Sounds just as brilliant as the classical idea to preload all links from a page... Addons like this kill the Internet. They're worse than the problem they're trying to solve.
Speed bumps are also extremely effective in injuring bicyclists and doubling the amount of car exhaust due to unneccessary braking and accelerating (in my country even to the point that speedbumps singlehandedly cause pollution levels to cross acceptable thresholds in populated areas!). Though it's clear that they slow traffic down on average, there's hardly any evidence to back the idea that they also prevent accidents.
Sorry but I don't get this. The boy born on tuesday is just as relevant as the favorite color of the boy or whatever. The probability does not change because irrelevant details are added to the story. Otherwise, I'd suggest to also factor in the place the child was born, the year, month and the position of any random set of celestial bodies at the time of birth of both children as well as all their known ancestors. The chance her other child is a boy is equal to the chance of a child being a boy in general. So it is about 50% or probably a bit off since there's a slight difference between the number of boys and girls being born. It's not like children are like little balls blindly picked from a vessel filled with a finite amount of balls. Unless stated otherwise, which might happen because the family may not have been randomly selected, but in a way one picks balls from a vessel, but that is not stated in the problem so it is not the case and it should not be bothered about. Why is this on slashdot? And why are mathematicians discussing about this?! Am I a moron?!
Cool;-) I have looked up some facts about the longest undersea cable currently in use (NorNed, http://www.rovworld.com/article2610.html); it uses about 9000 tonnes of copper and 12000 tonnes of lead for 580km of cable with a maximum capacity of 700MW. That's way below your assumptions. The cable from the Sahara will have to be quite a bit longer if you factor in the powergrid-epansion required in the south of Europe for it to be usefull, but even that falls well within the limits of your calculation. So you're obviously correct. Thanks!
... only imagine the amount of energy needed to melt the copper for the long distance high voltage lines... somehow, I think this might not be the best approach to tapping Sahara Energy.
Oh come on please stop linking to the south park story. What they call a "New York-based Revolution Muslim Group" is merely a mad man that used to be a jew living as a colonist in Israel. And now all of the sudden he has turned into an Islamic terrorist? Yeah right. This story says more about the morons that run Comedy Central than about any muslim.
"You weren't going to drive off while I'm running your plates, were you?" vs "Could you please wait a moment, sir?"
In my world, starting a "normal" conversation like that qualifies at least as "rude" and actually more like an attempt to start a "conflict". This police dude is obviously completely incompetent.
What's really amazing is that we managed to burn up just about all "cheap" oil in a little over 100 years and now have to resort to drilling 1500 meters below sealevel.
Cow manure is obviously produced from plants that have been grown using fertilizer to provide - amongst others - phosphorus. Since we're rapidly running out of phosphate, I think it's an absolutely brilliant plan to burn it.
Particle accelerators are all about the destruction of minute amounts of material. Industry is about construction of massive amounts of material. Therefore particle accelerators are the exact opposite of industry and I doubt an industrial application for particle accelerators can be made up.
They didn't. The april fools joke is not the first video; it's that after clicking on some of the fake related videos you're actually going to believe it:P APRIL FOOLS!:D
The way the DNA samples are represented and compared is far from perfect. Evidence-samples are often incomplete or polluted. False positives occur and will occur increasingly as the number of samples grows. DNA profiling is NOT flawless, but you cannot defend yourself against the presumption that it is. Collecting everybody's DNA wil inevitably result in quite a few innocent people ending up in jail.
Definately Ubuntu. I use Debian myself, but I have recommended Ubuntu to several n00bs after bad experiences with other distros. Generally Ubuntu Just Works and they don't have to bother you for help; n00bs can install it themselves, keep it up-to-date themselves, they can install the software they want and plug in all their peripherals without fiddling with drivers and settings. Other distro's generally just don't have the critical n00b-userbase mass it takes to deliver user-friendly quality all-over on a broad range of hardware.
Having said that, I'll stick to Debian. But I find it much easier to ask my Ubuntu-using girlfriend to print something for me than to fiddle with cups:P
Apart from that you're completely right, I couldn't resist the urge to come up with some far-fetched counterarguments:Pp
1) That's not quite true. It is perfectly possible to cool something with "superhot" laser beams; no need to have something even cooler. Therefore, reaching absolute zero is not impossible by that definition. It is only the law of entropy that prevents us from reaching absolute zero. Or so it says.
2) Since we're reached the purely theoretical/philosophical discussion... zero-point energy only changes with time. So if you'd be able to stop time, it would be possible to stop all molecular motion (which also follows from the definition of motion and time anyway;)). But then again, without time, one cannot observe. We would not even notice if time stopped, maybe it just paused for quite some "time";-PPp
3) I believe (but am not sure) we merely don't know how to stop or slow photons (in a vacuum, that is). No known force can do it nor does there appear to be a gap in our knowledge in which such a force might eventually be found. So it is very likely that it is impossible indeed, but as far as I'm aware there's no proof of that.
It's not a proton but a photon that has a mass of zero at rest. But photons never are at rest. The question therefore is merely philosofical in nature and one might even say it is bullshit;-)
ALL (anti)matter, ALL forces, fields and waves and everything you can think of consists of particles. I'm not talking about neutrons and protons and the such, but even smaller particles known as subatomic particles or elementary particles. Most of us know the group of particles called quarks, but there are more groups of particle with cool names like leptons (an electron is a lepton) and bosons (a photon is a boson).
We know that a LOT of nature shows some kind of symmetry; this is the same in elementary particle physics. From this, it has been deduced that several particles not yet detected must exist in order to fill in the gaps in the symmetry. It is those particles we are looking for and they are predicted by the Standard Model, which is an enourmous collection of theories that together attempt to describe our entire universe (with the exception of gravity) (and to unify the newtonian and einsteinian physics).
Such particles have many hard-to-understand properties like spin, charge, mass etc. What we are looking for, however, is their specific energy. We do this by accelerating matter (protons typically) to incredible speed and then colliding it. In such a collision, enormous energies occur that cause elementary particles to cease to exist and create new elementary particles. All kinds of particles can sort of randomly be created during such a collision, but obviously the collision itself has to be powerful enough to reach at least the energy the particle we're looking for has. So we keep building more and more powerful particle accelerators in order to find these things. What we call the energy of such a particle is a bit complex; it sort of comparable to mass*speed, but that's not all there is to say about this; for example many particles have a fixed speed, namely the speed of light. Therefore, their mass is equivalent to their energy. That's the GeV number we're talking about here. Note that this is incredibly simplified; for example we don't really know the mass of the photon (except that it is 0 in rest, but photons don't exist in rest) but we DO know its' energy since we can measure that. Also, the charge is not factored into this equation. But, in general, elementary particle physicists think in "energy", not in "mass" or "speed".
Anyway, around the point of collision, enormous detectors have been built that attempt to trap the particles created in the collision. These detectors generate a small electric current comparable to the energy of the particle that collided, which is measured. Think about them as antenna's. After millions and millions of such collisions, patterns start to emerge and we can deduce a specific particle has been created in our collisions. For example, you see a lot of collisions with this energy and a lot with that energy, but none with energy such and so. The result is sort of like a spectrogram (but again, it's way more complex than that).
So in the case of the Higgs Boson, in this "spectrogram", we're looking for a peak somewhere between 115 and 150 GeV. This is obviously an incredibly simplified explanation, but I think this should make you understand just a bit more.
Basically there are several "types" of sampling in music.
The first one is simply sampling instruments. This can be considered the same as using the same words as another author. This is more about the technical process of recording such instruments than it is about the composition. No problem here, I think.
The second one is sampling musical phrases. A drumloop or a guitar-riff or so. Once again, this is quite a lot about the recording-aspect and just a little bit about the composition. Even though there are incredible many possibilities in combining tones and rhythms, a lot of similarities can be pointed out, not in the least place since music is influenced heavily by fashion and culture. This could be compared to using well-known phrases from literature (to be or not to be?:-)).
And then there's the sampling of lyrics. This is a bit more complex; an important aspect of this is the voice of the singer, which is something very personal. This aspect can be compared (a little bit) to the font of a book. Reusing such fonts is commonly accepted, but if you'd imitate a writers handwriting, this becomes something else entirely.
In general, the comparison is hard to make. Music is a sort of three-dimensional; many phrases play at the same time, but also they repeat, often in complex ways. Also, such phrases can be transposed in frequency. It's a composition of layers. Literature is not; it is - by definition - one-dimensional. Linear. Also, there is no extensive use of repetition (with the exception of poetry, I will discuss that below). Where in music, one can sample a single layer without capturing the essence of (that part of) of the musical piece, in literature this is not really possible. If one copies an entire paragraph, it's just that: a copy. No reordering, repetition or layering occurs.
And then there's the way we make music. One always uses an instrument created by someone else and that is often played according to certain rules. In this sense, reusing sounds has always been acceptable in music and the rules cause the reusing of phrases to be rather common as well. It's even the way everybody learns how to make music: by copying others. Even the reuse of a "type of sound" is extremely common; that's why we have different musical genres. There are millions of possibilities to combine sound, but we only choose an extremely small subset of them, as determined by our culture, which demands similarities in music. Music that does not copy as least a small aspect of other music is generally not very popular.
Also, music is poetry a lot more like poetry, not prose. When lyrics are involved, it even IS poetry. So there is a rather fine line between some kinds of music an some kinds of literature while an enourmous gap exists between other kinds of music and literature.
More in general, no two forms of reuse can be compared. They're all completely different and the act of reusing has always been allowed until copyright-laws made it illegal sometime in the past two centuries. Therefore, what we're discussing here is a LEGAL and FINANCIAL problem, not a MORAL one. The moral part of this is actually quite simple and extremely hard at the same time: on the one hand, mankind produces art, which is and always has been meant to be spread since such art only has value withing the culture that consumes it and provides feedback. On the other hand, most of us know the feeling (moral is about feeling) when someone copies something you put a lot of work in without giving you credit. Some may also know the proud feeling when you find that a theory or trick you thought up was reused somewhere. So whether credit is given or not, we can often not even explain for our own intellectual property whether reuse of it is morally acceptable. Reusing art can been seen as a compliment or as theft. It is a complex interaction between the original author, the reuser and their audience. Sometimes such reuse is even encouraged (remixing of music, youtube mashups) while sometimes one explicitly attempts to preve
I use scrum too. But that's not a way of estimating programming time, it is merely a way to manage a software project. And it works. Use it. It's good for your heart and blood pressure:P
Anyway. Estimating programming time is actually really simple. You take your time to plan, up to 10% of the duration of the project, and discuss the result with your peers. Make a work breakdown and make sure there's nothing in there that you estimate takes more than about a day. Preferably much shorter. Also, use fixed ranges. I use less than 1 hour, 1-4 hours, 4-8 hours, 1-3 days and more than 3 days. The latter two are to be avoided. The result of all this is obviously a range you expect your project to take, not a fixed number of hours. Note that according to pretty ancient research, engineers often need 2.18 times their estimate to complete a task; this is sort-of built-in in the fixed ranges I mentioned.
Also, it is very important to keep a log of what you've done, how long it took and why. That's part of the reason it takes some time to get it right. Find entries in your log that look a bit like the entries on your work breakdown and compare them; that way you can learn from mistakes you made in previous plans.
So far for estimating. But that's only a third of the job. It is very important to acknowledge that what you've just calculated is just an estimate and to be open about it. So you need safeguards. I use the following: 1. Plan for overhead. 20% is usually fine. 2. Talk to your stakeholders and prioritize your project from a functional POV. Scrum uses http://en.wikipedia.org/wiki/MoSCoW_Method for that. Commit only to the requirements with the highest priority (and if that's all of them, just make up optional requirements:P). 3. Make sure your maximum estimate plus the overhead is enough time to fix those requirements.
The last thing you need to make your estimates turn out to be correct, is some form of project management. Make sure you discuss the state of the project (as compared to the original plan!) daily. Let all team members have their say and if something does not go according to plan, act on it early, don't safe the problems for release day. Make sure everybody has the right focus and works on the requirements with the highest priorities. Nobody should work on prio 1 requirements when prio 2 requirements are still not finished. Ever.
Obviously you're guaranteed to fail if you don't commit, integrate, test, build and package early and often. Use a continuous integration build-server, use version control, write unit-tests (yes, they safe time), use a proper issue-tracker (with workflow and support for estimates, actual time, priority etc) and make sure you have a quality assurance person on board that tests EVERYTHING (yes, that'll safe time too). Just the usual common sense stuff.
Of course some of us work on projects at companies that are run by douchebags; they won't give you enough time to plan, they do not want to prioritize, they don't understand why they need to pay for servers, issue-trackers, meetings, continuous integration servers, quality assurance ppl and all that "bullshit". Always share your concerns with them; never ever give them the chance to blame you. Blame them instead. And look for a better job that does not remind you of Dilbert; such jobs do exist;-)
Now if you stick to all that and evaluate early and often, you'll probably get it completely wrong the first few times, but you'll quite often get it spot on eventually. 99% of correctly estimating programming time is to get to know yourself and to stick to your plan. And those two things are incredibly hard;-P
Well, those would not really be problems if the shuttle were just shut down and kept around for whenever it might prove to be useful. Or if it were adapted (by stuffing it full of solar panels for example) in order to solve those problems before becoming a part of the ISS. But that's not done either for the one and only real reason: in order to stay in orbit, the ISS needs a boost every now and then. That takes a tremendous amount of energy and since the Shuttle is really heavy because it has to withstand the forces of launch and reentry, keeping it around simply is not a good idea.
Slashdot Mirror
Sounds just as brilliant as the classical idea to preload all links from a page... Addons like this kill the Internet. They're worse than the problem they're trying to solve.
Gravity is also "only a theory" but that doesn't mean you can fly if you don't "believe" in it.
Obviously not, because as we all know, flying requires gravity, otherwise it'd be floating;P
Speed bumps are also extremely effective in injuring bicyclists and doubling the amount of car exhaust due to unneccessary braking and accelerating (in my country even to the point that speedbumps singlehandedly cause pollution levels to cross acceptable thresholds in populated areas!). Though it's clear that they slow traffic down on average, there's hardly any evidence to back the idea that they also prevent accidents.
Sorry but I don't get this. The boy born on tuesday is just as relevant as the favorite color of the boy or whatever. The probability does not change because irrelevant details are added to the story. Otherwise, I'd suggest to also factor in the place the child was born, the year, month and the position of any random set of celestial bodies at the time of birth of both children as well as all their known ancestors. The chance her other child is a boy is equal to the chance of a child being a boy in general. So it is about 50% or probably a bit off since there's a slight difference between the number of boys and girls being born. It's not like children are like little balls blindly picked from a vessel filled with a finite amount of balls. Unless stated otherwise, which might happen because the family may not have been randomly selected, but in a way one picks balls from a vessel, but that is not stated in the problem so it is not the case and it should not be bothered about. Why is this on slashdot? And why are mathematicians discussing about this?! Am I a moron?!
Cool ;-) I have looked up some facts about the longest undersea cable currently in use (NorNed, http://www.rovworld.com/article2610.html); it uses about 9000 tonnes of copper and 12000 tonnes of lead for 580km of cable with a maximum capacity of 700MW. That's way below your assumptions. The cable from the Sahara will have to be quite a bit longer if you factor in the powergrid-epansion required in the south of Europe for it to be usefull, but even that falls well within the limits of your calculation. So you're obviously correct. Thanks!
... only imagine the amount of energy needed to melt the copper for the long distance high voltage lines ... somehow, I think this might not be the best approach to tapping Sahara Energy.
Oh come on please stop linking to the south park story. What they call a "New York-based Revolution Muslim Group" is merely a mad man that used to be a jew living as a colonist in Israel. And now all of the sudden he has turned into an Islamic terrorist? Yeah right. This story says more about the morons that run Comedy Central than about any muslim.
Brawndo! The thirst mutilator!
http://www.brawndo.com/
"You weren't going to drive off while I'm running your plates, were you?" vs "Could you please wait a moment, sir?"
In my world, starting a "normal" conversation like that qualifies at least as "rude" and actually more like an attempt to start a "conflict". This police dude is obviously completely incompetent.
Obviously you couldn't resist linking to exactly the single spot where a subaru impreza wagon is driving, by far the ugliest subaru ever made:P
What's really amazing is that we managed to burn up just about all "cheap" oil in a little over 100 years and now have to resort to drilling 1500 meters below sealevel.
Cow manure is obviously produced from plants that have been grown using fertilizer to provide - amongst others - phosphorus. Since we're rapidly running out of phosphate, I think it's an absolutely brilliant plan to burn it.
http://www.energybulletin.net/node/33164
Particle accelerators are all about the destruction of minute amounts of material. Industry is about construction of massive amounts of material. Therefore particle accelerators are the exact opposite of industry and I doubt an industrial application for particle accelerators can be made up.
Am smoker. IQ is 143. So lonely.... boohoo:Ppp
They didn't. The april fools joke is not the first video; it's that after clicking on some of the fake related videos you're actually going to believe it:P APRIL FOOLS! :D
Oh come on why not do it properly and port aalib to flash.
The way the DNA samples are represented and compared is far from perfect. Evidence-samples are often incomplete or polluted. False positives occur and will occur increasingly as the number of samples grows. DNA profiling is NOT flawless, but you cannot defend yourself against the presumption that it is. Collecting everybody's DNA wil inevitably result in quite a few innocent people ending up in jail.
Random link about the subject: http://dna-view.com/profile.htm
Definately Ubuntu. I use Debian myself, but I have recommended Ubuntu to several n00bs after bad experiences with other distros. Generally Ubuntu Just Works and they don't have to bother you for help; n00bs can install it themselves, keep it up-to-date themselves, they can install the software they want and plug in all their peripherals without fiddling with drivers and settings. Other distro's generally just don't have the critical n00b-userbase mass it takes to deliver user-friendly quality all-over on a broad range of hardware.
Having said that, I'll stick to Debian. But I find it much easier to ask my Ubuntu-using girlfriend to print something for me than to fiddle with cups:P
Apart from that you're completely right, I couldn't resist the urge to come up with some far-fetched counterarguments:Pp
1) That's not quite true. It is perfectly possible to cool something with "superhot" laser beams; no need to have something even cooler. Therefore, reaching absolute zero is not impossible by that definition. It is only the law of entropy that prevents us from reaching absolute zero. Or so it says.
2) Since we're reached the purely theoretical/philosophical discussion... zero-point energy only changes with time. So if you'd be able to stop time, it would be possible to stop all molecular motion (which also follows from the definition of motion and time anyway;)). But then again, without time, one cannot observe. We would not even notice if time stopped, maybe it just paused for quite some "time" ;-PPp
3) I believe (but am not sure) we merely don't know how to stop or slow photons (in a vacuum, that is). No known force can do it nor does there appear to be a gap in our knowledge in which such a force might eventually be found. So it is very likely that it is impossible indeed, but as far as I'm aware there's no proof of that.
Never say never;-)
It's not a proton but a photon that has a mass of zero at rest. But photons never are at rest. The question therefore is merely philosofical in nature and one might even say it is bullshit;-)
particle physics for dummies
ALL (anti)matter, ALL forces, fields and waves and everything you can think of consists of particles. I'm not talking about neutrons and protons and the such, but even smaller particles known as subatomic particles or elementary particles. Most of us know the group of particles called quarks, but there are more groups of particle with cool names like leptons (an electron is a lepton) and bosons (a photon is a boson).
We know that a LOT of nature shows some kind of symmetry; this is the same in elementary particle physics. From this, it has been deduced that several particles not yet detected must exist in order to fill in the gaps in the symmetry. It is those particles we are looking for and they are predicted by the Standard Model, which is an enourmous collection of theories that together attempt to describe our entire universe (with the exception of gravity) (and to unify the newtonian and einsteinian physics).
Such particles have many hard-to-understand properties like spin, charge, mass etc. What we are looking for, however, is their specific energy. We do this by accelerating matter (protons typically) to incredible speed and then colliding it. In such a collision, enormous energies occur that cause elementary particles to cease to exist and create new elementary particles. All kinds of particles can sort of randomly be created during such a collision, but obviously the collision itself has to be powerful enough to reach at least the energy the particle we're looking for has. So we keep building more and more powerful particle accelerators in order to find these things. What we call the energy of such a particle is a bit complex; it sort of comparable to mass*speed, but that's not all there is to say about this; for example many particles have a fixed speed, namely the speed of light. Therefore, their mass is equivalent to their energy. That's the GeV number we're talking about here. Note that this is incredibly simplified; for example we don't really know the mass of the photon (except that it is 0 in rest, but photons don't exist in rest) but we DO know its' energy since we can measure that. Also, the charge is not factored into this equation. But, in general, elementary particle physicists think in "energy", not in "mass" or "speed".
Anyway, around the point of collision, enormous detectors have been built that attempt to trap the particles created in the collision. These detectors generate a small electric current comparable to the energy of the particle that collided, which is measured. Think about them as antenna's. After millions and millions of such collisions, patterns start to emerge and we can deduce a specific particle has been created in our collisions. For example, you see a lot of collisions with this energy and a lot with that energy, but none with energy such and so. The result is sort of like a spectrogram (but again, it's way more complex than that).
So in the case of the Higgs Boson, in this "spectrogram", we're looking for a peak somewhere between 115 and 150 GeV. This is obviously an incredibly simplified explanation, but I think this should make you understand just a bit more.
It's like that too in the Netherlands. Sometimes it leads to rather unwanted exaggerated results. For example this one:
Real person - convicted but almost certainly innocent (http://en.wikipedia.org/wiki/Lucia_de_Berk):
http://www.luciadeb.nl/luciana/Lucia12-wijst-op-kwal_ORI.jpg
Sketch (note for example the nose):
http://www.destentor.nl/multimedia/archive/00904/Zaak-Lucia_de_B__wo_904785b.jpg
Basically there are several "types" of sampling in music.
The first one is simply sampling instruments. This can be considered the same as using the same words as another author. This is more about the technical process of recording such instruments than it is about the composition. No problem here, I think.
The second one is sampling musical phrases. A drumloop or a guitar-riff or so. Once again, this is quite a lot about the recording-aspect and just a little bit about the composition. Even though there are incredible many possibilities in combining tones and rhythms, a lot of similarities can be pointed out, not in the least place since music is influenced heavily by fashion and culture. This could be compared to using well-known phrases from literature (to be or not to be?:-)).
And then there's the sampling of lyrics. This is a bit more complex; an important aspect of this is the voice of the singer, which is something very personal. This aspect can be compared (a little bit) to the font of a book. Reusing such fonts is commonly accepted, but if you'd imitate a writers handwriting, this becomes something else entirely.
In general, the comparison is hard to make. Music is a sort of three-dimensional; many phrases play at the same time, but also they repeat, often in complex ways. Also, such phrases can be transposed in frequency. It's a composition of layers. Literature is not; it is - by definition - one-dimensional. Linear. Also, there is no extensive use of repetition (with the exception of poetry, I will discuss that below). Where in music, one can sample a single layer without capturing the essence of (that part of) of the musical piece, in literature this is not really possible. If one copies an entire paragraph, it's just that: a copy. No reordering, repetition or layering occurs.
And then there's the way we make music. One always uses an instrument created by someone else and that is often played according to certain rules. In this sense, reusing sounds has always been acceptable in music and the rules cause the reusing of phrases to be rather common as well. It's even the way everybody learns how to make music: by copying others. Even the reuse of a "type of sound" is extremely common; that's why we have different musical genres. There are millions of possibilities to combine sound, but we only choose an extremely small subset of them, as determined by our culture, which demands similarities in music. Music that does not copy as least a small aspect of other music is generally not very popular.
Also, music is poetry a lot more like poetry, not prose. When lyrics are involved, it even IS poetry. So there is a rather fine line between some kinds of music an some kinds of literature while an enourmous gap exists between other kinds of music and literature.
More in general, no two forms of reuse can be compared. They're all completely different and the act of reusing has always been allowed until copyright-laws made it illegal sometime in the past two centuries. Therefore, what we're discussing here is a LEGAL and FINANCIAL problem, not a MORAL one. The moral part of this is actually quite simple and extremely hard at the same time: on the one hand, mankind produces art, which is and always has been meant to be spread since such art only has value withing the culture that consumes it and provides feedback. On the other hand, most of us know the feeling (moral is about feeling) when someone copies something you put a lot of work in without giving you credit. Some may also know the proud feeling when you find that a theory or trick you thought up was reused somewhere. So whether credit is given or not, we can often not even explain for our own intellectual property whether reuse of it is morally acceptable. Reusing art can been seen as a compliment or as theft. It is a complex interaction between the original author, the reuser and their audience. Sometimes such reuse is even encouraged (remixing of music, youtube mashups) while sometimes one explicitly attempts to preve
I use scrum too. But that's not a way of estimating programming time, it is merely a way to manage a software project. And it works. Use it. It's good for your heart and blood pressure:P
Anyway. Estimating programming time is actually really simple. You take your time to plan, up to 10% of the duration of the project, and discuss the result with your peers. Make a work breakdown and make sure there's nothing in there that you estimate takes more than about a day. Preferably much shorter. Also, use fixed ranges. I use less than 1 hour, 1-4 hours, 4-8 hours, 1-3 days and more than 3 days. The latter two are to be avoided. The result of all this is obviously a range you expect your project to take, not a fixed number of hours. Note that according to pretty ancient research, engineers often need 2.18 times their estimate to complete a task; this is sort-of built-in in the fixed ranges I mentioned.
Also, it is very important to keep a log of what you've done, how long it took and why. That's part of the reason it takes some time to get it right. Find entries in your log that look a bit like the entries on your work breakdown and compare them; that way you can learn from mistakes you made in previous plans.
So far for estimating. But that's only a third of the job. It is very important to acknowledge that what you've just calculated is just an estimate and to be open about it. So you need safeguards. I use the following:
1. Plan for overhead. 20% is usually fine.
2. Talk to your stakeholders and prioritize your project from a functional POV. Scrum uses http://en.wikipedia.org/wiki/MoSCoW_Method for that. Commit only to the requirements with the highest priority (and if that's all of them, just make up optional requirements:P).
3. Make sure your maximum estimate plus the overhead is enough time to fix those requirements.
The last thing you need to make your estimates turn out to be correct, is some form of project management. Make sure you discuss the state of the project (as compared to the original plan!) daily. Let all team members have their say and if something does not go according to plan, act on it early, don't safe the problems for release day. Make sure everybody has the right focus and works on the requirements with the highest priorities. Nobody should work on prio 1 requirements when prio 2 requirements are still not finished. Ever.
Obviously you're guaranteed to fail if you don't commit, integrate, test, build and package early and often. Use a continuous integration build-server, use version control, write unit-tests (yes, they safe time), use a proper issue-tracker (with workflow and support for estimates, actual time, priority etc) and make sure you have a quality assurance person on board that tests EVERYTHING (yes, that'll safe time too). Just the usual common sense stuff.
Of course some of us work on projects at companies that are run by douchebags; they won't give you enough time to plan, they do not want to prioritize, they don't understand why they need to pay for servers, issue-trackers, meetings, continuous integration servers, quality assurance ppl and all that "bullshit". Always share your concerns with them; never ever give them the chance to blame you. Blame them instead. And look for a better job that does not remind you of Dilbert; such jobs do exist;-)
Now if you stick to all that and evaluate early and often, you'll probably get it completely wrong the first few times, but you'll quite often get it spot on eventually. 99% of correctly estimating programming time is to get to know yourself and to stick to your plan. And those two things are incredibly hard;-P
Well, those would not really be problems if the shuttle were just shut down and kept around for whenever it might prove to be useful. Or if it were adapted (by stuffing it full of solar panels for example) in order to solve those problems before becoming a part of the ISS. But that's not done either for the one and only real reason: in order to stay in orbit, the ISS needs a boost every now and then. That takes a tremendous amount of energy and since the Shuttle is really heavy because it has to withstand the forces of launch and reentry, keeping it around simply is not a good idea.