Actually the USB scam that he referred to was a case where they just left them laying around. It was in a widely reported article a year or so ago. If I remember correctly they left some of them laying on the ground outside the company they were penetration testing.
Actually the USB drives don't even fall under the heading of 'Social Engineering'. Social engineering involves communicating with someone. The only way it could be social engineering is if you are interacting with your hardware on WAY to much of a personal level.
Think about it. If they allowed people to yammer away (loudly) on their cells on airplanes (where we can't get away from them) the FAA/TSA would have to let us take our guns on the plane to shut them up!
Interesting. The UK link loads identical to what I pulled up on google but the North America view is definitely off as it isn't zoomed out an additional click (as you noted). It also comes up miss centered as Alaska is cut off. (Grew up in Alaska so I should never miss that!)
I guess the 'preview' thing could have used a little link checking. Messing up the example kind of reduces the impact...
Notice central Europe, Greenland, Newfoundland, Norway, Sweden, the Middle East, northern Africa, Russia, etc..., all fit in the same sized view.
Hmmm... I've seen more then one visitor from the other side of the pond completely miscalculate the length of time their road trip would take.
The quality of the chipset doing the scaling is of huge importance. I have a couple upconverting DVD players, which I purchased mostly to watch PAL videos on NTSC equipment. (All the good rally videos are from the UK!)
The really sweet player is the Oppo DV-971. The test reviews put it at the top of the list with the $1600 Denon player but it was only $200. It has been replaced by the DV-981 which is pretty similar. Outputting HDMI at 1080 really shows a difference. Also zooming in at 4X shows how much can be shown.
The NeuNeo/Helios H4000 is nice but not quite as polished as the Oppo. The cool thing is that it will ignore all of the 'command inhibit' features on a dvd. Basically you can fast-forward/skip through everything including the stupid FBI warnings, previews, silly intros, etc.
The small sample size is indeed the overriding feature of these failure/success stories. In the last 10 years I have gone through about 10,000 computers in the sites my guys support. Currently we have almost 2,500 computers out there in service.
With my larger statistical sample the data smooths out. Every week I get at least one drive that is sent in that they want me to attempt a recovery on. This doesn't include the number of failed HDs where they didn't want to attempt recovery because they didn't have any thing critical or they had everything backed up. So basically we are talking about over 50 drives a year from a sample of about 2500 computers.
A while ago there was a/. story listing the drive failure stats from Google's server farms. It had a seriously large sample and they had some really detailed findings.
1. User just deleted a "critical" data directory/file.
2. User just deleted an OS directory and their computer will not run.
3. User kept everything on his/her local drive and it just caught fire.
4. User wants an email from 3 years ago that user had deleted from his/her last computer 2 years ago.
5. The legal department wants all email to/from Mr.X, Mr.Y and Mr.Z.
6. User keeps getting infected with viruses.
With centralized control, all of those are simple. Once you start allowing users to choose what to run, how to configure it and so forth, all of those become major issues.
This first step is some simple instructions to the users beforehand:
- "Look at your computer and know that it is going to fail. It is just a matter of time. Backup your data like your life depends on it. When it goes 'bonk' you don't want to be left crying in the closet."
- A corollary the the above: "Put all of the office's data in one location so you only have to do one backup. It will also insure that you don't end up with multiple versions of the same document."
- "Boring is good. A boring computer is one that just starts up and works every day. A cool, exciting computer has cool, exciting problems. Keep it plain and boring."
- Related to the above: "There is nothing free on the internet. If you can't figure out how they are making the money to pay the programmer then they are doing something that you don't know about and aren't going to like."
- "Run the Symantec Corporate Edition (or the new Symantec Endpoint Protection that we are just rolling out) and no other antivirus software. More then one antivirus program will cause problems."
- "Don't run any resident antispyware program in the background. If you do have a problem try the following: Spybot Search & Destroy, AdAware, SuperAntiSpyware (horrible name...), and TrendMicro's Webscan. Remember that they really are out to get you so stay with business related sites." (We have found that running resident antispyware programs generates more support calls then spyware infections do.)
Those are the basics of preventative training. Now onto the specific answers.
(1) "Let's go to your backup... Not backed up? Lets check deleted files... Not there? Too bad. (we don't actually say that) It is lost (Now you should repeat the training mantras from above so they learn something for the future.)"
(2) "You can send the computer in or I can send out an imaged HD and we will walk you through putting it in. Then we can remote in and transfer your files across to the new drive. What version of word processing do you use because we can preload it before we ship the drive. Do you have the install disks for your software? If it isn't a disk that I have in my library then you will need to go get it."
(3) I have never had a computer catch fire. (10,000+ and counting) The closest thing were the computers in an office in Chicago that were caught in a highrise fire. The data was all recoverable. But to get to the point: "We will need your backups and I will send you an imaged HD and/or computer. You can send the drive here and I will attempt to recover the data..." Any lost data is dealt with like the previous examples.
(4) "Sorry it is gone." Suggest that if that is important to them they will need a sophisticated archive rotation scheme. If someone wants this we will write a DOS batchfile to help implement it for them.
(5) Email retention isn't a problem in a small office until it is mandated. Then we would simply come up with a backup scheme probably using a batchfile running on a schedule.
(6) The user pretty much learns after the first or second infection. Infections really don't destroy data anymore like they used to. That went away about 3 years ago. We always council people on safe computing and it is exceedingly rare when they don't listen. In the couple of times where they kept doing it we added Spybot or similar to run resi
We have 7 techs supporting 2000+ computers in 800+ offices. We give guidance but we don't tell them they have to run them any any specific manner. The biggest advice is, "Boring is good".
License compliance is one detail were you can't offer any wiggle room. There are a number of good auditing software (including some free ones!) that will report on the installed software. That will keep you out of legal trouble.
On the other hand dumb people deserve to be ripped off. They call it 'evolution'. Evolution requires that something dies.
I suggest that we might be witnessing Creative getting involved with the evolution process here...
The real issue is still being missed here. With all of the promises that have been PRed our way and the years of available technology and programming technique to back it up: It shouldn't be possible to crash the kernel because of a driver. (well maybe a disk driver...)
I can see the driver going bonk and having to reset itself but it shouldn't be possible to take down the whole system. It is supposed to be the end of such things..
Actually an analog tape is easier to wipe then a digital tape. Digital has some pretty firm rules seeing that there are only 2 states and the length of each bit is a fixed value. Analog has no fixed anything except for the width and location of the tracks. (That doesn't mean that there wasn't any funny business going on in the attempt to recover the 18 minutes.)
So does a simple low-level format. Unless you can cite any actual cases of data being recovered from a low-level-formatted drive that involve modern (IE *not* MFM) drives. Had lunch last Wednesday with a guy who has a full time job recovering data from drives that are anything short of a full DOD wipe. He is a forensic computer examiner and has degrees in mathematics and in cryptography. He had a number of fascinating stories about nailing people who thought a couple complete overwrites of the drive would cover their tracks. A repeated low level format is a cake walk for him because there is no alternation of the bit pattern. The regular repeating pattern makes it easy to analyze the magnetic boundaries and recover a drive.
The IT staff either is malicious or highly incompetent.
Or following orders. They were almost certainly following policy. The complaint here is that the data is missing/destroyed. The data is supposed to be retained by a backup solution. The hard drives are only a 'working area'. Sure the data is stored there while someone is actively using the computer but as soon as it leaves the person's desk it is now a security risk.
The drives should be thoroughly wiped and then recycled or destroyed. That is good IT policy. I run the IT hardware division for my company that supplies and supports customer's computers. When any computer is repaired or replaced the old drive is dated, put into secure storage for a minimum of 30 days, and then DOD wiped, and then recycled or physically destroyed. (The magnets are really good for hanging things on cubical walls.)
The reason our drives are 'aged' for 30 days is because we can't trust our customers to have a good backup. (or ANY backup...) The White House shouldn't have any issues with their backups so they have no reason to retain the drives. This brings us back to the backup question. The rule for a really secure backup methodology is, "Multiple methods of backup, and multiple media". About 10 years ago I saw an article in a trade journal (InfoWorld?) that quoted the statistic that after a catastrophic data loss, 15% of the time the backup method itself is found to be flawed. Having 2 methods of backup would reduce the chance of an unrecoverable flaw to 2.25% which is much more acceptable.
The solution to the White House problem is the judicious use of pink slips. Fire any one who bowed to pressure and allowed this to happen. (or was incompetent enough to allow a flawed backup scheme...)
The freeway meter will keep you from the car equivalent of the "packing 10 pounds of sugar in a 5 pound sack" merging problem.
The reason that the meters are still a problem is that the meters are too close to the freeway so there is no way that anything less then a drag racer can get to freeway speed before getting to the merge zone.
If it creates a guaranteed slowdown from every car that enters a flowing roadway then it has lost its purpose.
You bring up an issue that connects with fuel consumption and safety on the road.
It is pretty rare that anyone truly questions the vehicles that we buy today. People have accepted SUVs as the norm for driving around in the US for some reason. People will recite a number of reasons but in reality the only real reason is that they have become accepted as normal and 'cool'. It is just a change in peoples perception. If you had asked someone in the 1970s to select a 'people hauler' they would select a station wagon. It is lower to the ground making it safer to drive and is a much better layout for a vehicle. No one would have accepted a 70s Suburban, Blazer, or Bronco (even with a more luxurious interior) because of the perception, "That's a truck!"
This change of perception is actively damaging our country. Moving the increased mass of these vehicles around just plain costs energy and increases wear and tear on our roadways. If you are conscious of this and want to get a reduced mass commuter vehicle you are taking your life in your hands because of the battering ram reality of a large percentage of the vehicles.
It is really time that we do something realistic about the mass of the vehicles on our roads. A general switch to smaller lightweight vehicles would massively reduce fuel expenditures, pollution, and the smaller size would help to reduce congestion. The solution to this is to change public perception, which will probably only come about by economic reasons. The price of gas will do part of it but taxing vehicles by weight will go a long way towards making it a more equitable situation. The lighter vehicles would be rewarded for their lessened impact on the roadway and the environment. More massive vehicles would pay for increased impact on the environment, wear to the roadway, and the increased risk they pose to lighter vehicles.
People talk about rail/mass transit as a solution to LA's transportation problems but usually it is people who haven't been here. This area is so spread out in all directions that it would take an indescribable quantity of money to build such a system. The land is insanely expensive and with the sprawling area you could spend a few years of our whole nation's federal budget to build such a system. It just won't work.
(That guy who stole the tank down in San Diego about 5 years ago is starting to look saner and saner...)
BTW - From trips to Europe: I love the mass transit! Munich has a rail, subway, tram, and bus system that is so good it is just fun to use it! For 15 euro you get a pass good for unlimited use of all of the above for a week! It is just amazingly convenient and cool.
I really hope that this isn't truly a "new" discovery. If someone sits and thinks about it it should be really obvious. I have posted a basic explanation as a comment to a number of blogs and I'm not a traffic engineer.
Once traffic reaches a point of saturation ANY change is flow will bring traffic to a halt. This includes things like a road feature that makes people accelerate, a merging or diverging ramp, or a hill or corner that allows people to see farther ahead inducing them to adjust their speed.
Any change in relative speed will at some point cause a person to slow down. If they are accelerating they will slow when they get close to the car in front. If they are slowing then that is obviously a slow down. Each car behind this change reacts to it after a delay. The longer the delay the more they have to react. People tend to react much slower then they normally would because very few drivers focus primarily on driving. They only use the minimum attention that is necessary. This just makes the problem worse. It only takes a few cars for a subtle adjustment to become a complete stop. The length of time each successive car is stopped will become longer and longer.
To make the problem worse the same 1 to 2 second delay in reaction applies to the acceleration of the vehicles after the slowdown/stop. Every fraction of a second that a person delays accelerating is adding to the stacking of the delay.
To look at another aspect of a slowdown...
If you have a smooth flow of traffic at a fixed speed you will have a certain number of cars passing a point on the road per minute. If you have a slowdown you will reduce the number of cars passing per minute. But the traffic was already at a capacity flow so the number of cars feeding into this situation continues unabated. It is obvious that the flow of traffic is done until the quantity of vehicles feeding into the situation is drastically slowed to less then the flow of traffic at the restriction. (In Orange County, CA that means waiting till after 6:30PM for a situation that started at 3:00PM.)
What can be done about this without building a vastly increased number of lanes? (The I-405 is already 14 lanes in central Orange County. Increasing it to 20+ lanes would cost billions and in 20 years when they are done we would need 30+ lanes...)
A big improvement could be made through driver training (Yeah right...). Teaching people how to merge can reduce the constant forced slowdown from cars merging onto a freeway at less then freeway speed. The correct speed to merge at is 5 to 10 MPH FASTER then the flow of traffic. A car won't accelerate quickly but it will slowdown quickly so you simply drive down the on ramp picking the hole in traffic you will merge into and brake into that hole matching speeds. This minimizes the disruption. "Freeway Meters" on an onramp actually make this problem worse on a freeway that is still flowing at a reasonable speed because they reduce the distance that a car has to accelerate insuring that they enter the roadway at a reduced speed causing traffic to slow down for them.
Teaching people to slowdown after they are on an offramp will also help reduce the disruption to traffic flow. Most drivers slow down a minimum of 10mph before the exit the roadway causing large backups for open free flowing offramps.
To reduce the effect of slowdowns you can teach people to look past the car in front of them and try to slowdown before the car in front of them, which can reduce the quantity of speed they have to scrub off. If they look ahead and start to accelerate earlier this will cause a similar improvement in reduction of traffic impediment.
(Truth is that you will never be able to teach people to change their driving habits because their cell phone, their coffee, and their daydreams are way more important then driving the 1-1/2 tons of steel they are sitting in.)
'If governments or other people with millions of dollars can listen to your conversations right now, why shouldn't your next-door neighbor?' Muller says."
What a stupid comment. In other words, if some people are going to break the law, let's make sure everyone can. Good idea.
Let him sit on his couch eating Cheetos. He has the right to be happily oblivious as every personal right slowly disappears because no one is complaining (too busy eating Cheetos!) while the technology that makes it possible keeps getting cheaper and more powerful.
Slashdot Mirror
Actually the USB scam that he referred to was a case where they just left them laying around. It was in a widely reported article a year or so ago. If I remember correctly they left some of them laying on the ground outside the company they were penetration testing.
Actually the USB drives don't even fall under the heading of 'Social Engineering'. Social engineering involves communicating with someone. The only way it could be social engineering is if you are interacting with your hardware on WAY to much of a personal level.
The real issue weapons on planes...
Think about it. If they allowed people to yammer away (loudly) on their cells on airplanes (where we can't get away from them) the FAA/TSA would have to let us take our guns on the plane to shut them up!
Interesting. The UK link loads identical to what I pulled up on google but the North America view is definitely off as it isn't zoomed out an additional click (as you noted). It also comes up miss centered as Alaska is cut off. (Grew up in Alaska so I should never miss that!)
I guess the 'preview' thing could have used a little link checking. Messing up the example kind of reduces the impact...
Here lets give him a picture so he can compare...
This links to a satellite view of the United States:
http://maps.google.com/maps?hl=en&ie=UTF8&t=k&ll=38.68551,-100.019531&spn=33.079911,60.117187&z=4
This links to a satellite view of the same scale centered on England:
http://maps.google.com/maps?hl=en&ie=UTF8&ll=51.508742,0&spn=53.711322,120.234375&t=k&z=3
Notice central Europe, Greenland, Newfoundland, Norway, Sweden, the Middle East, northern Africa, Russia, etc..., all fit in the same sized view.
Hmmm... I've seen more then one visitor from the other side of the pond completely miscalculate the length of time their road trip would take.
The quality of the chipset doing the scaling is of huge importance. I have a couple upconverting DVD players, which I purchased mostly to watch PAL videos on NTSC equipment. (All the good rally videos are from the UK!)
The really sweet player is the Oppo DV-971. The test reviews put it at the top of the list with the $1600 Denon player but it was only $200. It has been replaced by the DV-981 which is pretty similar. Outputting HDMI at 1080 really shows a difference. Also zooming in at 4X shows how much can be shown.
The NeuNeo/Helios H4000 is nice but not quite as polished as the Oppo. The cool thing is that it will ignore all of the 'command inhibit' features on a dvd. Basically you can fast-forward/skip through everything including the stupid FBI warnings, previews, silly intros, etc.
Here is a really good DVD player comparison page:
http://www.hometheaterhifi.com/volume_10_1/dvd-benchmark-guide-to-progressive-scan-shootout-1-2003.html
Here is an explination of their their testing methodology:
http://www.hometheaterhifi.com/volume_10_1/dvd-benchmark-guide-to-progressive-scan-shootout-1-2003.html
More to the point: BlueRay won't hit 50% until the price drops so there is a $150 player and the disks have dropped to a sub-"premium" price.
The small sample size is indeed the overriding feature of these failure/success stories. In the last 10 years I have gone through about 10,000 computers in the sites my guys support. Currently we have almost 2,500 computers out there in service.
/. story listing the drive failure stats from Google's server farms. It had a seriously large sample and they had some really detailed findings.
With my larger statistical sample the data smooths out. Every week I get at least one drive that is sent in that they want me to attempt a recovery on. This doesn't include the number of failed HDs where they didn't want to attempt recovery because they didn't have any thing critical or they had everything backed up. So basically we are talking about over 50 drives a year from a sample of about 2500 computers.
A while ago there was a
1. User just deleted a "critical" data directory/file.
2. User just deleted an OS directory and their computer will not run.
3. User kept everything on his/her local drive and it just caught fire.
4. User wants an email from 3 years ago that user had deleted from his/her last computer 2 years ago.
5. The legal department wants all email to/from Mr.X, Mr.Y and Mr.Z.
6. User keeps getting infected with viruses.
With centralized control, all of those are simple. Once you start allowing users to choose what to run, how to configure it and so forth, all of those become major issues.
This first step is some simple instructions to the users beforehand:
- "Look at your computer and know that it is going to fail. It is just a matter of time. Backup your data like your life depends on it. When it goes 'bonk' you don't want to be left crying in the closet."
- A corollary the the above: "Put all of the office's data in one location so you only have to do one backup. It will also insure that you don't end up with multiple versions of the same document."
- "Boring is good. A boring computer is one that just starts up and works every day. A cool, exciting computer has cool, exciting problems. Keep it plain and boring."
- Related to the above: "There is nothing free on the internet. If you can't figure out how they are making the money to pay the programmer then they are doing something that you don't know about and aren't going to like."
- "Run the Symantec Corporate Edition (or the new Symantec Endpoint Protection that we are just rolling out) and no other antivirus software. More then one antivirus program will cause problems."
- "Don't run any resident antispyware program in the background. If you do have a problem try the following: Spybot Search & Destroy, AdAware, SuperAntiSpyware (horrible name...), and TrendMicro's Webscan. Remember that they really are out to get you so stay with business related sites." (We have found that running resident antispyware programs generates more support calls then spyware infections do.)
Those are the basics of preventative training. Now onto the specific answers.
(1) "Let's go to your backup... Not backed up? Lets check deleted files... Not there? Too bad. (we don't actually say that) It is lost (Now you should repeat the training mantras from above so they learn something for the future.)"
(2) "You can send the computer in or I can send out an imaged HD and we will walk you through putting it in. Then we can remote in and transfer your files across to the new drive. What version of word processing do you use because we can preload it before we ship the drive. Do you have the install disks for your software? If it isn't a disk that I have in my library then you will need to go get it."
(3) I have never had a computer catch fire. (10,000+ and counting) The closest thing were the computers in an office in Chicago that were caught in a highrise fire. The data was all recoverable. But to get to the point: "We will need your backups and I will send you an imaged HD and/or computer. You can send the drive here and I will attempt to recover the data..." Any lost data is dealt with like the previous examples.
(4) "Sorry it is gone." Suggest that if that is important to them they will need a sophisticated archive rotation scheme. If someone wants this we will write a DOS batchfile to help implement it for them.
(5) Email retention isn't a problem in a small office until it is mandated. Then we would simply come up with a backup scheme probably using a batchfile running on a schedule.
(6) The user pretty much learns after the first or second infection. Infections really don't destroy data anymore like they used to. That went away about 3 years ago. We always council people on safe computing and it is exceedingly rare when they don't listen. In the couple of times where they kept doing it we added Spybot or similar to run resi
We have 7 techs supporting 2000+ computers in 800+ offices. We give guidance but we don't tell them they have to run them any any specific manner. The biggest advice is, "Boring is good".
License compliance is one detail were you can't offer any wiggle room. There are a number of good auditing software (including some free ones!) that will report on the installed software. That will keep you out of legal trouble.
I suggest that we might be witnessing Creative getting involved with the evolution process here...
The real issue is still being missed here. With all of the promises that have been PRed our way and the years of available technology and programming technique to back it up:
It shouldn't be possible to crash the kernel because of a driver. (well maybe a disk driver...)
I can see the driver going bonk and having to reset itself but it shouldn't be possible to take down the whole system. It is supposed to be the end of such things..
Actually an analog tape is easier to wipe then a digital tape. Digital has some pretty firm rules seeing that there are only 2 states and the length of each bit is a fixed value. Analog has no fixed anything except for the width and location of the tracks. (That doesn't mean that there wasn't any funny business going on in the attempt to recover the 18 minutes.)
Or following orders. They were almost certainly following policy. The complaint here is that the data is missing/destroyed. The data is supposed to be retained by a backup solution. The hard drives are only a 'working area'. Sure the data is stored there while someone is actively using the computer but as soon as it leaves the person's desk it is now a security risk.
The drives should be thoroughly wiped and then recycled or destroyed. That is good IT policy. I run the IT hardware division for my company that supplies and supports customer's computers. When any computer is repaired or replaced the old drive is dated, put into secure storage for a minimum of 30 days, and then DOD wiped, and then recycled or physically destroyed. (The magnets are really good for hanging things on cubical walls.)
The reason our drives are 'aged' for 30 days is because we can't trust our customers to have a good backup. (or ANY backup...) The White House shouldn't have any issues with their backups so they have no reason to retain the drives. This brings us back to the backup question. The rule for a really secure backup methodology is, "Multiple methods of backup, and multiple media". About 10 years ago I saw an article in a trade journal (InfoWorld?) that quoted the statistic that after a catastrophic data loss, 15% of the time the backup method itself is found to be flawed. Having 2 methods of backup would reduce the chance of an unrecoverable flaw to 2.25% which is much more acceptable.
The solution to the White House problem is the judicious use of pink slips. Fire any one who bowed to pressure and allowed this to happen. (or was incompetent enough to allow a flawed backup scheme...)
The freeway meter will keep you from the car equivalent of the "packing 10 pounds of sugar in a 5 pound sack" merging problem.
The reason that the meters are still a problem is that the meters are too close to the freeway so there is no way that anything less then a drag racer can get to freeway speed before getting to the merge zone.
If it creates a guaranteed slowdown from every car that enters a flowing roadway then it has lost its purpose.
You bring up an issue that connects with fuel consumption and safety on the road.
It is pretty rare that anyone truly questions the vehicles that we buy today. People have accepted SUVs as the norm for driving around in the US for some reason. People will recite a number of reasons but in reality the only real reason is that they have become accepted as normal and 'cool'. It is just a change in peoples perception. If you had asked someone in the 1970s to select a 'people hauler' they would select a station wagon. It is lower to the ground making it safer to drive and is a much better layout for a vehicle. No one would have accepted a 70s Suburban, Blazer, or Bronco (even with a more luxurious interior) because of the perception, "That's a truck!"
This change of perception is actively damaging our country. Moving the increased mass of these vehicles around just plain costs energy and increases wear and tear on our roadways. If you are conscious of this and want to get a reduced mass commuter vehicle you are taking your life in your hands because of the battering ram reality of a large percentage of the vehicles.
It is really time that we do something realistic about the mass of the vehicles on our roads. A general switch to smaller lightweight vehicles would massively reduce fuel expenditures, pollution, and the smaller size would help to reduce congestion. The solution to this is to change public perception, which will probably only come about by economic reasons. The price of gas will do part of it but taxing vehicles by weight will go a long way towards making it a more equitable situation. The lighter vehicles would be rewarded for their lessened impact on the roadway and the environment. More massive vehicles would pay for increased impact on the environment, wear to the roadway, and the increased risk they pose to lighter vehicles.
People talk about rail/mass transit as a solution to LA's transportation problems but usually it is people who haven't been here. This area is so spread out in all directions that it would take an indescribable quantity of money to build such a system. The land is insanely expensive and with the sprawling area you could spend a few years of our whole nation's federal budget to build such a system. It just won't work.
(That guy who stole the tank down in San Diego about 5 years ago is starting to look saner and saner...)
BTW - From trips to Europe: I love the mass transit! Munich has a rail, subway, tram, and bus system that is so good it is just fun to use it! For 15 euro you get a pass good for unlimited use of all of the above for a week! It is just amazingly convenient and cool.
I really hope that this isn't truly a "new" discovery. If someone sits and thinks about it it should be really obvious. I have posted a basic explanation as a comment to a number of blogs and I'm not a traffic engineer.
Once traffic reaches a point of saturation ANY change is flow will bring traffic to a halt. This includes things like a road feature that makes people accelerate, a merging or diverging ramp, or a hill or corner that allows people to see farther ahead inducing them to adjust their speed.
Any change in relative speed will at some point cause a person to slow down. If they are accelerating they will slow when they get close to the car in front. If they are slowing then that is obviously a slow down. Each car behind this change reacts to it after a delay. The longer the delay the more they have to react. People tend to react much slower then they normally would because very few drivers focus primarily on driving. They only use the minimum attention that is necessary. This just makes the problem worse. It only takes a few cars for a subtle adjustment to become a complete stop. The length of time each successive car is stopped will become longer and longer.
To make the problem worse the same 1 to 2 second delay in reaction applies to the acceleration of the vehicles after the slowdown/stop. Every fraction of a second that a person delays accelerating is adding to the stacking of the delay.
To look at another aspect of a slowdown...
If you have a smooth flow of traffic at a fixed speed you will have a certain number of cars passing a point on the road per minute. If you have a slowdown you will reduce the number of cars passing per minute. But the traffic was already at a capacity flow so the number of cars feeding into this situation continues unabated. It is obvious that the flow of traffic is done until the quantity of vehicles feeding into the situation is drastically slowed to less then the flow of traffic at the restriction. (In Orange County, CA that means waiting till after 6:30PM for a situation that started at 3:00PM.)
What can be done about this without building a vastly increased number of lanes? (The I-405 is already 14 lanes in central Orange County. Increasing it to 20+ lanes would cost billions and in 20 years when they are done we would need 30+ lanes...)
A big improvement could be made through driver training (Yeah right...). Teaching people how to merge can reduce the constant forced slowdown from cars merging onto a freeway at less then freeway speed. The correct speed to merge at is 5 to 10 MPH FASTER then the flow of traffic. A car won't accelerate quickly but it will slowdown quickly so you simply drive down the on ramp picking the hole in traffic you will merge into and brake into that hole matching speeds. This minimizes the disruption. "Freeway Meters" on an onramp actually make this problem worse on a freeway that is still flowing at a reasonable speed because they reduce the distance that a car has to accelerate insuring that they enter the roadway at a reduced speed causing traffic to slow down for them.
Teaching people to slowdown after they are on an offramp will also help reduce the disruption to traffic flow. Most drivers slow down a minimum of 10mph before the exit the roadway causing large backups for open free flowing offramps.
To reduce the effect of slowdowns you can teach people to look past the car in front of them and try to slowdown before the car in front of them, which can reduce the quantity of speed they have to scrub off. If they look ahead and start to accelerate earlier this will cause a similar improvement in reduction of traffic impediment.
(Truth is that you will never be able to teach people to change their driving habits because their cell phone, their coffee, and their daydreams are way more important then driving the 1-1/2 tons of steel they are sitting in.)
Right on the front page of the article it clearly says "4th March 2007".
Most likely their "slashdot" button has received some current activity as someone has finally gotten around to trying Vista...
Yeah all that stock that the CEO was given is really going to make him some money!
The only thing he has to worry about is if the stock were to (for some unknown reason, god forbid!) become worthless...
They didn't patent the single click. They patented a process that was initiated by a single click. The process (method) is the point.
What a stupid comment. In other words, if some people are going to break the law, let's make sure everyone can. Good idea.
Let him sit on his couch eating Cheetos. He has the right to be happily oblivious as every personal right slowly disappears because no one is complaining (too busy eating Cheetos!) while the technology that makes it possible keeps getting cheaper and more powerful.So a good EMP is the only way to keep the people who kidnapped you out of your house?
"... This finding has the potential to improve our understanding of the causes of addictive and compulsive behaviors."
Contrary to their conjecture I have found that learning is instrumental to developing my addictive and compulsive behaviors!
"2^31 should be enough for anyone..."
You've never heard of Mr. Bill have you...