No. I meant to say the two most important. I certainly have never seen anything like good science that argues successfully for the idea that more gun laws will, in the US, decrease violent crime victimization. Of course, if we could magically press the button and vanish all the guns it would reduce gun crime. But that's not one of the options.
Lott seems to have admitted to falsifying an online personality. But I have not seen anyone actually attacking his most important research with counter-research. Sure he may be flippant, he may be frustrated, and he may be a self-promoter, and he may quote other's research off the cuff, but the core research that he did in "More Guns Less Crime" seems to stand. Concealed carry laws reduce violent crime.
Please, point me in the direction of the counter-research. (No, not methodological attacks or personal attacks, just cold hard data.)
The data on gun ownership alone is not particularly correlated with crime deterrent, but that's conveniently ignoring the data on concealed carry licenses published by John Lott, not-coincidentally in a book called "More Guns Less Crime"
His data showed a consistent and predictable decline in violent crime after the passage of concealed carry laws. Furthermore his data shows that violent crime was exchanged for crimes where there was less risk of meeting a person during commision (car theft, etc). Both of these are consistent with basic economic hypotheses (ie. greater risk costs means less people participate)
Of course when it comes to criminals evaluating their risks, it doesn't matter how many people have guns locked in cabinets at home, it matters how many people MIGHT have them hidden under their jacket.
John Lott: More Guns Less Crime Kleck and Kates: Armed, new perspectives on gun control.
are the two most important available books that use logic and statistics to examine how firearms affect crime.
My wife works with a neurologist who is an expert in pain management. He and most of his colleagues now believe that basically all headaches are the same, migraines are simply MORE of the same.
In other words the underlying biological causes of almost all headaches (other than brain tumors/strokes and blocked sinuses. etc) is basically an inflammatory response that can be set off by a wide variety of factors. People who have classic migraines are simply more susceptible to this pathway activation.
The only "truly random" ie. completely in-principle unpredictable events are quantum events. So they're using the energy levels of electrons in an array of diodes to produce quantum noise. This noise is in fact unpredictable as long as it isn't biased in some way.
The way to bias this noise is to use radio waves or static electric fields or some other electric effect to cause the diodes to produce 1 more often than 0 or the other way around.
Random numbers are always run through encryption algorithms to "smooth them out" because of this possibility to bias the results. The encryption algorithm spreads the real entropy around.
This method is not particularly more secure than the method used in/dev/random except that it's probably a little harder to tamper with.
Weather simulators are chaotic (ie. small changes produce large fluctuations over time) but for the short term they are very predictable, ie. you can predict the weather reasonably well for 3 days in advance.
What you want is a random number generator that gives you a sequence where each new number is completely unpredictable even if you know the entire previous sequence.
This book is designed to teach you step by step all the calculus you would learn in 2+ semesters of college calculus classes. It is workbook style. That is they teach you something and then have you work individual problems. I tought myself calculus in 10th grade by using this book.
PHYSICS:
The Feynman Lectures on Physics:
I've only read volume 1 but I have 2 and 3 queued up. These are good for getting an understanding of how and why physics works if you know a fair amount about calculus and you've taken some physics (high school at least). THESE WILL NOT teach you how to solve physics problems (as far as I can tell they don't publish the problem set anymore).
Schaum's Outlines: Physics for Scientists and Engineers by Michael E Browne
This one will give you practical problems to solve and practice with, plus a concise explanation of topics that Feynman blew past you too quickly.
STATISTICS and DATA ANALYSIS:
It's hard to recommend anything specifically here because it's a hard subject to teach and I've never found a great book.
Principles of Statistics by M.G. Bulmer (dover)
It's an inexpensive paperback and it gives a very good overview of the basic concepts of statistics.
An introduction to error analysis by John R Taylor
I haven't read this book but I've had it recommended. If you want to understand why you need to be skeptical of numerical data, you at least need to know something about this subject.
Statistics for Experimenters by Box Hunter and Hunter
This is another one that's supposed to be a great book. If you want to do experiments and analyze the results you need to study this subject.
MATHEMATICS:
Mathematics books are often aweful, and what makes a good mathematics book is very personal (ie. your learning style), so here's a general list of subjects and why you should study them.
Calculus and differential equations Without calculus you can't do physics effectively. see my recommendation for Quick Calculus above. Differential equations are effective for modelling the behavior of physical systems.
Linear Algebra This topic forms the basis of several important fields, such as signal processing, statistics, differential equations, and much of numerical analysis.
Topology This is a field that will teach you more about important properties of functions, and of sets. It's basically about invariance: properties that do not change when you transform something (continuously)
Combinatorics or discrete math This is about counting, probability, and sequences of numbers. It's entertaining and important for computer science.
AS FOR MATH BOOKS:
The thing to know is that there is a huge variability in math books. I'd recommend starting with cheap Dover paperbacks and trying several in a particular field. Once you've exhausted those (either too poorly written or too complicated for you) at least you haven't spent a lot of money.
If you need more after the Dover paperbacks, move on to something hardback and expensive but sit down in the book store and read through it first. Does the author take pains to explain things, or just use a flurry of symbols?
Remember you can't start at the top. Work your way up a mathematical subject, preferrably with some application or core reason that drives you.
I worked at a financial software company that had a heavy academic background. They used LaTeX for lots of stuff.
One day I was at lunch with the group admin assistant who was a visual artist who worked for us as a day job. She had no sci/tech background and had never heard of LaTeX. She told a story about how the boss had sent her an email saying something like
"Hi, I need you to learn about LaTeX, come see me this afternoon".
Of course the only thing she could think of was "i'm not that kind of girl".
There are 3 sources of momentum transfer as I see it.
1) Light impinging on the sail and reflecting back towards the sun. The photons have momentum due to relativity.
2) Photons being absorbed by the sail (increasing its temperature and transferring momentum to the sail)
2) Photons being radiated in all directions by the sail (radiant heat).
Conservation of momentum shows that the sail has to accellerate, but he's right that it will start out increasing rapidly, and as it heats up it will slow down its accelleration (because it starts to radiate infra-red on the side away from the sun)
I think this is the sense in which it is a heat engine.
The conservation of energy and the fact that the sail accellerates away from the sun does imply red shifts of the reflected photons (ie. reduction in their energy). This doesn't seem to bother me at all. It seems to be what bothers Gold.
Yes but lasers don't require megawatthours of electricity to generate. This sort of thing absolutely requires super high energies...
Therefore there will probably never be a commercial application to quark gluon plasma generation.
Of course it's possible that some quark-gluon plasma fusion reaction may be discovered that allows us to generate massive terawatt power plants the size of a volkswagen that run off lithium pellets or something, but I'm not holding my breath for that.
Fundamentally we know enough about physics in this region of the universe to know how much energy we can get from a certain quantity of mass (ie. e=mc^2) and to know the limitations of generating and distributing that energy (ie. conductivity of metals, and cooling requirements of superconductors). From our fundamental understanding of physics as we know it so far, we know that in order to do useful work you have to manipulate the electroweak force (ie. move electrons and atoms around). Fundamentally, all useful chemical reactions and intermolecular forces in our everyday world are electric phenomena. Now THAT's what I call neat physics.
If you want "Practical" you have to look to the engineering industry. They are the ones creating more efficient power plants, lower emissions engines, higher strength construction techniques, higher efficiency agriculture, and better water treatment systems.
Re:A couple real reasons...
on
A Mighty Wind
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· Score: 1
Here in California, the altamont pass has virtually continual wind, the wind farm has tons of non-operational mills, and they kill quite a few birds, including quite a few golden eagles.
It works, but it's not necessarily all that it seems to be.
I'm against the idea of more nuke plants. I personally think it's a good idea to keep using oil and natural gas. Especially if we can actually successfully convert it from ag waste
The main thing the US needs to do is work on energy usage reduction, and distributed generation technologies. I'm fairly sure we could cut our energy use in half for the same price as building nuke plants and waste storage facilities if we revised our regulations and revised our foreign policy in the middle east.
1) Time of day metering. It works, and it cuts peak loads which are the most important loads.
incidental to this is also STOP PRICE FIXING of electric energy (ie. california's stupidity). Create real free markets for energy. When energy is in low supply, you should be forced to pay for it or cut back your usage.
2) Break down regulatory barriers to extensive cogeneration of heat and power in all states.
3) Reduce heat islanding and smog with more extensive use of trees and rooftop gardens in urban areas.
4) Use geothermal heat pumping more extensively, especially in large buildings, but also at residences.
Imagine if it were possible (ie. regulations didn't make it difficult) for companies to sell cogeneration plants and service contracts to hospitals, health clubs, office buildings, apartment complexes, and similar buildings. We'd probably cut our energy usage in half and the businesses would cut heating or cooling costs at the same time.
The real problem we have in the US is that we have only a few large companies like Duke and Enron, and soforth that control most of the distribution and generation capacity of the US, and they have politicians in their pockets. It's regulations that give us massively centralized energy generation with little price sensitivity.
Energy is cheap, as long as you don't count the amount of money we spend on wars in the middle east, california's taxpayer paid long term contracts, and the cost of nuclear fuel storage into the equation (for a few examples).
In other words the bill is cheap, but the costs are not reflected in the bill.
here's some more ideas you can google for:
Thermoacoustic refrigeration for natural gas liquifaction. (See LANL)
Hybrid multi-fuel diesel/natural gas engines that have low NOx emissions and low particulates.
Highly reflective roof materials to reduce heat islanding and cooling loads.
One of my favorite ideas for technology solutions is actually real-time automated distributed generation power marketplace (ie. a small local generator company can buy and sell power online with a data-logging power meter that enforces the contract)
We don't need more massive centralized power plants, we need more power plants in the basements of buildings WHERE THE ELECTRIC AND HEAT GENERATION POWER IS NEEDED.
that's my two cents.
A couple real reasons...
on
A Mighty Wind
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· Score: 2, Interesting
Wind farms aren't all that...
Environmentally and economically there are good reasons to dislike them. They kill a lot of birds. They break down a lot, requiring a fair energy input to maintain, and they only work when the wind blows.
Here are some alternatives that may be better:
Cogeneration of heat and power. A decent quality diesel engine runs in a soundproofed enclosure. The coolant liquid runs through radiators in your house, or to a heat pump that heats your house. Electricity from the generator is sent back through your meter onto the grid. This works with TODAYS technology. Some states already allow it. It produces power at much higher fuel efficiency than centralized plants and its distributed nature allows reduced transmission loss and increased reliability.
Conservation: instead of building million dollar wind farms, change the way people consume energy. The biggest consumer is probably heating and cooling. Therefore, white roofs, and geothermal heat pumps are both probably going to save thousands of kilowatts vs. older heating and cooling techniques. White roofs considerably reduce heat gain during the summer.
Geothermal heat pumps use heat from groundwater to heat, and reject heat into the groundwater to cool. Much more efficient than regular heat pumps which are already quite efficient.
Combine this with cogeneration and you have a very attractive heating/cooling/power generation technique.
The life of a typical quality diesel engine is about 20-30,000 hours. Then it needs an overhaul then it gets another 20-30,000 hours. Some run as long as 40 or 50 thousand. This means that with a monthly service contract and overhauls every 3 years or so you can have high efficiency reliable distributed generation.
One engine will put out typically say 10 kilowatts of electric power, which will on average power 10 houses, though at peak times it might only power 1 house. A decent engine costs around $5000. It can burn the same #2 heating oil probably already in use for heating.
By running the cogeneration plants only during the appropriate peak heating/cooling/electric demands you could probably stretch the life of the engine to 10 years or so.
Schools, govt buildings, hospitals, gyms, apartment complexes, and other reasonably large energy consumers can usually do quite well with cogeneration units in their basements, making money off the power, and saving a bundle in heating or cooling (the reject heat can be used with the proper type of refrigeration unit to cool the building).
Plus this technique acts as a "backup" generator for power outages and bad weather situations.
Economically and environmentally speaking there are plenty of other responsible techniques for decreasing power requirements and increasing availability.
perhaps this article is biased so as not to report the good technical reasons against this project?
I think you picked an unfortunate set of examples. I think threads, statistics and basic undergraduate operating systems concepts are all so well understood at this point that instructors are really not necessary. There are several books that will teach you everything you want to know about all three.
Now take something like engineering thermodynamics. There are so many different ways to approach thermodynamics, and there are a ton of arbitrary experimentally derived constants (like emissivity of a material etc). If you want to learn to design a thermodynamic system such as a passive cooling system, or a chiller, or a thermoacoustic refrigerator or soforth, you'll definitely want lots of in-class, and in-lab experimental hands on experience.
When it comes to math, computer science, software engineering, natural language composition, ethics, economics, and soforth, you can learn most of the undergraduate topics via independent study, because they're all basically about learning to think. When it comes to engineering, physics, biology, chemistry, etc. beyond the basics you will need hands on experience and experimentation.
That isn't to say that instruction won't help you in all topics, just that for some topics it's more absolutely necessary than others.
That's the point. For some programs, you can choose client input to the server to intentionally create the worst case and cause the server to bog down.
Seems like stepper motors are not that difficult to control. A simple darlington transistor, resistor, and diode are all that's needed for the driver, for the control circuitry I suggest Atmel AVR microcontrollers, some of them have built in A/D etc, they're cheap, and they are programmable via GNU C compilers available under linux.
An AVR running at 10 mhz gives you a lot of processing power, and plenty of i/o to step 2 motors forwards and backwards. The main question is how to tell the AVR what to do.
It depends on how complicated your control algorithm is, ie. do you just need to run through a set of rote steps, or are you doing feedback control, or responding to the outside world?
If you're doing feedback control, then get an AVR with A/D channels built in, if you're responding more complicatedly then perhaps use the sound card output of your computer to tell the AVR what to do?
Admittedly all of this is likely more trouble than installing windows and writing your software in VB, but once you've done it, you've got a system that you can have some control over vs. an off the shelf solution from a non-responsive vendor (ie. there's not necessarily a guarantee that the thing works all that well under windows either)
Plus, with this kind of experience you will rapidly find other uses for a general purpose microcontroller platform, you'll be able to bypass buying expensive proprietary PCI cards and build some of the simpler control systems you need yourself.
NOTE: if you're building things yourself you have to deal with debugging the hardware and the software. Keep focused on the cost to benefit ratio of doing it yourself vs. buying off the shelf. Remember you're trying to do research, which means you need the flexibility of do-it-yourself, but you've also got a hard enough time doing the research, so adding hardware design and debugging on top is added hassle.
Getting an undergraduate electronics engineer to work with you for work-study credit is probably a good idea.
How hard would it be to get a couple of Atmel AVR chips and control the damn thing via hardware that you can program from linux using GNU tools?
Just talking off the top of my head, but if you're talking about sending the proper number of pulses at the proper times wouldn't it be relatively easy via a little board like the dontronics rAVeR?
Running at 10 mhz it seems like you'd be able to do a lot with one of these puppies.
I don't know how much intelligence is in the signals vs. in the motors, so i don't know whether it's as easy as it seems. Probably not, but it's worth stepping back from the problem perhaps.
Sorry. I sort of glossed over the main point, which is that even under normal conditions, a reasonable AC unit is still 300% efficient (ie. energy efficiency rating of 9 BTU/hr / watt, which is about 2.6 watts of heat removal / watt of electricity).
The groundwater is just a way to make them EVEN MORE efficient.
This isn't right. You've got the carnot cycle upside down. You want to know how much heat can be transferred per unit of work input, not how much work can be generated per unit of heat available.
A typical efficient air conditioner has an energy efficiency ratio of about 9, this means 9 BTU/hr per watt of electricity used.
or about 2.6 watts of heat extracted from the cold side per watt of electricity consumed.
You can see that your calculation is wrong because it predicts higher efficiency when you pump up a larger gradient, in other words if you are trying to pump heat out of my room directly into the sun's surface it would predict a very high efficiency, obviously the wrong formula.
The formula you've given is for the efficiency of a heat engine trying to extract work from a temperature differential, not for a refrigeration system trying to extract heat using work.
The internet to the rescue: Hyperphysics shows some information on heat pumps.
A typical efficiency is therefore about 300%, whereas if you use the air conditioner to pump heat into ground water (ie. use the earth as a heat sink) you can get very high efficiency, in that case you're acting like a heat pump, ie. heating ground water from a high temperature room.
If the inverse carnot equation held and you had ground water at 55F (286K) and air at 95F (308K), you'd get about 1300% efficiency.
This is clearly the best way to cool your house, use a heat pump to pump heat out of your room into the earth.
Slashdot Mirror
No. I meant to say the two most important. I certainly have never seen anything like good science that argues successfully for the idea that more gun laws will, in the US, decrease violent crime victimization. Of course, if we could magically press the button and vanish all the guns it would reduce gun crime. But that's not one of the options.
Lott seems to have admitted to falsifying an online personality. But I have not seen anyone actually attacking his most important research with counter-research. Sure he may be flippant, he may be frustrated, and he may be a self-promoter, and he may quote other's research off the cuff, but the core research that he did in "More Guns Less Crime" seems to stand. Concealed carry laws reduce violent crime.
Please, point me in the direction of the counter-research. (No, not methodological attacks or personal attacks, just cold hard data.)
The data on gun ownership alone is not particularly correlated with crime deterrent, but that's conveniently ignoring the data on concealed carry licenses published by John Lott, not-coincidentally in a book called "More Guns Less Crime"
His data showed a consistent and predictable decline in violent crime after the passage of concealed carry laws. Furthermore his data shows that violent crime was exchanged for crimes where there was less risk of meeting a person during commision (car theft, etc). Both of these are consistent with basic economic hypotheses (ie. greater risk costs means less people participate)
Of course when it comes to criminals evaluating their risks, it doesn't matter how many people have guns locked in cabinets at home, it matters how many people MIGHT have them hidden under their jacket.
John Lott: More Guns Less Crime
Kleck and Kates: Armed, new perspectives on gun control.
are the two most important available books that use logic and statistics to examine how firearms affect crime.
Listen up. Overdoses on tylenol are fatal and there isn't much they can do about it. It destroys your liver.
Oh sure, it's spelled Gnoppix but it's pronounced "throatwobbler mangrove"
My wife works with a neurologist who is an expert in pain management. He and most of his colleagues now believe that basically all headaches are the same, migraines are simply MORE of the same.
In other words the underlying biological causes of almost all headaches (other than brain tumors/strokes and blocked sinuses. etc) is basically an inflammatory response that can be set off by a wide variety of factors. People who have classic migraines are simply more susceptible to this pathway activation.
The only "truly random" ie. completely in-principle unpredictable events are quantum events. So they're using the energy levels of electrons in an array of diodes to produce quantum noise. This noise is in fact unpredictable as long as it isn't biased in some way.
/dev/random except that it's probably a little harder to tamper with.
The way to bias this noise is to use radio waves or static electric fields or some other electric effect to cause the diodes to produce 1 more often than 0 or the other way around.
Random numbers are always run through encryption algorithms to "smooth them out" because of this possibility to bias the results. The encryption algorithm spreads the real entropy around.
This method is not particularly more secure than the method used in
Weather simulators are chaotic (ie. small changes produce large fluctuations over time) but for the short term they are very predictable, ie. you can predict the weather reasonably well for 3 days in advance.
What you want is a random number generator that gives you a sequence where each new number is completely unpredictable even if you know the entire previous sequence.
Hopefully someone will find these interesting:
CALCULUS
Quick Calculus by Kleppner and Ramsey.
This book is designed to teach you step by step all the calculus you would learn in 2+ semesters of college calculus classes. It is workbook style. That is they teach you something and then have you work individual problems. I tought myself calculus in 10th grade by using this book.
PHYSICS:
The Feynman Lectures on Physics:
I've only read volume 1 but I have 2 and 3 queued up. These are good for getting an understanding of how and why physics works if you know a fair amount about calculus and you've taken some physics (high school at least). THESE WILL NOT teach you how to solve physics problems (as far as I can tell they don't publish the problem set anymore).
Schaum's Outlines: Physics for Scientists and Engineers by Michael E Browne
This one will give you practical problems to solve and practice with, plus a concise explanation of topics that Feynman blew past you too quickly.
STATISTICS and DATA ANALYSIS:
It's hard to recommend anything specifically here because it's a hard subject to teach and I've never found a great book.
Principles of Statistics by M.G. Bulmer (dover)
It's an inexpensive paperback and it gives a very good overview of the basic concepts of statistics.
An introduction to error analysis by John R Taylor
I haven't read this book but I've had it recommended. If you want to understand why you need to be skeptical of numerical data, you at least need to know something about this subject.
Statistics for Experimenters by Box Hunter and Hunter
This is another one that's supposed to be a great book. If you want to do experiments and analyze the results you need to study this subject.
MATHEMATICS:
Mathematics books are often aweful, and what makes a good mathematics book is very personal (ie. your learning style), so here's a general list of subjects and why you should study them.
Calculus and differential equations Without calculus you can't do physics effectively. see my recommendation for Quick Calculus above. Differential equations are effective for modelling the behavior of physical systems.
Linear Algebra This topic forms the basis of several important fields, such as signal processing, statistics, differential equations, and much of numerical analysis.
Topology This is a field that will teach you more about important properties of functions, and of sets. It's basically about invariance: properties that do not change when you transform something (continuously)
Combinatorics or discrete math This is about counting, probability, and sequences of numbers. It's entertaining and important for computer science.
AS FOR MATH BOOKS:
The thing to know is that there is a huge variability in math books. I'd recommend starting with cheap Dover paperbacks and trying several in a particular field. Once you've exhausted those (either too poorly written or too complicated for you) at least you haven't spent a lot of money.
If you need more after the Dover paperbacks, move on to something hardback and expensive but sit down in the book store and read through it first. Does the author take pains to explain things, or just use a flurry of symbols?
Remember you can't start at the top. Work your way up a mathematical subject, preferrably with some application or core reason that drives you.
I worked at a financial software company that had a heavy academic background. They used LaTeX for lots of stuff.
One day I was at lunch with the group admin assistant who was a visual artist who worked for us as a day job. She had no sci/tech background and had never heard of LaTeX. She told a story about how the boss had sent her an email saying something like
"Hi, I need you to learn about LaTeX, come see me this afternoon".
Of course the only thing she could think of was "i'm not that kind of girl".
There are 3 sources of momentum transfer as I see it.
1) Light impinging on the sail and reflecting back towards the sun. The photons have momentum due to relativity.
2) Photons being absorbed by the sail (increasing its temperature and transferring momentum to the sail)
2) Photons being radiated in all directions by the sail (radiant heat).
Conservation of momentum shows that the sail has to accellerate, but he's right that it will start out increasing rapidly, and as it heats up it will slow down its accelleration (because it starts to radiate infra-red on the side away from the sun)
I think this is the sense in which it is a heat engine.
The conservation of energy and the fact that the sail accellerates away from the sun does imply red shifts of the reflected photons (ie. reduction in their energy). This doesn't seem to bother me at all. It seems to be what bothers Gold.
Since we're talking about english teaching...
one thing that gets me is when people use "disinterested" to mean "uninterested".
I guess it may be a common secondary meaning, but using it sort of ruins the very useful primary meaning, which is "unbiased"
ie. "we sought out a disinterested party to settle the dispute"
Now i'm all for language evolution so don't jump on my as a grammar nazi...
In ex-Soviet russia, Gary Kasparov beats YOU..
wait....
I'm not the original person you were replying to but I'm INTP as well. and yes I do.
Though lately I'm trying hard to alter that behavior slightly, mainly by picking a few things as longer term activities.
It's a rough urge to fight though.
Yes but lasers don't require megawatthours of electricity to generate. This sort of thing absolutely requires super high energies...
Therefore there will probably never be a commercial application to quark gluon plasma generation.
Of course it's possible that some quark-gluon plasma fusion reaction may be discovered that allows us to generate massive terawatt power plants the size of a volkswagen that run off lithium pellets or something, but I'm not holding my breath for that.
Fundamentally we know enough about physics in this region of the universe to know how much energy we can get from a certain quantity of mass (ie. e=mc^2) and to know the limitations of generating and distributing that energy (ie. conductivity of metals, and cooling requirements of superconductors). From our fundamental understanding of physics as we know it so far, we know that in order to do useful work you have to manipulate the electroweak force (ie. move electrons and atoms around). Fundamentally, all useful chemical reactions and intermolecular forces in our everyday world are electric phenomena. Now THAT's what I call neat physics.
If you want "Practical" you have to look to the engineering industry. They are the ones creating more efficient power plants, lower emissions engines, higher strength construction techniques, higher efficiency agriculture, and better water treatment systems.
Here in California, the altamont pass has virtually continual wind, the wind farm has tons of non-operational mills, and they kill quite a few birds, including quite a few golden eagles.
It works, but it's not necessarily all that it seems to be.
I'm against the idea of more nuke plants. I personally think it's a good idea to keep using oil and natural gas. Especially if we can actually successfully convert it from ag waste
The main thing the US needs to do is work on energy usage reduction, and distributed generation technologies. I'm fairly sure we could cut our energy use in half for the same price as building nuke plants and waste storage facilities if we revised our regulations and revised our foreign policy in the middle east.
1) Time of day metering. It works, and it cuts peak loads which are the most important loads.
incidental to this is also STOP PRICE FIXING of electric energy (ie. california's stupidity). Create real free markets for energy. When energy is in low supply, you should be forced to pay for it or cut back your usage.
2) Break down regulatory barriers to extensive cogeneration of heat and power in all states.
3) Reduce heat islanding and smog with more extensive use of trees and rooftop gardens in urban areas.
4) Use geothermal heat pumping more extensively, especially in large buildings, but also at residences.
Imagine if it were possible (ie. regulations didn't make it difficult) for companies to sell cogeneration plants and service contracts to hospitals, health clubs, office buildings, apartment complexes, and similar buildings. We'd probably cut our energy usage in half and the businesses would cut heating or cooling costs at the same time.
The real problem we have in the US is that we have only a few large companies like Duke and Enron, and soforth that control most of the distribution and generation capacity of the US, and they have politicians in their pockets. It's regulations that give us massively centralized energy generation with little price sensitivity.
Energy is cheap, as long as you don't count the amount of money we spend on wars in the middle east, california's taxpayer paid long term contracts, and the cost of nuclear fuel storage into the equation (for a few examples).
In other words the bill is cheap, but the costs are not reflected in the bill.
here's some more ideas you can google for:
Thermoacoustic refrigeration for natural gas liquifaction. (See LANL)
Hybrid multi-fuel diesel/natural gas engines that have low NOx emissions and low particulates.
Highly reflective roof materials to reduce heat islanding and cooling loads.
One of my favorite ideas for technology solutions is actually real-time automated distributed generation power marketplace (ie. a small local generator company can buy and sell power online with a data-logging power meter that enforces the contract)
We don't need more massive centralized power plants, we need more power plants in the basements of buildings WHERE THE ELECTRIC AND HEAT GENERATION POWER IS NEEDED.
that's my two cents.
Wind farms aren't all that...
Environmentally and economically there are good reasons to dislike them. They kill a lot of birds. They break down a lot, requiring a fair energy input to maintain, and they only work when the wind blows.
Here are some alternatives that may be better:
Cogeneration of heat and power. A decent quality diesel engine runs in a soundproofed enclosure. The coolant liquid runs through radiators in your house, or to a heat pump that heats your house. Electricity from the generator is sent back through your meter onto the grid. This works with TODAYS technology. Some states already allow it. It produces power at much higher fuel efficiency than centralized plants and its distributed nature allows reduced transmission loss and increased reliability.
Conservation: instead of building million dollar wind farms, change the way people consume energy. The biggest consumer is probably heating and cooling. Therefore, white roofs, and geothermal heat pumps are both probably going to save thousands of kilowatts vs. older heating and cooling techniques. White roofs considerably reduce heat gain during the summer.
Geothermal heat pumps use heat from groundwater to heat, and reject heat into the groundwater to cool. Much more efficient than regular heat pumps which are already quite efficient.
Combine this with cogeneration and you have a very attractive heating/cooling/power generation technique.
The life of a typical quality diesel engine is about 20-30,000 hours. Then it needs an overhaul then it gets another 20-30,000 hours. Some run as long as 40 or 50 thousand. This means that with a monthly service contract and overhauls every 3 years or so you can have high efficiency reliable distributed generation.
One engine will put out typically say 10 kilowatts of electric power, which will on average power 10 houses, though at peak times it might only power 1 house. A decent engine costs around $5000. It can burn the same #2 heating oil probably already in use for heating.
By running the cogeneration plants only during the appropriate peak heating/cooling/electric demands you could probably stretch the life of the engine to 10 years or so.
Schools, govt buildings, hospitals, gyms, apartment complexes, and other reasonably large energy consumers can usually do quite well with cogeneration units in their basements, making money off the power, and saving a bundle in heating or cooling (the reject heat can be used with the proper type of refrigeration unit to cool the building).
Plus this technique acts as a "backup" generator for power outages and bad weather situations.
Economically and environmentally speaking there are plenty of other responsible techniques for decreasing power requirements and increasing availability.
perhaps this article is biased so as not to report the good technical reasons against this project?
Stop watching TV. They'll be the only non-brainwashed portion of the population.
I think you picked an unfortunate set of examples. I think threads, statistics and basic undergraduate operating systems concepts are all so well understood at this point that instructors are really not necessary. There are several books that will teach you everything you want to know about all three.
Now take something like engineering thermodynamics. There are so many different ways to approach thermodynamics, and there are a ton of arbitrary experimentally derived constants (like emissivity of a material etc). If you want to learn to design a thermodynamic system such as a passive cooling system, or a chiller, or a thermoacoustic refrigerator or soforth, you'll definitely want lots of in-class, and in-lab experimental hands on experience.
When it comes to math, computer science, software engineering, natural language composition, ethics, economics, and soforth, you can learn most of the undergraduate topics via independent study, because they're all basically about learning to think. When it comes to engineering, physics, biology, chemistry, etc. beyond the basics you will need hands on experience and experimentation.
That isn't to say that instruction won't help you in all topics, just that for some topics it's more absolutely necessary than others.
You need ghostscript and pdflatex at a minimum.
ghostscript comes with ps2pdf, and pdflatex will make pdfs directly without dvips and ps2pdf.
That's the point. For some programs, you can choose client input to the server to intentionally create the worst case and cause the server to bog down.
GNU R an implementation of the "S" language is about as good as it gets for statistics.
For a matlab type clone there is octave, which won't run all the fancy toolkits, but then it doesn't cost $15,000 either.
If you need to do some heavy algebraic formula crunching to solve model equations, YACAS, Maxima, and Jacal are all good.
If anything, the data analysis arena is where Linux is completely taking over many labs. It's the hardware that's hard to talk with.
Oh and not to mention that Matlab, Mathematica, and S-Plus were all available under Linux last I checked. (proprietary of course)
Jones on stepping motors found via google
Seems like stepper motors are not that difficult to control. A simple darlington transistor, resistor, and diode are all that's needed for the driver, for the control circuitry I suggest Atmel AVR microcontrollers, some of them have built in A/D etc, they're cheap, and they are programmable via GNU C compilers available under linux.
Get a Dontronics rAVeR to run the control circuit.
An AVR running at 10 mhz gives you a lot of processing power, and plenty of i/o to step 2 motors forwards and backwards. The main question is how to tell the AVR what to do.
It depends on how complicated your control algorithm is, ie. do you just need to run through a set of rote steps, or are you doing feedback control, or responding to the outside world?
If you're doing feedback control, then get an AVR with A/D channels built in, if you're responding more complicatedly then perhaps use the sound card output of your computer to tell the AVR what to do?
Admittedly all of this is likely more trouble than installing windows and writing your software in VB, but once you've done it, you've got a system that you can have some control over vs. an off the shelf solution from a non-responsive vendor (ie. there's not necessarily a guarantee that the thing works all that well under windows either)
Plus, with this kind of experience you will rapidly find other uses for a general purpose microcontroller platform, you'll be able to bypass buying expensive proprietary PCI cards and build some of the simpler control systems you need yourself.
NOTE: if you're building things yourself you have to deal with debugging the hardware and the software. Keep focused on the cost to benefit ratio of doing it yourself vs. buying off the shelf. Remember you're trying to do research, which means you need the flexibility of do-it-yourself, but you've also got a hard enough time doing the research, so adding hardware design and debugging on top is added hassle.
Getting an undergraduate electronics engineer to work with you for work-study credit is probably a good idea.
How hard would it be to get a couple of Atmel AVR chips and control the damn thing via hardware that you can program from linux using GNU tools?
Just talking off the top of my head, but if you're talking about sending the proper number of pulses at the proper times wouldn't it be relatively easy via a little board like the dontronics rAVeR?
Running at 10 mhz it seems like you'd be able to do a lot with one of these puppies.
I don't know how much intelligence is in the signals vs. in the motors, so i don't know whether it's as easy as it seems. Probably not, but it's worth stepping back from the problem perhaps.
Sorry. I sort of glossed over the main point, which is that even under normal conditions, a reasonable AC unit is still 300% efficient (ie. energy efficiency rating of 9 BTU/hr / watt, which is about 2.6 watts of heat removal / watt of electricity).
The groundwater is just a way to make them EVEN MORE efficient.
This isn't right. You've got the carnot cycle upside down. You want to know how much heat can be transferred per unit of work input, not how much work can be generated per unit of heat available.
A typical efficient air conditioner has an energy efficiency ratio of about 9, this means 9 BTU/hr per watt of electricity used.
or about 2.6 watts of heat extracted from the cold side per watt of electricity consumed.
You can see that your calculation is wrong because it predicts higher efficiency when you pump up a larger gradient, in other words if you are trying to pump heat out of my room directly into the sun's surface it would predict a very high efficiency, obviously the wrong formula.
The formula you've given is for the efficiency of a heat engine trying to extract work from a temperature differential, not for a refrigeration system trying to extract heat using work.
The internet to the rescue: Hyperphysics shows some information on heat pumps.
A typical efficiency is therefore about 300%, whereas if you use the air conditioner to pump heat into ground water (ie. use the earth as a heat sink) you can get very high efficiency, in that case you're acting like a heat pump, ie. heating ground water from a high temperature room.
If the inverse carnot equation held and you had ground water at 55F (286K) and air at 95F (308K), you'd get about 1300% efficiency.
This is clearly the best way to cool your house, use a heat pump to pump heat out of your room into the earth.