a while, and it's solved!
First you want to know if the system works in "normal operation". Then you go and test the extremes. Getting started, and extreme environments.
In cryptography (and that's what you're doing) you should assume that the adversary knows the "algorithms" involved, just the "key" is the think he doesn't know.
In this case, there are two keys: In your example: "bank" (too easy to guess) and the laminated card. The laminated card is easy to get hold of "offline".
You mean that I can ask your company not to call me? Problem is there are dozens of companies that call me, and enough new ones to keep on annoying me while I'm having dinner.
Just like there are thousands of companies who each have a procedure to be removed from their Email spam list.
Yesterday I got a call from a telemarketer, and after telling her I wanted to be on a do-not-call list, she suggested the one I handed my info over to last june. "be prepared that it may take a couple of weeks before the listing takes effect".
Next time I'll try to remember their name, and take more violent action against the *&^*&%% who call people on the do-not-call-list that they for sure know about...
On the NASA site, a version is available with micro-second-resolution timestamps in the bottom of the frame.
I deduce that the images were timestamped on the spaceship: The 3 millisecond longer speed-of-light delay for successive images to reach earth would have been very measurable.
They claim patent for the principle to figure out some dynamic stuff first, and then delegate to pure webservers.
I was hoping to be able to say that prior art of this principle could be found on slashdot, but the patent is '96, and slashdot '97 as far as I can see.
Here (the Netherlands) a patent should be "non-obvious to someone in the trade, faced with the problem". I claim that this is NOT the case. It IS obvious that with limited resources, lots of stuff of a site like slashdot still has lots of sub-elements that can be served from a simple page-serving server. Invented independedly by the slashdot guys when faced with the problem.
It depends on what tools you have, and what the target is.
I can imagine a bank having a computer under or on the desk where they advise clients (with the mortgage calculation program and things like that). Now wouldn't you feel bad if some crook could come in, and plant a program ON the bank's computer by just inserting something looking like an USB key into the computer for a couple of seconds?
It's easy to get the bank employee to go and fetch a coffee for a couple of quick seconds, it's difficult to start unscrewing the box. The Physical security of the bank employee not being gone for more than 3 minutes at a time is enough to prevent that kind of attack.
If the thieves look at EXACTLY this part, there is no problem correcting this one "brandmark" in the map.
However if they miss ONE of say 100 of the marks, they can be succesfully sued for thievery. You know the area. You're able to find this one. Now go ahead and find more than 5 of the other 99 markers... Tricky ey?
The "options" make up most of the price of the software, leading him to conclude that the actual licence is worth next to nothing. However, a big part of the options is the $50 discount you get if you already own the software.
If the bare licence would cost $0, then so would the upgrade.
This could be one of those planted errors. They plant an error in the map-data, so that if someone steals their map-data, and has the same error, they can prove it was stolen. Google (or whomever owns the map data) would appreciate you not publishing the address of the drainage ditch...:-)
Somewhere in the late seventies, a company had a bright idea. Instead of asking the developers to recompile their source code for the new processor, they would give the new processor at least a mode wherein it would simply execute the binary code of the old processor.
This idea made them big. This idea made them the biggest. And they are still called Intel.
People are replying: "they cater for a large group".
Agreed. However, the WEB is such a success because it's standards based. You can develop a new browser that conforms to the standards, and if it's good it will gather marketshare. On the other end, you can design webservers and webpages that conform to standards. And voila, everybody will be able to access your server and content.
It takes a genuine EFFORT to make a site that only works on a certain platform.
If you make a simple site, and think a bit about what you want, and need, you can easily make a site that works for everybody.
In this case, what do you need?
In the simplest form, you just fill in all the blanks, hit submit and you're done. Problem is, there are so very many "blanks", and most people don't need them all, that you want "quick-skip" feature. For example, a pre-selection: "did you have income-from-work? Do you have a house? Do you have a spouse?". All very simple stuff, easy to do in plain HTML.
If you want, you can use a little "works on allmost all browsers" java script that adds a bunch of blanks "live", without the user having to go through a submit-and-fetch-a-new-page process.
Just a little more effort is required to allow both processes to work, allowing even the browsers wtihout javascript full access.
How would you feel if your town hall had a sign outside: We have installed a new anti-terrorist measure. Cameras recognize faces. However we regret to inform you that this system does not work on Asian faces. People with an Asian origin are requested to use the internet: All features of this town hall can now be accessed over the internet. If you don't have internet, there is an internet cafe across the street.
Fair, right? Most (>90%) of the community can access the public place straight away. There is an "escape" for those who can't. Right?
In this case, it's illegal discrimination. Whats the difference with making a "tax form" available to people who have a certain operating system?
Ah, this internet tax-return form is a new feature, the old way still works. What about a new area on the town hall with (for some) desirable features (but nothing that can't be done in the old town hall), but a "no blacks" on the entrance?
Suppose that you get a big country like the US to invest something like US$5B into this project.
Fine. Now you are blocking the sun on bunch of other countries that A) didn't pay for it B) don't want you to block their sun.
This thing would be way TOO big not to block unwanted countries.
If my math is correct, For each 8 tons of gold (or similar material that you can make very thin) you can create a ring of 1m wide, 10nm thick around the earth. (I did the math for "just above sealevel", or about where the spaceshuttle flies).
This 8 ton ring would block.1 millionths of the sun's radiation. You need about a million tons to shield 1% of the sun's radiation, requiring only 25 thousand space shuttle flights.....
I was just reading the Dutch Copyright Law (Dated 1912, amended 2004), and it mentions (in a convoluted way) that copies you make, purely for a viewing experience, are not considered an infingement of the copyright.
i.e. a while ago, a discussion arose wether or not the cached copy of a copyrighted page on the web, would constitute copyright infringement. Well in Holland it doesn't: The law explicitly mentions this situation.
The FSF would LOVE to own the copyright and handle the case in court. The violators are going to argue in court: "Sorry mr Torvalds, we asked the FSF for premission to use your code in our product and they agreed"? Or: "Oh, we thought the FSF owned the copyright to the code we copied, and they are in a different jurisdiction, so we thought you couldn't sue us"?
This argument is completely bull. You don't need to know who will sue you to adhere to the rules. The rules are pretty clear.
Now if you want to ask for permission to copy part of the code, and accidentally ask the FSF instead of the real copyright holder, a genuine problem could ensue: If the FSF would blindly say: "Sure, go ahead, you can use any code we have the copyright on in your commercial closed-source product". However, the chances of that happening are very, very slim. A commercial entity stands a slight chance with everybody BUT the FSF.
If you shut down the WIFI every hour for say 10 to fifteen minutes, then it's enormously annoying for those who want to spend their whole day there, and not much of a problem for those who want to come in for a coffee and just read some emails.
If the first requirement is that 911 (or 112 in europe) works, then you can regulate that a best-effort location guess should be attempted. Most people will be able to tell the operator where they are. Some might not. Is that "some might not" reason for not requiring 911 service at all?
Magnetic fields get stronger the closer you get. If the magnet you use is 1cm, then the magnetic field doesn't get much strong when you get closer than say 1mm. So a harddrive uses a TINY (electro-)magnet, and then funnels the magnetic field even smaller.
Magnetic field strenghts are pretty enormous there.
The magnetic fields in a BLDC motor are very moderate.
Try writing some (unimportant) data to a floppy and sticking the floppy onto the fridge with a magnet. You'll be surprised that in most cases, you will still be able to read the data afterwards. And compared to a harddrive, a floppy has an ENORMOUS head, and thus a very small fieldstrength.
Slashdot Mirror
Where does this thing run on?
"surround the construct by 10-20m of black concrete or gravel". Right! It is a solar energy collector. And a bad one at that.
A normal solar collector will work whenever there is sun. This thing will only work if there is sun AND the atmosphere is unstable. In that case it might be able to "amplify" the solar energy by about a factor of two. If it becomes more than a factor of two, then "shutting down the base" which the inventor claims to shut the thing down, won't be effective anymore. And your vortex might escape.
This depends on the weather. i.e. is inherently unpredictable.
could two (or more) SATA1 drives on a SATA2 bus exceed 150 MB/s in total? I would think not, in which case SATA2 is a big advantage if you want multiple drives on a bus.
Well...... I'd vote against two drives on one bus. SATA is point to point. Max one drive per connection.
So the article, and the WDC website claim 300MB per second transfer rate. That's THEORETICAL buffer-to-host. Apparently someone measured that at 170 Mbyte per second.
Platter to buffer is an impressive 748 Mbit per second. That's an impressive 93.5 Mbyte per second!!!!! Read on and "sustained max" is 65 Mbyte per second. Duh. That's pretty normal for a 2005 drive. Nothing out of the ordinary.
Now about the advantage of SATA2 (300MB/s) versus SATA1 (150MB/s).
You get to use the extra bandwidth if you let the disk buffer (16 MB) fill with data from the platter (65Mb/sec) -> about 250 ms. And then suddenly you decide that you need all that data in the computer's main memory.
If this happens just once, you win some 200ms. That's hardly noticable. It would matter if it happens lots of times in a row. But it is a very very funny traffic pattern where your disk is able to cache 250 ms worth of data into its buffer while the computer doesn't "see it coming", and has to take full advantage of the much smarter drive. Right! Nah.
The buffer should be large enough that if you're streaming say 200Mbyte per second off 4 drives in striping RAID, the drive should "stay ahead", and while you're handling the other three drives, the buffer shouldn't overflow. So the RAID block size should not exceed about 10 mbyte. Well, that's outrageous. The buffer is QUITE large enough.
At 7200 RPM, or 120 rotations per second, and 65 Mbyte per second. we can calculate the data density to be about 0.5 Mbyte per track. So with a buffer of more than two tracks (one megabyte), you quickly approach the theoretical throughput.
Really, there is nothing special about this drive.
The wavelenght of say 10Hz sound, or about 30m is too large to fit in ahouse. So the only way to experience 10Hz "sounds" inside a house is to pressurise/depressurise the whole house in the right rhythm.
So the claimed configuration: in the attic, with the back of the device into the attic, and the front into the rest of the house is one of the rare configurations that CAN work.
Opening a window will spoil the effect quite a bit: Lots of pressure will escape at 10Hz through an open window.
Wether or not the device will produce irritating overtones in the audible range remains to be seen....
We have the Altera Stratix development kit. It's a PCI card with a Stratix on it among lots of other goodies. Leave off the goodies, and you're in business, right? Well, there is the issue of cost. The stratix we have costs around $600, clean. i.e. no board, no peripherals. That is one expensive chip. The computing power you can get from a $600 CPU is quite a lot higher than what you get from the stratix.
Of course, there are a bunch of things that the Stratix is good at.
So what do you do if you KNOW that the system will work poorly in sub-zero? Don't test it? Test it in sub-zero and conclude it failed?
what do you do if the system MIGHT not work flawlessly in sub-zero? It is the FIRST test, remember?
It is a proof-of-concept situation. And if there is a problem with cold temperatures, that can be fixed.
IIRC, diesel engines also have a problem getting started if their temperature is low. The engineers have been working on that problem for a while, and it's solved!
First you want to know if the system works in "normal operation". Then you go and test the extremes. Getting started, and extreme environments.
In cryptography (and that's what you're doing) you should assume that the adversary knows the "algorithms" involved, just the "key" is the think he doesn't know.
In this case, there are two keys: In your example: "bank" (too easy to guess) and the laminated card. The laminated card is easy to get hold of "offline".
You mean that I can ask your company not to call me? Problem is there are dozens of companies that call me, and enough new ones to keep on annoying me while I'm having dinner.
Just like there are thousands of companies who each have a procedure to be removed from their Email spam list.
Yesterday I got a call from a telemarketer, and after telling her I wanted to be on a do-not-call list, she suggested the one I handed my info over to last june. "be prepared that it may take a couple of weeks before the listing takes effect".
Next time I'll try to remember their name, and take more violent action against the *&^*&%% who call people on the do-not-call-list that they for sure know about...
On the NASA site, a version is available with micro-second-resolution timestamps in the bottom of the frame.
I deduce that the images were timestamped on the spaceship: The 3 millisecond longer speed-of-light delay for successive images to reach earth would have been very measurable.
They claim patent for the principle to figure out some dynamic stuff first, and then delegate to pure webservers.
I was hoping to be able to say that prior art of this principle could be found on slashdot, but the patent is '96, and slashdot '97 as far as I can see.
Here (the Netherlands) a patent should be "non-obvious to someone in the trade, faced with the problem". I claim that this is NOT the case. It IS obvious that with limited resources, lots of stuff of a site like slashdot still has lots of sub-elements that can be served from a simple page-serving server. Invented independedly by the slashdot guys when faced with the problem.
It depends on what tools you have, and what the target is.
I can imagine a bank having a computer under or on the desk where they advise clients (with the mortgage calculation program and things like that). Now wouldn't you feel bad if some crook could come in, and plant a program ON the bank's computer by just inserting something looking like an USB key into the computer for a couple of seconds?
It's easy to get the bank employee to go and fetch a coffee for a couple of quick seconds, it's difficult to start unscrewing the box. The Physical security of the bank employee not being gone for more than 3 minutes at a time is enough to prevent that kind of attack.
If the thieves look at EXACTLY this part, there is no problem correcting this one "brandmark" in the map.
However if they miss ONE of say 100 of the marks, they can be succesfully sued for thievery. You know the area. You're able to find this one. Now go ahead and find more than 5 of the other 99 markers... Tricky ey?
The "options" make up most of the price of the software, leading him to conclude that the actual licence is worth next to nothing. However, a big part of the options is the $50 discount you get if you already own the software.
If the bare licence would cost $0, then so would the upgrade.
This could be one of those planted errors. They plant an error in the map-data, so that if someone steals their map-data, and has the same error, they can prove it was stolen. Google (or whomever owns the map data) would appreciate you not publishing the address of the drainage ditch... :-)
Somewhere in the late seventies, a company had a bright idea. Instead of asking the developers to recompile their source code for the new processor, they would give the new processor at least a mode wherein it would simply execute the binary code of the old processor.
This idea made them big. This idea made them the biggest. And they are still called Intel.
People are replying: "they cater for a large group".
Agreed. However, the WEB is such a success because it's standards based. You can develop a new browser that conforms to the standards, and if it's good it will gather marketshare. On the other end, you can design webservers and webpages that conform to standards. And voila, everybody will be able to access your server and content.
It takes a genuine EFFORT to make a site that only works on a certain platform.
If you make a simple site, and think a bit about what you want, and need, you can easily make a site that works for everybody.
In this case, what do you need?
In the simplest form, you just fill in all the blanks, hit submit and you're done. Problem is, there are so very many "blanks", and most people don't need them all, that you want "quick-skip" feature. For example, a pre-selection: "did you have income-from-work? Do you have a house? Do you have a spouse?". All very simple stuff, easy to do in plain HTML.
If you want, you can use a little "works on allmost all browsers" java script that adds a bunch of blanks "live", without the user having to go through a submit-and-fetch-a-new-page process.
Just a little more effort is required to allow both processes to work, allowing even the browsers wtihout javascript full access.
How would you feel if your town hall had a sign outside: We have installed a new anti-terrorist measure. Cameras recognize faces. However we regret to inform you that this system does not work on Asian faces. People with an Asian origin are requested to use the internet: All features of this town hall can now be accessed over the internet. If you don't have internet, there is an internet cafe across the street.
Fair, right? Most (>90%) of the community can access the public place straight away. There is an "escape" for those who can't. Right?
In this case, it's illegal discrimination. Whats the difference with making a "tax form" available to people who have a certain operating system?
Ah, this internet tax-return form is a new feature, the old way still works. What about a new area on the town hall with (for some) desirable features (but nothing that can't be done in the old town hall), but a "no blacks" on the entrance?
Suppose that you get a big country like the US to invest something like US$5B into this project.
.1 millionths of the sun's radiation. You need about a million tons to shield 1% of the sun's radiation, requiring only 25 thousand space shuttle flights.....
Fine. Now you are blocking the sun on bunch of other countries that A) didn't pay for it B) don't want you to block their sun.
This thing would be way TOO big not to block unwanted countries.
If my math is correct, For each 8 tons of gold (or similar material that you can make very thin) you can create a ring of 1m wide, 10nm thick around the earth. (I did the math for "just above sealevel", or about where the spaceshuttle flies).
This 8 ton ring would block
I was just reading the Dutch Copyright Law (Dated 1912, amended 2004), and it mentions (in a convoluted way) that copies you make, purely for a viewing experience, are not considered an infingement of the copyright.
i.e. a while ago, a discussion arose wether or not the cached copy of a copyrighted page on the web, would constitute copyright infringement. Well in Holland it doesn't: The law explicitly mentions this situation.
No, at 300,000 feet, the screen is not blue, but black.....
But the FSF will NEVER EVER grant permission to use any code they own the copyrights on. Case closed.
The FSF would LOVE to own the copyright and handle the case in court. The violators are going to argue in court: "Sorry mr Torvalds, we asked the FSF for premission to use your code in our product and they agreed"? Or: "Oh, we thought the FSF owned the copyright to the code we copied, and they are in a different jurisdiction, so we thought you couldn't sue us"?
This argument is completely bull. You don't need to know who will sue you to adhere to the rules. The rules are pretty clear.
Now if you want to ask for permission to copy part of the code, and accidentally ask the FSF instead of the real copyright holder, a genuine problem could ensue: If the FSF would blindly say: "Sure, go ahead, you can use any code we have the copyright on in your commercial closed-source product". However, the chances of that happening are very, very slim. A commercial entity stands a slight chance with everybody BUT the FSF.
If you shut down the WIFI every hour for say 10 to fifteen minutes, then it's enormously annoying for those who want to spend their whole day there, and not much of a problem for those who want to come in for a coffee and just read some emails.
In a shop selling coffee, call it "coffee break".
The shuttle engineers did an outstanding job, ...
... Boom!
The engineers, maybe, management: no.
In '86 engineers shouted: Don't know. Not sure. Let's abort. Managers decided: all systems go.
In 2002, engineers said: let's have look. we're not sure what happened. Managers decided: Nah, we'll chance it. Boom!
Exactly the same mistakes, just a slightly different field.
If the first requirement is that 911 (or 112 in europe) works, then you can regulate that a best-effort location guess should be attempted. Most people will be able to tell the operator where they are. Some might not. Is that "some might not" reason for not requiring 911 service at all?
It is up to you - what do you want. Show (a good reading) or substance (good temperature of your drive platters and heads).
Well, when the electronics go, the data is gone as well (for most users).
Some drives have "fragile" electronics. Simply because it gets pretty hot, and cooling wouldn't be bad.
Magnetic fields get stronger the closer you get. If the magnet you use is 1cm, then the magnetic field doesn't get much strong when you get closer than say 1mm. So a harddrive uses a TINY (electro-)magnet, and then funnels the magnetic field even smaller.
Magnetic field strenghts are pretty enormous there.
The magnetic fields in a BLDC motor are very moderate.
Try writing some (unimportant) data to a floppy and sticking the floppy onto the fridge with a magnet. You'll be surprised that in most cases, you will still be able to read the data afterwards. And compared to a harddrive, a floppy has an ENORMOUS head, and thus a very small fieldstrength.