I took 3 American History classes at Wellesley circa 1971. In Boston, the Boston Public Library is a good resource, and (at that time, I don't know about now) access to the libraries at Harvard were open to the general public, or at least to everyone who looked like he belonged there. The first two courses were taught by a woman who didn't bring any noticeable bias to the material and offered some supplemental background. I don't wish to be critical of her because she did a good job, but I don't think she added a whole lot that wasn't available from the reading material. The man who taught the third course brought an obvious (but not severe) leftist bias that made understanding the material more difficult because of the extra effort required to sort out the opinion of authors from the teacher's opinion and from what was actually happening.
About half of modern college level American history courses is not the study of history but rather the study of "historiography". This is the study of the opinions of historians and how they fall into various schools of thought. It's considered as important to know what Hofstadter and Turner think as what Adams and Jackson did. In my opinion, this is a scandalous state of affairs, equivalent to a college course in navel-gazing.
High density corn production is fertilizer and mineral intensive, which causes polution and soil depletion, respectively. Perhaps a good tradeoff, but not a free ride.
People already die from third rail systems on railroads and subways, and they are pretty well fenced off from public access. A high voltage electrical conductor close to the ground would pretty much guarantee a >50% fatality rate in childhood.
I don't know what the actual numbers are, but the claim of 10,000x volume (or 2,500x volume) is for ultracapacitors, not batteries. Presumably ultracapacitors have a very low specific gravity. A 12 gallon gas tank is 2 cubic feet, times 2500 is 5000 cubic feet, or 10 feet wide by 10 feet high by 50 feet long for ultracapacitors.
The two things you most want to protect in a collision are the passengers and the gas tank. To avoid having to provide two separate crushproof areas, the gas tank goes in the same crushproof area as the passengers. Usually just below and slightly behind the rear seat.
For a bullet train between DC and Boston, a whole lot of upgraes need to be made. I'm only familiar with the NYC to Boston stretch, but consider this:
From New Haven to Boston, there are only two tracks, one each direction, for all traffic (passenger and freight). This would need to be upgraded to 4 tracks to give the bullet trains (or passenger trains) exclusive access to the fast tracks. Property in this region is expensive, and would have to be purchased or eminent-domain-stolen. Some portions are long stretches of track over water on trestles or stone breakwaters. Building upgrades will be very expensive, and there is no guarantee the investment will ever pay for itself. The smoothness of the track itself needs to be improved, although it's a lot better than, say, Los Angeles to San Diego is now.
NYC to DC has already had improvements made for high speed trains, although not the highest currently available technology. AFAIK it has not been an economic success, and it's the most obvious place for such a train in the whole country. If it can't make it there, it can't make it anywhere (in the USA).
I looked at the article, and the numbers are impressive. However, some of the charts contradict others. For instance, one leaves out electric transmission losses. Another problem is he compares a mediocre efficiency car (24 mpg) to what I presume is a carefully tuned and inconvenient electric. Generally, I think the author cherry-picked the studies he cited, because he ends up claiming efficiency advantages for an electric car over an ICE of from 2:1 to almost 3:1. I'll grant that efficiency advantages may exist, but I don't think they're as good as he claims.
Alas, DirecTiVo has none of the nice features you mention. Record is from satellite only. No recording from XM. No commercial skip of any sort whatsoever. No warning is issued when disk space is about to run out, and there is no way to check how much is left. As a result, I have to go through all the recordings I want to keep and set them to "never erase" or risk having them mysteriously disappear.
If it weren't for automatic scheduling, I'd be much better off with 2 conventional DirecTV boxes and a MythTV with IR blaster.
It does not follow that the gov't is working for a portion of the people 100% of the time, if you exclude people in gov't from "a portion of the people". There are many obvious cases (particularly undeserved pay raises) where the gov't is working only for itself, AGAINST everyone else.
Furthermore, most of the time the net long-term effect of government action hurts everyone.
But the cell phone service market requires you to own bandwidth, which was auctioned off back in the early 1990s. There's no way for a new company to join the market
IIRC, Trac-Fone buys bandwidth from the owner, and the've entered many markets by doing so.
Some cron jobs can really degrade a system. I run an older Linux (RH8), and sometimes tripwire or updatedb takes the system to a crawl, despite running at nice +19. Particularly bad is when updatedb crashes with interupts disabled, resulting in an unkillable resource hog that can prevent shutdown (!).
AFAIK, none of Brittanica's competition measured up. Compton's is clearly inferior, World Book is for kids, Americana is a wannabe. Libraries generally wouldn't even bother with Funk & Wagnalls; in 1960 it was $1 a volume in supermarket sales.
When I was looking for a summer job in 1968, Brittanica was hiring college students for sales. They claimed that they only tried to sell to people who had already expressed interest. I don't know if that was true, but it makes sense: consider the alternatives.
Currently, the processes used to make photocells are energy intensive: repeatedly melting a lot of silicon, sawing it up, applying impurities and partially melting it again. It's already the cheapest semiconductor silicon available; making a plant and starting it running are a smaller part of the cost than with ICs and transistors. The economies of scale you seem to think are available for future cost improvemnt probably don't exist. The trick is to make production less energy intensive. It's being worked on and there's progress; but we've got a way to go yet.
Not only is there no contradiction between the two claims, one causes the other. Given the need to hire a certain number of employees, being unable to hire as many foreigners as they wanted meant they had to spend more to hire U.S. citizens.
That said, I'm a Google stockholder and I think they've been careless in their hiring and acquisitions. Their claim that they've been making only superb hires is dubious at best.
Popular Electronics and Byte both had a particular problem for which I see no easy cure: technological and production advances have made it very difficult to make hobbyist projects as good as commercial products. Good hifi equipment is available dirt cheap. Six layer PC motherboards are beyond the capability of a hobbyist. Software products are huge; no-one wants to type in ten thousand lines of code, or even read about the principles behind it. Electronic parts suppliers are no longer available in most neighborhoods.
"Circuit Cellar" and "Nuts and Volts" live in the hobbyist realm; but they're not mass market magazines.
Buy used. In my experience, you can get an instrument that is as good as new for half the price. Just be sure you examine it before you buy.
You might not want to spend the money on a computerized drive, but you do want some sort of motorized drive so that you don't have to continually reposition the scope. If you're going to do astrophotography, you definitely want a drive.
If you're up for a real challenge, grind your own mirror.
The suit should be microporous, except for the head, which should be the traditional goldfish bowl. Vacuum insulates very well, so heating is no problem because the body can heat itself. Cooling is achieved the old-fashioned way, by sweating. Sweat evaporates through the micropores; the "heat of evaporation" cools the body.
On a microscopic scale skin has no problem being exposed to vacuum for short periods of time (hours). The purpose of the suit is to hold back moderate pressures on a scale of greater than about a millimeter, so that air pressure doesn't explode your chest, so that blood an other body fluids don't boil, and so that blisters don't form from fluids trying to escape the body's fluid-tight skin.
According to wikipedia, the best (hydrogen) fuel cells have an efficiency of 70%, carbon fuel cells 80%. Gasoline IC engines generally don't exceed 30%. This makes up most of hydrogen's price disadvantage. Of course, lots of difficulties remain.
Slashdot Mirror
About half of modern college level American history courses is not the study of history but rather the study of "historiography". This is the study of the opinions of historians and how they fall into various schools of thought. It's considered as important to know what Hofstadter and Turner think as what Adams and Jackson did. In my opinion, this is a scandalous state of affairs, equivalent to a college course in navel-gazing.
High density corn production is fertilizer and mineral intensive, which causes polution and soil depletion, respectively. Perhaps a good tradeoff, but not a free ride.
People already die from third rail systems on railroads and subways, and they are pretty well fenced off from public access. A high voltage electrical conductor close to the ground would pretty much guarantee a >50% fatality rate in childhood.
Silicon dioxide used in gate insulators has a breakdown in excess of 500 MV/m. Alas, the dielectric constant is rather low.
The two things you most want to protect in a collision are the passengers and the gas tank. To avoid having to provide two separate crushproof areas, the gas tank goes in the same crushproof area as the passengers. Usually just below and slightly behind the rear seat.
It's not the same thing. The GP suggested a detachable ICE, which is a nice idea, although probably not practical from a convenience standpoint.
From New Haven to Boston, there are only two tracks, one each direction, for all traffic (passenger and freight). This would need to be upgraded to 4 tracks to give the bullet trains (or passenger trains) exclusive access to the fast tracks. Property in this region is expensive, and would have to be purchased or eminent-domain-stolen. Some portions are long stretches of track over water on trestles or stone breakwaters. Building upgrades will be very expensive, and there is no guarantee the investment will ever pay for itself. The smoothness of the track itself needs to be improved, although it's a lot better than, say, Los Angeles to San Diego is now.
NYC to DC has already had improvements made for high speed trains, although not the highest currently available technology. AFAIK it has not been an economic success, and it's the most obvious place for such a train in the whole country. If it can't make it there, it can't make it anywhere (in the USA).
Note that TFA doesn't mention any patent numbers, so it's not easy to check the claim.
I looked at the article, and the numbers are impressive. However, some of the charts contradict others. For instance, one leaves out electric transmission losses. Another problem is he compares a mediocre efficiency car (24 mpg) to what I presume is a carefully tuned and inconvenient electric. Generally, I think the author cherry-picked the studies he cited, because he ends up claiming efficiency advantages for an electric car over an ICE of from 2:1 to almost 3:1. I'll grant that efficiency advantages may exist, but I don't think they're as good as he claims.
Gee, I wish I'd thought of that. I hired a bunch of portrait painters to watch my TV.
If it weren't for automatic scheduling, I'd be much better off with 2 conventional DirecTV boxes and a MythTV with IR blaster.
Perhaps you would have gotten more hits with Rodriguez.
Furthermore, most of the time the net long-term effect of government action hurts everyone.
Some cron jobs can really degrade a system. I run an older Linux (RH8), and sometimes tripwire or updatedb takes the system to a crawl, despite running at nice +19. Particularly bad is when updatedb crashes with interupts disabled, resulting in an unkillable resource hog that can prevent shutdown (!).
When I was looking for a summer job in 1968, Brittanica was hiring college students for sales. They claimed that they only tried to sell to people who had already expressed interest. I don't know if that was true, but it makes sense: consider the alternatives.
1 sq ft at 100% efficiency would yield about 100W. This is enough for a modest computer and TV, provided that the displays are LCDs lit by sunlight.
Currently, the processes used to make photocells are energy intensive: repeatedly melting a lot of silicon, sawing it up, applying impurities and partially melting it again. It's already the cheapest semiconductor silicon available; making a plant and starting it running are a smaller part of the cost than with ICs and transistors. The economies of scale you seem to think are available for future cost improvemnt probably don't exist. The trick is to make production less energy intensive. It's being worked on and there's progress; but we've got a way to go yet.
That said, I'm a Google stockholder and I think they've been careless in their hiring and acquisitions. Their claim that they've been making only superb hires is dubious at best.
"Circuit Cellar" and "Nuts and Volts" live in the hobbyist realm; but they're not mass market magazines.
You might not want to spend the money on a computerized drive, but you do want some sort of motorized drive so that you don't have to continually reposition the scope. If you're going to do astrophotography, you definitely want a drive.
If you're up for a real challenge, grind your own mirror.
Spacecraft generally use about 1/3 atm (5 psi), so it's more like being 10 feet under water.
On a microscopic scale skin has no problem being exposed to vacuum for short periods of time (hours). The purpose of the suit is to hold back moderate pressures on a scale of greater than about a millimeter, so that air pressure doesn't explode your chest, so that blood an other body fluids don't boil, and so that blisters don't form from fluids trying to escape the body's fluid-tight skin.
According to wikipedia, the best (hydrogen) fuel cells have an efficiency of 70%, carbon fuel cells 80%. Gasoline IC engines generally don't exceed 30%. This makes up most of hydrogen's price disadvantage. Of course, lots of difficulties remain.