You can't just "store and forward" them because the received signals are quite noisy (especially before despreading!). You really have to receive and regenerate the signals. It's not a trivial thing to do, but it's not like there are only six people in the world who could do it (I used to work on CSMA and a bit of GPS).
Old news. If you want a less sensationalistic, more technical discussion of how this is done, see this article http://www.gpsworld.com/drone-hack/.
In brief: 1) Yes, it's possible but there are a lot of issues that make it less than practical 2) It's a non-issue for military positioning systems, which use encrypted, time-stamped signals. 3) Experts are already aware of the problem and are working on solutions.
What issues make it less than practical? I read the article and I didn't see any major problems with doing it, nor did the authors.
As for "experts are already aware of the problem and are working on solutions", it reminds me of the last scene in the 1st Indiana Jones movie, where the Ark of the Covenant is being put into a seemingly endless warehouse. "Don't worry Dr. Jones, we have top people working on it". "Who?" asks Jones. "Top people".
Yes, it is possible to fix, but does that mean it isn't worth paying attention to? It hasn't been fixed yet. I also didn't find the article Slashdot linked to to be terribly sensationalistic.
The P signal is only available to the military. I doubt they're spoofing it. Last I heard the weekly(?) code distributions are such a security pain that sometimes even the military doesn't use it. The military might benefit from an unspoofed P signal, but it won't help civilian planes or ships.
This is where my regional snobbery kicks in. In NY you never order pizza from a chain. Even a randomly chosen neighborhood place is practically guaranteed to be better, let alone your choice neighborhood places.
In New York, you also got a cracker with cheese on it.
New York makes wafers, Chicago makes pizza.
Chicago pizza is for human consumption? I thought it was how the 'hog butcher to the world' fattened livestock.
Yes, every single person who eats that pizza throws up.
No, but it looks like it to some people. I've had people who grew up in places without pizza say that to me. That was a while ago, so maybe there's no place left without pizza, but I'd be interested in more recent stories.
One guy I knew came here from the Lesser Antilles when he was 14. His new friend in America took him to a pizza place, but he thought it was a practical joke. Only after his friend started eating it did he try it.
This is where my regional snobbery kicks in. In NY you never order pizza from a chain. Even a randomly chosen neighborhood place is practically guaranteed to be better, let alone your choice neighborhood places.
Kids today. In my day programmers ate cold pizza and they liked it! Bonus points for pepperoni or sausage - there's nothing like cold congealed grease.
I disagree. The guy was 34-35. Presumably he didn't get hit by a truck or shot in the head, as you don't need an ME to figure out the basic cause. Do people that age just drop dead? Sure, sometimes, especially if they have known serious health problems. Even if they don't, it can happen (e.g. major aneurysm due to congenital weakness in an artery). It doesn't happen very often though.
I'm no conspiracy theorist and I wouldn't go around screaming ah ha! A little suspicion though, when it happens a few days before a hacker conference, and considering other things that have been happening lately, is another story.
just a few large-bag hit and runs could net millions in CC#.
Credit cards? You think small. How about getting access to the Federal Reserve? Considering all the money they give away to bail out financial institutions that should be in receivership, you could probably take a few billion and it would be dismissed as a rounding error.
No doubt this is because terrorists/spies have changed tactics
Or simply because the Feds can get away with it. KGB wannabees are like any other power hungry bastards - give them an inch and they'll take a mile. They want more because they want more. There may be some excuses they use to justify it, but the real reason is simply that they want more.
Benchmarks have been done and Java can often out-perform C
Cite? I've often seen that claim but don't recall many benchmarks. Maybe somebody found a ten line loop that a JIT optimizes the hell out of, but I'm very skeptical that Java can regularly outperform C.
The email you cite also contains (quoting a previous email?) what I've long considered the real secret of Java's success:
Java did not achieve acceptance based mainly on the
features it has (or does not have). It was accepted because
Sun expended a huge amount of effort (not to mention money)
promoting Java and the things built from it, and wisely
positioned it against the nightmare that is C++.
The Guy Steele wrote:
We were not out to win over the Lisp programmers; we were after the C++ programmers. We managed to drag a lot of them about halfway to Lisp.
Halfway to Lisp? Other than GC, there isn't much about Java that's Lisp like. Guy was rationalizing.
IMHO, without Java being pushed as an alternative to C/C++, I don't think we would have gotten the renaissance of dynamic languages we have today
I think Moore's law had a lot more to do with it than Java. Computers are now fast enough and have enough memory that you can afford to write many things in languages that are slow and memory intensive.
Lisp may be an interesting language, but Lispers scare me. The glow in their eyes when they evangelize about the Mother of All Languages reminds me of Village of the Damned.
for cars in Europe, the rule is that the brakes must always be stronger than the motor, and that applies to both independent hydraulic strands
It's also true of US cars, and probably all cars. But ABS involves valves in the brake lines that stop the flow from the master cylinder to the wheel cylinders (that's how it works). That's under computer control. I suspect this is how they're disabling the brakes.
Importing some folks for their brains and them having kids is a happy side effect, not eugenics.
From our old friend Wikipedia:
Eugenics (\yü-je-niks\) is the bio-social movement which advocates practices to improve the genetic composition of a population, usually a human population.
Clearly, importing people who are smart, on the argument that their progeny will increase the average intelligence of the population, is exactly what eugenics is about.
Once again the Slashdot moderators are working overtime on censoring any opinions the disagree with. I got modded down because I pointed out a few facts which support my argument that LI teachers are overpaid. No ranting, ad hominems, profanity, personal insults or anything. Heaven forbid.
He wants to import some workers that are smart. That is not eugenics.
Assuming that these people don't have children here, or that the US has a birth rate below replacement (it doesn't), or that this country can and should support an endlessly growing population (it can't and it shouldn't). Otherwise we're left with people who have children here, and the IQ's of those children will figure into the US average. So either he's talking about a short term unsustainable gain (each smart person good for only one generation) or he believes that it will improve the US genetic pool. The latter is eugenics.
Slashdot Mirror
You can't just "store and forward" them because the received signals are quite noisy (especially before despreading!). You really have to receive and regenerate the signals. It's not a trivial thing to do, but it's not like there are only six people in the world who could do it (I used to work on CSMA and a bit of GPS).
Old news. If you want a less sensationalistic, more technical discussion of how this is done, see this article http://www.gpsworld.com/drone-hack/.
In brief:
1) Yes, it's possible but there are a lot of issues that make it less than practical
2) It's a non-issue for military positioning systems, which use encrypted, time-stamped signals.
3) Experts are already aware of the problem and are working on solutions.
What issues make it less than practical? I read the article and I didn't see any major problems with doing it, nor did the authors.
As for "experts are already aware of the problem and are working on solutions", it reminds me of the last scene in the 1st Indiana Jones movie, where the Ark of the Covenant is being put into a seemingly endless warehouse. "Don't worry Dr. Jones, we have top people working on it". "Who?" asks Jones. "Top people".
Yes, it is possible to fix, but does that mean it isn't worth paying attention to? It hasn't been fixed yet. I also didn't find the article Slashdot linked to to be terribly sensationalistic.
The P signal is only available to the military. I doubt they're spoofing it. Last I heard the weekly(?) code distributions are such a security pain that sometimes even the military doesn't use it. The military might benefit from an unspoofed P signal, but it won't help civilian planes or ships.
This is why ships still have gyros.
Are you talking gyro compasses or full blown inertial nav?
Ever try a Domino's Thin Crust with Double Bacon?
This is where my regional snobbery kicks in. In NY you never order pizza from a chain. Even a randomly chosen neighborhood place is practically guaranteed to be better, let alone your choice neighborhood places.
In New York, you also got a cracker with cheese on it.
New York makes wafers, Chicago makes pizza.
Chicago pizza is for human consumption? I thought it was how the 'hog butcher to the world' fattened livestock.
Yes, every single person who eats that pizza throws up.
No, but it looks like it to some people. I've had people who grew up in places without pizza say that to me. That was a while ago, so maybe there's no place left without pizza, but I'd be interested in more recent stories.
One guy I knew came here from the Lesser Antilles when he was 14. His new friend in America took him to a pizza place, but he thought it was a practical joke. Only after his friend started eating it did he try it.
Ever try a Domino's Thin Crust with Double Bacon?
This is where my regional snobbery kicks in. In NY you never order pizza from a chain. Even a randomly chosen neighborhood place is practically guaranteed to be better, let alone your choice neighborhood places.
Kids today. In my day programmers ate cold pizza and they liked it! Bonus points for pepperoni or sausage - there's nothing like cold congealed grease.
It doesn't sound suspicious at all
I disagree. The guy was 34-35. Presumably he didn't get hit by a truck or shot in the head, as you don't need an ME to figure out the basic cause. Do people that age just drop dead? Sure, sometimes, especially if they have known serious health problems. Even if they don't, it can happen (e.g. major aneurysm due to congenital weakness in an artery). It doesn't happen very often though.
I'm no conspiracy theorist and I wouldn't go around screaming ah ha! A little suspicion though, when it happens a few days before a hacker conference, and considering other things that have been happening lately, is another story.
just a few large-bag hit and runs could net millions in CC#.
Credit cards? You think small. How about getting access to the Federal Reserve? Considering all the money they give away to bail out financial institutions that should be in receivership, you could probably take a few billion and it would be dismissed as a rounding error.
No doubt this is because terrorists/spies have changed tactics
Or simply because the Feds can get away with it. KGB wannabees are like any other power hungry bastards - give them an inch and they'll take a mile. They want more because they want more. There may be some excuses they use to justify it, but the real reason is simply that they want more.
Benchmarks have been done and Java can often out-perform C
Cite? I've often seen that claim but don't recall many benchmarks. Maybe somebody found a ten line loop that a JIT optimizes the hell out of, but I'm very skeptical that Java can regularly outperform C.
The email you cite also contains (quoting a previous email?) what I've long considered the real secret of Java's success:
Java did not achieve acceptance based mainly on the
features it has (or does not have). It was accepted because
Sun expended a huge amount of effort (not to mention money)
promoting Java and the things built from it, and wisely
positioned it against the nightmare that is C++.
The Guy Steele wrote:
We were not out to win over the Lisp programmers; we were after the C++ programmers. We managed to drag a lot of them about halfway to Lisp.
Halfway to Lisp? Other than GC, there isn't much about Java that's Lisp like. Guy was rationalizing.
IMHO, without Java being pushed as an alternative to C/C++, I don't think we would have gotten the renaissance of dynamic languages we have today
I think Moore's law had a lot more to do with it than Java. Computers are now fast enough and have enough memory that you can afford to write many things in languages that are slow and memory intensive.
Sure: reimplement it in Java.
That's called Clojure.
Even better, use it within J2EE so that it takes 45 seconds to start up.
They sped it up?
Do you have a cite for that? Serious question. I've never seen such a study and would be very interested.
Lisp may be an interesting language, but Lispers scare me. The glow in their eyes when they evangelize about the Mother of All Languages reminds me of Village of the Damned.
May you spend 100 years in purgatory, writing AI programs in COBOL.
for cars in Europe, the rule is that the brakes must always be stronger than the motor, and that applies to both independent hydraulic strands
It's also true of US cars, and probably all cars. But ABS involves valves in the brake lines that stop the flow from the master cylinder to the wheel cylinders (that's how it works). That's under computer control. I suspect this is how they're disabling the brakes.
"Emergency" brakes are a joke for stopping. Fortunately the hydraulic brakes have redundancy. Dual circuit has been mandatory since the 1960's.
Importing some folks for their brains and them having kids is a happy side effect, not eugenics.
From our old friend Wikipedia:
Eugenics (\yü-je-niks\) is the bio-social movement which advocates practices to improve the genetic composition of a population, usually a human population.
Clearly, importing people who are smart, on the argument that their progeny will increase the average intelligence of the population, is exactly what eugenics is about.
people should report these employers when that happens
You have a great sense of humor.
Now if you think teachers are just shit ...
Something which I not only didn't say, but made a point of saying otherwise.
If you think that education is not your problem so why should you pay taxes
Another thing I didn't say, or even suggest.
With statements like those, it's obvious that you're either unwilling or unable to engage in honest debate.
How does that contradict what I said? You're talking about boards and I'm talking about residencies.
Once again the Slashdot moderators are working overtime on censoring any opinions the disagree with. I got modded down because I pointed out a few facts which support my argument that LI teachers are overpaid. No ranting, ad hominems, profanity, personal insults or anything. Heaven forbid.
He wants to import some workers that are smart. That is not eugenics.
Assuming that these people don't have children here, or that the US has a birth rate below replacement (it doesn't), or that this country can and should support an endlessly growing population (it can't and it shouldn't). Otherwise we're left with people who have children here, and the IQ's of those children will figure into the US average. So either he's talking about a short term unsustainable gain (each smart person good for only one generation) or he believes that it will improve the US genetic pool. The latter is eugenics.