But if they're not gimbaled a huge amount of energy will be wasted fighting precession as the earth rotates.
You don't need to gimbal them. If oriented correctly you can draw energy from the rotation of the earth to fight the precession effects. Basically nearly all of the force that keeps the axis aligned is transmitted through the mounting, and only tiny amounts will be derived from the rotation. Induced currents will be a more significant source of losses.
See my post above. Windmills used to be used in hybrid (wind+gasoline generation, flywheel+gravity storage) designs, back before we all had electricity at home.
Basement flywheels have been considered for solar or wind energy storage, but as with any energy storage, if the energy is released suddenly in a small volume, you've got a bomb on your hands. You certainly wouldn't want to skimp on maintenance for such a device.
Flywheels used to be used for energy storage on farms before electrification. Often for pumping ground water. The classic farm windmill would be hooked to a gas motor with a flywheel and a pump. The motor had a governor to cut the fuel/air intake and spark if the flywheel was above a specific RPM. In no wind, and no pumping load, the motor might fire every 100 revolutions. If the wind was fast enough the motor might not fire at all. When pumping was needed energy would first be extracted from the flywheel, then the motor would start firing. Pumping moved the water to secondary energy storage (a water tower). Of course, it's all done with electric motors now.
Yes, there will be dissipative currents in the flywheel itself and the surrounding structure if it is conductive, unless the flywheel is superconducting. You also need a means to input and extract the energy. That could be done through the suspension magnets, or through smaller magnets on the flywheel, and coils on the structure. There will be some losses there as well. Probably more loss than a capacitor bank, but less than a bank of batteries.
Water is the important component to plate tectonics. Venus, which has no water, has no active volcanism or plate tectonics, yet has a significantly denser atmosphere than we do despite being about the same size.
So you're telling me you understand every feature of MS Word (or Open Office for that matter), all of the principles of both corporate and academic style/formatting/typesetting, and can apply them without a second thought?
Yes. I prepare documents for publication all the time. The style/formatting/typesetting requirements vary by publisher, so it's the publisher's rules that matter, not the rules you find in a book on MS Word.
Or in the case of Excel, you know all of the available functions, and how to produce effective visuals from the resulting data, and can apply this knowledge to any task without so much as a reference guide?
Not necessarily all of the available functions, but the ones I need. A function list is available in help, if I need something I don't know the mangled name for. It's impossible to produce effective visuals in Excel. Excel graphs are only useful for near real time updates when data changes. For publication you need to export the data and use a real plotting package.
And you know all of this without having either taken a course or studied it on your own time?
Yes, unless you consider using Word and Excel in my own projects to be "studying it on your own time". I'm not suggesting that high school kids shouldn't know this stuff. I'm suggesting that if they don't know it already by the time they are in high school, most of the time it's probably not going to do any good to try to teach it to them now.
Who in their right minds wants to use a spreadsheet application?
Spreadsheets do have their place in the scientific and engineering world. If your desired output is a table that can be computed in place, use a spreadsheet. If your inputs need to be entered by hand into a table, use a spreadsheet, even if only for the inputs to be exported as CSV. I've used spreadsheets to compute model stellar atmospheres, to solve differential equations numerically, to compute efficiencies for optical systems, to perform error analysis for any number of experiments, to model electrical circuits, to model digital logic, to track engineering change orders, to track component orders and deliveries, to prepare budgets... Spreadsheets are useful tools, but they shouldn't be the only one in a tool chest.
I manage this despite having no training on use of spreadsheets, or ever having owned a book about spreadsheets. I'm sure there are features that I don't know how to use, but thus far it's been easier to use another tool than to learn those features.
I had a (well known and respected) professor in college who used to use spreadsheets to build neural networks.
That seems to be common in some fields. I was collaborating with some folks at a medical school on time series analysis methods. All of the data files I sent them were to large for Excel.:(
I heard that before 1955, temperatures weren't measured in quite the same way as they are now, so historical data from before that time is invalid.
You may have heard it, but that doesn't make it true. Even if it were there are a large number of temperature proxies with which to calibrate the pre-1955 temperatures. In addition there is this thing called error analysis which allows us to take into account any uncertainty in the temperature record.
Luckily we got other scientists who can tell us for sure what weather we'll have 10 or even 100 years from now.
Posting anonymously and too stupid to understand the difference between weather and climate. Do I really need to respond to the rest? You already know you're wrong about all that stuff, except for the glacier prediction, which was an error in a summary and not part of the scientific portion of the report. I haven't heard about this burning well prediction, but I'm pretty sure it wasn't a consensus of climate scientists like global warming is. And the CO2 level was 40% lower before we got here. So learn something, and post non-anonymously next time.
Actually, if he's in a college town, just go sit in on some college courses. Not for CS, though. Depending on where you are, the home town college might not be very good. I've always been in the "introductory programming is best self taught" camp. A bad intro course can do real damage. Back in the day comp.std.c was the best textbook for C programming, and comp.lang.c was the best "what not to do" reference. Save the courses for the hard stuff (algorithms, operating systems, etc).
If you've got a computer at home, and your kid can't use a word processor by high school, then something is wrong. Even more so, I think something is very wrong when we need courses to teach people to word process or use a spreadsheet. If you need a course to teach something, you must not want to do it very much.
No, he's calling someone who thinks using a word processor is computer science stupid. Home schooled kid aren't necessarily stupid. They're not necessarily smart either.
An Apple IIe with an assembler, and a few compilers. Or an IBM XT with the same. Give it to them with some old books and tell them to do something fun with it.
That should keep them out of your hair for a while. Isn't that the whole point of a home school curriculum?
Plus people can move. I don't see way that's a problem.
Are you rich or just an asshole? It's hard to move when all of your equity is in a house nobody will buy because it's going to be below sea level. It's hard to move when most of the country you live in will be underwater. So as long as you'll be fine it's OK?
Just like last year was the worst year for hurricanes ever.
He said storms, not hurricanes. Hurricane formation relies on having very still air and water in the tropics. A very small breeze can screw that up.
It's better to use the number of named storms as an indicator. Even that won't rise monotonically any more than the temperature will. But last year had 19 named storms in the Atlantic, which is nearly twice the 1966-2009 average (11). It also had 12 hurricanes which is twice the average for that period (6). It also had 5 major hurricanes which is more than twice the average (2). By any measure 2010 had a lot of tropical activity in the Atlantic.
To list a few... Temperature rises put additional strain on agricultural water supplies. Temperature rises increase topsoil erosion. Agriculture will move toward the poles as temperatures increase, but soils get worse toward the poles. There will be more summer deaths due to heat (which will exceed the lives saved due to warmer winters). Malaria and other tropical diseases are likely to spread to higher latitudes. There will be increased iceberg hazards to shipping. Sea levels will rise as the Greenland and Antarctic ice caps are reduced. Populations that rely on glacial melt water for agriculture or drinking use will have reduced supplies. Increased droughts, fires, and vegetation die off due to them. Extinction of some types of corals and destructions of the reefs they created. Extinction of some species that can't move to adapt. Massive migrations of refugees due to flooding of low lying regions. Possible disruptions to global trade, transport, energy supplies and labor markets, banking and finance, investment and insurance. Developing countries, some of which are already embroiled in military conflict, may be drawn into larger and more protracted disputes over water, energy supplies or food, all of which may disrupt economic growth at a time when developing countries are beset by more egregious manifestations of climate change.
Solar is already cheaper than nuclear. Paying people to ride exercise bikes to generate power would be cheaper than nuclear. Solar cells already have problems with chemicals used in manufacture and enormous water use (thousands of gallons per cell-watt). Large Photovoltaic plants shade a lot of ground. Solar thermal plants can be damaging to local wildlife. A realist knows that nothing is perfect and any means to generate power needs to be compared against the other options.
Yeah, it will stop. I anticipate extinction due to a combination of environmental damage and wars over the remaining resources within a few decade of that. I don't care as long as I'm rich as hell for the rest of my life.
I'm only guessing that if I injected you with large quantities of potassium chloride solution, you would die. Let's try it, because you wouldn't prevent me based upon my guess, right?
I know you're just another anonymous denialist troll, but can't you guys come up with some new lies at least? The benefit of the old lies, however, is that the responses to the are readily available.
"Global Warming" as an urgent crisis caused by human activity is a scam. Average temperatures haven't gone up in a decade and the climate models that the Global Warming alarmists are pointing to can't even accurately predict current conditions from historical data.
The primary driving factors of world wide climate (absent widespread volcanic activity, which is not cyclic and not predictable) are insolation and the oceans, not atmospheric CO2 levels.
Most fish farms aren't nearly as ecological as you might think. The problem is the food for carnivorous fish is made out of fish. That fish is caught by dragging big nets through the oceans. Or gill netting. Or is imported from places that have even worse fishing practices.
The only species for which fish farming makes sense is the vegetarian species. Tilapia and Chinese Carp are vegetarian. But unfortunately most farms supplement their vegetarian diet with fish meal.
Slashdot Mirror
But if they're not gimbaled a huge amount of energy will be wasted fighting precession as the earth rotates.
You don't need to gimbal them. If oriented correctly you can draw energy from the rotation of the earth to fight the precession effects. Basically nearly all of the force that keeps the axis aligned is transmitted through the mounting, and only tiny amounts will be derived from the rotation. Induced currents will be a more significant source of losses.
See my post above. Windmills used to be used in hybrid (wind+gasoline generation, flywheel+gravity storage) designs, back before we all had electricity at home.
Basement flywheels have been considered for solar or wind energy storage, but as with any energy storage, if the energy is released suddenly in a small volume, you've got a bomb on your hands. You certainly wouldn't want to skimp on maintenance for such a device.
Flywheels used to be used for energy storage on farms before electrification. Often for pumping ground water. The classic farm windmill would be hooked to a gas motor with a flywheel and a pump. The motor had a governor to cut the fuel/air intake and spark if the flywheel was above a specific RPM. In no wind, and no pumping load, the motor might fire every 100 revolutions. If the wind was fast enough the motor might not fire at all. When pumping was needed energy would first be extracted from the flywheel, then the motor would start firing. Pumping moved the water to secondary energy storage (a water tower). Of course, it's all done with electric motors now.
Yes, there will be dissipative currents in the flywheel itself and the surrounding structure if it is conductive, unless the flywheel is superconducting. You also need a means to input and extract the energy. That could be done through the suspension magnets, or through smaller magnets on the flywheel, and coils on the structure. There will be some losses there as well. Probably more loss than a capacitor bank, but less than a bank of batteries.
Since they start from a stop and will eventually end up stopped, the net effect on the rotation of the earth will be zero.
Water is the important component to plate tectonics. Venus, which has no water, has no active volcanism or plate tectonics, yet has a significantly denser atmosphere than we do despite being about the same size.
Try posting in a non-anonymous mode. The mods are less likely to think you are trolling.
So you're telling me you understand every feature of MS Word (or Open Office for that matter), all of the principles of both corporate and academic style/formatting/typesetting, and can apply them without a second thought?
Yes. I prepare documents for publication all the time. The style/formatting/typesetting requirements vary by publisher, so it's the publisher's rules that matter, not the rules you find in a book on MS Word.
Or in the case of Excel, you know all of the available functions, and how to produce effective visuals from the resulting data, and can apply this knowledge to any task without so much as a reference guide?
Not necessarily all of the available functions, but the ones I need. A function list is available in help, if I need something I don't know the mangled name for. It's impossible to produce effective visuals in Excel. Excel graphs are only useful for near real time updates when data changes. For publication you need to export the data and use a real plotting package.
And you know all of this without having either taken a course or studied it on your own time?
Yes, unless you consider using Word and Excel in my own projects to be "studying it on your own time". I'm not suggesting that high school kids shouldn't know this stuff. I'm suggesting that if they don't know it already by the time they are in high school, most of the time it's probably not going to do any good to try to teach it to them now.
Yeah, well most people have trouble adding two numbers with a pocket calculator. That's part of why most people aren't suited for a CS education.
Who in their right minds wants to use a spreadsheet application?
Spreadsheets do have their place in the scientific and engineering world. If your desired output is a table that can be computed in place, use a spreadsheet. If your inputs need to be entered by hand into a table, use a spreadsheet, even if only for the inputs to be exported as CSV. I've used spreadsheets to compute model stellar atmospheres, to solve differential equations numerically, to compute efficiencies for optical systems, to perform error analysis for any number of experiments, to model electrical circuits, to model digital logic, to track engineering change orders, to track component orders and deliveries, to prepare budgets... Spreadsheets are useful tools, but they shouldn't be the only one in a tool chest.
I manage this despite having no training on use of spreadsheets, or ever having owned a book about spreadsheets. I'm sure there are features that I don't know how to use, but thus far it's been easier to use another tool than to learn those features.
I had a (well known and respected) professor in college who used to use spreadsheets to build neural networks.
That seems to be common in some fields. I was collaborating with some folks at a medical school on time series analysis methods. All of the data files I sent them were to large for Excel. :(
I heard that before 1955, temperatures weren't measured in quite the same way as they are now, so historical data from before that time is invalid.
You may have heard it, but that doesn't make it true. Even if it were there are a large number of temperature proxies with which to calibrate the pre-1955 temperatures. In addition there is this thing called error analysis which allows us to take into account any uncertainty in the temperature record.
Luckily we got other scientists who can tell us for sure what weather we'll have 10 or even 100 years from now.
Posting anonymously and too stupid to understand the difference between weather and climate. Do I really need to respond to the rest? You already know you're wrong about all that stuff, except for the glacier prediction, which was an error in a summary and not part of the scientific portion of the report. I haven't heard about this burning well prediction, but I'm pretty sure it wasn't a consensus of climate scientists like global warming is. And the CO2 level was 40% lower before we got here. So learn something, and post non-anonymously next time.
Actually, if he's in a college town, just go sit in on some college courses. Not for CS, though. Depending on where you are, the home town college might not be very good. I've always been in the "introductory programming is best self taught" camp. A bad intro course can do real damage. Back in the day comp.std.c was the best textbook for C programming, and comp.lang.c was the best "what not to do" reference. Save the courses for the hard stuff (algorithms, operating systems, etc).
If you've got a computer at home, and your kid can't use a word processor by high school, then something is wrong. Even more so, I think something is very wrong when we need courses to teach people to word process or use a spreadsheet. If you need a course to teach something, you must not want to do it very much.
No, he's calling someone who thinks using a word processor is computer science stupid. Home schooled kid aren't necessarily stupid. They're not necessarily smart either.
An Apple IIe with an assembler, and a few compilers. Or an IBM XT with the same. Give it to them with some old books and tell them to do something fun with it.
That should keep them out of your hair for a while. Isn't that the whole point of a home school curriculum?
Current sea level measurements indicate that the worst case might be the best we can hope for.
Sea level measurements have been consistently over estimated for years.
We've got very good measurements of sea level. It's rising.
Plus people can move. I don't see way that's a problem.
Are you rich or just an asshole? It's hard to move when all of your equity is in a house nobody will buy because it's going to be below sea level. It's hard to move when most of the country you live in will be underwater. So as long as you'll be fine it's OK?
Just like last year was the worst year for hurricanes ever.
He said storms, not hurricanes. Hurricane formation relies on having very still air and water in the tropics. A very small breeze can screw that up. It's better to use the number of named storms as an indicator. Even that won't rise monotonically any more than the temperature will. But last year had 19 named storms in the Atlantic, which is nearly twice the 1966-2009 average (11). It also had 12 hurricanes which is twice the average for that period (6). It also had 5 major hurricanes which is more than twice the average (2). By any measure 2010 had a lot of tropical activity in the Atlantic.
Why? Why is a 4C temperature rise necessary bad?
To list a few... Temperature rises put additional strain on agricultural water supplies. Temperature rises increase topsoil erosion. Agriculture will move toward the poles as temperatures increase, but soils get worse toward the poles. There will be more summer deaths due to heat (which will exceed the lives saved due to warmer winters). Malaria and other tropical diseases are likely to spread to higher latitudes. There will be increased iceberg hazards to shipping. Sea levels will rise as the Greenland and Antarctic ice caps are reduced. Populations that rely on glacial melt water for agriculture or drinking use will have reduced supplies. Increased droughts, fires, and vegetation die off due to them. Extinction of some types of corals and destructions of the reefs they created. Extinction of some species that can't move to adapt. Massive migrations of refugees due to flooding of low lying regions. Possible disruptions to global trade, transport, energy supplies and labor markets, banking and finance, investment and insurance. Developing countries, some of which are already embroiled in military conflict, may be drawn into larger and more protracted disputes over water, energy supplies or food, all of which may disrupt economic growth at a time when developing countries are beset by more egregious manifestations of climate change.
Solar is already cheaper than nuclear. Paying people to ride exercise bikes to generate power would be cheaper than nuclear. Solar cells already have problems with chemicals used in manufacture and enormous water use (thousands of gallons per cell-watt). Large Photovoltaic plants shade a lot of ground. Solar thermal plants can be damaging to local wildlife. A realist knows that nothing is perfect and any means to generate power needs to be compared against the other options.
Yeah, it will stop. I anticipate extinction due to a combination of environmental damage and wars over the remaining resources within a few decade of that. I don't care as long as I'm rich as hell for the rest of my life.
I'm only guessing that if I injected you with large quantities of potassium chloride solution, you would die. Let's try it, because you wouldn't prevent me based upon my guess, right?
"Global Warming" as an urgent crisis caused by human activity is a scam. Average temperatures haven't gone up in a decade and the climate models that the Global Warming alarmists are pointing to can't even accurately predict current conditions from historical data.
For global records, 2010 is the hottest year on record, tied with 2005. Satellites provide unmistakable evidence that the Earth has been warming for the past 30 years. Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean.
The primary driving factors of world wide climate (absent widespread volcanic activity, which is not cyclic and not predictable) are insolation and the oceans, not atmospheric CO2 levels.
In the last 35 years of global warming, sun and climate have been going in opposite directions. The oceans are warming because of atmospheric CO2 and moreover are becoming more acidic, threatening the food chain.
Feel free to lie to yourself, but please don't lie to us.
Most fish farms aren't nearly as ecological as you might think. The problem is the food for carnivorous fish is made out of fish. That fish is caught by dragging big nets through the oceans. Or gill netting. Or is imported from places that have even worse fishing practices.
The only species for which fish farming makes sense is the vegetarian species. Tilapia and Chinese Carp are vegetarian. But unfortunately most farms supplement their vegetarian diet with fish meal.
http://news.stanford.edu/news/2009/september7/woods-fishfarm-study-090709.html