The reason is simple, because the plane is travelling so fast, and the ground system is more or less designed for automobile speeds, the cell system hands off to the next cell very rapidly causing grief for the cell system owners.
That is not the main reason. On the ground you are most likely to be in sight of 2 or 3 towers. When you are using a radio frequency, it is in use for all the towers you are in site of. You can't have multiple signals on the same frequency in the same proximity at the same time. Interferance would result. A plane load of passengers aproaching LAX could heavily load the closest towers and provide channel signal strength to most of downtown Los Angeles on most cell towers. It is true only one tower would talk to each cell phone at a time while they were handed off, but the normal ground geography keeping the phone sgnal to the tower would no longer limit the phone to just a few towers. It could busy out the system as most towers would not accept new connections while their recievers have ample signal strength from the airborne phones. The towers would not accept a new call until the handoff is complete and the phone leaves the area so the frequency is clear for a new connection in that location. A plane simply does not leave one cell and hop to another. It blankets the entire city area for miles.
This isn't to say the connection will be stable, it likely will not be. 9/11 worked because they were in a populated area flying relatively low.
The flying low is why the system worked. They were close to some towers and far from others. At 20,000 feet most of a city is about the same distance from most towers which causes the problem for the system tying up the receive channels on most cell towers.
Well, it's not friendly to first post trolls perhaps.
Not friendly to anyone who can't do a Google search. My kids got a genuine I-Pod. The machine I provided them has Ubuntu Daper Drake. I gathered from Google that the Banchee Music player supports the I-Pod except for the DRM stuff. In addition to sending music to the player, it can upload from the player. It that respect it's better than I-Tunes for my kids. Installing it was a snap. On the menu bar I selected Applications. On the pull down I selected Add/Remove. This brought up a list of installed applications and a list of applications that can be installed. Under Audio I selected the Banchee Music Player and let it install after providing the administrator password.
My kids do not have software install privilages which keeps the cruft and malware at bay.
Instead of having to go to each vendor's website to get and install applications, it is nice to simply to have an Add/Remove item with everyting there. Nice! It is kind of like using Microsoft Updates, but for your applications instead of just security updates.
Linux zealots are far too forgiving when judging the difficultly of Linux configuration issues and far too harsh when judging the difficulty of Windows configuration issues.
I have a mix of machines here at the house. I have a couple Win 2K machines, a XP machine and a 98 and 95 machine.
I have a couple HP printers. They were placed on the network using Hawking Printservers. All windows machines except the XP box required drivers to be installed to connect. The XP box and the Ubuntu box simply used IPP protocol with no additional drivers required.
I have a Cannon flatbed scanner. The windows machines required drivers. The Ubuntu machine only required the XSine Image Scanner application to be installed. I prefer to use the Ubuntu machine to scan. The program gives a color histogram in addition to the basic features provided by the factory TWAIN driver. Very nice if you need to touch up color balance on an old print.
Why do I have such a mix of machines?
The days of a general purpose machine is over.
The The Windows 95 machine is used for the MIDI stuff I do. It is a laptop with a max of 72 Meg of EDO memory. It runs my keyboard applications just fine with it's built in Joystick/MIDI port. I haven't found a suitable replacement. I also use it with the GPS for Geocaching. It is the lowest power laptop I have.
The wife uses the XP machine. It's hers and she guards it as she does not like to lose her email on the next rebuild due to some malware someone would manage to acquire for her.
The kids machine ran 98 for a while, required rebuilt within 4 months. They like myspace and sites like it. Tried Win2k with them running as limited users instead of administrator along with a current install of Norton. It became slower than my Windows 95 laptop within 8 weeks. What a shame. It has the fastest processor in the house. It got rebuilt with Ubuntu as soon as Daper Drake came out. No issues. The hardest thing was to install flash. It needed installed from the command line and I managed it as a complete novice. The only thing I haven't figured out yet is how to get edit privilages to the \etc directory so I can edit the hosts file. Given time, I will find out. The advertisements are an annoyance only.
I will say that Microsoft Powerpoint is nicer to use than Openoffice Presentation. So please don't put me down as a Microsoft basher. I haven't found how to adjust photo brightness, contrast and resise while maintaining aspect ratio of photos in OpenOffice Presentation. Maybe it's a learning curve thing, or maybe the features just are not there.
Overall, Ubuntu installed and found more hardware with the least amount of searching for drivers of all the machines I have here except the XP box which came with the drivers installed in the image software except for the additional hardware added later.
I needed to scan a bunch of pages to fax. My W2K laptop locked up 3 times while scanning 28 pages. I moved over to the Ubuntu machine and finished the remainder of the job with the same scanner. No glitches.
I hope the judge gets a clue that we are in a war. I hope he gets a clue before a plan is executed that brings a plane down on my house. I would rather have it go like the most recent foiled plan. Sorry guys, but in war, military inteligence is important. Lets let them do their job and protect the freedom. Protecting the terrorists freedom is a good way to get hurt.
"If you haven't done anything wrong, what do you have to hide?"
What would happen if all your credit cards were posted online with your name address and such?
Why do you have a password to log in to your online banking?
Is having a credit card or bank account a crime?
Would you be willing to post your tax return online?
Everybody has stuff to hide and it has nothing to do with doing anything wrong. The best part of the article was the caption for the photo that mentioned that more criminals are using encryption.
Well duh. With identity theft, many more people in general are using encryption. That's why I bought a Simple Share NAS drive. It has the ability to encrypt the filesystem. I use it for all my finance data. It plays nice on my mixed lan. It supports both the windows SMB share and the NFS shares.
My MP3's are one it simply because I can then run the playlist in either the den, living room, bedroom or wherever without needing many copies of the files.
Doesn't it already skip commercials automatically?
Who cares? With the junk on TV, I've ditched the tv entirely. I'm online instead. Now if a site gets buried in junk that can't be blocked by a hosts file, I move on. Unlike TV where the same ad is showing on almost all stations, I can go to sites where the hosts file works.
Too bad TIVO does not have a hosts file with a button to add content from this advertiser to the block list.
What are they going to do when they report that 95% of the customers skip commercials and that pisses off networks/advertisers?
I wonder if they will track people who skip it after they have seen it twice in 3 minutes thumbing the networks and want to find something new instead of the same drivel over and over and over and over and over...
The whole system is low pressure and has no moving parts. The mirros would have to track, but those moving parts wouldn't ever have interract with the volatiles.
Low pressure is news to me. An absobption cycle RV refrigerator does use low vapor pressures to evaporate ammonia to create cooling. However to keep the water where it belongs, the system is under high pressure. Water and ammonia are the working coolant. Water is the absorbant. However the ammonia is not boiled. It is evaporated. To seprate the water and ammonia, it is heated in a boiler under pressure to force off the ammonia and condense the water back into a liquid. The entire system is under a single pressure. Remember it is run without a compressor.
If interested in the continous cycle absorption cycle refrigeration, pick up a copy of Modern Refrigeration and air contitioning.
Slashbots continually harp about how bands should be doing that kind of thing, bypassing the RIAA in favor of self-promotion - but when the bands actually start having a little success in doing so, the slashbots all line up to rag on them for it.
What I have seen from my kids being online is the language and noise. Too bad there is very little talent shown either by the graphic artists online or the bands.
My point is time is very limited. Will this happen before or after the rocket meets the target?
If the destruction of the rocket is delayed (not eliminated) it may have enough life to reach it's target intact. Just how long is the flight time of a RPG shot at a plane leaving an airstrip?
That shouldn't be a problem. The mirror would have to be virtually flawless.
Quick experiment.. Take a dark rock and set it on your lawn on a bright sunny day. Take another identical rock and paint it white and set it near the dark rock.
To get the white rock as hot as the dark rock would need lots more power.
Warming up a RPG with a laser will take a lot longer if it is painted white or it is reflective at the laser wavelength used. It may take too long to warm it enough to destroy it in time.
I wouldn't recommend on counting on a speck of dust to cause fast destruction of enough reflective material in enough time to destroy the rocket.
A few test shots to scope out the power and wavelength of the defense is all it takes to engineer a paint to reflect energy long enough to deliver the payload.
I shudder to think what would've happened if I made a truly questionable post under my real name.
I have a unique name also. Anyone in the US with my last name is a relative. The only place online with my real name are related to technical sites which I am proud to have contributed to. For example a google search for my name turns up that I have contributed to the wooden perodic table and provided information about the sample provided.
I could see where a kid in a flame war saying all kinds of things may live to regret it later.
(Yes, I realize that AllOfMP3.com believes it has a license to do this legally, but that is arguably AT MOST valid only in Russia, besides which, let's just forget about that for a moment.)
Here is the problem.. I visited the site to see the Russian artists offerings that are so popular on the site.
Hmmm Backstreet Boys, Arvil, 9 Inch Nails, Smashing Pumpkins.. Since when are these Russian artists selling to the Russian market? Somehow I doubt they have any agreement with these copyright holders and therin lies the problem. It isn't Russian artists selling only to a Russian market and beyond. It's artists and their distributors that have not authorized this retailer. Their IP has been stolen.
Those signs around some neighborhoods for the neighborhood crime watch don't seem to work all that well....
Nobody said it was 100% effective. Maybe the signs are working quite well. Take the signs down for a few weeks and report if anything has changed. The signs are put up where there is an existing problem. Where there is never any problem, there are rarely any signs because they are not needed.
Some fake cameras are easy to spot and pro theives are quick to spot them. If you want to be effective, either put up real cameras or use dummy cameras from the manufacture of real cameras. A warped painted lens is a dead giveaway of a dummy. A Sanyo dummy using a real camera case, lens, and cables is the twin of the real camera except the guts are missing.
Here is what a real Sanyo dummy camera looks like. It even takes real lenses.
it will fail too. Don't you think that if the insulation failed in the old design that the same thing would happen with a coaxal cable as well. Once the insulation has failed the grounding jacket would be the first to degrade
You are correct. I have had the oppertunity to locate a fault from a lightning damaged cable. Lightning punched holes in the outer jacket leaving the grounded sheath open to corrosion. The initial strike faulted the cable which was repaired but not all the damage was found and fixed. 2 years later the cable failed again from the original strike. The salts and minerals from moisture in the jacket degraded the insulation long before the outer conductor fully corroded back. The insulation degradation and resulting fault shorted the cable long before the outer conductor would have corroded far enough to cause a serious ground fault. In short the products of the corrosion of the outer conductor permeates the inner insulation causing its failure long before the outer conductor is missing.
where not only does the circuit die, but so does the backhoe, its operator and anyone standing near it.
FUD.... Check the construction of underground direct burial high voltage lines of 5KV and higher. They are coaxal. They do not have the big fire arcing and killing of people that crane and boom trucks into power lines create. To hit the high voltage conductor, you cut through it's coaxal shielding wires. The arc zaps from the center conductor to the damaged shield which isn't cut all the way through. Many times the shield wires are not cut at all, but the insulater is crushed first causin the short fully contained inside the cable. Big deal, the cable goes pow in the ditch as the fuse gets toasted. A flash burn is the only major risk. The backhoe may have a flash weld burn on the bucket, but otherwise should be fine. Same for the operator. I helped find a lightning damaged 5 KV line using a TDR. The line had a 9 amp fuse. Digging into the 240 volt 200 Amp service to a house is more dangerous than hitting the 5 KV line due to the high arc current. FYI 9 Amps at 5 KV is 45,000 Volt Amps. 240 Volts at 200 Amps is 48,000 Volt Amps.
None of the fault current would go through the backhoe operator. Very little fault current would go though the backhoe zapping anyone nearby. Most fault current would simply go from the center conductor to the shield. The biggest hazzard is the arc flash and someone very near (using a shovel) may get a flash burn.
pets (and people) getting electrocuted from lines that were buried 40 or more years ago and were now corroding or fraying.
We have learned from our mistakes. All newer high voltage buried cable is coaxal in design. The hot conductor is surrounded by a grounded jacket. A fault shorts the cable to the grounded jacket tripping the overcurrent protection instead of putting lots of voltage to the ground.
Yes he is sure. In any wire there are a few factors causing problems getting power from one end to the other without loss. First is resistance. Too much current simply heats the wire. Power lost in the wire is power put in and not delivered to the other end.
In addition to resistance, two conductors near each other are a capacitor. Capacitance goes up if the conductors are placed closer together or are larger, or the material between them is something other than a vacuumm Overhead high tension lines are 8 feet or more apart and are insulated by air which has a dielectric constant very close to the same as a vacuum. Making a direct burial cable places a grounded shield conductor quite close to the hot conductor (reduced distance). It surrounds the conductor (bigger area). The area in between is no longer air but an insulator with a dielectric constant several times greater then air. Feeding this long capacitor lots of AC voltage requires lots of AC current. As the parent poster noted, in a relatively short distance the current needed to feed the cable can equal the total amount of Amps the cable is designed to carry without drawing any power from the other end.
Inductance is also a factor in getting power from one end of a wire to the other. All wire has inductance. Inductance caused loading is unaffected by applied voltage. It is unaffected by the insulation used on a wire. The amount of inductive current is influenced by the current fed on the wire.
Hmmm is there a balance where the inductive current will cancel the capacitive current? I am glad you asked!! The answer is YES!! The solution lies in what is called the impedance of a cable. If you put a load resistor on the far end of a cable that matches the impedance of a cable, then the inductive current will match the capacitve current in a cable and they null each other out.
Is this the answer? Nope. Why.. The load is not a fixed resistance on the end of a transmission line. The load changes as lights, heat, AC, etc changes with demand.
To get a lot of power with reasonable cost transported long distance, high tension is used to keep the size of the conductors reasonable to keep the cost down and the huge magnetic fields that tend to induce current into anything nearby like rail tracks, fences and such. Losses from heat and magnetic fields are much less at higher voltage and lower current. Now you have a line with an impedance that does not match the load and power factor correction is needed.
A buried line at very high voltage needs a lot of corrective inductive current due to the very high capacitance per foot as the parent stated.
Sorry for the crash course in power factor correction and transmission line theory but it is on topic.
FYI, that is why a CAT5 cable is terminated into 120 ohms. It's the impedance of the UTP cable.
At about 30 km on a regular high voltage cable, you reach a point where the reactive power drain reaches the maximum power the cable can transport - the cable is saturated without draining a single watt at the end.
Absolutely true depending on the voltage on the line. Higher voltage on a line increases the current. In a capacitive load, the current leads the voltage. This is easly compensated by using a few inductive loads on the line. Load end transformers do fine if matched properly. Most loads are inductive because of the transformers and motors on the line including distribution transformers, pump motors and AC units.
Many of you have seen the big arc on the web from a substation opening a disconnect and the arc climbs high. The disconnect was connected to a power factor correcting inductor (transformer without a connected load). Check the video. The big transformer behind the truck is connected to the disconnect, but there is nothing else connected to the transformer. It is there simply to provide phase angle correction for the capacitance on the line. The transformer provided about 100 amps of inductive load to correct for that much capacitive reactance on the 500KV line. On lower voltage lines of less than 125 KV, they don't have that much capacitive current and the high current in the line contributes to a lot of inductive current loss in the line. Many of these lower voltage lines use power factor correcting capacitors on the line. If you haven't seen it yet, look up a video of Lugo. It is the name of the high tension line to the substation. The arc is very impressive. The arc generated because one of the 3 phase circuit breakers failed to open so the disconnect opened under load. It had problems in the past which is why they were filming the operation. The arc went out when they manualy opened the line breaker feeding the line from the other end.
There is a big cost diffrence if putting in a subdivision and burying the 7200 volt line into the subdivision transformers and burying a 500,000 transmission line. Safety is also a concern. Which line would you rather hit with a backhoe?
On a high tension line, the capacitance per foot is much higher for a buried line than for an overhead line. For long distance feeding this capacitive load adds greatly to the power loss in the line. Burried is OK in New York City, but forget it for the grid. There are too many losses. Putting the 2 top grounded lines above the high tension lines have greatly reduced lightning strikes to the power conductors and their resulting outages from damaged insulators and substation equipment.
Disclaimer.. My father was a substation operator for Bonniville Power Administration. I've seen the MegaVar meters on some long lines.
Also there are "Audio" CD-ROMs which carry a royalty. However, there's no reason to use them unless you have a standalone stereo component CD copier.
Are you kidding? It's a pre-paid royalty on all my friends CD's I copy. The price for that royalty is much cheaper than i-tunes and doesn't usualy include DRM so I can load it on any portable device.
I loved the idea when they came out with royalty pre-paid CDR's. It takes a lot of bite out of the RIAA in court. I use Data CDR's for data and Music CDR's for copies of CD's.
I refuse to spend real money on a disappearing product.
You mean like internet access, phone service, rent, car insurance, gasoline, fireworks, ice cream,.....
Some items I purchase and expect it to last.. Durable goods. Some times I buy rental time, and sometimes I buy single use items. Traditionaly CD purchases have been priced in the first catagory. Your milage may vary. Expensive items with a short life I seldom buy. I don't invest much in ice sculptures or DRM music. They have no resale value.
What most people don't know is in a thunderstorm, the power lines are your friend. Stay away from the poles as that is where the high current will reach the ground. An area about 30 degrees wide is protected under power lines. Get in the zone. This is good for the flat farm land. If in a field, run to the road and get under the power line. Stay away from a fence as it can pack a strong punch if it is hit.
This is the reason many high tension lines have 2 elevated wires above the 3 or 6 conductors on the towers. The top grounded wire protects the switchgear and substations and reduces lighting caused outages by reducing strikes to the high voltage wires. You also can be protected by being under the power line.
Slashdot Mirror
The reason is simple, because the plane is travelling so fast, and the ground system is more or less designed for automobile speeds, the cell system hands off to the next cell very rapidly causing grief for the cell system owners.
That is not the main reason. On the ground you are most likely to be in sight of 2 or 3 towers. When you are using a radio frequency, it is in use for all the towers you are in site of. You can't have multiple signals on the same frequency in the same proximity at the same time. Interferance would result. A plane load of passengers aproaching LAX could heavily load the closest towers and provide channel signal strength to most of downtown Los Angeles on most cell towers. It is true only one tower would talk to each cell phone at a time while they were handed off, but the normal ground geography keeping the phone sgnal to the tower would no longer limit the phone to just a few towers. It could busy out the system as most towers would not accept new connections while their recievers have ample signal strength from the airborne phones. The towers would not accept a new call until the handoff is complete and the phone leaves the area so the frequency is clear for a new connection in that location. A plane simply does not leave one cell and hop to another. It blankets the entire city area for miles.
This isn't to say the connection will be stable, it likely will not be. 9/11 worked because they were in a populated area flying relatively low.
The flying low is why the system worked. They were close to some towers and far from others. At 20,000 feet most of a city is about the same distance from most towers which causes the problem for the system tying up the receive channels on most cell towers.
Well, it's not friendly to first post trolls perhaps.
Not friendly to anyone who can't do a Google search. My kids got a genuine I-Pod. The machine I provided them has Ubuntu Daper Drake. I gathered from Google that the Banchee Music player supports the I-Pod except for the DRM stuff. In addition to sending music to the player, it can upload from the player. It that respect it's better than I-Tunes for my kids. Installing it was a snap. On the menu bar I selected Applications. On the pull down I selected Add/Remove. This brought up a list of installed applications and a list of applications that can be installed. Under Audio I selected the Banchee Music Player and let it install after providing the administrator password.
My kids do not have software install privilages which keeps the cruft and malware at bay.
Instead of having to go to each vendor's website to get and install applications, it is nice to simply to have an Add/Remove item with everyting there. Nice! It is kind of like using Microsoft Updates, but for your applications instead of just security updates.
Linux zealots are far too forgiving when judging the difficultly of Linux configuration issues and far too harsh when judging the difficulty of Windows configuration issues.
I have a mix of machines here at the house. I have a couple Win 2K machines, a XP machine and a 98 and 95 machine.
I have a couple HP printers. They were placed on the network using Hawking Printservers. All windows machines except the XP box required drivers to be installed to connect. The XP box and the Ubuntu box simply used IPP protocol with no additional drivers required.
I have a Cannon flatbed scanner. The windows machines required drivers. The Ubuntu machine only required the XSine Image Scanner application to be installed. I prefer to use the Ubuntu machine to scan. The program gives a color histogram in addition to the basic features provided by the factory TWAIN driver. Very nice if you need to touch up color balance on an old print.
Why do I have such a mix of machines?
The days of a general purpose machine is over.
The The Windows 95 machine is used for the MIDI stuff I do. It is a laptop with a max of 72 Meg of EDO memory. It runs my keyboard applications just fine with it's built in Joystick/MIDI port. I haven't found a suitable replacement. I also use it with the GPS for Geocaching. It is the lowest power laptop I have.
The wife uses the XP machine. It's hers and she guards it as she does not like to lose her email on the next rebuild due to some malware someone would manage to acquire for her.
The kids machine ran 98 for a while, required rebuilt within 4 months. They like myspace and sites like it. Tried Win2k with them running as limited users instead of administrator along with a current install of Norton. It became slower than my Windows 95 laptop within 8 weeks. What a shame. It has the fastest processor in the house. It got rebuilt with Ubuntu as soon as Daper Drake came out. No issues. The hardest thing was to install flash. It needed installed from the command line and I managed it as a complete novice. The only thing I haven't figured out yet is how to get edit privilages to the \etc directory so I can edit the hosts file. Given time, I will find out. The advertisements are an annoyance only.
I will say that Microsoft Powerpoint is nicer to use than Openoffice Presentation. So please don't put me down as a Microsoft basher. I haven't found how to adjust photo brightness, contrast and resise while maintaining aspect ratio of photos in OpenOffice Presentation. Maybe it's a learning curve thing, or maybe the features just are not there.
Overall, Ubuntu installed and found more hardware with the least amount of searching for drivers of all the machines I have here except the XP box which came with the drivers installed in the image software except for the additional hardware added later.
I needed to scan a bunch of pages to fax. My W2K laptop locked up 3 times while scanning 28 pages. I moved over to the Ubuntu machine and finished the remainder of the job with the same scanner. No glitches.
I hope the judge gets a clue that we are in a war. I hope he gets a clue before a plan is executed that brings a plane down on my house. I would rather have it go like the most recent foiled plan. Sorry guys, but in war, military inteligence is important. Lets let them do their job and protect the freedom. Protecting the terrorists freedom is a good way to get hurt.
I have lots of things to hide..
"If you haven't done anything wrong, what do you have to hide?"
What would happen if all your credit cards were posted online with your name address and such?
Why do you have a password to log in to your online banking?
Is having a credit card or bank account a crime?
Would you be willing to post your tax return online?
Everybody has stuff to hide and it has nothing to do with doing anything wrong. The best part of the article was the caption for the photo that mentioned that more criminals are using encryption.
Well duh. With identity theft, many more people in general are using encryption. That's why I bought a Simple Share NAS drive. It has the ability to encrypt the filesystem. I use it for all my finance data. It plays nice on my mixed lan. It supports both the windows SMB share and the NFS shares.
My MP3's are one it simply because I can then run the playlist in either the den, living room, bedroom or wherever without needing many copies of the files.
Doesn't it already skip commercials automatically?
Who cares? With the junk on TV, I've ditched the tv entirely. I'm online instead. Now if a site gets buried in junk that can't be blocked by a hosts file, I move on. Unlike TV where the same ad is showing on almost all stations, I can go to sites where the hosts file works.
Too bad TIVO does not have a hosts file with a button to add content from this advertiser to the block list.
What are they going to do when they report that 95% of the customers skip commercials and that pisses off networks/advertisers?
I wonder if they will track people who skip it after they have seen it twice in 3 minutes thumbing the networks and want to find something new instead of the same drivel over and over and over and over and over...
The whole system is low pressure and has no moving parts. The mirros would have to track, but those moving parts wouldn't ever have interract with the volatiles.
Low pressure is news to me. An absobption cycle RV refrigerator does use low vapor pressures to evaporate ammonia to create cooling. However to keep the water where it belongs, the system is under high pressure. Water and ammonia are the working coolant. Water is the absorbant. However the ammonia is not boiled. It is evaporated. To seprate the water and ammonia, it is heated in a boiler under pressure to force off the ammonia and condense the water back into a liquid. The entire system is under a single pressure. Remember it is run without a compressor.
If interested in the continous cycle absorption cycle refrigeration, pick up a copy of Modern Refrigeration and air contitioning.
Slashbots continually harp about how bands should be doing that kind of thing, bypassing the RIAA in favor of self-promotion - but when the bands actually start having a little success in doing so, the slashbots all line up to rag on them for it.
What I have seen from my kids being online is the language and noise. Too bad there is very little talent shown either by the graphic artists online or the bands.
Soon, it will be palm-sized.
My point is time is very limited. Will this happen before or after the rocket meets the target?
If the destruction of the rocket is delayed (not eliminated) it may have enough life to reach it's target intact. Just how long is the flight time of a RPG shot at a plane leaving an airstrip?
That shouldn't be a problem. The mirror would have to be virtually flawless.
Quick experiment.. Take a dark rock and set it on your lawn on a bright sunny day. Take another identical rock and paint it white and set it near the dark rock.
To get the white rock as hot as the dark rock would need lots more power.
Warming up a RPG with a laser will take a lot longer if it is painted white or it is reflective at the laser wavelength used. It may take too long to warm it enough to destroy it in time.
I wouldn't recommend on counting on a speck of dust to cause fast destruction of enough reflective material in enough time to destroy the rocket.
A few test shots to scope out the power and wavelength of the defense is all it takes to engineer a paint to reflect energy long enough to deliver the payload.
I shudder to think what would've happened if I made a truly questionable post under my real name.
I have a unique name also. Anyone in the US with my last name is a relative. The only place online with my real name are related to technical sites which I am proud to have contributed to. For example a google search for my name turns up that I have contributed to the wooden perodic table and provided information about the sample provided.
I could see where a kid in a flame war saying all kinds of things may live to regret it later.
(Yes, I realize that AllOfMP3.com believes it has a license to do this legally, but that is arguably AT MOST valid only in Russia, besides which, let's just forget about that for a moment.)
Here is the problem.. I visited the site to see the Russian artists offerings that are so popular on the site.
Hmmm Backstreet Boys, Arvil, 9 Inch Nails, Smashing Pumpkins.. Since when are these Russian artists selling to the Russian market? Somehow I doubt they have any agreement with these copyright holders and therin lies the problem. It isn't Russian artists selling only to a Russian market and beyond. It's artists and their distributors that have not authorized this retailer. Their IP has been stolen.
Would it have killed you to simply include a link to that video, asshole?
No.. would it have killed you to plug the info into a search engine?
Your anger is disturbing. Have you considered anger management?
Here pick one.
http://www.google.com/search?hl=en&lr=&q=Lugo+arc
Those signs around some neighborhoods for the neighborhood crime watch don't seem to work all that well....
Nobody said it was 100% effective. Maybe the signs are working quite well. Take the signs down for a few weeks and report if anything has changed. The signs are put up where there is an existing problem. Where there is never any problem, there are rarely any signs because they are not needed.
Some fake cameras are easy to spot and pro theives are quick to spot them. If you want to be effective, either put up real cameras or use dummy cameras from the manufacture of real cameras. A warped painted lens is a dead giveaway of a dummy. A Sanyo dummy using a real camera case, lens, and cables is the twin of the real camera except the guts are missing.
Here is what a real Sanyo dummy camera looks like. It even takes real lenses.
http://www.camerasuperstore.com/simdumcam.html
it will fail too. Don't you think that if the insulation failed in the old design that the same thing would happen with a coaxal cable as well. Once the insulation has failed the grounding jacket would be the first to degrade
You are correct. I have had the oppertunity to locate a fault from a lightning damaged cable. Lightning punched holes in the outer jacket leaving the grounded sheath open to corrosion. The initial strike faulted the cable which was repaired but not all the damage was found and fixed. 2 years later the cable failed again from the original strike. The salts and minerals from moisture in the jacket degraded the insulation long before the outer conductor fully corroded back. The insulation degradation and resulting fault shorted the cable long before the outer conductor would have corroded far enough to cause a serious ground fault. In short the products of the corrosion of the outer conductor permeates the inner insulation causing its failure long before the outer conductor is missing.
where not only does the circuit die, but so does the backhoe, its operator and anyone standing near it.
FUD.... Check the construction of underground direct burial high voltage lines of 5KV and higher. They are coaxal. They do not have the big fire arcing and killing of people that crane and boom trucks into power lines create. To hit the high voltage conductor, you cut through it's coaxal shielding wires. The arc zaps from the center conductor to the damaged shield which isn't cut all the way through. Many times the shield wires are not cut at all, but the insulater is crushed first causin the short fully contained inside the cable. Big deal, the cable goes pow in the ditch as the fuse gets toasted. A flash burn is the only major risk. The backhoe may have a flash weld burn on the bucket, but otherwise should be fine. Same for the operator. I helped find a lightning damaged 5 KV line using a TDR. The line had a 9 amp fuse. Digging into the 240 volt 200 Amp service to a house is more dangerous than hitting the 5 KV line due to the high arc current. FYI 9 Amps at 5 KV is 45,000 Volt Amps. 240 Volts at 200 Amps is 48,000 Volt Amps.
None of the fault current would go through the backhoe operator. Very little fault current would go though the backhoe zapping anyone nearby. Most fault current would simply go from the center conductor to the shield. The biggest hazzard is the arc flash and someone very near (using a shovel) may get a flash burn.
pets (and people) getting electrocuted from lines that were buried 40 or more years ago and were now corroding or fraying.
We have learned from our mistakes. All newer high voltage buried cable is coaxal in design. The hot conductor is surrounded by a grounded jacket. A fault shorts the cable to the grounded jacket tripping the overcurrent protection instead of putting lots of voltage to the ground.
Are you sure that isn't inductance?
Yes he is sure. In any wire there are a few factors causing problems getting power from one end to the other without loss. First is resistance. Too much current simply heats the wire. Power lost in the wire is power put in and not delivered to the other end.
In addition to resistance, two conductors near each other are a capacitor. Capacitance goes up if the conductors are placed closer together or are larger, or the material between them is something other than a vacuumm Overhead high tension lines are 8 feet or more apart and are insulated by air which has a dielectric constant very close to the same as a vacuum. Making a direct burial cable places a grounded shield conductor quite close to the hot conductor (reduced distance). It surrounds the conductor (bigger area). The area in between is no longer air but an insulator with a dielectric constant several times greater then air. Feeding this long capacitor lots of AC voltage requires lots of AC current. As the parent poster noted, in a relatively short distance the current needed to feed the cable can equal the total amount of Amps the cable is designed to carry without drawing any power from the other end.
Inductance is also a factor in getting power from one end of a wire to the other. All wire has inductance. Inductance caused loading is unaffected by applied voltage. It is unaffected by the insulation used on a wire. The amount of inductive current is influenced by the current fed on the wire.
Hmmm is there a balance where the inductive current will cancel the capacitive current? I am glad you asked!! The answer is YES!! The solution lies in what is called the impedance of a cable. If you put a load resistor on the far end of a cable that matches the impedance of a cable, then the inductive current will match the capacitve current in a cable and they null each other out.
Is this the answer? Nope. Why.. The load is not a fixed resistance on the end of a transmission line. The load changes as lights, heat, AC, etc changes with demand.
To get a lot of power with reasonable cost transported long distance, high tension is used to keep the size of the conductors reasonable to keep the cost down and the huge magnetic fields that tend to induce current into anything nearby like rail tracks, fences and such. Losses from heat and magnetic fields are much less at higher voltage and lower current. Now you have a line with an impedance that does not match the load and power factor correction is needed.
A buried line at very high voltage needs a lot of corrective inductive current due to the very high capacitance per foot as the parent stated.
Sorry for the crash course in power factor correction and transmission line theory but it is on topic.
FYI, that is why a CAT5 cable is terminated into 120 ohms. It's the impedance of the UTP cable.
At about 30 km on a regular high voltage cable, you reach a point where the reactive power drain reaches the maximum power the cable can transport - the cable is saturated without draining a single watt at the end.
Absolutely true depending on the voltage on the line. Higher voltage on a line increases the current. In a capacitive load, the current leads the voltage. This is easly compensated by using a few inductive loads on the line. Load end transformers do fine if matched properly. Most loads are inductive because of the transformers and motors on the line including distribution transformers, pump motors and AC units.
Many of you have seen the big arc on the web from a substation opening a disconnect and the arc climbs high. The disconnect was connected to a power factor correcting inductor (transformer without a connected load). Check the video. The big transformer behind the truck is connected to the disconnect, but there is nothing else connected to the transformer. It is there simply to provide phase angle correction for the capacitance on the line. The transformer provided about 100 amps of inductive load to correct for that much capacitive reactance on the 500KV line. On lower voltage lines of less than 125 KV, they don't have that much capacitive current and the high current in the line contributes to a lot of inductive current loss in the line. Many of these lower voltage lines use power factor correcting capacitors on the line. If you haven't seen it yet, look up a video of Lugo. It is the name of the high tension line to the substation. The arc is very impressive. The arc generated because one of the 3 phase circuit breakers failed to open so the disconnect opened under load. It had problems in the past which is why they were filming the operation. The arc went out when they manualy opened the line breaker feeding the line from the other end.
There is a big cost diffrence if putting in a subdivision and burying the 7200 volt line into the subdivision transformers and burying a 500,000 transmission line. Safety is also a concern. Which line would you rather hit with a backhoe?
On a high tension line, the capacitance per foot is much higher for a buried line than for an overhead line. For long distance feeding this capacitive load adds greatly to the power loss in the line. Burried is OK in New York City, but forget it for the grid. There are too many losses. Putting the 2 top grounded lines above the high tension lines have greatly reduced lightning strikes to the power conductors and their resulting outages from damaged insulators and substation equipment.
Disclaimer.. My father was a substation operator for Bonniville Power Administration. I've seen the MegaVar meters on some long lines.
Also there are "Audio" CD-ROMs which carry a royalty. However, there's no reason to use them unless you have a standalone stereo component CD copier.
Are you kidding? It's a pre-paid royalty on all my friends CD's I copy. The price for that royalty is much cheaper than i-tunes and doesn't usualy include DRM so I can load it on any portable device.
I loved the idea when they came out with royalty pre-paid CDR's. It takes a lot of bite out of the RIAA in court. I use Data CDR's for data and Music CDR's for copies of CD's.
I refuse to spend real money on a disappearing product.
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You mean like internet access, phone service, rent, car insurance, gasoline, fireworks, ice cream,
Some items I purchase and expect it to last.. Durable goods. Some times I buy rental time, and sometimes I buy single use items. Traditionaly CD purchases have been priced in the first catagory. Your milage may vary. Expensive items with a short life I seldom buy. I don't invest much in ice sculptures or DRM music. They have no resale value.
What most people don't know is in a thunderstorm, the power lines are your friend. Stay away from the poles as that is where the high current will reach the ground. An area about 30 degrees wide is protected under power lines. Get in the zone. This is good for the flat farm land. If in a field, run to the road and get under the power line. Stay away from a fence as it can pack a strong punch if it is hit.
This is the reason many high tension lines have 2 elevated wires above the 3 or 6 conductors on the towers. The top grounded wire protects the switchgear and substations and reduces lighting caused outages by reducing strikes to the high voltage wires. You also can be protected by being under the power line.