Everything else being equal, higher compression engines have higher efficiency and higher compression requires higher octane gas. There is an efficiency / cost tradeoff with compression and reuqired octane that resulted in 87 being most common, but 92 octane being used in cars, and 100 octane being standard for almost all aircraft piston engines.
Turbines and diesels use similar (often identical) fuels that are completely different from gasoline. Diesels are high compression, but rely on the fuel spontaneously igniting when it is injected, as opposed to gas engines that rely on the fuel not igniting util the spark fires. Turbines are fairly low compression and relatively low efficiency, but much better power to weight which makes them better for high power aircraft use.
Diesels in general are more efficient than spark ignition engines, but (all else being equal) are heavier and more expensive.
For tons of information read the Taylor, "the internal combustion engine in theory and practice" .
I'm afraid Spaaaaace IS the argument - just think of it as religion.
Also though, Alaska, the Australian outback etc are all part of the Earth's overloaded ecosystem - one of the big advantages of space is that you don't need to worry about trashing it.
I don't disagree with your idea that China wants power, but I don't think orbital weapons are particularly useful in modern warfare. We (and several other countries) have enough raw firepower to utterly destroy any enemy. The problem is that for us (and China) our enemies are mixed with our friends. Nuclear weapons are completely useless against groups like Al-qaeda. Information collection and analysis is far better, and the US and China are both pushing very hard on that.
I'm not poor or broke, but I don't know how to set up a VM, and I'm not sure my computer security is very good. I also don't know how to rebuild the engine of a car, skin a deer, use a forge, do an appendectomy, use a gun, or perform a host of other valuable skills. The miracle of civilization is that since I know how to operate a linear accelerator, fly an airplane, and build femtosecond timing systems, I can somehow trade those skills for the vast array of skills that I'm missing. My computer skills are sufficient to protect the low value information that I have from casual hackers. I would not have the skill to protect a large value in bitcoins from a skilled attacker (and my computer skills are far above national average).
The advantage of conventional banks is that they can be used to provide good security for large amounts of value with minimal skill.
All depends on your goals. If you goal is manned exploration of space, then I believe that putting people in orbit is vital. If you goal is improving the standard of living on earth, or even doing space research, then it isn't.
A quick check seems to show the NASA budget as 1/2 the NIH budget. Then remember that NASA represents the majority of the space budget, NIH only represents a small fraction of healthcare spending (>2T/year last I checked). Of course it all depends on your priorities and how you want to count things.
The amount we spend on space is a tiny fraction of government spending.
Are you so sure that space colonization is impossible? No new science is required. We can easily imagine most of the engineering that is needed. It would be fantastically expensive - but even at say $10T, (something like 100X apollo) that is only 10 years wasted healthcare money in the US.
As an aside, I believe the goal of space IS space, not somehow enriching lives on earth. To ridiculous precision everything in the universe is not on earth - the goal is everything.
That will be the critical point. If someone takes a serous shot at a manned mars mission for example, will the US space race revive, or will we just decide that we could but don't want to. For a while we've been letting the Russians launch our astronauts into space, something that would have been unthinkable when I was growing up.
Properly setting up a VM, or in fact doing any proper security or even backups is beyond the abilities of most people. If those sorts of measures are required, bitcoins can't become a universal currency.
Maybe it is. Seriously, imagine that you have just broken into a missile launch complex and are trying to guess the combo. Would 00000000 really be one of the first you would try?
More seriously, nuclear launch is too important for passwords of any kind. If some reasonable set of people know the password you can threaten or torture it out of them - a minor effort compared to breaking the physical security around a launch complex. Remember its not like you can remotely log in to the launch computer for a Titan missile complex. (more modern missiles now....???)
If the trading computers were located in satellites in low earth orbit, they could arrange to always have one withing a few hundred miles and line-of-sight to each of the big exchanges.......
3-d printing is more expensive than conventional production methods for large volume production. Its not clear yet at what volume it will be competitive, but I expect that it will mostly be used for small / semi-custom production. (which is quite useful).
China does lots of things besides providing cheap labor. The have infrastructure (roads, rail, electricity, etc), and laws that make it efficient to do large scale production, though arguably at the expense of quality of life for the workers. (I say arguable because the income from the efficient production has improved the overall standard of living substantially, not clear how to balance against the substantial negative effects).
Not quite the same. The supermarket is performing a valuable service of providing a central location where I can purchase most of my food. It provides some level of quality control and acts as a single legal entity that I can deal with if there is a dispute. The supermarket also manages some of the transportation of the food from the locations where it is produced.
Financial trading can be valuable if it re-directs investment money to enterprises with higher productivity. High speed trading does not seem to me to do this in any way, it is simply a zero-sum game where real resources (in high speed computers and data links) are used in a way that does not increase overall productivity. It is not unique in this, bitcoin mining is also inefficient in that it consumes real resources to produce an artificially scarce good to use as a medium of exchange. It would be more efficient (but would lose other advantages) if there were a central repository of free to generate but limited number "coins" that were directly exchanged for money.
Well there is a plan to build a neutrino factory that would create directional highly intense neutrino beams. While the goal is neutrino physics, it could be used as a transmitter. Its only ~$1B, maybe worth it to the financial guys. If they pay, they can have have 50% of the beam time.....
In my field (accelerator physics) in 25 years, the only thing resembling misconduct that I've seen is overselling of future applications. By this I mean presenting an overly optimistic picture of future possibilities (typically known as marketing), not misrepresenting any work that was already done. This may be due to the way that most of the field is supported by large grants to large laboratories rather than grants to individual researchers. Might be a useful model to apply elsewhere.
Yes, that is the problem. If you limit pay, people will find some other form of compensation - company shares, use of the "company" bizjet. Also as someone suggested the execs will work for a company that has no low paid employees, but owns other companies that do.
The real question is why executives are compensated so highly. Is this an economically efficient result - is a good CEO really worth 10s to 100s of millions a year to a large company - the answer may be yes (certainly a bad executive can to tremendous damage). Or, is executive pay distorted by de-facto collusion between interlocking boards of directors?
If the second case is true, then we could change regulations on the management of companies, maybe require more input from smaller share holders, or specifically prevent interlocking boards - if you are on the board of directors for one company you can't be an executive at another for some period of time.
Maybe the problem is something completely different.
I'd don't think the Swiss model will help - I'm a fairly well paid tech worker, but there are a lot of shops in Zurich where I can't afford ANYTHING - Switzerland does not appear to be a model of low income disparity, though it may be better than the US.
I believe that the cost of an electric car is still significantly higher than for a low-medium end conventional car (Honda Civic for example). The operating costs might be lower, but its not clear that is true. Now a Tesla is a much nicer car that a Civic, but out of the price range of most people. (If this isn't true, and electrics really are cheaper overall, then their marketing departments are doing a bad job).
Then there is the range issue. I can get in a standard compact car and drive pretty much anywhere, I don't need to check if there are gas stations on the way. If I want to drive from the SF bay area to Los Angeles, I can stop for lunch anywhere on the I5, fill my tank in 5 minutes and be on my way. With an electric I'd need to be sure that a station was available, and it would take considerably longer to charge than it does to fill a gas tank.
Its true that probably less than 5% of my driving would cause any range concerns, but I still want to be able to do that 5%. Renting a car for those missions is time consuming.
An electric sounds great as a commute car - charge at home, charge at work (if available), no wasted time at gas stations. It might be a perfectly reasonable car for a person or family with 2 cars. It does need to compete though with the very reliable, high quality, low cost cars that are already on the market.
Yes, on linux when things don't work, I just search for my problem on google, find some website with a "fix", and then enter that command that I don't understand with root privs......
Often 2 interns, sometimes 3. We make them use an RF spectrum analyzer that dates from the Cretaceous to teach them character. (and because our "good" spectrum analyzer still dates from the Pliocene and is usually busy). Despite our best efforts at abuse, the last set of interns managed to measure timing noise down to a few femtoseconds.
Multiple scopes: cheap ones for general purpose, fast (>3GHz (20gs/s) single shot) for looking at high speed electronics (would like a 10GHz singl eshot but $$). RF synthesizers, spectrum analyzers, signal source analyzer, RF power meter, picosecond impulse genrator, Power supplies DVMs, precision voltmeters, TDRs, temperature measurement, accelerometers, Transient digitizers, with A-D / D-A and instrument control for automated testing Fiber power meters, polarization controllers, detectors, transmitters A large number of RF mixers, adapters, amplifiers, etc. And most importantly - duct tape, cable ties, vice grips and cutters - to hold things together or take them apart.....
I have a lab that does femtosecond timing systems for the accelerator / X-ray laser at SLAC, so we have a wide variety of cool stuff. Some is old, some new if we can't get by with the old stuff.
If you still have it - and are good at duplicating the magic that lets companies pack a cubic meter of stuff in a half-cubic meter box.
If the agreement click happens as soon as you buy the set, then taking it back may be reasonable. If it is a new agreement that appears months later, you may have disposed of the box, bolted the set to the wall, etc and it becomes a much larger effort. Very tempting to just click the box rather than go through all that work.
Of course its not a coincidence. China is run by centralized authoritarian government that carefully plans policies for its own good - which sometimes benefits the population as well: in general it is better to rule a prosperous peaceful country rather than a poor rebellious one.
Unlike the US, China does not pretend to be a free society. Personally I find that less distasteful than American hypocrisy. The US is still considerably less oppressive, but we are doing our best to close that gap.
Sounds nice, but "return the TV' means somehow finding an appropriate shipping box, filling out the required paperwork and paying to mail it back. If you are lucky you will then eventually get another TV to unpack and set up - and then have to repeat the process. Maybe you "win" and get your money back. The TV company doesn't care - very few of their customers will go to that effort rather than just click on the box, and your return will just be in the "user too stupid to use our TV" category.
This is the general problem with "returning" any sort of high tech product. The cost of the users time to do it is so high that most people simply won't bother - especially when they realize that the competitors product will likely have the same problem.
A strong source of very high energy neutrinos (which a muon collider produces) would look very different from a natural source, but I don't think it would be detectable at large distances with any technology I can imagine. the sun produces a HUGE amount of neutrino radiation - though all at low energies.
It is only near the muon collider that the neutrinos are a problem and that is because they are in such a tight beam (or thin fan).
I think you are right. The cross-section for photon / photon scattering at low energies is really tiny - maybe never observed at optical wavelengths or longer. (there might be some result I don't know about).
The article makes it sound much cooler than it is - but its still kind of a nice demonstration and not easy.
Slashdot Mirror
All correct.
Everything else being equal, higher compression engines have higher efficiency and higher compression requires higher octane gas. There is an efficiency / cost tradeoff with compression and reuqired octane that resulted in 87 being most common, but 92 octane being used in cars, and 100 octane being standard for almost all aircraft piston engines.
Turbines and diesels use similar (often identical) fuels that are completely different from gasoline. Diesels are high compression, but rely on the fuel spontaneously igniting when it is injected, as opposed to gas engines that rely on the fuel not igniting util the spark fires. Turbines are fairly low compression and relatively low efficiency, but much better power to weight which makes them better for high power aircraft use.
Diesels in general are more efficient than spark ignition engines, but (all else being equal) are heavier and more expensive.
For tons of information read the Taylor, "the internal combustion engine in theory and practice" .
I'm afraid Spaaaaace IS the argument - just think of it as religion.
Also though, Alaska, the Australian outback etc are all part of the Earth's overloaded ecosystem - one of the big advantages of space is that you don't need to worry about trashing it.
I don't disagree with your idea that China wants power, but I don't think orbital weapons are particularly useful in modern warfare. We (and several other countries) have enough raw firepower to utterly destroy any enemy. The problem is that for us (and China) our enemies are mixed with our friends. Nuclear weapons are completely useless against groups like Al-qaeda. Information collection and analysis is far better, and the US and China are both pushing very hard on that.
I'm not poor or broke, but I don't know how to set up a VM, and I'm not sure my computer security is very good. I also don't know how to rebuild the engine of a car, skin a deer, use a forge, do an appendectomy, use a gun, or perform a host of other valuable skills. The miracle of civilization is that since I know how to operate a linear accelerator, fly an airplane, and build femtosecond timing systems, I can somehow trade those skills for the vast array of skills that I'm missing. My computer skills are sufficient to protect the low value information that I have from casual hackers. I would not have the skill to protect a large value in bitcoins from a skilled attacker (and my computer skills are far above national average).
The advantage of conventional banks is that they can be used to provide good security for large amounts of value with minimal skill.
All depends on your goals. If you goal is manned exploration of space, then I believe that putting people in orbit is vital. If you goal is improving the standard of living on earth, or even doing space research, then it isn't.
A quick check seems to show the NASA budget as 1/2 the NIH budget. Then remember that NASA represents the majority of the space budget, NIH only represents a small fraction of healthcare spending (>2T/year last I checked). Of course it all depends on your priorities and how you want to count things.
The amount we spend on space is a tiny fraction of government spending.
Are you so sure that space colonization is impossible? No new science is required. We can easily imagine most of the engineering that is needed. It would be fantastically expensive - but even at say $10T, (something like 100X apollo) that is only 10 years wasted healthcare money in the US.
As an aside, I believe the goal of space IS space, not somehow enriching lives on earth. To ridiculous precision everything in the universe is not on earth - the goal is everything.
Maybe we will fail, but isn't it worth it to try?
That will be the critical point. If someone takes a serous shot at a manned mars mission for example, will the US space race revive, or will we just decide that we could but don't want to. For a while we've been letting the Russians launch our astronauts into space, something that would have been unthinkable when I was growing up.
Properly setting up a VM, or in fact doing any proper security or even backups is beyond the abilities of most people. If those sorts of measures are required, bitcoins can't become a universal currency.
Maybe it is. Seriously, imagine that you have just broken into a missile launch complex and are trying to guess the combo. Would 00000000 really be one of the first you would try?
More seriously, nuclear launch is too important for passwords of any kind. If some reasonable set of people know the password you can threaten or torture it out of them - a minor effort compared to breaking the physical security around a launch complex. Remember its not like you can remotely log in to the launch computer for a Titan missile complex. (more modern missiles now....???)
If the trading computers were located in satellites in low earth orbit, they could arrange to always have one withing a few hundred miles and line-of-sight to each of the big exchanges.......
Finally a way to fund the space program.
3-d printing is more expensive than conventional production methods for large volume production. Its not clear yet at what volume it will be competitive, but I expect that it will mostly be used for small / semi-custom production. (which is quite useful).
China does lots of things besides providing cheap labor. The have infrastructure (roads, rail, electricity, etc), and laws that make it efficient to do large scale production, though arguably at the expense of quality of life for the workers. (I say arguable because the income from the efficient production has improved the overall standard of living substantially, not clear how to balance against the substantial negative effects).
Not quite the same. The supermarket is performing a valuable service of providing a central location where I can purchase most of my food. It provides some level of quality control and acts as a single legal entity that I can deal with if there is a dispute. The supermarket also manages some of the transportation of the food from the locations where it is produced.
Financial trading can be valuable if it re-directs investment money to enterprises with higher productivity. High speed trading does not seem to me to do this in any way, it is simply a zero-sum game where real resources (in high speed computers and data links) are used in a way that does not increase overall productivity. It is not unique in this, bitcoin mining is also inefficient in that it consumes real resources to produce an artificially scarce good to use as a medium of exchange. It would be more efficient (but would lose other advantages) if there were a central repository of free to generate but limited number "coins" that were directly exchanged for money.
Well there is a plan to build a neutrino factory that would create directional highly intense neutrino beams. While the goal is neutrino physics, it could be used as a transmitter. Its only ~$1B, maybe worth it to the financial guys. If they pay, they can have have 50% of the beam time.....
In my field (accelerator physics) in 25 years, the only thing resembling misconduct that I've seen is overselling of future applications. By this I mean presenting an overly optimistic picture of future possibilities (typically known as marketing), not misrepresenting any work that was already done. This may be due to the way that most of the field is supported by large grants to large laboratories rather than grants to individual researchers. Might be a useful model to apply elsewhere.
Yes, that is the problem. If you limit pay, people will find some other form of compensation - company shares, use of the "company" bizjet. Also as someone suggested the execs will work for a company that has no low paid employees, but owns other companies that do.
The real question is why executives are compensated so highly. Is this an economically efficient result - is a good CEO really worth 10s to 100s of millions a year to a large company - the answer may be yes (certainly a bad executive can to tremendous damage). Or, is executive pay distorted by de-facto collusion between interlocking boards of directors?
If the second case is true, then we could change regulations on the management of companies, maybe require more input from smaller share holders, or specifically prevent interlocking boards - if you are on the board of directors for one company you can't be an executive at another for some period of time.
Maybe the problem is something completely different.
I'd don't think the Swiss model will help - I'm a fairly well paid tech worker, but there are a lot of shops in Zurich where I can't afford ANYTHING - Switzerland does not appear to be a model of low income disparity, though it may be better than the US.
I believe that the cost of an electric car is still significantly higher than for a low-medium end conventional car (Honda Civic for example). The operating costs might be lower, but its not clear that is true. Now a Tesla is a much nicer car that a Civic, but out of the price range of most people. (If this isn't true, and electrics really are cheaper overall, then their marketing departments are doing a bad job).
Then there is the range issue. I can get in a standard compact car and drive pretty much anywhere, I don't need to check if there are gas stations on the way. If I want to drive from the SF bay area to Los Angeles, I can stop for lunch anywhere on the I5, fill my tank in 5 minutes and be on my way. With an electric I'd need to be sure that a station was available, and it would take considerably longer to charge than it does to fill a gas tank.
Its true that probably less than 5% of my driving would cause any range concerns, but I still want to be able to do that 5%. Renting a car for those missions is time consuming.
An electric sounds great as a commute car - charge at home, charge at work (if available), no wasted time at gas stations. It might be a perfectly reasonable car for a person or family with 2 cars. It does need to compete though with the very reliable, high quality, low cost cars that are already on the market.
Yes, on linux when things don't work, I just search for my problem on google, find some website with a "fix", and then enter that command that I don't understand with root privs......
Often 2 interns, sometimes 3. We make them use an RF spectrum analyzer that dates from the Cretaceous to teach them character. (and because our "good" spectrum analyzer still dates from the Pliocene and is usually busy). Despite our best efforts at abuse, the last set of interns managed to measure timing noise down to a few femtoseconds.
Multiple scopes: cheap ones for general purpose, fast (>3GHz (20gs/s) single shot) for looking at high speed electronics (would like a 10GHz singl eshot but $$).
RF synthesizers, spectrum analyzers, signal source analyzer, RF power meter, picosecond impulse genrator,
Power supplies DVMs, precision voltmeters, TDRs, temperature measurement, accelerometers,
Transient digitizers, with A-D / D-A and instrument control for automated testing
Fiber power meters, polarization controllers, detectors, transmitters
A large number of RF mixers, adapters, amplifiers, etc.
And most importantly - duct tape, cable ties, vice grips and cutters - to hold things together or take them apart.....
I have a lab that does femtosecond timing systems for the accelerator / X-ray laser at SLAC, so we have a wide variety of cool stuff. Some is old, some new if we can't get by with the old stuff.
If you still have it - and are good at duplicating the magic that lets companies pack a cubic meter of stuff in a half-cubic meter box.
If the agreement click happens as soon as you buy the set, then taking it back may be reasonable. If it is a new agreement that appears months later, you may have disposed of the box, bolted the set to the wall, etc and it becomes a much larger effort. Very tempting to just click the box rather than go through all that work.
Of course its not a coincidence. China is run by centralized authoritarian government that carefully plans policies for its own good - which sometimes benefits the population as well: in general it is better to rule a prosperous peaceful country rather than a poor rebellious one.
Unlike the US, China does not pretend to be a free society. Personally I find that less distasteful than American hypocrisy. The US is still considerably less oppressive, but we are doing our best to close that gap.
Sounds nice, but "return the TV' means somehow finding an appropriate shipping box, filling out the required paperwork and paying to mail it back. If you are lucky you will then eventually get another TV to unpack and set up - and then have to repeat the process. Maybe you "win" and get your money back. The TV company doesn't care - very few of their customers will go to that effort rather than just click on the box, and your return will just be in the "user too stupid to use our TV" category.
This is the general problem with "returning" any sort of high tech product. The cost of the users time to do it is so high that most people simply won't bother - especially when they realize that the competitors product will likely have the same problem.
A strong source of very high energy neutrinos (which a muon collider produces) would look very different from a natural source, but I don't think it would be detectable at large distances with any technology I can imagine. the sun produces a HUGE amount of neutrino radiation - though all at low energies.
It is only near the muon collider that the neutrinos are a problem and that is because they are in such a tight beam (or thin fan).
I think you are right. The cross-section for photon / photon scattering at low energies is really tiny - maybe never observed at optical wavelengths or longer. (there might be some result I don't know about).
The article makes it sound much cooler than it is - but its still kind of a nice demonstration and not easy.