Bare numbers? You can't do simply use cost/pupil-year that the building will remain standing as a metric.
For example. Spend 78 million on a new building, have 500 million left over.
Invest this with a return of 8%.
The returns will allow you to hire well over 500 extra staff.
And in 20 years, your initial 500 million is now around 1.2 billion.
Inflation will have torn into that somewhat - but you can still easily afford to knock the school down and build a new one.
I would also suggest that the students would perform far, far, far better with a student-teacher ratio of around 5:1 that this would enable than the tiny effect of a shiny building.
Not quite. For example - face recognition plus "now smile" "now frown" - required the attacker to be using some sort of video system.
Face recognition plus a short list of words that the user has assigned an emotion - for example - the phone displays in sequence the words Fish (erman drowned) = frown Localsportsteam (won) = smile...
It comes in a 6*6mm package, with under 5 tiny cheap external components required, simply adds onto the I2C bus present in most all phones, and the total price at 100K is around $1.2. The operating current is at 10mA typically a small fraction of the power needed to decode mp3, and when unused it draws essentially no power.
In newer chipsets, it tends to come along for free, as it's integrated into many bluetooth chipsets these days.
mplayer - 60% CPU at 500MHz. 460mA. This is software.
Built in player. 30% CPU at 500MHz. 270mA. This is hardware.
Or - around a half more to do it in software.
However. This is pretty much the worst case.
If you up the brightness to max - then it's more like an extra third (120mA is added on in both cases).
With brightness at max, and streaming the video over 3G - it's under an extra quarter.
Technically, with integrated hardware decoders - playing video can be remarkably inexpensive. Playing video with no sound at minimum brightness uses around 50mA more - around an additional 5% of the battery an hour over just having the system idle.
But - especially for the original questioner - this isn't very interesting information, as 3G or screen brightness will often swamp this.
There are some good reasons why they are potentially safer than some ohter designs though.
For example, the fact that the engines are runup and develop full thrust while the vehicle is still tied down, and can be shut down if they do not perform to spec removes a large slice of hazard.
As of this moment. 64K momo - BBC World Service, Premier Christian, Talk Sport, UCB christian, Shared access, Amazing Radio, BBC Asian 80K mono - BBC Radio 5 live, BBC radio 7
96K mono - NME Radio UK.
112K stereo - Heat radio, Magic,
128K stereo - BBC Radio 1/1xtra/ 2/ 4/Scotland/BFBS, Planet Rock/6Music , Tay AM, Tay FM, Absolute 80s, Absolute, Gaelic
160K stereo - Classic FM
192K stereo - BBC Radio 3
I note that 4 of the 64K stations were broadcasting music. That managed to sound bad on my 3" mono DAB radio.
Even 128K can sound _lots_ worse than FM.
On some programming, this is not a subtle effect, and mp3 at 128K is much, much better.
My personal listening is largely on DAB. Simply as I rarely listen to radio as more than a background, and much is speech based.
And I have one of these - http://www.radio-now.co.uk/pure_oasis.htm - which is awesome - 13h battery life, and I can drop bricks on it in the rain, and it carries on working.
To expand on this. It's not only petroleum, it's all the commodities from steel to cocoa.
The elephant in the room that everyone is studiously ignoring while it begins to munch on the Canapés is that 'we' are currently living off several centuries of investment.
In 'the west' - since around the beginning of the industrial revolution, we have been putting down infrastructure that enables us to compete now - somewhat - on a global scale with other countries with vastly lower labour costs.
The somewhat is there now - due to the truly massive amount of money that is owed to china and other countries.
The standard of living in china/india/... is rising.
Not for everyone, but probably for a majority.
As the incomes in the developing world rise, their purchasing power for global commodities for their own markets rises. And the cost of their labour to the 'west' skyrockets.
This leads to a 'perfect storm'.
Currently all major manufacturing - with some exceptions - is offshore, as it's cheaper.
Imagine that nothing is done.
Chinas economy takes off, and keeps experiencing double digit growth for a couple of decades, due to growth of an internal market. Perhaps india does similar. (the same argument works if it's slower over 50 years).
The purchasing power of the west for all commodities including oil plummets.
If we're spending - now - 5% of GDP on oil, and then the demand for oil rises hugely, while US purchasing power drops, we could find ourselves spending 20% of GDP on oil, at the very same time that we're frantically trying to move our heavy industry back onshore.
The time to act is now - when we are doing well. We need to reduce fuel imports - and other commodities - not because of the environment - but because in well under a couple of generations we won't be able to afford them.
If we can halve fuel imports - then that means that we do not have to spend precious - and increasingly more so - foreign currency on fuel.
My personal view is that a truly massive nuclear building program is the sensible way out.
Truly massive as in large enough to completely replace all of the electricity generation, and to move all fixed consumers of oil/gas onto electricity.
We have only a limited time to do this, before our purchasing power that would make this 'easy' runs out with the world.
This is however substantially different to sailing. Sailing uses an aerofoil with a high lift/drag ratio.
This works when the wind is not directly ahead of you. When a sailboat - nomatter how advanced - tries to sail directly into the wind - it goes backwards.
This contraption however can go forward directly into a headwind.
(Indeed it wouldn't be as efficient on the water, as you would need a somewhat lossy water-screw too, instead of nice low-loss wheels - to act as the 'reference' for the 'differential'.
Firstly, ignore that it's moving. You have 0m/s ground, and a 10m/s wind.
You put up a wind turbine - it can extract power from this 10m/s difference.
The funky part of this idea is that this still works when you're moving faster than 10m/s.
For the moment - imagine that the turbine is a pure 'airscrew'.
It describes a helix in space - like the DNA molecule. For every meter the air moves "forward" relative to it, it turns 1m clockwise. Considering the air as completely rigid for the moment, the airscrew goes forward in a rigid helix, unchanged by load.
So - 10m/s wind - airscrew turns at 10m/s. Simple. You can extract - say - 100N * 10m/s = 1kW of power.
Funky part coming up.
Now. You're moving at 20m/s. Twice as fast as the wind. Of course this will slow you down - you can't use this to make power!
Well - not quite.
If you are moving at 20m/s in the direction of the wind - for a total speed with regards to the wind of 30m/s then the blades need to be spinning at 30m/s in order to keep up.
But, you can use gearing from the wheels so that the 'base' speed of this spin is 20m/s.
That is - when you push the car along on a windless day - the airscrew creates no drag - because it is spun at exactly the right speed by gearing from the wheels. It has effectively - by rotating at the right speed - cancelled out the movement of the car.
This cancellation then allows you to ignore the speed of the car, and instead work off the speed difference between the wind and ground!
In reality - it's very far from an airscrew, and turbines have a lot of drag. It's the same basic concept though.
Another beautiful and 'obvious' when you think of it bit of physics.
Doing the wear leveling this way drastically reduces the amount of CPU and other data storage you need to keep track of where the blocks are.
The OLPC project http://wiki.laptop.org/go/NAND_Testing#SD_Cards - did some interesting tests, writing and rewriting two 20M files. This failed in one SD of 6 tested, at 16terabytes written.
The wear leveling algorithms of 99.9% of flash devices are not public. You don't know what the wear leveling span was in the above test. It may reasonably have been a thousand eraseblocks - 130M or so. This will mean that the actual writes per block were on the order of 12 million. This is not a completely surprising number to me for the ~5% of the spare blocks in the wear leveling block to have been used.
Unfortunately, the secrecy means that the chip you order next week may perform differently.
If the terrain is hilly - then working out that there is a overall 4"/mile^2 curve is hard when the terrain might go up and down a thousand times that.
This is pretty much the state we're in at the moment - most measurements are in the 'local area' - and they all seem to not contradict the model of the flat earth - to within the limits of experimental error.
Anyone suggesting the earth is spherical may get 'Hmm - interesting theory - can you prove it?' - and they can't - as there is no data.
It's been known for a long time that the standard model has problems. To continue your analogy.
The earth is flat works really well as a model. If you're in a hilly terrain, you might suspect early on that the flat earth model isn't quite right.
To find out that earth is actually a slightly disorted sphere with a radius of some 6000km means that you have to go quite far (distance wise) to realise that the errors in the flat-earth model actually add up to a coherent alternative theory - a spherical earth.
It's much like this in physics.
Saying 'the standard model is wrong' - and giving plausible arguments - doesn't give much for alternative theorists to get their teeth into.
If however, you can produce a concrete measurement that can say 'The standard model is off by 0.3% here, 0.6% here, 1.2% here, and this looks _really_ like a curve of 0.5x+x^2 in the energy/bias ratio' - this can eliminate whole classes of alternate theories.
At the moment, string theory (and the descendant fields) suffer from an embarrasment of possibilities. There are people arguing that the world is flat, round, toroidal, duck-shaped,...
These theories are generally internally consistent, and can only be proved wrong with measurements of the real world. Without these measurements, the theories are interesting maths that you can make a career in maths about, but not predict the world in a useful way.
To drag this off-topic - Gore may have helped the internet to win.
It diddn't have to. If prodigy/compuserve/AOL - and the giants of yore - had gotten mail between them working without the use of the internet, a large driver of the internet dies. At one point, the internet, and other corporate networks that were poorly connected to each other - were growing rapidly.
These networks did not always run tcp/ip - for example AOL.
Gore helped (in some degree) get the legislation that encouraged the internet to grow a bit faster at that crucial period.
If it hadn't grown as fast, we might have ended up with something like http://en.wikipedia.org/wiki/Minitel - driven by a conglomerate formed by a merger of several of the large ISPs.
Oh - and maybe the internet may be kicking around as a research project still, or in use in academia.
Fundamentally - if you manage to get users locked into a platform that serves them - getting tehm to switch, and break all their applications is hard.
'Invented the internet' - clearly not. 'Had a vital role in making the internet win' - maybe.
Putting the parts of a DIY aid together in the package - not a problem. Getting it to work for more than an hour on a battery in the same package - problem. OTOH - something like a BT headset, with a shirt-pocket mounted audio sender might work OK.
Total output from distillation column 2,257,710.0000 MJ
Run away, run far away!
These are not test results.
These are at best numbers from someone who has taken a wild stab at a reasonable output for the maximum theoretical output of an _ENERGY_CONSUMING_ process, and someone else who has done a writeup based on these numbers at best not understanding this, at worst fraudulently.
These are _HOPELESSLY_ optimistic. It's assuming 100% of the carbon is converted into useful fuel oil.
Slashdot Mirror
Bare numbers?
You can't do simply use cost/pupil-year that the building will remain standing as a metric.
For example.
Spend 78 million on a new building, have 500 million left over.
Invest this with a return of 8%.
The returns will allow you to hire well over 500 extra staff.
And in 20 years, your initial 500 million is now around 1.2 billion.
Inflation will have torn into that somewhat - but you can still easily afford to knock the school down and build a new one.
I would also suggest that the students would perform far, far, far better with a student-teacher ratio of around 5:1 that this would enable than the tiny effect of a shiny building.
Not quite.
For example - face recognition plus "now smile" "now frown" - required the attacker to be using some sort of video system.
Face recognition plus a short list of words that the user has assigned an emotion - for example - the phone ...
displays in sequence the words
Fish (erman drowned) = frown
Localsportsteam (won) = smile
Or gaze tracking on a virtual keyboard.
In many cases it's completely impossible to accurately determine the speed that you will get before the equipment is actually installed.
Modern receivers are small, cheap and low power to integrate.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TEA5767HN/V3,118-ND - for example is a FM radio chip.
It comes in a 6*6mm package, with under 5 tiny cheap external components required, simply adds onto the I2C bus present in most all phones, and the total price at 100K is around $1.2.
The operating current is at 10mA typically a small fraction of the power needed to decode mp3, and when unused it draws essentially no power.
In newer chipsets, it tends to come along for free, as it's integrated into many bluetooth chipsets these days.
Some numbers.
Nokia n900.
Medium brightness.
480x272 h264.
mplayer - 60% CPU at 500MHz. 460mA. This is software.
Built in player. 30% CPU at 500MHz. 270mA. This is hardware.
Or - around a half more to do it in software.
However. This is pretty much the worst case.
If you up the brightness to max - then it's more like an extra third (120mA is added on in both cases).
With brightness at max, and streaming the video over 3G - it's under an extra quarter.
Technically, with integrated hardware decoders - playing video can be remarkably inexpensive.
Playing video with no sound at minimum brightness uses around 50mA more - around an additional 5% of the battery an hour over just having the system idle.
But - especially for the original questioner - this isn't very interesting information, as 3G or screen brightness will often swamp this.
With the
Paragons of safety - certainly not.
There are some good reasons why they are potentially safer than some ohter designs though.
For example, the fact that the engines are runup and develop full thrust while the vehicle is still tied down, and can be shut down if they do not perform to spec removes a large slice of hazard.
Unfortunately, people are reading you correctly.
You state "Watts per Day * 0.00004167 will give you your coveted Kilowatt Hours. Enjoy."
This is incorrect.
Watts per day is a measure of power increase.
That is - my fridge uses at the moment around 41.66W average.
41.66W * 24 hours = 1000Wh.
This is a unit of energy, and coincidentally what I'm billed around 10p for.
As it's coming on to summer, the temperature in my kitchen is rising - and the consumption of the fridge is rising at 1 watt per day.
In 10 days, it'll be 51.66W, or 1240Wh every 24h.
To recast this back in distance units.
Your stated "Watts per Day * 0.00004167 will give you your coveted Kilowatt Hours. Enjoy." becomes
"mph per day * .0146 will give you your coveted miles. Enjoy"
DAB _can_ be 128K - but.
As of this moment.
64K momo - BBC World Service, Premier Christian, Talk Sport, UCB christian, Shared access, Amazing Radio, BBC Asian
80K mono - BBC Radio 5 live, BBC radio 7
96K mono - NME Radio UK.
112K stereo - Heat radio, Magic,
128K stereo - BBC Radio 1/1xtra/ 2/ 4 /Scotland /BFBS, Planet Rock/6Music , Tay AM, Tay FM, Absolute 80s, Absolute, Gaelic
160K stereo - Classic FM
192K stereo - BBC Radio 3
I note that 4 of the 64K stations were broadcasting music. That managed to sound bad on my 3" mono DAB radio.
Even 128K can sound _lots_ worse than FM.
On some programming, this is not a subtle effect, and mp3 at 128K is much, much better.
My personal listening is largely on DAB.
Simply as I rarely listen to radio as more than a background, and much is speech based.
And I have one of these - http://www.radio-now.co.uk/pure_oasis.htm - which is awesome - 13h battery life, and I can drop bricks on it in the rain, and it carries on working.
To expand on this.
It's not only petroleum, it's all the commodities from steel to cocoa.
The elephant in the room that everyone is studiously ignoring while it begins to munch on the Canapés is that 'we' are currently living off several centuries of investment.
In 'the west' - since around the beginning of the industrial revolution, we have been putting down infrastructure that enables us to compete now - somewhat - on a global scale with other countries with vastly lower labour costs.
The somewhat is there now - due to the truly massive amount of money that is owed to china and other countries.
The standard of living in china/india/... is rising.
Not for everyone, but probably for a majority.
As the incomes in the developing world rise, their purchasing power for global commodities for their own markets rises.
And the cost of their labour to the 'west' skyrockets.
This leads to a 'perfect storm'.
Currently all major manufacturing - with some exceptions - is offshore, as it's cheaper.
Imagine that nothing is done.
Chinas economy takes off, and keeps experiencing double digit growth for a couple of decades, due to growth of an internal market. Perhaps india does similar. (the same argument works if it's slower over 50 years).
The purchasing power of the west for all commodities including oil plummets.
If we're spending - now - 5% of GDP on oil, and then the demand for oil rises hugely, while US purchasing power drops, we could find ourselves spending 20% of GDP on oil, at the very same time that we're frantically trying to move our heavy industry back onshore.
The time to act is now - when we are doing well. We need to reduce fuel imports - and other commodities - not because of the environment - but because in well under a couple of generations we won't be able to afford them.
If we can halve fuel imports - then that means that we do not have to spend precious - and increasingly more so - foreign currency on fuel.
My personal view is that a truly massive nuclear building program is the sensible way out.
Truly massive as in large enough to completely replace all of the electricity generation, and to move all fixed consumers of oil/gas onto electricity.
We have only a limited time to do this, before our purchasing power that would make this 'easy' runs out with the world.
There is clearly one easily accessible way to describe 100 petabytes of data.
'The same information content as half a pint of sperm.'
This is however substantially different to sailing.
Sailing uses an aerofoil with a high lift/drag ratio.
This works when the wind is not directly ahead of you.
When a sailboat - nomatter how advanced - tries to sail directly into the wind - it goes backwards.
This contraption however can go forward directly into a headwind.
(Indeed it wouldn't be as efficient on the water, as you would need a somewhat lossy water-screw too, instead of nice low-loss wheels - to act as the 'reference' for the 'differential'.
Firstly, ignore that it's moving.
You have 0m/s ground, and a 10m/s wind.
You put up a wind turbine - it can extract power from this 10m/s difference.
The funky part of this idea is that this still works when you're moving faster than 10m/s.
For the moment - imagine that the turbine is a pure 'airscrew'.
It describes a helix in space - like the DNA molecule.
For every meter the air moves "forward" relative to it, it turns 1m clockwise.
Considering the air as completely rigid for the moment, the airscrew goes forward in a rigid helix, unchanged by load.
So - 10m/s wind - airscrew turns at 10m/s. Simple.
You can extract - say - 100N * 10m/s = 1kW of power.
Funky part coming up.
Now. You're moving at 20m/s. Twice as fast as the wind.
Of course this will slow you down - you can't use this to make power!
Well - not quite.
If you are moving at 20m/s in the direction of the wind - for a total speed with regards to the wind of
30m/s then the blades need to be spinning at 30m/s in order to keep up.
But, you can use gearing from the wheels so that the 'base' speed of this spin is 20m/s.
That is - when you push the car along on a windless day - the airscrew creates no drag - because it is spun at exactly the right speed by gearing from the wheels. It has effectively - by rotating at the right speed - cancelled out the movement of the car.
This cancellation then allows you to ignore the speed of the car, and instead work off the speed difference between the wind and ground!
In reality - it's very far from an airscrew, and turbines have a lot of drag. It's the same basic concept though.
Another beautiful and 'obvious' when you think of it bit of physics.
Tapping generation after generation?
Isn't that why they went into rock?
By volume sold, I was meaning.
There are a half-dozen at most high volume vendors.
The nokia N900's root filesystem is ubifs - and hence the wear leveling algorithm is public - this is part of the .1%
You are implicitly assuming that the wear leveling algorithm spans the whole device.
That is - a write to block 407 will have the wear evenly distributed.
There are several issues here.
Firstly - eraseblocks are typically around 150K or so.
Secondly - http://www.mail-archive.com/linux-kernel@vger.kernel.org/msg170028.html - many flash devices may wear level only on 'zones'. So a write to block 407 may only wear level across .5% of the device.
Doing the wear leveling this way drastically reduces the amount of CPU and other data storage you need to keep track of where the blocks are.
The OLPC project http://wiki.laptop.org/go/NAND_Testing#SD_Cards - did some interesting tests, writing and rewriting two 20M files.
This failed in one SD of 6 tested, at 16terabytes written.
The wear leveling algorithms of 99.9% of flash devices are not public. You don't know what the wear leveling span was in the above test. It may reasonably have been a thousand eraseblocks - 130M or so.
This will mean that the actual writes per block were on the order of 12 million.
This is not a completely surprising number to me for the ~5% of the spare blocks in the wear leveling block to have been used.
Unfortunately, the secrecy means that the chip you order next week may perform differently.
If the terrain is hilly - then working out that there is a overall 4"/mile^2 curve is hard when the terrain might go up and down a thousand times that.
This is pretty much the state we're in at the moment - most measurements are in the 'local area' - and they all seem to not contradict the model of the flat earth - to within the limits of experimental error.
Anyone suggesting the earth is spherical may get 'Hmm - interesting theory - can you prove it?' - and they can't - as there is no data.
It's been known for a long time that the standard model has problems.
To continue your analogy.
The earth is flat works really well as a model. If you're in a hilly terrain, you might suspect early on that the flat earth model isn't quite right.
To find out that earth is actually a slightly disorted sphere with a radius of some 6000km means that you have to go quite far (distance wise) to realise that the errors in the flat-earth model actually add up to a coherent alternative theory - a spherical earth.
It's much like this in physics.
Saying 'the standard model is wrong' - and giving plausible arguments - doesn't give much for alternative theorists to get their teeth into.
If however, you can produce a concrete measurement that can say 'The standard model is off by 0.3% here, 0.6% here, 1.2% here, and this looks _really_ like a curve of 0.5x+x^2 in the energy/bias ratio' - this can eliminate whole classes of alternate theories.
At the moment, string theory (and the descendant fields) suffer from an embarrasment of possibilities. ...
There are people arguing that the world is flat, round, toroidal, duck-shaped,
These theories are generally internally consistent, and can only be proved wrong with measurements of the real world. Without these measurements, the theories are interesting maths that you can make a career in maths about, but not predict the world in a useful way.
To get truly astonishing pictures, they should add a black pixel, to improve contrast.
To drag this off-topic - Gore may have helped the internet to win.
It diddn't have to.
If prodigy/compuserve/AOL - and the giants of yore - had gotten mail between them working without the use of the internet, a large driver of the internet dies.
At one point, the internet, and other corporate networks that were poorly connected to each other - were growing rapidly.
These networks did not always run tcp/ip - for example AOL.
Gore helped (in some degree) get the legislation that encouraged the internet to grow a bit faster at that crucial period.
If it hadn't grown as fast, we might have ended up with something like http://en.wikipedia.org/wiki/Minitel - driven by a conglomerate formed by a merger of several of the large ISPs.
Oh - and maybe the internet may be kicking around as a research project still, or in use in academia.
Fundamentally - if you manage to get users locked into a platform that serves them - getting tehm to switch, and break all their applications is hard.
'Invented the internet' - clearly not.
'Had a vital role in making the internet win' - maybe.
http://cgi.ebay.co.uk/KEYLLAMA-4-MB-PS2-PS-2-KEYLOGGER-KEY-LOGGER-PRIVATE-NEW-/170479007477?cmd=ViewItem&pt=PCA_Mice_Trackballs&hash=item27b15736f5 - the board inside most of these is around 10mm*20mm*3mm.
It will fit inside most (clients) laptops.
If you use their hardware, and they care enough, they can generally snoop your keyboard/mouse quite easily - display is a fair bit harder, and RAM still harder.
267dpi on n900 - the screen is only 3.5"
Linux has had this long ago.
http://www.complang.tuwien.ac.at/ulrich/mergemem/ - for example.
Note that the savings referred to are on kernel 2.0.33.
I used it on my 8M laptop - worked well.
Bluetooth headsets are small, and have been engineered to get several hours of battery life.
The power usage in the shirt-pocket side isn't really an issue.
Putting the parts of a DIY aid together in the package - not a problem.
Getting it to work for more than an hour on a battery in the same package - problem.
OTOH - something like a BT headset, with a shirt-pocket mounted audio sender might work OK.
Alas it's worse.
http://pesn.com/2010/02/19/959019_GPI_3rd-party_test_results_trash-to-fuel/material-energy%20balance%202010.pdf
Right.
Test results. Okaaaay.
Inputs totalling 2,257,710.0000 MJ.
Total output from distillation column 2,257,710.0000 MJ
Run away, run far away!
These are not test results.
These are at best numbers from someone who has taken a wild stab at a reasonable output for the maximum theoretical output of an _ENERGY_CONSUMING_ process, and someone else who has done a writeup based on these numbers at best not understanding this, at worst fraudulently.
These are _HOPELESSLY_ optimistic. It's assuming 100% of the carbon is converted into useful fuel oil.