The biggest problem with electric bikes in Europe is not technology but politicians. (in the UK, the Government still has not legalised the Segway, despite its obvious utility for post and packet delivery and beat policing.) Under EU regulations soon as an electric bike exceeds 250W, it is classed as a moped (i.e. max. 2200W). This is a huge gap, especially given that you can ride a horse (approx. 1kw and 750kg) on the roads with no legal controls. 250W is too little to be really useful.
A bicycle is unusable for most people where I live because our town is on the sides of a steep sided valley, and the combination of traffic going up the hills at 30mph, and cyclists at 3mph, on narrow English roads, is lethal. To be really useful, an electric bike needs to be able to go up those hills at 20mph.
If there was a political will for this, there would be a Europe-wide specification for an electric bicycle of, say, about 1200W maximum output and a continuous rating of 800, with a test and licence requirement but zero tax and a State-sponsored insurance scheme to overcome the objections of insurance companies, who detest anything new in the way of risk.
Of course there would be a need for new regulations - such as limiting them to 12mph on cycle tracks - but this is nothing that technology couldn't handle (e.g. a "cycle track mode" which flashes a green light, to assist law enforcement.) But an electric bicycle that was fast enough to be safe in European urban traffic would be vastly better than the current situation, where only the very fit can ride a heavy, limited electric bicycle on anything other than the level.
"Unglücklich das Land, das keinen Helden hat", entgegnet Galilei im Theaterstück, "Unglücklich das Land, das Helden nötig hat."
(Unlucky is the land that has no heroes....unlucky is the land that needs heroes". Sadly, the fact that the US has such a need of heroes points to something wrong in the US psyche. I have sometimes felt that the US need for heroes derives, in fact, from a fear caused by the lack of social security and medical security in the US. Social democracies like Sweden don't need heroes.
I would also add that sociological research says no such thing, and I challenge you to produce a list of reputable papers that suggest that IQ is not correlated with income or social class, other than popsci books.
You're doing a great job, and I'm impressed, but here is a bit of advice from someone in the UK who has in the past been responsible for training. Don't let what you're doing get in the way of getting the widest range of A levels at the highest grades you can reach, and consider NOT doing comp sci at University but doing something more like physics or business studies. The people Google allows to write kernel level code may be PhD-educated computer scientists, but you're already going down the route of thinking commercially, even if only to fund your project. You have started doing this too early to make me think you would be happy doing comp sci for 7 years before getting a job. Now think carefully: who do you want to be, Linus Torvalds or Mark Shuttleworth? You probably aren't going to be Torvalds; one is enough. In physics, the glorious days of Feynman and Dirac and Schroedinger, when it was all exciting and new, gave way to anonymous large teams. The same is happening to IT. But the industry has room for plenty of Shuttleworths, and that role gives you far more opportunity to do the things you want.
Your teachers almost certainly don't know nearly enough to be able to advise you. Ask around. But one thing to remember is this: even nowadays, a degree from a reputable university is necessary to open the door at any reputable company. The days when you could go straight from school to a computer company are gone because in those days there were no relevant degree courses (I know, I was there.) But I have never regretted NOT going straight to ICL but going to Cambridge instead.
(6/6 in modern countries). Experience with previous influenza variants showed that initially mild waves could be followed by very severe ones, as happened after WW1. Considering the number of people who died in the WW1 pandemic, a billion dollars or so is peanuts. It could easily have represented about $50 per life saved.
I had influenza in 1976. The 1976 strain was a variant of the current swine flu. It nearly killed me, an active person in his twenties of correct body weight who was running up to 6 miles a day. It took nearly 2 years before I was fully recovered. Based on personal experience, I do not think the reaction was alarmist. Influenza can be a major killer, and we simply do not know which strain will be the next one.
This demonstrates the European objection to GMO. It is not, as the manufacturers would like to suggest, a Luddite fear of new technology. It is a growing perception that there is no proper oversight of GMO development. In the US, the NIH acts as a counter to the pharmaceutical companies and does a lot of fundamental research. The GMO companies are perceived as being able to carry out inadequate trials, and not make their seeds and research sufficiently available to genuine independent researchers to ensure that the result is properly evaluated. (In the UK, the chief cheerleader for Monsanto is George Bush's pal Tony Blair, which goes a lot of the way to explain our concern. He's lied to us so often that now anything he promotes is immediately seen as being evil.)
During the 19th century the issue was contaminated food produced by the new breed of large processed food manufacturers: in the early 20th it was the meat packing industry. Now it's Monsanto. In the first two cases it turned out industry was unfit to regulate itself, and bribery of Government officials was rife. But nowadays we regard processed food manufacturers as mostly benign (well, except for the junk food industry), and nobody worries about tinned meat. Regulation in the end was good for the industry. Monsanto needs to stop pissing on anyone who suggests it isn't perfect, and start to come clean. It would be in its long term benefit.
For many years the UK Government claimed that it was safest to discharge tritium as tritiated water. That's because they were dumping loads of it in the North Sea and wanted to justify themselves. But in fact we argued that our plant was capable of discharging the (small amount of)waste as cold tritium gas mixed with nitrogen and argon, and the best thing to do was to blast it straight up a stack and let it diffuse away. Unofficially we were right, officially we were contrary to Government policy, and in this country (as under Bush) being right but contrary to policy gets you sacked.
I once worked in a plant that used tritium that went into a similar application, and worked with a radiological protection supervisor and a specialist from HSE. Even in a plant that uses the stuff, your risk of any significant exposure is negligible on the scale of health risks, way below mercury, radon, soot particles, potassium (which is radioactive), and medical X-rays. Since we stopped dumping the stuff into the North Sea in megacuries, it has become a non-issue.
Now, where does most of the release of mercury, radon, and soot come from? Ah. The mining and burning of fossil fuels (plus faulted granite in places like Cornwall and Scotland.)
Yup. Working with tritium made me very safety conscious. It made me a strong supporter of nuclear power as a replacement for all those nasty polluting technologies.
You are just repeating tabloid guff, so either you don't really live here or you just commute from your company flat to the office and watch television in the evenings.
I too can manage lazy stereotypes about many cultures - but I've worked in enough countries to know they are nonsense. And I know that the only people who complain about political correctness in the UK are private school educated drones working for right wing newspapers.
Actually that is the case, and they wouldn't. Policing in the UK varies with social context. In Northern Ireland and other Irish-heavy areas of the UK there is a huge culture of car crime and the police pay little attention to it. Communities won't identify or testify against the perpetrators. Elsewhere young male car crime often appears as a lesser offence - TWOCing (taking without consent.) Whereas in some places car theft will result in rapid detection and punishment.
This is because in the UK we do not have a written Constitution but we do have common law - so in the absence of intervention by the tabloids and the attention-seekers in Government, law evolves according to community expectations. If it was not for the tabloids and politicians, cannabis would have been de facto legalised in the South-West thirty years ago by lack of interest from police and magistrates.
I'm an admirer of Copernicus (my nick is his actual name) and the story is a lot more complicated than that. During the writing of de Revolutionibus Orbium Caelestium, Kupfernigk discovered that, owing to the greater accuracy of observations available to him, his system was becoming just as complicated as that of Ptolemaus. He was, as a good pre-scientist, well aware that he was building a mathematical structure on a theory which, like String Theory now, wasn't really testable. He was also living in a much more backward culture than was Galileo. His caution is natural.
The Eastern bloc was more backward even then. Kepler has to return in a hurry to Regensberg at one point to defend his mother who was accused of witchcraft. Galileo on the other hand was a very important man, the top technical expert in Florence, the public face of the most advanced science of the day. He was the equivalent of Edison, Fermi, Einstein and Feynman rolled into one. Of course he thought he could push his views further than could much lesser academics. We need Galileos to stand up to be counted in a world where people can take a Sarah Palin seriously.
Epicycles do not depend on the Earth being the centre of the Universe. They are a way of approximating observations when you don't have ellipses and Kepler's laws to work with. I suspect one reason that Kupfernigk(Copernicus) delayed publication was that by the end of de Revolutionibus he had just as many epicycles and deferents as the Ptolemaic theory - because the observations he worked with were better and there was more to explain.
Epicycles were used because they had, wait for it, predictive power - they predicted future events quite well. In the state of knowledge at the time, with observations made from the Earth, it was natural to use the Earth as the frame of reference. The simple heliocentric theory is equally "wrong" from that point of view - the center of the Sun is not the exact center of the Solar System.
Very, very few actors, bankers or politicians earn a great deal of money.
In the City boom, the most-demanded skills were in maths, physics and computing.
Structural engineers now earn more than architects.
Maths and science graduates can expect accelerated training and promotion in teaching
Plumbers and electricians often earn more than the bulk of lawyers and accountants, and I know at least one who has an arts degree and retrained when he found out how much more he could earn.
Public perception and reality are very different. People see a few "celebrities" in each profession and think they are the norm. A few footballers earn millions; most earn less than their contemporaries who became plumbers or carpenters. A few lawyers earn millions (Jonathan Sumption to be exact), most do not. A few actors earn millions; most are lucky to earn minimum wage. A few engineers and scientists earn millions but few people hear of them; most of them earn quite reasonable salaries. The most famous former pupil of the school just down the road is a multi-millionaire F1 driver, but it is hardly a common job; many other kids who were at that school have good jobs in technical industries, engineering, science, teaching and banking. As do mine...the only people who assign low social status to scientists, engineers and mathematicians are the underclass and the people with arts degrees who don't earn as much as they think they should.
The younger generation don't know what it was like coding for packed BCD. It's getting so bad I'm fixing an alarm to stop them getting onto my lawn in the first place.
Kids, when you've written code to drive 40-character HP 7 by 5 LED displays, with the data and the buffers having to fit into 256 bytes of memory, then you can argue with msuave.
Mirrors do not reverse left-right as was explained most clearly by Richard Feynman. If you turn a book round and then look at it in a mirror, the actual text you see in the mirror is the same way round as it currently is in the book (you can prove this very easily - write in felt tip on a plastic bag and try that. You will see that the mirror writing, and the writing seen through the back of the bag are exactly the same way round
The answer to the question, why do mirrors reverse left/right and not up/down is simple: they do neither. A few seconds of ray tracing show that they reverse front to back.
Some North Americans really do overestimate the penetration of their own popular culture. Globally, most people wouldn't think of anyone at all. On Slashdot - Mr. Torvalds.
The father of Blashford Snell, the British soldier and explorer, was a Church of England clergyman in a small town near Maidenhead, Berks. He somehow acquired a pair of fox cubs whose mother had been killed, and they were raised by one of his cats. He liked to tell the story of how the wife of the local MFH (Master of Fox Hounds) came to tea and suddenly realised what was unusual about the two little "kittens" sleeping by the fire. She took it as a personal insult.
They are not suitable pets unless they live outside when older and have a lot of space for territory, so are unsuited to urban areas, but the whole point of the Russian breeding program is to overcome this.
It's perhaps worth pointing out that there are similar breeding programs for "super-domesticated" dogs, like the cockapoo.
As someone who has been involved in battery system design, could I make a point? Looking at your earlier post on the subject, you seem to be missing a couple of points.
First, you really need a lot more than a mere 100AH for a 2.4KVA inverter. Second, your continuous charger is unlikely to deliver anything like 30A into 100AH. If it did, the risk of combustion would be non-negligible, and also you would shorten the battery life - not a good idea in a standby application.
I take as a rule of thumb an absolute short term max of C1. That means 100A from a 100AH battery. To power a 2.4KVA inverter I would recommend 400AH min. For this, a 30A smart charger is about right as this gives a nice safe 8% charge. The cells should be paralleled with minimum 35 sq millimetre cable (50 preferred) with properly crimped contacts and hot melt adhesive lined heatshrink over the exposed wire. The fuse should be 400A and a 50 sq millimeter cable should connect to the inverter.
A better idea if you can manage it is to find a suitable DC motor for the pump, but for this you might need to put your cells in a 24V configuration. This gives a much more manageable 120A, though of course you do need a rather large relay for the motor.
I would say in my experience the proportion of men and women who are unable to understand a logical argument and respond appropriately is roughly equal. Men and women are equally irrational and emotional except for a few days each month. But men don't have babies. Physics, maths and computers give them kind of emotional substitutes. Therefore, women tend to be more happy in a process environment and men tend to be more happy in a completion environment.
Of course this is a generalisation and the strength of the tendency does not, I think, explain the gender bias in these jobs. That is almost entirely social. I am going to go out on a complete limb and suggest that the increase in numbers of people from the East and Far East in IT is one of the factors that is driving gender equality backwards. In the UK, lots of Asian women go into medicine,law and accountancy because these jobs are seen as acceptable by their parents, while engineering, maths and science are seen as more male roles.
Really this is a huge fuss over nothing, and some of the more wacko conspiracy theories about CIA honeypots and the like (above) are just as silly as the "shoot General Atomics" mob.
Is there any real security risk in this? I suspect it is very small. The Russians never bothered to encrypt the telemetry on their ICBM tests, because after all even assuming someone was reading it, they had no way of stopping the thing. Even if you know where the drone is, it is going to be very hard to shoot down; RPGs and IEDs really aren't much use. And given that this is a video feed, how do you ray trace back to the actual position of the camera?
Unfortunately there are plenty of assholes out there who will exaggerate anything in order to claim that they are more security conscious than the next person (and perhaps hope to get a contract for their company). But this is surely small war, no-one dead, move along please.
I very much like the idea of a battery powered robot lawnmower, as the kids have left home and therefore I would otherwise have to mow the lawn myself.
It worries the dog when it backs it into a corner, though.
My father was in the first wave on Juno, in charge of an LCT. They went in very close to the beach. 50% of them were hit by mines. His group of junior officers were mainly from the same Jewish area of North London. Several of them are still alive.
The people in the first wave were selected to be the ones who would keep going regardless of what happened around them. They were more likely to respond properly in an emergency. And in the case of my father and his crowd, they were shall we say motivated not to hesitate when firing at Germans. As Max Hastings has pointed out, in traditional wars 90% of soldiers were cannon fodder. They were there to stand around and get shot, acting as a kind of camouflage while the other 10% won the battle. Me, I'm a second wave type.
The amazing thing is that journalists, few of whom have any technical or scientific qualifications, really do work the way they think scientists work. Based on very shallow knowledge, they make wild conjectures from little bits of information, and will prefer an exciting lie over a boring truth. My belief is that in reporting on science, they are assuming that scientists are just like them, so a climatologist is someone who takes a polar bear out to lunch and then writes a story about global warming.
The East Anglia case should sound warning bells for what Murdoch and co have done to journalism - because it is not only science they lie about and misrepresent but politics, law, and religion. In their effort to get exciting stories, journalists are devaluing almost everything.
The trend is not new. I can't remember the author, but this is a well known verse:
You cannot hope to bribe or twist Thank God, the British Journalist But seeing what the chap will do Unbribed, there's not much reason to.
Which makes 3: Android, Maemo, bada. 4 if you count Moblin. It will be interesting to see how the market share of the iPhone stacks up against the total for the 4 Linux flavors this time next year.
I think some people are misunderstanding diversity. For a consumer device like a mobile phone, having multiple versions in the market is held to stimulate demand. It makes sense for manufacturers to optimise their kernels and support for the devices they want to use, then offer a consistent developer interface. It also makes sense for developers - large manufacturers like Samsung want to have a "community" of developers, not people who produce a product that works with the competition as well. It is then worth investing support effort in those developers, because they are not giving it away to the competition.
As I say, we'll see in a year how this pans out. Meanwhile, 4 multitasking relatively open platforms versus a pretty and slick but less capable one. 2010 looks interesting.
Slashdot Mirror
A bicycle is unusable for most people where I live because our town is on the sides of a steep sided valley, and the combination of traffic going up the hills at 30mph, and cyclists at 3mph, on narrow English roads, is lethal. To be really useful, an electric bike needs to be able to go up those hills at 20mph.
If there was a political will for this, there would be a Europe-wide specification for an electric bicycle of, say, about 1200W maximum output and a continuous rating of 800, with a test and licence requirement but zero tax and a State-sponsored insurance scheme to overcome the objections of insurance companies, who detest anything new in the way of risk.
Of course there would be a need for new regulations - such as limiting them to 12mph on cycle tracks - but this is nothing that technology couldn't handle (e.g. a "cycle track mode" which flashes a green light, to assist law enforcement.) But an electric bicycle that was fast enough to be safe in European urban traffic would be vastly better than the current situation, where only the very fit can ride a heavy, limited electric bicycle on anything other than the level.
(Unlucky is the land that has no heroes....unlucky is the land that needs heroes". Sadly, the fact that the US has such a need of heroes points to something wrong in the US psyche. I have sometimes felt that the US need for heroes derives, in fact, from a fear caused by the lack of social security and medical security in the US. Social democracies like Sweden don't need heroes.
I would also add that sociological research says no such thing, and I challenge you to produce a list of reputable papers that suggest that IQ is not correlated with income or social class, other than popsci books.
Your teachers almost certainly don't know nearly enough to be able to advise you. Ask around. But one thing to remember is this: even nowadays, a degree from a reputable university is necessary to open the door at any reputable company. The days when you could go straight from school to a computer company are gone because in those days there were no relevant degree courses (I know, I was there.) But I have never regretted NOT going straight to ICL but going to Cambridge instead.
I had influenza in 1976. The 1976 strain was a variant of the current swine flu. It nearly killed me, an active person in his twenties of correct body weight who was running up to 6 miles a day. It took nearly 2 years before I was fully recovered. Based on personal experience, I do not think the reaction was alarmist. Influenza can be a major killer, and we simply do not know which strain will be the next one.
If you check the reports, the people who died of swine flu were not saved by suppression of symptoms.
During the 19th century the issue was contaminated food produced by the new breed of large processed food manufacturers: in the early 20th it was the meat packing industry. Now it's Monsanto. In the first two cases it turned out industry was unfit to regulate itself, and bribery of Government officials was rife. But nowadays we regard processed food manufacturers as mostly benign (well, except for the junk food industry), and nobody worries about tinned meat. Regulation in the end was good for the industry. Monsanto needs to stop pissing on anyone who suggests it isn't perfect, and start to come clean. It would be in its long term benefit.
For many years the UK Government claimed that it was safest to discharge tritium as tritiated water. That's because they were dumping loads of it in the North Sea and wanted to justify themselves. But in fact we argued that our plant was capable of discharging the (small amount of)waste as cold tritium gas mixed with nitrogen and argon, and the best thing to do was to blast it straight up a stack and let it diffuse away. Unofficially we were right, officially we were contrary to Government policy, and in this country (as under Bush) being right but contrary to policy gets you sacked.
Now, where does most of the release of mercury, radon, and soot come from? Ah. The mining and burning of fossil fuels (plus faulted granite in places like Cornwall and Scotland.)
Yup. Working with tritium made me very safety conscious. It made me a strong supporter of nuclear power as a replacement for all those nasty polluting technologies.
I too can manage lazy stereotypes about many cultures - but I've worked in enough countries to know they are nonsense. And I know that the only people who complain about political correctness in the UK are private school educated drones working for right wing newspapers.
This is because in the UK we do not have a written Constitution but we do have common law - so in the absence of intervention by the tabloids and the attention-seekers in Government, law evolves according to community expectations. If it was not for the tabloids and politicians, cannabis would have been de facto legalised in the South-West thirty years ago by lack of interest from police and magistrates.
The Eastern bloc was more backward even then. Kepler has to return in a hurry to Regensberg at one point to defend his mother who was accused of witchcraft. Galileo on the other hand was a very important man, the top technical expert in Florence, the public face of the most advanced science of the day. He was the equivalent of Edison, Fermi, Einstein and Feynman rolled into one. Of course he thought he could push his views further than could much lesser academics. We need Galileos to stand up to be counted in a world where people can take a Sarah Palin seriously.
Epicycles were used because they had, wait for it, predictive power - they predicted future events quite well. In the state of knowledge at the time, with observations made from the Earth, it was natural to use the Earth as the frame of reference. The simple heliocentric theory is equally "wrong" from that point of view - the center of the Sun is not the exact center of the Solar System.
Public perception and reality are very different. People see a few "celebrities" in each profession and think they are the norm. A few footballers earn millions; most earn less than their contemporaries who became plumbers or carpenters. A few lawyers earn millions (Jonathan Sumption to be exact), most do not. A few actors earn millions; most are lucky to earn minimum wage. A few engineers and scientists earn millions but few people hear of them; most of them earn quite reasonable salaries. The most famous former pupil of the school just down the road is a multi-millionaire F1 driver, but it is hardly a common job; many other kids who were at that school have good jobs in technical industries, engineering, science, teaching and banking. As do mine...the only people who assign low social status to scientists, engineers and mathematicians are the underclass and the people with arts degrees who don't earn as much as they think they should.
Kids, when you've written code to drive 40-character HP 7 by 5 LED displays, with the data and the buffers having to fit into 256 bytes of memory, then you can argue with msuave.
(The UK Government name for its side of the Manhattan Project in WW2)
The answer to the question, why do mirrors reverse left/right and not up/down is simple: they do neither. A few seconds of ray tracing show that they reverse front to back.
Some North Americans really do overestimate the penetration of their own popular culture. Globally, most people wouldn't think of anyone at all. On Slashdot - Mr. Torvalds.
They are not suitable pets unless they live outside when older and have a lot of space for territory, so are unsuited to urban areas, but the whole point of the Russian breeding program is to overcome this.
It's perhaps worth pointing out that there are similar breeding programs for "super-domesticated" dogs, like the cockapoo.
First, you really need a lot more than a mere 100AH for a 2.4KVA inverter. Second, your continuous charger is unlikely to deliver anything like 30A into 100AH. If it did, the risk of combustion would be non-negligible, and also you would shorten the battery life - not a good idea in a standby application.
I take as a rule of thumb an absolute short term max of C1. That means 100A from a 100AH battery. To power a 2.4KVA inverter I would recommend 400AH min. For this, a 30A smart charger is about right as this gives a nice safe 8% charge. The cells should be paralleled with minimum 35 sq millimetre cable (50 preferred) with properly crimped contacts and hot melt adhesive lined heatshrink over the exposed wire. The fuse should be 400A and a 50 sq millimeter cable should connect to the inverter.
A better idea if you can manage it is to find a suitable DC motor for the pump, but for this you might need to put your cells in a 24V configuration. This gives a much more manageable 120A, though of course you do need a rather large relay for the motor.
Of course this is a generalisation and the strength of the tendency does not, I think, explain the gender bias in these jobs. That is almost entirely social. I am going to go out on a complete limb and suggest that the increase in numbers of people from the East and Far East in IT is one of the factors that is driving gender equality backwards. In the UK, lots of Asian women go into medicine,law and accountancy because these jobs are seen as acceptable by their parents, while engineering, maths and science are seen as more male roles.
Is there any real security risk in this? I suspect it is very small. The Russians never bothered to encrypt the telemetry on their ICBM tests, because after all even assuming someone was reading it, they had no way of stopping the thing. Even if you know where the drone is, it is going to be very hard to shoot down; RPGs and IEDs really aren't much use. And given that this is a video feed, how do you ray trace back to the actual position of the camera?
Unfortunately there are plenty of assholes out there who will exaggerate anything in order to claim that they are more security conscious than the next person (and perhaps hope to get a contract for their company). But this is surely small war, no-one dead, move along please.
It worries the dog when it backs it into a corner, though.
The people in the first wave were selected to be the ones who would keep going regardless of what happened around them. They were more likely to respond properly in an emergency. And in the case of my father and his crowd, they were shall we say motivated not to hesitate when firing at Germans. As Max Hastings has pointed out, in traditional wars 90% of soldiers were cannon fodder. They were there to stand around and get shot, acting as a kind of camouflage while the other 10% won the battle. Me, I'm a second wave type.
The East Anglia case should sound warning bells for what Murdoch and co have done to journalism - because it is not only science they lie about and misrepresent but politics, law, and religion. In their effort to get exciting stories, journalists are devaluing almost everything.
The trend is not new. I can't remember the author, but this is a well known verse:
You cannot hope to bribe or twist
Thank God, the British Journalist
But seeing what the chap will do
Unbribed, there's not much reason to.
I think some people are misunderstanding diversity. For a consumer device like a mobile phone, having multiple versions in the market is held to stimulate demand. It makes sense for manufacturers to optimise their kernels and support for the devices they want to use, then offer a consistent developer interface. It also makes sense for developers - large manufacturers like Samsung want to have a "community" of developers, not people who produce a product that works with the competition as well. It is then worth investing support effort in those developers, because they are not giving it away to the competition.
As I say, we'll see in a year how this pans out. Meanwhile, 4 multitasking relatively open platforms versus a pretty and slick but less capable one. 2010 looks interesting.