I'd compare it to top-fuel dragsters and funny cars. They can hit 300+ mph while traveling in a straight line. If the driver doesn't keep the vehicle pointed in the right direction, things get very ugly, very quickly. Rockets have the same problem. They are designed to travel along the roll axis of the vehicle. It only takes a small amount of pitch or yaw error to generate aerodynamic forces that will produce "rapid unplanned disassembly" of the rocket.
It stands for High-level Aerospace Language / Shuttle, designed by Intermetrics for NASA. I suspect that the acronym was selected first, and then they found some words to fit it, a common practice in those days.
The Challenger didn't "blow up", it disintegrated due to loss of attitude control at high speed. The orbiter experienced aerodynamic forces that greatly exceeded its structural design limits. Similar things happen when a high-performance jet aircraft loses attitude control at high speed.
In many places, the city can legally condemn the apartment building, and evict all of the tenants, if the landlord fails to deal with tenants who engage in criminal activity. A bar owner can lose his liquor license if his bar becomes a nexus for criminal activity, even if he has no personal involvement in the crimes.
The client is an idiot for making their business dependent on the reliability of public data networks and SMTP. If the information is that valuable, they can afford to invest in hardware, software and redundant communications channels to guarantee delivery of their inventory reports.
You need a water treatment plant to keep it clean and pure. They do this for water-cooled transmitter tubes in high-power radio transmitters, like those used in shortwave broadcasting.
Due to the insane current and voltage regulation requirements of today's motherboards, the power supply for the CPU and associated chips has to be physically close and tightly integrated into the motherboard. You can't just pipe in regulated DC voltages from an external power supply directly to the chips on the motherboard. In your typical PC, the power supply (the metal box) provides bulk regulated DC power. Some stuff can run directly from the power supply. Components with demanding power requirements, like the CPU, are powered by dc-to-dc converters on the motherboard. These take DC power from the power supply, convert it to high-frequency AC, and back to regulated DC.
The general rule is that stricter requirements for power supply performance can only be met by decreasing the physical distance between the power supply and the load. The trend towards lower supply voltages and higher currents makes the problem worse.
AC power wiring is cheap and well understood. It doesn't require huge buss bars or custom components. It is the most economical way to distribute electrical energy.
Once you reach the box level, you want to convert the AC to low-voltage DC. Confining the high-voltage AC to the power supply means that the rest of the box doesn't have to deal with the electrical safety issues associated with high-voltage AC. The wiring between the power supply and load is short enough to provide decent quality DC power at a reasonable cost. Those components that require higher quality power can use the DC power from the power supply as the energy source for local dc-to-dc converters.
You could feed the box with -48 VDC like the telephone company does with its hardware. You would still end up with about the same amount of hardware inside the box to provide all of the regulated DC voltages needed to make it work. Cost would increase because of the lower production volumes associated with non-standard power supplies.
In the end, it boils down to economics. DC power distribution costs more money and it doesn't meet the performance requirements of modern hardware. The days of racks full of relays, powered directly from battery banks, are long gone.
The space suit may not be designed to get wet. The Apollo suits had a fabric covering of beta cloth, which is made from teflon and glass fibers. Water can cause corrosion to metal parts and there is also the problem of drying the suit before it becomes a breeding ground for various microorganisms.
It's wonderful if you work for a company, or agency, where the only way to get a new computer is to build it from scrap. I'm not exaggerating, that's how it is in some places. There is no money in the capital budget to buy new computers. If you're lucky, you can buy parts, as long as you don't spend too much money at once. At my last job, we used to visit the local government surplus warehouse, looking for hardware that we could use to build new systems, or strip for parts.
You can build a good RNG from a cheap Geiger counter and a smoke detector (radioactive source). I did this with an old laptop computer. It wasn't fast, but it produced more than enough random bits for keys and one-time pads.
From what I remember reading, KRON was involved in a nasty dispute with NBC over the renewal of their affiliate agreement. NBC was also trying to buy KRON for themselves. They wanted an "owned and operated" affiliate in San Francisco, which would be more profitable for NBC.
This sort of thing is becoming more common. In the old days, the major networks paid their affiliates to carry the network's programming. The economics of television broadcasting have changed over the years, and the affiliates have lost much of their bargaining power. This has led the networks to push for revised affiliate agreements that reduce, eliminate, or reverse fees paid to the affiliates by the networks.
Even without satellites, they can air freight the video tapes. That's what they used to do in Hawaii for entertainment programming. The news was carried on satellite. Everything else was on a one week delay.
Deterrence only works if the threat is plausible. That means that potential enemies have to believe that we are willing and capable of delivering functional weapons on target with a high probability of success. Whatever you do to us, we will still be capable of turning your country into a radioactive wasteland.
Mirrors don't work as well as you might think. It has to be reflective at the frequency of interest. Mirrors are not 100% efficient. Mirror efficiency drops as it absorbs energy, which increases the energy absorbed, which reduces mirror efficiency, etc.
In practice, mirror finishes have limited defensive value. They delay, not prevent, the destruction of the target.
It may be an April's Fool joke, but Scientific American has exhibited some rather obvious biases in the past. They've never seen an arms control treaty that they didn't like, and they've consistently attacked all proposals for strategic defense. It's not that these are issues that shouldn't be debated, it's the one-sided approach that the magazine has pursued in this and other areas. They tend to lose their objectivity when covering issues that are dear to the editors and publisher.
If I use direct sequence spread spectrum with a high chip rate, you are going to have a difficult time detecting that I am transmitting a signal, and the power requirements for a brute-force jammer can be made impractical, not to mention that your jammer is going to attract a lot of unwanted attention.
You can't do a true low-level format on the vast majority of modern drives. The drives do not have the hardware needed to write a low-level format on the platters. That is done at the factory with the use of special equipment. All the drive is capable of doing is overwriting the user data field in each sector.
My life savings are just a few entries in some financial institution's database. Their value is a matter of convention and law.
If someone stole my money and the police told me to get lost, I would probably grab a shotgun and start looking for the bastard that stole my "virtual property".
If you are really paranoid, use a cryptographically secure PN sequence generator to drive the spreader and despreader. You need a very high quality clock at each end to synchronize the system.
The law usually makes a distinction between things in your brain and written records. You can be forced to hand over written records, even if they contain incriminating information. The fifth amendment usually protects stuff in your brain from involuntary disclosure. If the prosecutor wants to be nasty, he can offer you full or limited immunity, which negates the fifth amendment. Then you either testify or sit in jail for contempt of court. This is a real problem for people who are being asked to testify against organized crime and gangs, and aren't important enough to get put in a witness protection program.
Slashdot Mirror
No. See "B1. How did the Challenger explode? And what happened to the astronauts?" at sci.space.shuttle FAQ Part B.
I'd compare it to top-fuel dragsters and funny cars. They can hit 300+ mph while traveling in a straight line. If the driver doesn't keep the vehicle pointed in the right direction, things get very ugly, very quickly. Rockets have the same problem. They are designed to travel along the roll axis of the vehicle. It only takes a small amount of pitch or yaw error to generate aerodynamic forces that will produce "rapid unplanned disassembly" of the rocket.
It stands for High-level Aerospace Language / Shuttle, designed by Intermetrics for NASA. I suspect that the acronym was selected first, and then they found some words to fit it, a common practice in those days.
The Challenger didn't "blow up", it disintegrated due to loss of attitude control at high speed. The orbiter experienced aerodynamic forces that greatly exceeded its structural design limits. Similar things happen when a high-performance jet aircraft loses attitude control at high speed.
I'd also buy a fax machine, for use when the network is broken due to backhoes, natural disasters, worms, etc.
In many places, the city can legally condemn the apartment building, and evict all of the tenants, if the landlord fails to deal with tenants who engage in criminal activity. A bar owner can lose his liquor license if his bar becomes a nexus for criminal activity, even if he has no personal involvement in the crimes.
The client is an idiot for making their business dependent on the reliability of public data networks and SMTP. If the information is that valuable, they can afford to invest in hardware, software and redundant communications channels to guarantee delivery of their inventory reports.
With a properly designed equipment room, the rack is part of the ducting for the cold air. It enters the rack through a set of louvers in the floor.
Hard disk drives don't like high altitudes.
You need a water treatment plant to keep it clean and pure. They do this for water-cooled transmitter tubes in high-power radio transmitters, like those used in shortwave broadcasting.
The general rule is that stricter requirements for power supply performance can only be met by decreasing the physical distance between the power supply and the load. The trend towards lower supply voltages and higher currents makes the problem worse.
AC power wiring is cheap and well understood. It doesn't require huge buss bars or custom components. It is the most economical way to distribute electrical energy.
Once you reach the box level, you want to convert the AC to low-voltage DC. Confining the high-voltage AC to the power supply means that the rest of the box doesn't have to deal with the electrical safety issues associated with high-voltage AC. The wiring between the power supply and load is short enough to provide decent quality DC power at a reasonable cost. Those components that require higher quality power can use the DC power from the power supply as the energy source for local dc-to-dc converters.
You could feed the box with -48 VDC like the telephone company does with its hardware. You would still end up with about the same amount of hardware inside the box to provide all of the regulated DC voltages needed to make it work. Cost would increase because of the lower production volumes associated with non-standard power supplies.
In the end, it boils down to economics. DC power distribution costs more money and it doesn't meet the performance requirements of modern hardware. The days of racks full of relays, powered directly from battery banks, are long gone.
The space suit may not be designed to get wet. The Apollo suits had a fabric covering of beta cloth, which is made from teflon and glass fibers. Water can cause corrosion to metal parts and there is also the problem of drying the suit before it becomes a breeding ground for various microorganisms.
It's wonderful if you work for a company, or agency, where the only way to get a new computer is to build it from scrap. I'm not exaggerating, that's how it is in some places. There is no money in the capital budget to buy new computers. If you're lucky, you can buy parts, as long as you don't spend too much money at once. At my last job, we used to visit the local government surplus warehouse, looking for hardware that we could use to build new systems, or strip for parts.
You can build a good RNG from a cheap Geiger counter and a smoke detector (radioactive source). I did this with an old laptop computer. It wasn't fast, but it produced more than enough random bits for keys and one-time pads.
This sort of thing is becoming more common. In the old days, the major networks paid their affiliates to carry the network's programming. The economics of television broadcasting have changed over the years, and the affiliates have lost much of their bargaining power. This has led the networks to push for revised affiliate agreements that reduce, eliminate, or reverse fees paid to the affiliates by the networks.
Even without satellites, they can air freight the video tapes. That's what they used to do in Hawaii for entertainment programming. The news was carried on satellite. Everything else was on a one week delay.
Deterrence only works if the threat is plausible. That means that potential enemies have to believe that we are willing and capable of delivering functional weapons on target with a high probability of success. Whatever you do to us, we will still be capable of turning your country into a radioactive wasteland.
It's the International Big-Endian Conspiracy. Move along, citizen.
In practice, mirror finishes have limited defensive value. They delay, not prevent, the destruction of the target.
It may be an April's Fool joke, but Scientific American has exhibited some rather obvious biases in the past. They've never seen an arms control treaty that they didn't like, and they've consistently attacked all proposals for strategic defense. It's not that these are issues that shouldn't be debated, it's the one-sided approach that the magazine has pursued in this and other areas. They tend to lose their objectivity when covering issues that are dear to the editors and publisher.
If I use direct sequence spread spectrum with a high chip rate, you are going to have a difficult time detecting that I am transmitting a signal, and the power requirements for a brute-force jammer can be made impractical, not to mention that your jammer is going to attract a lot of unwanted attention.
You can't do a true low-level format on the vast majority of modern drives. The drives do not have the hardware needed to write a low-level format on the platters. That is done at the factory with the use of special equipment. All the drive is capable of doing is overwriting the user data field in each sector.
If someone stole my money and the police told me to get lost, I would probably grab a shotgun and start looking for the bastard that stole my "virtual property".
If you are really paranoid, use a cryptographically secure PN sequence generator to drive the spreader and despreader. You need a very high quality clock at each end to synchronize the system.
The law usually makes a distinction between things in your brain and written records. You can be forced to hand over written records, even if they contain incriminating information. The fifth amendment usually protects stuff in your brain from involuntary disclosure. If the prosecutor wants to be nasty, he can offer you full or limited immunity, which negates the fifth amendment. Then you either testify or sit in jail for contempt of court. This is a real problem for people who are being asked to testify against organized crime and gangs, and aren't important enough to get put in a witness protection program.