Ex cab driver, Australia late 80'. Drivers here are not anonymous, passengers are. Drivers are more much more likely to be bashed and robbed than passengers. One thing though, driving a cab may not pay much but it teaches you a lot about people, it taught me there are a lot of snobby, rude, cunts in this city dressed as respectable people..
So only mathematicians should ponder and discuss their own mind? In case you hadn't noticed every field of science is polluted by woo and the less science knows about a subject the more woo there is. Besides I like TED talks, they are not trying to replicate a university lecture hall, they are providing a platform for an interesting and informative "show and tell" for adults, not a great deal different to the aims of Slashdot but a lot better at filtering out trolls.
What precisely do you believe is the difference between a model and a theory?
A theory is itself a mathematical model, a simulation simply computes the answer to the equations in those theories in order to "visualise" and explore a particular physical system at a particular scale. For the majority of the questions involving the real world calculating the answer requires an electronic number cruncher.
This does not mean they are not on the right path, of course
Indeed, when talking about the accuracy of any scientific theory (model) it should be noted that imperfect certainly does not imply useless.
Yep, it took almost a century, several geniuses, the invention of telescopes and calculus, and years of painstaking observations, to refine the heliocentric model to a point where it outperformed the predictions of the ancient geocentric model. Now that we have space craft we can (finally?) determine which model is correct by observing the sun-earth system from an external viewpoint.
By definition there is no point in space outside the Universe, and we still can't even observe our home galaxy from the outside. For at least the last century the field of physics has been based on what Hawking has called model dependent reality.
Next time you go to the airport think about the following. The skyscrapers you pass, the bridges you cross, the car you ride in, the multi-level car park you park in, the plane you board were all designed with CS masturbation. The fact that over the last 30yrs (about half of my life time) it's become virtually impossible to get finance for any engineering projects without first performing CS masturbation is testament to it's power and utility. Numerical integration is what these simulations are doing, and it's as valid as any other branch of mathematics for exploring the physical world. Simulation is how we find the results of solving the equations that comprise the so called "physical laws". Many (if not most) of the equations in those laws can only be solved through numerical integration since no analytical solution has been found. The laws themselves are just mathematical models that have been tested to a high level of confidence, they are no more or less "real" than the maths inside a well tested computer sim.
As an example there are no known analytical solutions to newtons laws of gravity when applied to a physical system such as the solar system (ie: the n-body problem). Since humans first started shooting rockets into space their trajectories have been planned using n-body simulations, such simulation are very accurate but not perfect, which is why we put small navigation rockets on space probes to correct it's course if it strays too far.
Isn't it a tautology that the simulations correctly reproduce the universe we would expect as they were generated from laws derived from observations of this universe?
No, simulations make predictions by solving the equations (laws) using numerical analysis. If the simulation does not match observations it could be a bug in the sim or a bug in the laws themselves (new knowledge), even better is when a sim predicts phenomena nobody has seen but is confirmed by later observations (new knowledge)
If the results that were reproduced differed then wouldn't the simulation be a poor simulation?
More often than not, yes. Things don't get interesting until the sim turns out to be correct when new observations are performed. For example the much maligned climate sims have discovered dozens of unknown phenomena that were later confirmed by observations. "polar amplification" and "stratospheric cooling" are two well documented examples.
It's not like these simulations are a true experiment.
As in they don't have a "control" and a "subject"? - Of course they don't, where do you get a "control" for a unique system such as the universe, the climate, the biosphere, the flow of molten metal in an engine block casting, a skyscraper that has yet to be built? Most practical problems in both nature and engineering have neither a control subject, or an analytical solution to the mathematical laws that (we think) govern them. In the modern world we attack those problems with a methodology known as systems science, we do that because it's track record says it works.. WP claims the field got started in the 50's but my CS degree covered the subject in depth, as such I think it can be more accurately traced back to the very first computer built during WW2, the first "real world" application of that computer was to run a numerical analysis of artillery fire to create artillery tables for use in the field, prior to this the tables were calculated by hand by thousands of people with adding machines and a note book. I very much doubt the WW2 generals and admirals would have used them if they had not provided a tangible military advantage.
What changed in the 50's was that well funded corporations and academics got to play
People get up in court and tell unbelievable tales of grief and injustice everyday, it's why people come there in the first place. The parents have a right to grieve and seek "closure" thru the courts, but they don't ALL have a right to compensation other than "our deepest sympathy". The kind of control software we are talking about are "real engineering", not corporate plumbing. When real engineering goes wrong the law ignores the tears and looks at the "due diligence" of the defendant. In most modern nations, the law holds the chief engineer who signed off on the software personally responsible and manslaughter charges are not unusual if they cannot convince the coroner that their decision processes were adequate.
The legal side is more or less the same thing as a doctor removing the wrong kidney, if he was drunk he goes to jail, if he is incompetent he goes to jail, if he was grossly negligent he might go to jail, if he was mislead because someone else screwed up the process without his knowledge and beyond his reasonable control then he's off the hook with a "misadventure" finding.
Presumably the car is swerving out of the way of a car in front of it and has a choice of two other cars hit on either side, in other words the car has detected it is about to hit a wall (of cars). The most human thing to do would be don't swerve unless the car is about to roll (rolling the car tends to interfere with brakes and traction control). The common human reaction of gritting your teeth, tightening your sphincter, and staying on course also happens to be the smartest reaction since a head on impact is more survivable than a side impact, cheaper cars that are swerving may not have side air bags, intrusion bars, etc.
Bad form to reply to oneself and all that. If you (the submitter) are trying to drill down through the dependencies in an attempt to find the "bottom". There' isn't one, it just sort of fades into hardware in the same way life fades into chemistry at the cellular level. However a very practical idea is to consider C "the bottom" and work up as well as down. Programming requires the ability to mentally move through levels of abstraction, nobody truly "knows how to program" but there are plenty of people who practise it quite well. My employers don't pay me "Senior Software engineer" wages because they think I'm a wizard. Yes I have the beard for it, but it's irrelevant because they are paying me to find solutions to their business problems.
K&R's "The C Language" is not "a" classic programming book, it is "The" classic programming book.
Indeed, the last time the atmosphere naturally reached 400ppm (today's level), sea levels stabilised 150ft above what we see now, the oceans massive thermal inertia means it may not rise 15ft this century but it will certainly exceed that in the next if we continue down the "BAU" path. Bangladesh has already lost a kilometre of shore line in the past 30yrs, a 15ft rise would see the entire nation disappear into the sea. Those 150M people are going to go the only place they can, India. The nuclear armed Indians won't be happy about it and no amount of fairy dust will alter that.
Despite all the horse shit spoken about AGW in the US senate (and the current Aussie government), since ~2005 the hard nosed generals and admirals at the pentagon have been putting AGW at the top of the list in their annual "21st century threat assessment" report to congress.
You've got the right project and you seem to know more about it's finances than I do. This report was on the ABC's "Lateline Business". Perhaps I'm mistaken about the mine itself, maybe it was just the port and not the mine that the multinationals backed out of. The report said Gina had sold her stake to the multinationals when coal was at it's peak price of ~$140/ton, I took that to mean the her stake in the mine but maybe it was the port. The report was based on a study by the "Rockefeller foundation" but I couldn't find it on the net.
The point I was attempting to make was less about the actual project and more about the steadily improving economics of wind and solar.
Agree, find a problem. Work out an algorithm/heuristic that solves it, then attempt to implement it. If you are not sure how to implement it then you have found a problem of suitable difficulty and you may then want to look at how others have attacked it.
AI, simulations, and number theory are (for my tastes) great places to find intermediate to difficult problems (and the algorithms that solve them), 25yrs as a commercial developer and I'm still finding new stuff in those fields. For example I started learning python (for work) by implementing my favourite intermediate "hello world" program, an n-body gravity simulation. I'm currently looking at CUDA (for fun) using my trusty "hello world" sim, they supply an optimised example of the same problem but I won't look at it until I have mine working.
Also it depends on what you call "intermediate". Python is a "batteries included" language, how much do you know about language independent data structures such as trees, vector, matrices? Take a look at "The art and science of programming" by Donald Knuth, it's examples are in Pascal but if you inhale the wisdom in the book you will understand when I say that the language it uses is irrelevant.
Here's an ancient problem I found in the early 80's that I still don't have a programmatic solution for, pretty sure algorithms exists to solve it but I don't want to look at any "spoilers", would much rather find an answer on my own.
1. Create a 6x6 magic square
2. All columns, rows and diagonals must sum to 666
3. All 36 numbers in the square must be prime numbers
4. Marvel at the fact that Issac Newton solved it in his head! Ironically while hand-writing nearly a million words of drivel on the "number of the beast".
5. Bonus points if you find more than one solution.
Like the Syrian civil war? - Sure social media assisted in the Arab spring once the uprising began but what triggered the uprising? Why did that lone protester set himself on fire in the public square? - Did all these people all suddenly wake up one day and suddenly realise "OMG, I've been living under tyranny my entire life" or could the worst drought ever in the fertile crescent (the birth place of agriculture), and the food riots it caused in major cities such a Cairo have something to do with it?
Prior to the civil war, 10% of Syria's population (2M people) abandoned their farms due to lack of water and moved to the cities looking for work. Food prices across N. Africa and the ME skyrocketed. The leaked diplomatic cables talk about the internal migration and warn about civil unrest, one diplomat went so far as to correctly predict the city where trouble first broke. Yet if you ask a random Joe on the street what are they fighting about in Syria, the answer will almost certainly be "religion".
All wars are resource wars, religion simply provides a moral defence for morally indefensible acts. Water is a scarce recourse in many places around the world, while other places are getting so much water they are quite literally drowning. They say there's a 70% chance of a very strong El-Nino this season, similar in strength to '83 and '98, meaning the mid-west US will get massive floods and Australia will be dry as a tinder-box. Australia ran very low on drinking water during the last drought, the major city reservoirs were around 10-15% of capacity, the rural situation was worse. We spent billions on some of the largest de-sal plants in the world only to have the drought break as they came on line. I think the politicians and their fans who have been bitching about the costs of these "white elephants" will be eating their words in the next year of two..
The Arctic sea ice has melted much faster than anyone was predicting just a decade ago. Ice, aerosols, and cloud cover are not very well understood, when you get a bunch of experts together to agree on a statement about those things in a report like the IPCC, the statement is almost certainly going to be conservative. What has changed recently is our ability to measure the changes in the ice mass of the Antarctic and Greenland ice caps to a high level of precision using the GRACE satellite. It doesn't really help scientists make better predictions but it does provide a better test, and allow them to make more confident statements about what is happening now.
A silver lining? - I heard what could be considered good news to everyone (except coal barons). Here in Oz we're busily industrialising the great barrier reef by building a controversial coal mine and the largest coal port in the world. The multi-nationals who were behind the project (BHP, Rio, some banks,..) have all walked away from the project. It's now been reported (on a local business show) that the mine will probably not have the customers in India it expects. Why? - Because wind and solar are now roughly at parity price with imported coal in India and prices are dropping at a rate such that in 2-3yrs time renewables in India will be 10% cheaper than imported Aussie coal. What's is sounding even better is that coal exports have dropped significantly in price since the project was announced and yet it is still neck-to-neck with the price of renewables in India.
If those reports are not a gross exaggeration then it looks like some developing nations really will leapfrog the west and go straight to renewables.
Agree, but it's still pretty weird to think that your brain is always a quarter second ahead of your body and manages to trick the ghost into believing it's in sync with the machinery.
The network lag from eye to hand is about 200-250ms and it's not that hard to prove it by experiment (there are many and varied fairground/gambling games that rely on that delay to make money). Anything faster means you're picking up early clues, other senses are in play, or you're not human. Fast reactions are obviously an evolutionary feedback that has been sharpened by time, predicting the trajectory of a moving object is a primary survival skill for both predators and prey.
Humans are the super-dominant predator on the planet, top cricket players use electronic blindfolds to practice their batting, the goggles the batsmen wear turn opaque the instant the ball leaves the bowlers hand (detected by an electronic sensor). It's amazing how often they hit the ball "out of the park" especially considering the skill of the bowler hurling 90mph cricket balls at them. Thing is the bowler can't even attempt to hide the clues he is giving because (past a basic level) even the batsman doesn't know what they are, they just "feel it" and connect with the ball.
Not all muscle movement goes via the brain, one modification nature made to vertebrates is that she put specialized high speed processing nodes along the spinal cord that control involuntary reflex's, but I'm pretty sure they don't have anything to do with eyes and ears..
What "measurements" are you talking about wrt climate change? The strength of gravity, the chemical composition of the ocean, the shape of the Earth?
Historical instrument records are used to test the model they are NOT used as input, initial conditions such as temperature are RANDOM the correct values emerge from the laws of physics and numerical integration. Scientific opinion is not the same as democratic opinion, in Science you have to know something about what you are discussing. The fact that you make very basic mistakes in your assumptions about the models indicates no actual understanding of how climate modelling works other than parroting the sponsored nonsense you read in opinion columns. Do the planet a favour, either educate yourself on the topic or stop being somebody's "useful idiot".
That seems to be what is confusing you, you assume weather is the same thing a climate. Although the two use basically the same models, weather is chaotic and the best models on the most powerful computers can only look about a week into the future before model and reality diverge to the point where the model fails. Climate is the statistics of weather and is extremely stable over human time scales. As the video says models do a good job of modelling global climate and a reasonable job of regional climate, they tell us nothing about local climate or the weather.
As an example here's a trivial climate prediction: In the year 3000, summer will still be warmer than winter, CO2 in the atmosphere will continue to pulsate as N. Hemisphere trees lose and regrow their leaves. The monsoon season will continue to track the sun. The average global temperature will almost certainly be higher than now, by how much depends on what we do in the next 100yrs.
Watch the video again, especially the question at the end, find out what climate is and look at the skill of the models, don't stand with the luddites who would send us back to the dark ages, it's already obvious to an interested observer that they are on the wrong side of history.
Seriously, don't pay any attention to the beautiful mathematics and painstaking research that created the dancing hurricanes on the screen and go straight to the quote at the end of that Ted talk, roughly translated into politics, it means you're a luddite using creationist debating tactics.
Do you not realise that these models work on the same finite element analysis techniques and "physical laws" (mathematical models) used to successfully model everything from atomic bombs, to the flow of molten metal in an engine block cast. These everyday and exotic engineering models are so successful that over the last 30yrs (just over half my lifetime) it has become virtually impossible to finance an engineering project without them. And if you do realise that, then why are you so quick to argue these methods cannot provide useful insights into the behaviour of Earth's climate but are presumably ok with passenger jets flying around that were designed by these techniques? Perhaps Boeing added one molecule too many to the missing jet's wing tip? Turbulence is the physical manifestation of chaos , so it's like totally unpredictable, right? - Please, give rational discussion a fucking break and shut the fuck up with this tiresome "scientists are know-nothing morons" nonsense.
In the philosophy of Science ALL models are "wrong" by definition, what matters is the degree of "wrongness" (or "truthiness" as it's known in the US). When we look at observations of water vapour over the past few decades they are a very good match for model outputs from 1980's models, they are a much better match for the average of ALL 1980's model outputs. Why? - because the models are just as likely to be "wrong" in either direction.
There are plenty of solid examples on google detailing phenomena that were first seen in climate models and later observed in nature, but I doubt you have heard about phenomena such as "polar amplification" or "stratospheric cooling", Why? - because google will tell you "anything you want to hear", right?
“Climate change’’ is less frightening than “global warming” As one focus group participant
noted, climate change “sounds like you’re going from Pittsburgh to Fort Lauderdale.” While
global warming has catastrophic connotations attached to it, climate change suggests a more
controllable and less emotional challenge. - Page 11, point 1.
Life permeates the Earth's crust down to the bottom of the deepest bores we have drilled, it gets it energy from minerals such as sulphur, and water. From what we know the surface of Mars appears to be dead due to the fact that water (the universal solvent) can not exist in liquid form on the Martian surface, but it can (and does) exist in liquid form just below the surface (due to pressure from the overlaying material).
We know that life arose on Earth pretty much as soon as the ocean formed, and there's a high probability it arose around undersea thermal vents, which provide the thermal gradient required to kick start the chemistry of life. Recent research has also postulated the porous rocks found around these vents may also have played a role. My personal theory is that "adam and eve" bugs are probably still spontaneously emerging near these vents but modern life living around the vents is gobbling it up as soon as it appears.
We now know with a great deal of certainty that Mars had oceans and volcanism in it's distant past. Assuming that the boffins are correct about how life arose on Earth, it would be surprising NOT to find Martian bugs permeating the crust down to several km across the entire planet.
The challenge in detecting life emerging around modern vents and life existing under the surface of Mars is the same, how do you prevent modern Earth life from contaminating the test equipment? As I understand it, this is one of the main reasons why the rovers do not include specific tests for microbial life, the uncertainty of the results makes them worthless.
The question is not weather they will spread on Mars, the question is how do you prevent experimental equipment designed to detect Martian microbes from detecting Earth microbes that came along for the ride. Also they do not need to be exotic Earth species to survive inside the equipment, common lichen for example can survive the vacuum/radiation of space for at least a year, as demonstrated by experiments performed at the ISS.
Slashdot Mirror
It's a technology that will only be found in race cars.
They said the same thing about rear vision mirrors in the 1920's.
Ex cab driver, Australia late 80'. Drivers here are not anonymous, passengers are. Drivers are more much more likely to be bashed and robbed than passengers. One thing though, driving a cab may not pay much but it teaches you a lot about people, it taught me there are a lot of snobby, rude, cunts in this city dressed as respectable people..
So only mathematicians should ponder and discuss their own mind? In case you hadn't noticed every field of science is polluted by woo and the less science knows about a subject the more woo there is. Besides I like TED talks, they are not trying to replicate a university lecture hall, they are providing a platform for an interesting and informative "show and tell" for adults, not a great deal different to the aims of Slashdot but a lot better at filtering out trolls.
This does not mean they are not on the right path, of course
Indeed, when talking about the accuracy of any scientific theory (model) it should be noted that imperfect certainly does not imply useless.
Parameters are inputs, physical constants such as the gravitational constant. The model OUTPUTS are what you compare to observations
Observations use regression techniques, physical simulations do not. Two Nobel's in one day, that's gotta hurt!
Yep, it took almost a century, several geniuses, the invention of telescopes and calculus, and years of painstaking observations, to refine the heliocentric model to a point where it outperformed the predictions of the ancient geocentric model. Now that we have space craft we can (finally?) determine which model is correct by observing the sun-earth system from an external viewpoint.
By definition there is no point in space outside the Universe, and we still can't even observe our home galaxy from the outside. For at least the last century the field of physics has been based on what Hawking has called model dependent reality.
Regardless of what Hawking thinks, you can always rely on Feynman to nail the root cause of the "problem" in layman's terms.
Always seemed a bit like CS masturbation to me.
Nice troll, here's your cookie.
Next time you go to the airport think about the following. The skyscrapers you pass, the bridges you cross, the car you ride in, the multi-level car park you park in, the plane you board were all designed with CS masturbation. The fact that over the last 30yrs (about half of my life time) it's become virtually impossible to get finance for any engineering projects without first performing CS masturbation is testament to it's power and utility. Numerical integration is what these simulations are doing, and it's as valid as any other branch of mathematics for exploring the physical world. Simulation is how we find the results of solving the equations that comprise the so called "physical laws". Many (if not most) of the equations in those laws can only be solved through numerical integration since no analytical solution has been found. The laws themselves are just mathematical models that have been tested to a high level of confidence, they are no more or less "real" than the maths inside a well tested computer sim.
As an example there are no known analytical solutions to newtons laws of gravity when applied to a physical system such as the solar system (ie: the n-body problem). Since humans first started shooting rockets into space their trajectories have been planned using n-body simulations, such simulation are very accurate but not perfect, which is why we put small navigation rockets on space probes to correct it's course if it strays too far.
Isn't it a tautology that the simulations correctly reproduce the universe we would expect as they were generated from laws derived from observations of this universe?
No, simulations make predictions by solving the equations (laws) using numerical analysis. If the simulation does not match observations it could be a bug in the sim or a bug in the laws themselves (new knowledge), even better is when a sim predicts phenomena nobody has seen but is confirmed by later observations (new knowledge)
If the results that were reproduced differed then wouldn't the simulation be a poor simulation?
More often than not, yes. Things don't get interesting until the sim turns out to be correct when new observations are performed. For example the much maligned climate sims have discovered dozens of unknown phenomena that were later confirmed by observations. "polar amplification" and "stratospheric cooling" are two well documented examples.
It's not like these simulations are a true experiment.
As in they don't have a "control" and a "subject"? - Of course they don't, where do you get a "control" for a unique system such as the universe, the climate, the biosphere, the flow of molten metal in an engine block casting, a skyscraper that has yet to be built? Most practical problems in both nature and engineering have neither a control subject, or an analytical solution to the mathematical laws that (we think) govern them. In the modern world we attack those problems with a methodology known as systems science, we do that because it's track record says it works.. WP claims the field got started in the 50's but my CS degree covered the subject in depth, as such I think it can be more accurately traced back to the very first computer built during WW2, the first "real world" application of that computer was to run a numerical analysis of artillery fire to create artillery tables for use in the field, prior to this the tables were calculated by hand by thousands of people with adding machines and a note book. I very much doubt the WW2 generals and admirals would have used them if they had not provided a tangible military advantage.
What changed in the 50's was that well funded corporations and academics got to play
People get up in court and tell unbelievable tales of grief and injustice everyday, it's why people come there in the first place. The parents have a right to grieve and seek "closure" thru the courts, but they don't ALL have a right to compensation other than "our deepest sympathy". The kind of control software we are talking about are "real engineering", not corporate plumbing. When real engineering goes wrong the law ignores the tears and looks at the "due diligence" of the defendant. In most modern nations, the law holds the chief engineer who signed off on the software personally responsible and manslaughter charges are not unusual if they cannot convince the coroner that their decision processes were adequate.
The legal side is more or less the same thing as a doctor removing the wrong kidney, if he was drunk he goes to jail, if he is incompetent he goes to jail, if he was grossly negligent he might go to jail, if he was mislead because someone else screwed up the process without his knowledge and beyond his reasonable control then he's off the hook with a "misadventure" finding.
Presumably the car is swerving out of the way of a car in front of it and has a choice of two other cars hit on either side, in other words the car has detected it is about to hit a wall (of cars). The most human thing to do would be don't swerve unless the car is about to roll (rolling the car tends to interfere with brakes and traction control). The common human reaction of gritting your teeth, tightening your sphincter, and staying on course also happens to be the smartest reaction since a head on impact is more survivable than a side impact, cheaper cars that are swerving may not have side air bags, intrusion bars, etc.
Bad form to reply to oneself and all that. If you (the submitter) are trying to drill down through the dependencies in an attempt to find the "bottom". There' isn't one, it just sort of fades into hardware in the same way life fades into chemistry at the cellular level. However a very practical idea is to consider C "the bottom" and work up as well as down. Programming requires the ability to mentally move through levels of abstraction, nobody truly "knows how to program" but there are plenty of people who practise it quite well. My employers don't pay me "Senior Software engineer" wages because they think I'm a wizard. Yes I have the beard for it, but it's irrelevant because they are paying me to find solutions to their business problems.
K&R's "The C Language" is not "a" classic programming book, it is "The" classic programming book.
Indeed, the last time the atmosphere naturally reached 400ppm (today's level), sea levels stabilised 150ft above what we see now, the oceans massive thermal inertia means it may not rise 15ft this century but it will certainly exceed that in the next if we continue down the "BAU" path. Bangladesh has already lost a kilometre of shore line in the past 30yrs, a 15ft rise would see the entire nation disappear into the sea. Those 150M people are going to go the only place they can, India. The nuclear armed Indians won't be happy about it and no amount of fairy dust will alter that.
Despite all the horse shit spoken about AGW in the US senate (and the current Aussie government), since ~2005 the hard nosed generals and admirals at the pentagon have been putting AGW at the top of the list in their annual "21st century threat assessment" report to congress.
You've got the right project and you seem to know more about it's finances than I do. This report was on the ABC's "Lateline Business". Perhaps I'm mistaken about the mine itself, maybe it was just the port and not the mine that the multinationals backed out of. The report said Gina had sold her stake to the multinationals when coal was at it's peak price of ~$140/ton, I took that to mean the her stake in the mine but maybe it was the port. The report was based on a study by the "Rockefeller foundation" but I couldn't find it on the net.
The point I was attempting to make was less about the actual project and more about the steadily improving economics of wind and solar.
Agree, find a problem. Work out an algorithm/heuristic that solves it, then attempt to implement it. If you are not sure how to implement it then you have found a problem of suitable difficulty and you may then want to look at how others have attacked it.
AI, simulations, and number theory are (for my tastes) great places to find intermediate to difficult problems (and the algorithms that solve them), 25yrs as a commercial developer and I'm still finding new stuff in those fields. For example I started learning python (for work) by implementing my favourite intermediate "hello world" program, an n-body gravity simulation. I'm currently looking at CUDA (for fun) using my trusty "hello world" sim, they supply an optimised example of the same problem but I won't look at it until I have mine working.
Also it depends on what you call "intermediate". Python is a "batteries included" language, how much do you know about language independent data structures such as trees, vector, matrices? Take a look at "The art and science of programming" by Donald Knuth, it's examples are in Pascal but if you inhale the wisdom in the book you will understand when I say that the language it uses is irrelevant.
Here's an ancient problem I found in the early 80's that I still don't have a programmatic solution for, pretty sure algorithms exists to solve it but I don't want to look at any "spoilers", would much rather find an answer on my own.
1. Create a 6x6 magic square
2. All columns, rows and diagonals must sum to 666
3. All 36 numbers in the square must be prime numbers
4. Marvel at the fact that Issac Newton solved it in his head! Ironically while hand-writing nearly a million words of drivel on the "number of the beast".
5. Bonus points if you find more than one solution.
Like the Syrian civil war? - Sure social media assisted in the Arab spring once the uprising began but what triggered the uprising? Why did that lone protester set himself on fire in the public square? - Did all these people all suddenly wake up one day and suddenly realise "OMG, I've been living under tyranny my entire life" or could the worst drought ever in the fertile crescent (the birth place of agriculture), and the food riots it caused in major cities such a Cairo have something to do with it?
Prior to the civil war, 10% of Syria's population (2M people) abandoned their farms due to lack of water and moved to the cities looking for work. Food prices across N. Africa and the ME skyrocketed. The leaked diplomatic cables talk about the internal migration and warn about civil unrest, one diplomat went so far as to correctly predict the city where trouble first broke. Yet if you ask a random Joe on the street what are they fighting about in Syria, the answer will almost certainly be "religion".
All wars are resource wars, religion simply provides a moral defence for morally indefensible acts. Water is a scarce recourse in many places around the world, while other places are getting so much water they are quite literally drowning. They say there's a 70% chance of a very strong El-Nino this season, similar in strength to '83 and '98, meaning the mid-west US will get massive floods and Australia will be dry as a tinder-box. Australia ran very low on drinking water during the last drought, the major city reservoirs were around 10-15% of capacity, the rural situation was worse. We spent billions on some of the largest de-sal plants in the world only to have the drought break as they came on line. I think the politicians and their fans who have been bitching about the costs of these "white elephants" will be eating their words in the next year of two..
The Arctic sea ice has melted much faster than anyone was predicting just a decade ago. Ice, aerosols, and cloud cover are not very well understood, when you get a bunch of experts together to agree on a statement about those things in a report like the IPCC, the statement is almost certainly going to be conservative. What has changed recently is our ability to measure the changes in the ice mass of the Antarctic and Greenland ice caps to a high level of precision using the GRACE satellite. It doesn't really help scientists make better predictions but it does provide a better test, and allow them to make more confident statements about what is happening now.
A silver lining? - I heard what could be considered good news to everyone (except coal barons). Here in Oz we're busily industrialising the great barrier reef by building a controversial coal mine and the largest coal port in the world. The multi-nationals who were behind the project (BHP, Rio, some banks,..) have all walked away from the project. It's now been reported (on a local business show) that the mine will probably not have the customers in India it expects. Why? - Because wind and solar are now roughly at parity price with imported coal in India and prices are dropping at a rate such that in 2-3yrs time renewables in India will be 10% cheaper than imported Aussie coal. What's is sounding even better is that coal exports have dropped significantly in price since the project was announced and yet it is still neck-to-neck with the price of renewables in India.
If those reports are not a gross exaggeration then it looks like some developing nations really will leapfrog the west and go straight to renewables.
Agree, but it's still pretty weird to think that your brain is always a quarter second ahead of your body and manages to trick the ghost into believing it's in sync with the machinery.
The network lag from eye to hand is about 200-250ms and it's not that hard to prove it by experiment (there are many and varied fairground/gambling games that rely on that delay to make money). Anything faster means you're picking up early clues, other senses are in play, or you're not human. Fast reactions are obviously an evolutionary feedback that has been sharpened by time, predicting the trajectory of a moving object is a primary survival skill for both predators and prey.
Humans are the super-dominant predator on the planet, top cricket players use electronic blindfolds to practice their batting, the goggles the batsmen wear turn opaque the instant the ball leaves the bowlers hand (detected by an electronic sensor). It's amazing how often they hit the ball "out of the park" especially considering the skill of the bowler hurling 90mph cricket balls at them. Thing is the bowler can't even attempt to hide the clues he is giving because (past a basic level) even the batsman doesn't know what they are, they just "feel it" and connect with the ball.
Not all muscle movement goes via the brain, one modification nature made to vertebrates is that she put specialized high speed processing nodes along the spinal cord that control involuntary reflex's, but I'm pretty sure they don't have anything to do with eyes and ears..
What "measurements" are you talking about wrt climate change? The strength of gravity, the chemical composition of the ocean, the shape of the Earth?
Historical instrument records are used to test the model they are NOT used as input, initial conditions such as temperature are RANDOM the correct values emerge from the laws of physics and numerical integration. Scientific opinion is not the same as democratic opinion, in Science you have to know something about what you are discussing. The fact that you make very basic mistakes in your assumptions about the models indicates no actual understanding of how climate modelling works other than parroting the sponsored nonsense you read in opinion columns. Do the planet a favour, either educate yourself on the topic or stop being somebody's "useful idiot".
let's assume
That seems to be what is confusing you, you assume weather is the same thing a climate. Although the two use basically the same models, weather is chaotic and the best models on the most powerful computers can only look about a week into the future before model and reality diverge to the point where the model fails. Climate is the statistics of weather and is extremely stable over human time scales. As the video says models do a good job of modelling global climate and a reasonable job of regional climate, they tell us nothing about local climate or the weather.
As an example here's a trivial climate prediction: In the year 3000, summer will still be warmer than winter, CO2 in the atmosphere will continue to pulsate as N. Hemisphere trees lose and regrow their leaves. The monsoon season will continue to track the sun. The average global temperature will almost certainly be higher than now, by how much depends on what we do in the next 100yrs.
Watch the video again, especially the question at the end, find out what climate is and look at the skill of the models, don't stand with the luddites who would send us back to the dark ages, it's already obvious to an interested observer that they are on the wrong side of history.
Grease in your graphite powder? - Use a lead pencil.
What a load of frog shit!.
Seriously, don't pay any attention to the beautiful mathematics and painstaking research that created the dancing hurricanes on the screen and go straight to the quote at the end of that Ted talk, roughly translated into politics, it means you're a luddite using creationist debating tactics.
Do you not realise that these models work on the same finite element analysis techniques and "physical laws" (mathematical models) used to successfully model everything from atomic bombs, to the flow of molten metal in an engine block cast. These everyday and exotic engineering models are so successful that over the last 30yrs (just over half my lifetime) it has become virtually impossible to finance an engineering project without them. And if you do realise that, then why are you so quick to argue these methods cannot provide useful insights into the behaviour of Earth's climate but are presumably ok with passenger jets flying around that were designed by these techniques? Perhaps Boeing added one molecule too many to the missing jet's wing tip? Turbulence is the physical manifestation of chaos , so it's like totally unpredictable, right? - Please, give rational discussion a fucking break and shut the fuck up with this tiresome "scientists are know-nothing morons" nonsense.
In the philosophy of Science ALL models are "wrong" by definition, what matters is the degree of "wrongness" (or "truthiness" as it's known in the US). When we look at observations of water vapour over the past few decades they are a very good match for model outputs from 1980's models, they are a much better match for the average of ALL 1980's model outputs. Why? - because the models are just as likely to be "wrong" in either direction.
There are plenty of solid examples on google detailing phenomena that were first seen in climate models and later observed in nature, but I doubt you have heard about phenomena such as "polar amplification" or "stratospheric cooling", Why? - because google will tell you "anything you want to hear", right?
And now that I have had time to look...
“Climate change’’ is less frightening than “global warming” As one focus group participant noted, climate change “sounds like you’re going from Pittsburgh to Fort Lauderdale.” While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge. - Page 11, point 1.
Life permeates the Earth's crust down to the bottom of the deepest bores we have drilled, it gets it energy from minerals such as sulphur, and water. From what we know the surface of Mars appears to be dead due to the fact that water (the universal solvent) can not exist in liquid form on the Martian surface, but it can (and does) exist in liquid form just below the surface (due to pressure from the overlaying material).
We know that life arose on Earth pretty much as soon as the ocean formed, and there's a high probability it arose around undersea thermal vents, which provide the thermal gradient required to kick start the chemistry of life. Recent research has also postulated the porous rocks found around these vents may also have played a role. My personal theory is that "adam and eve" bugs are probably still spontaneously emerging near these vents but modern life living around the vents is gobbling it up as soon as it appears.
We now know with a great deal of certainty that Mars had oceans and volcanism in it's distant past. Assuming that the boffins are correct about how life arose on Earth, it would be surprising NOT to find Martian bugs permeating the crust down to several km across the entire planet.
The challenge in detecting life emerging around modern vents and life existing under the surface of Mars is the same, how do you prevent modern Earth life from contaminating the test equipment? As I understand it, this is one of the main reasons why the rovers do not include specific tests for microbial life, the uncertainty of the results makes them worthless.
The question is not weather they will spread on Mars, the question is how do you prevent experimental equipment designed to detect Martian microbes from detecting Earth microbes that came along for the ride. Also they do not need to be exotic Earth species to survive inside the equipment, common lichen for example can survive the vacuum/radiation of space for at least a year, as demonstrated by experiments performed at the ISS.
The Luntz memo.