Some would say the prize is premature, but this prize isn't about accomplishments. It's about one of the top leaders of the world, coming into office, and immediately doing everything in his power to apologize to the world for our arrogance, remind us and others that the US is one among many nations, reaching out to all other nations, friends and enemies, and making efforts to reduce nuclear arms around the world. Has he succeeded in all these things? Some. Will he succeed in more? Well that's the point of the award.
The award serves two purposes. One, he is rewarded for his intentions. It lets Obama know that the rest of the world perceives his intentions and actions favorably, and that he should continue in this way if he truly seeks peace and harmony among nations. Second, it gives him a slight boost in authority. He is now widely recognized for his intentions, and his desire to bring peace to the world, and that should help him (albeit, only slightly) when negotiating with others. It gives him credibility, and leaves less room for others to doubt his motivations. It encourages others to support his efforts if they also seek peace.
In other words, the award is recognition of his efforts so far, and will act as a tool to help him proceed with his peaceful goals in the future.
You don't need to "trick" the GPU anymore, but it is still lacking tons of functionality. I remember a coworker complaining that he got some double-precision operations working, but everything crashed if he used any for-loops. Additionally, there are different bit-representations for variables on CPU vs GPU which can complicate things to hell when trying to get the CPU and GPU to cooperate with each other. Yes, CUDA is like C or C++, but it's not the same, yet. Hence, new releases like this get people excited.
Personally, I've found it to require too much time-investment to learn how to do GPGPU programming, but new cards with updated functionality help flatten the learning curve.
I work at a physics lab, and demand for these newer NVIDIA cards are exploding due to general-purpose GPU programming. With a little bit of creativity and experience, many computational problems can be parallelized, and then run on the multiple GPU cores with fantastic speedup. In our case, we got a simulation from 2s/frame to 12ms/frame. It's not trivial though, and the guy in our group who got good at it... he found himself on 7 different projects simultaneously as everyone was craving this technology. He eventually left b/c of the stress. Now everyone and their mother either wants to learn how to do GPGPU, or recruit someone who does. This is why I bought NVIDIA stock (and they have doubled since I bought it).
But this technology isn't straightforward. Someone asked why not replace your CPU with it? Well for one, GPUs didn't use to be able to do ANY floating or double-precision calculations. You couldn't even program calculations directly -- you had to figure out how to represent your problem as texel- and polygon-operations so that you could trick your GPU into doing non-GPU calculations for you. With each new card released, NVIDIA is making strides to accommodate those who want GPGPU, and for everyone I know those advances couldn't come fast enough.
I've been following Nate ever since the 2008 elections, and I've much enjoyed his analysis. Being a mathematician, I can spot BS math, but Nate usually does a decent job with no BS. But this article is has so many analytical gaps that I feel awkward supporting him this time, even though the article as a whole is convincing. To make such a bold claim as he is, I would've expected him to assess this more completely. He did no comparisons to other pollsters, and sampled data that is not IID (identically and independently distributed). i.e. if a boolean poll has 49% for one side (9) the other answer has to be 51% (1) The last digits (1 and 9) are completely dependent. Not all polls are boolean, but there will still be correlations, and many polls in the sample are boolean. Not only that, but he mis-applied the reference to Benford's Law. I know he knows what Benford's law is, because he's had multiple other posts about it, but got it dead wrong in this article.
I'm glad there is someone sufficiently mathematical to look for things like this and have a wide enough audience to be heard, but I wish he'd taken some more time to do look at more control groups and do some confidence intervals before sticking his head into a potential legal mess.
Someone was talking about a nuclear reactor to get energy. That works if you are, say, generating evergy for a propeller that gives you thrust by moving lots of air. But in space, there's no way to convert energy into motion... you have to physically part with mass if you want to obtain thurst in a particular direction.
You need more than "energy" to propel yourself through space. With no atmosphere around you, the only way to gain thrust is by throwing [read: burning] fuel in the opposite direction you want to go. This means you physically have to impart momentum (permanently) onto fuel mass and there's no way to get it back, without cancelling the momentum (imagine a rope with a rock: you can throw the rock to the left, to obtain "thrust" to the right, but if you use the rope to get the rock back, you're imparting left-momentum onto yourself to get the right-momentum onto the rock... it's a zero-sum game).
The point of the story is that you have to part with mass, if you want to change your momentum. I think there was an article a couple years ago about a "relativity drive" which used various features of relativity to get a couple millinewtons out of microwave energy (which could be done with a nuclear source), but I haven't heard anything since, so the technology probably didn't pan out (as with most of these slashdot stories).
Just a comment before people get out of hand talking about how quickly we can go to Mars with better thrusters... anyone who's taken a class on Orbital mechanics should know that you can't just decide to go to Mars whenever you like. Part of the problem with trips to Mars is the distance, but also the timing. It would be extremely difficult to do an orbital transfer from Earth to Mars while they are on opposite sides of the sun. It would add months, if not years, to your trip, and the fuel requirements certainly wouldn't be aided by it. Unfortunately, because the an Earth-year and Mars-year are so close (like 1 mars-year is 1.8 earth years...?) it takes a while for the orbits to sync up again once they get out of sync (isn't this known as beat frequency in the audio world?).
Now don't quote me on this b/c it's been a while since I took orbital mechanics... but I seem to remember the "optimal" window for an Earth-to-Mars transfer opening up once every 2.5 years, it would take 8 months to travel there, 90-98% of your ship's mass would have to be fuel, and then you'd have to wait 1.5 more years for the "optimal" Mars-to-Earth orbital transfer window. In other words, doing a round-trip flight to Mars is no trivial matter.
Even with a more efficient fuel, perhaps you can stretch those windows, but you're not going to find an astronaut who is willing to leave now for a 1.5-year-commute to Mars, instead of waiting a year and doing an 8-month-commute. Even if those times are shrunk by a factor of 2 with a more efficient fuel, it's always going to be a huge operation.
In fact, I see you basically just spit out what was written on the "Grover's Algorithm" wiki page. Well, someone should update that page, because the "unsorted database search" is only one example of the usefulness of Grover's Algorithm.
Since you trust wiki so much, consider the wiki page on quantum computers which contains the explanation of Grover's algorithm as I described it.
I believe because of you, my post got modded down/out, which is a shame since I'm one of the few people here who's actually studied QCs before. Go read my other post about quantum computers.
I took a class on QC, and I assure you that you are mis-reading Grover's Algorithm. It applies to any pure-guessing problem for which all possible answers are equally likely. If you can create a quantum circuit that can check whether a given key is correct, and no one key is any more likely than any other key, then you can apply Grover's algorithm.
It appears you are a little trigger-happy with calling BS.
The power of Quantum Computers is in getting really smart people to figure out how to take advantage of quantum interference to our benefit. There have been some really impressive results for a variety of pure-math problems that only a few people care about. But integer factorization and discrete-logarithms are among them - hence why QCs threaten most/all asymmetric encryption protocols (they're all based on one or both of those problems). However, for a vast array of problems, QCs won't offer us any computational improvement.
There are some improvements for more-practical algorithms, but the speed-up isn't usually as impressive. However, using Grover's algorithm to reduce a pure guessing problem from O(n) to O(sqrt(n)) is intriguing, to say the least.
High Intensity Interval Training (HIIT) is fairly well-known activity for general fitness and weight loss. It's been found that 15 minutes of HIIT will get you better fitness and weight-loss benefits than 60 minutes of medium intensity running, biking, etc. Google "HIIT" you'll learn a bit about it.
The downside? It's tiring as hell. If you do it correctly, you only spend 15 min exercising, but you should hardly be able to walk when you're done (so add 5 minutes for catching your breath). This explains why some people have trouble losing weight through jogging, treadmills and stationary bikes. But playing soccer, basketball, or [in my case] kickboxing results in a very quick fitness results. It's been proven that HIIT raises your metabolism for a full 24 hours after you finish, even only doing 10-15 min.
The goal should be 15 rounds, 30s on, 30s off. Start with like 5 rounds of 30s on, 90s off, and try to improve to the 15-min goal. The activity can be anything you want: punching bags are great, or you can do sprint/walk intervals on a track, etc. But it is vital that you go 90% to 100% intensity for the "on" intervals. The only requirement for the "off" intervals is to try to stay standing/pacing (don't sit down/go to 0%). It is absolutely exhausting, but the health benefits are phenomenal. I do a variation of HIIT 2-3x per week in my kickboxing class, and I lost about 20 lbs and endurance went up 10-fold in the span of 2 months.
If you're going to ever have time for any kind of exercise, you'll have time for this, unless you're trying to figure out how to get exercise in front of your steering wheel or your desk. Come up with an exercise that you can do, or a variety of exercises you can do that will take all your energy for about 30 seconds, and alternate between them. In my case, I wrote a short python script that just dings ever 30s so that I don't have to try to watch a stopwatch or anything.
My recommendation is to alternate between 4-6 activities for the "on" intervals, using different muscle groups for each, so that you are working 100%, but different muscles. Try clapping pushups, speed burpees (google it), doing full squat jumps as high as you can, full crunches/situps/veeups, etc.... or get a punching bag and go nuts punching and kicking it. That's what I do, and it's very satisfying.
Parent is slightly off on the Quantum computing comment. Quantum computers can break cryptographic protocols based on the difficulty of integer factorization (RSA/PGP/GPG/PKI/SSL/TLS), and discrete-logarithms (all of the above plus elgamal, elliptic curves). However, AES is a block cipher which relies on neither of these pure-math problems.
The only advantage of QCs in breaking AES is that Grover's Algorithm can be applied for random guessing of the encryption key. AES-256 has 2^256 possible encryption keys. It takes a classical computer an average of n/2 guesses to find the right key, or 2^255 operations. However a QC running Grover's Algorithm does it in an average of approx sqrt(n) "guesses." This means that it takes about 2^128 operations to get the AES-256 key using a quantum computer.
As previous posters have mentioned, 2^128 is still far out of our reach. And to subvert QCs for this type of problem, all we have to do is double our key length to get the same security. Perhaps if we find a way to combine Grover's Algorithm with this new AES vulnerability, we can get it down to 2^60 to 2^64, but that is still extremely prohibitive. Additionally, that's a big "if," since Grover's Algorithm is intended for pure-guessing problems.
I took a class on Quantum computing, and studied many specific QC algorithms, so I know a little bit about them. A lot of misunderstandings about them, so let me summarize.
Quantum Computers are not super-computers. On a bit-for-bit (or qubit-for-qubit) scale, they're not necessarily faster than regular computers, they just process info differently. Since information is stored in a quantum "superposition" of states, as opposed to a deterministic state like regular computers, the qubits exhibit quantum interference around other qubits. Typically, your bit starts in 50% '0' and 50% '1', and thus when you measure it, you get a 50% chance of it being one or the other (and then it assumes that state). But if you don't measure, and push it through quantum circuits allowing them to interact with other qubits, you get the quantum phases to interfere and cancel out. If you are damned smart (as I realized you have to be, to design QC algorithms), you can figure out creative ways to encode your problem into qubits, and use the interference to cancel out the information you don't want, and leave the information you do want.
For instance, some calculations will start with the 50/50 qubit above, and end with 99% '0' and 1% '1' at the end of the calculation, or vice versa, depending on the answer. Then you've got a 99% chance of getting the right answer. If you run the calculation twice, you have a 99.99% chance of measuring the correct answer.
However, the details of these circuits which perform quantum algorithms are extremely non-intuitive to most people, even those who study it. I found it to require an amazing degree of creativity, to figure out how to combine qubits to take advantage of quantum interference constructively. But what does this get us?
Well it turns out that quantum computers can run anything a classical computer can do, and such algorithms can be written identically if you really wanted to, but doing so gets the same results as the classical computer (i.e. same order of growth). But, the smart people who have been publishing papers about this for the past 20 years have been finding new ways to combine qubits, to take advantage of nature of certain problems (usually deep, pure-math concepts), to achieve better orders of growth than possible on a classical computer. For instance, factoring large numbers is difficult on classical computers, which is why RSA/PGP/GPG/PKI/SSL is secure. It's order of growth is e^( n^(1/3) ). It's not quite exponential, but it's still prohibitive. It turns out that Shor figured out how to get it to n^2 on a quantum computer (which is the same order of growth as decrypting with the private key on a classical computer!). Strangely, trying to guess someone's encryption key, normally O(n) on classical computers (where n is the number of possible keys encryption keys) it's only O(sqrt(n)) on QCs. Weird (but sqrt(n) is still usually too big).
There's a vast number of other problems for which efficient quantum algorithms have been found. Unfortunately, a lot of these problems aren't particularly useful in real life (besides to the curious pure-mathematician). A lot of them are better, but not phenomenal. Like verifying that two sparse matrices were mulitplied correctly has order of growth n^(7/3) on a classical computer, n^(5/3) on a quantum computer. You can find a pretty extensive list by googling "quantum algorithm zoo."
Unfortunately [for humanity], there is no evidence yet that quantum computers will solve NP-complete problems efficiently. Most likely, they won't. So don't get your hopes up about solving the traveling salesmen problem any time soon. But there is still a lot of cool stuff we can do with them. In fact, the theory is so far ahead of the technology, that we're anxiously waiting for breakthroughs like this, so we can start plugging problems through known algorithms.
In general, it's not tied to a card. CUDA itself might be NVIDIA-dependent, but general-purpose GPU programming is not, and other manufacturers will have similar interfaces to GP-GPU programming, eventually.
As for my own experience with it... everyone at work is going crazy over them. One of our major simulations implements a high-fidelity IR scene modeler. It used to take 2 seconds per frame on CPU-only. They re-wrote it with GPU and got it down to 12 ms.
Anything that is highly parallelizable with low memory transfer reqts will get a pretty impressive speedup. My co-worker who has been doing this for a year now was explaining that computation is essentially free, it's the memory operations which are the bottleneck.
I got two Sony Micro Vault flash drives a year ago, like $20 for 2GB and $40 for 4GB. They are USB keys, but don't have the metallic anchor around them, making them about the same thickness as an SD card. I keep them in my wallet where I would normally keep my ID (relocated to CC pocket) and therefore have them accessible at all times. The 2GB key I keep encrypted (dmcrypt/LUKS) and that contains basically all my personal information. The 4GB key has anything and everything and constantly break it out to give or get data from people. I now can't live without them, and people are impressed by how nerdy I am that I have such small USB keys on me all the time.
I tried some similar Kingston USB keys (also tiny, with keychain hole) but both stopped working--completely, hopelessly dead--after 1 month.
The fact that we can store 16e9 bytes on a disk the size of our thumbnail for a price that is accessible to the average person, is evidence enough that we've reached "the future".
I'm mildly bothered by the 27 megapixel metric, as it tells you nothing about the scope of the image. I can take a 10 MP picture of the sky with my digital camera and half those pixels will be wasted on the trees around me, and the rest won't give us any new information that anyone else can't get.
It would be interesting to know the solid angle, or the field-of-view measurement that is associated with the image. If you are taking a 5000x5000 picture of something 1 light year across, from 10 billion light years away, that requires a hell of a tiny field of view. Approximately 100 picoradians of resolution. If you have that type of resolution, the picture could only be 5 megapixels and probably still contain a plethora of interesting stuff.
I don't post here much, but I have to write to promote this game. The game has been in development for 20 years, and the graphics have been exactly the same the whole time. So where did all the development go? Into pure depth of gameplay. I played this game off and on for like 7 years before I was able to finally finish the game once, and that's with just one of the 20 character types you can be. There's actually a portion of my brain devoted to nethack knowledge. Yes, I'm a nerd. But, this is a great game. As long as you don't mind your buddies making fun of you for playing a game produced exclusively from ASCII graphics (but it is the most efficient way for you to view and comprehend the current state of the game).
As an example of pure depth, consider the water traps that rust your weapons and armor. Well, if you are polymorphed into an iron golem, you can rust to death from walking into a water trap. Touching cockatrice corpses will turn you to stone instantly, but if you wear gloves you can wield it as a weapon to turn other creatures to stone. But if you are burdened carrying too much stuff, you are likely to fall down the steps and turn yourself to stone. Game over, try again. If you are confused from eating rotten food, reading scrolls will cast spells in ways you weren't expecting. They thought of everything in this game.
You can actually find a wand of wishing on the first level and get any three items in the game. The inexperienced player still won't make it very far. No matter how strong or amazing you are, you could still die from a falling drawbridge, cockatrice corpse, being digested by strange creatures, being drowned by an electric eel, or kicking a wall while you are near death. Even after all the years I've spent on this game, I still learn something new every time I play. It's that deep.
It seems that the MITM can accomplish his deception if he is sufficiently close to either the server or the client. If he's next to either of them, he can replace all the data going in or all the data going out, so that all I/O seems to be the same.
In other words, your officemate decides to bridge your network connection through his computer without you realizing he's switched your cables. It doesn't really matter what the notaries say, because he can manipulate all of them to say the same thing, since all their responses are routed through his computer first. Identically, if he's on the server side, he can modify all the outgoing notary requests so all notaries see the same thing.
With respect to that, there's not much that can save you. But, someone evil in the intarwebs who is randomly a few hops from either the server or client will no longer have the power to pull off a MITM. They have to compromise either network-bottleneck to break it. Actually it surprises me that no one thought of this earlier. It's a simple concept which appears to serve its purpose (at least until empirical evidence finds otherwise).
Thank god the server is encrypted but the laptop isn't. That makes a lot of sense.
Anyone else think this story is just a cover-up for the fact the laptop really is still lost? Falsely claiming it's been recovered is a lot less painful than dealing with the PR consequences.
I actually find this idea interesting. Clearly someone has to seed the network with the whole song, but once more than two people provide it, perhaps they only keep portions of songs on their share folder, so it's not even a whole song. It just so happens that other people sharing have different pieces. The RIAA would come up with an excuse for why this is just as bad, but technically you don't even have a working copy in your share folder to distribute so the legalease around it would be interesting.
but the problem is that it requires a human to seed the questions, which means they will be limited in number. If they're limited in number then the spammers will just go through and keep reloading the screen until they've seen all (or mostly all) of the answers and program their bot with the correct answers.
That is partially a true statement. You can use your limited number of items, and combine them in such a way that you are combinatorically increasing the answer space. For instance, you have 100 items in your limited database -- if you require two things be identified at once, there's 10,000 items in your answer space. Make that 4 things, and it's almost a billion unique captchas. Of course, this is an over simplification, but the concept is there if it's done correctly.
I prefer the math word-problems approach. A friend of mine who did his Master's in AI said the best AI can do on true/false kindergarten word-questions (i.e. "A dozen bagels is 12 bagels?") is like 60%. General comprehension of sentences and language constructs is very far behind human abilities, even at the kindergarten level. Of course, though, this requires more time to complete a CAPTCHA, but sounds like there aren't many other options.
I don't remember there being a standards war. There was not two parties competing. It was an established standard (ODF) and MS attempting to corrupt it, dilute it, bribe their way in with their own product. It is amusing that "ODF won" when there wasn't even a competition.
This is really just hype more than anything. Remember that article about like 50% of people with HDTVs think they are viewing in HD but it turns out they're not (b/c of having wrong cables, etc)? It's the same with colors--the eyes just can't distinguish between a display with 10 million colors and a billion colors. Personally I think you're wasting your money buying this thing. But at the very least, maybe the price of "inferior" monitors will go down if this goes mainstream, so I shouldn't complain.
Peer review is the single most important aspect of scientific/mathematical development, and that doesn't exist online, unless it's reprinting the peer reviewed journals. The process for journal publication is what ensures that there is quality being printed and that multiple other scientists agree with the results (or rather, don't find problems with it).
You'll notice http://www.claymath.org/millennium/ has seven, $1million problems and the money won't be awarded until a solution has been published, and survives the peer review process for two years. Without this process, there is no mechanism for separating people who sound like they know what they're talking about, and people who *actually* know what they're talking about.
Slashdot Mirror
Some would say the prize is premature, but this prize isn't about accomplishments. It's about one of the top leaders of the world, coming into office, and immediately doing everything in his power to apologize to the world for our arrogance, remind us and others that the US is one among many nations, reaching out to all other nations, friends and enemies, and making efforts to reduce nuclear arms around the world. Has he succeeded in all these things? Some. Will he succeed in more? Well that's the point of the award.
The award serves two purposes. One, he is rewarded for his intentions. It lets Obama know that the rest of the world perceives his intentions and actions favorably, and that he should continue in this way if he truly seeks peace and harmony among nations. Second, it gives him a slight boost in authority. He is now widely recognized for his intentions, and his desire to bring peace to the world, and that should help him (albeit, only slightly) when negotiating with others. It gives him credibility, and leaves less room for others to doubt his motivations. It encourages others to support his efforts if they also seek peace.
In other words, the award is recognition of his efforts so far, and will act as a tool to help him proceed with his peaceful goals in the future.
You don't need to "trick" the GPU anymore, but it is still lacking tons of functionality. I remember a coworker complaining that he got some double-precision operations working, but everything crashed if he used any for-loops. Additionally, there are different bit-representations for variables on CPU vs GPU which can complicate things to hell when trying to get the CPU and GPU to cooperate with each other. Yes, CUDA is like C or C++, but it's not the same, yet. Hence, new releases like this get people excited.
Personally, I've found it to require too much time-investment to learn how to do GPGPU programming, but new cards with updated functionality help flatten the learning curve.
I work at a physics lab, and demand for these newer NVIDIA cards are exploding due to general-purpose GPU programming. With a little bit of creativity and experience, many computational problems can be parallelized, and then run on the multiple GPU cores with fantastic speedup. In our case, we got a simulation from 2s/frame to 12ms/frame. It's not trivial though, and the guy in our group who got good at it... he found himself on 7 different projects simultaneously as everyone was craving this technology. He eventually left b/c of the stress. Now everyone and their mother either wants to learn how to do GPGPU, or recruit someone who does. This is why I bought NVIDIA stock (and they have doubled since I bought it).
But this technology isn't straightforward. Someone asked why not replace your CPU with it? Well for one, GPUs didn't use to be able to do ANY floating or double-precision calculations. You couldn't even program calculations directly -- you had to figure out how to represent your problem as texel- and polygon-operations so that you could trick your GPU into doing non-GPU calculations for you. With each new card released, NVIDIA is making strides to accommodate those who want GPGPU, and for everyone I know those advances couldn't come fast enough.
I've been following Nate ever since the 2008 elections, and I've much enjoyed his analysis. Being a mathematician, I can spot BS math, but Nate usually does a decent job with no BS. But this article is has so many analytical gaps that I feel awkward supporting him this time, even though the article as a whole is convincing. To make such a bold claim as he is, I would've expected him to assess this more completely. He did no comparisons to other pollsters, and sampled data that is not IID (identically and independently distributed). i.e. if a boolean poll has 49% for one side (9) the other answer has to be 51% (1) The last digits (1 and 9) are completely dependent. Not all polls are boolean, but there will still be correlations, and many polls in the sample are boolean. Not only that, but he mis-applied the reference to Benford's Law. I know he knows what Benford's law is, because he's had multiple other posts about it, but got it dead wrong in this article.
I'm glad there is someone sufficiently mathematical to look for things like this and have a wide enough audience to be heard, but I wish he'd taken some more time to do look at more control groups and do some confidence intervals before sticking his head into a potential legal mess.
Someone was talking about a nuclear reactor to get energy. That works if you are, say, generating evergy for a propeller that gives you thrust by moving lots of air. But in space, there's no way to convert energy into motion... you have to physically part with mass if you want to obtain thurst in a particular direction.
You need more than "energy" to propel yourself through space. With no atmosphere around you, the only way to gain thrust is by throwing [read: burning] fuel in the opposite direction you want to go. This means you physically have to impart momentum (permanently) onto fuel mass and there's no way to get it back, without cancelling the momentum (imagine a rope with a rock: you can throw the rock to the left, to obtain "thrust" to the right, but if you use the rope to get the rock back, you're imparting left-momentum onto yourself to get the right-momentum onto the rock... it's a zero-sum game).
The point of the story is that you have to part with mass, if you want to change your momentum. I think there was an article a couple years ago about a "relativity drive" which used various features of relativity to get a couple millinewtons out of microwave energy (which could be done with a nuclear source), but I haven't heard anything since, so the technology probably didn't pan out (as with most of these slashdot stories).
Just a comment before people get out of hand talking about how quickly we can go to Mars with better thrusters... anyone who's taken a class on Orbital mechanics should know that you can't just decide to go to Mars whenever you like. Part of the problem with trips to Mars is the distance, but also the timing. It would be extremely difficult to do an orbital transfer from Earth to Mars while they are on opposite sides of the sun. It would add months, if not years, to your trip, and the fuel requirements certainly wouldn't be aided by it. Unfortunately, because the an Earth-year and Mars-year are so close (like 1 mars-year is 1.8 earth years...?) it takes a while for the orbits to sync up again once they get out of sync (isn't this known as beat frequency in the audio world?).
Now don't quote me on this b/c it's been a while since I took orbital mechanics... but I seem to remember the "optimal" window for an Earth-to-Mars transfer opening up once every 2.5 years, it would take 8 months to travel there, 90-98% of your ship's mass would have to be fuel, and then you'd have to wait 1.5 more years for the "optimal" Mars-to-Earth orbital transfer window. In other words, doing a round-trip flight to Mars is no trivial matter.
Even with a more efficient fuel, perhaps you can stretch those windows, but you're not going to find an astronaut who is willing to leave now for a 1.5-year-commute to Mars, instead of waiting a year and doing an 8-month-commute. Even if those times are shrunk by a factor of 2 with a more efficient fuel, it's always going to be a huge operation.
In fact, I see you basically just spit out what was written on the "Grover's Algorithm" wiki page. Well, someone should update that page, because the "unsorted database search" is only one example of the usefulness of Grover's Algorithm.
Since you trust wiki so much, consider the wiki page on quantum computers which contains the explanation of Grover's algorithm as I described it.
I believe because of you, my post got modded down/out, which is a shame since I'm one of the few people here who's actually studied QCs before. Go read my other post about quantum computers.
I took a class on QC, and I assure you that you are mis-reading Grover's Algorithm. It applies to any pure-guessing problem for which all possible answers are equally likely. If you can create a quantum circuit that can check whether a given key is correct, and no one key is any more likely than any other key, then you can apply Grover's algorithm.
It appears you are a little trigger-happy with calling BS.
I probably should've linked to my post about Quantum Computing from yesterday.
The power of Quantum Computers is in getting really smart people to figure out how to take advantage of quantum interference to our benefit. There have been some really impressive results for a variety of pure-math problems that only a few people care about. But integer factorization and discrete-logarithms are among them - hence why QCs threaten most/all asymmetric encryption protocols (they're all based on one or both of those problems). However, for a vast array of problems, QCs won't offer us any computational improvement.
There are some improvements for more-practical algorithms, but the speed-up isn't usually as impressive. However, using Grover's algorithm to reduce a pure guessing problem from O(n) to O(sqrt(n)) is intriguing, to say the least.
High Intensity Interval Training (HIIT) is fairly well-known activity for general fitness and weight loss. It's been found that 15 minutes of HIIT will get you better fitness and weight-loss benefits than 60 minutes of medium intensity running, biking, etc. Google "HIIT" you'll learn a bit about it.
The downside? It's tiring as hell. If you do it correctly, you only spend 15 min exercising, but you should hardly be able to walk when you're done (so add 5 minutes for catching your breath). This explains why some people have trouble losing weight through jogging, treadmills and stationary bikes. But playing soccer, basketball, or [in my case] kickboxing results in a very quick fitness results. It's been proven that HIIT raises your metabolism for a full 24 hours after you finish, even only doing 10-15 min.
The goal should be 15 rounds, 30s on, 30s off. Start with like 5 rounds of 30s on, 90s off, and try to improve to the 15-min goal. The activity can be anything you want: punching bags are great, or you can do sprint/walk intervals on a track, etc. But it is vital that you go 90% to 100% intensity for the "on" intervals. The only requirement for the "off" intervals is to try to stay standing/pacing (don't sit down/go to 0%). It is absolutely exhausting, but the health benefits are phenomenal. I do a variation of HIIT 2-3x per week in my kickboxing class, and I lost about 20 lbs and endurance went up 10-fold in the span of 2 months.
If you're going to ever have time for any kind of exercise, you'll have time for this, unless you're trying to figure out how to get exercise in front of your steering wheel or your desk. Come up with an exercise that you can do, or a variety of exercises you can do that will take all your energy for about 30 seconds, and alternate between them. In my case, I wrote a short python script that just dings ever 30s so that I don't have to try to watch a stopwatch or anything.
My recommendation is to alternate between 4-6 activities for the "on" intervals, using different muscle groups for each, so that you are working 100%, but different muscles. Try clapping pushups, speed burpees (google it), doing full squat jumps as high as you can, full crunches/situps/veeups, etc.... or get a punching bag and go nuts punching and kicking it. That's what I do, and it's very satisfying.
Parent is slightly off on the Quantum computing comment. Quantum computers can break cryptographic protocols based on the difficulty of integer factorization (RSA/PGP/GPG/PKI/SSL/TLS), and discrete-logarithms (all of the above plus elgamal, elliptic curves). However, AES is a block cipher which relies on neither of these pure-math problems.
The only advantage of QCs in breaking AES is that Grover's Algorithm can be applied for random guessing of the encryption key. AES-256 has 2^256 possible encryption keys. It takes a classical computer an average of n/2 guesses to find the right key, or 2^255 operations. However a QC running Grover's Algorithm does it in an average of approx sqrt(n) "guesses." This means that it takes about 2^128 operations to get the AES-256 key using a quantum computer.
As previous posters have mentioned, 2^128 is still far out of our reach. And to subvert QCs for this type of problem, all we have to do is double our key length to get the same security. Perhaps if we find a way to combine Grover's Algorithm with this new AES vulnerability, we can get it down to 2^60 to 2^64, but that is still extremely prohibitive. Additionally, that's a big "if," since Grover's Algorithm is intended for pure-guessing problems.
I took a class on Quantum computing, and studied many specific QC algorithms, so I know a little bit about them. A lot of misunderstandings about them, so let me summarize.
Quantum Computers are not super-computers. On a bit-for-bit (or qubit-for-qubit) scale, they're not necessarily faster than regular computers, they just process info differently. Since information is stored in a quantum "superposition" of states, as opposed to a deterministic state like regular computers, the qubits exhibit quantum interference around other qubits. Typically, your bit starts in 50% '0' and 50% '1', and thus when you measure it, you get a 50% chance of it being one or the other (and then it assumes that state). But if you don't measure, and push it through quantum circuits allowing them to interact with other qubits, you get the quantum phases to interfere and cancel out. If you are damned smart (as I realized you have to be, to design QC algorithms), you can figure out creative ways to encode your problem into qubits, and use the interference to cancel out the information you don't want, and leave the information you do want.
For instance, some calculations will start with the 50/50 qubit above, and end with 99% '0' and 1% '1' at the end of the calculation, or vice versa, depending on the answer. Then you've got a 99% chance of getting the right answer. If you run the calculation twice, you have a 99.99% chance of measuring the correct answer.
However, the details of these circuits which perform quantum algorithms are extremely non-intuitive to most people, even those who study it. I found it to require an amazing degree of creativity, to figure out how to combine qubits to take advantage of quantum interference constructively. But what does this get us?
Well it turns out that quantum computers can run anything a classical computer can do, and such algorithms can be written identically if you really wanted to, but doing so gets the same results as the classical computer (i.e. same order of growth). But, the smart people who have been publishing papers about this for the past 20 years have been finding new ways to combine qubits, to take advantage of nature of certain problems (usually deep, pure-math concepts), to achieve better orders of growth than possible on a classical computer. For instance, factoring large numbers is difficult on classical computers, which is why RSA/PGP/GPG/PKI/SSL is secure. It's order of growth is e^( n^(1/3) ). It's not quite exponential, but it's still prohibitive. It turns out that Shor figured out how to get it to n^2 on a quantum computer (which is the same order of growth as decrypting with the private key on a classical computer!). Strangely, trying to guess someone's encryption key, normally O(n) on classical computers (where n is the number of possible keys encryption keys) it's only O(sqrt(n)) on QCs. Weird (but sqrt(n) is still usually too big).
There's a vast number of other problems for which efficient quantum algorithms have been found. Unfortunately, a lot of these problems aren't particularly useful in real life (besides to the curious pure-mathematician). A lot of them are better, but not phenomenal. Like verifying that two sparse matrices were mulitplied correctly has order of growth n^(7/3) on a classical computer, n^(5/3) on a quantum computer. You can find a pretty extensive list by googling "quantum algorithm zoo."
Unfortunately [for humanity], there is no evidence yet that quantum computers will solve NP-complete problems efficiently. Most likely, they won't. So don't get your hopes up about solving the traveling salesmen problem any time soon. But there is still a lot of cool stuff we can do with them. In fact, the theory is so far ahead of the technology, that we're anxiously waiting for breakthroughs like this, so we can start plugging problems through known algorithms.
In general, it's not tied to a card. CUDA itself might be NVIDIA-dependent, but general-purpose GPU programming is not, and other manufacturers will have similar interfaces to GP-GPU programming, eventually.
As for my own experience with it... everyone at work is going crazy over them. One of our major simulations implements a high-fidelity IR scene modeler. It used to take 2 seconds per frame on CPU-only. They re-wrote it with GPU and got it down to 12 ms.
Anything that is highly parallelizable with low memory transfer reqts will get a pretty impressive speedup. My co-worker who has been doing this for a year now was explaining that computation is essentially free, it's the memory operations which are the bottleneck.
I got two Sony Micro Vault flash drives a year ago, like $20 for 2GB and $40 for 4GB. They are USB keys, but don't have the metallic anchor around them, making them about the same thickness as an SD card. I keep them in my wallet where I would normally keep my ID (relocated to CC pocket) and therefore have them accessible at all times. The 2GB key I keep encrypted (dmcrypt/LUKS) and that contains basically all my personal information. The 4GB key has anything and everything and constantly break it out to give or get data from people. I now can't live without them, and people are impressed by how nerdy I am that I have such small USB keys on me all the time.
I tried some similar Kingston USB keys (also tiny, with keychain hole) but both stopped working--completely, hopelessly dead--after 1 month.
The fact that we can store 16e9 bytes on a disk the size of our thumbnail for a price that is accessible to the average person, is evidence enough that we've reached "the future".
I'm mildly bothered by the 27 megapixel metric, as it tells you nothing about the scope of the image. I can take a 10 MP picture of the sky with my digital camera and half those pixels will be wasted on the trees around me, and the rest won't give us any new information that anyone else can't get. It would be interesting to know the solid angle, or the field-of-view measurement that is associated with the image. If you are taking a 5000x5000 picture of something 1 light year across, from 10 billion light years away, that requires a hell of a tiny field of view. Approximately 100 picoradians of resolution. If you have that type of resolution, the picture could only be 5 megapixels and probably still contain a plethora of interesting stuff.
I don't post here much, but I have to write to promote this game. The game has been in development for 20 years, and the graphics have been exactly the same the whole time. So where did all the development go? Into pure depth of gameplay. I played this game off and on for like 7 years before I was able to finally finish the game once, and that's with just one of the 20 character types you can be. There's actually a portion of my brain devoted to nethack knowledge. Yes, I'm a nerd. But, this is a great game. As long as you don't mind your buddies making fun of you for playing a game produced exclusively from ASCII graphics (but it is the most efficient way for you to view and comprehend the current state of the game).
As an example of pure depth, consider the water traps that rust your weapons and armor. Well, if you are polymorphed into an iron golem, you can rust to death from walking into a water trap. Touching cockatrice corpses will turn you to stone instantly, but if you wear gloves you can wield it as a weapon to turn other creatures to stone. But if you are burdened carrying too much stuff, you are likely to fall down the steps and turn yourself to stone. Game over, try again. If you are confused from eating rotten food, reading scrolls will cast spells in ways you weren't expecting. They thought of everything in this game.
You can actually find a wand of wishing on the first level and get any three items in the game. The inexperienced player still won't make it very far. No matter how strong or amazing you are, you could still die from a falling drawbridge, cockatrice corpse, being digested by strange creatures, being drowned by an electric eel, or kicking a wall while you are near death. Even after all the years I've spent on this game, I still learn something new every time I play. It's that deep.
It seems that the MITM can accomplish his deception if he is sufficiently close to either the server or the client. If he's next to either of them, he can replace all the data going in or all the data going out, so that all I/O seems to be the same.
In other words, your officemate decides to bridge your network connection through his computer without you realizing he's switched your cables. It doesn't really matter what the notaries say, because he can manipulate all of them to say the same thing, since all their responses are routed through his computer first. Identically, if he's on the server side, he can modify all the outgoing notary requests so all notaries see the same thing.
With respect to that, there's not much that can save you. But, someone evil in the intarwebs who is randomly a few hops from either the server or client will no longer have the power to pull off a MITM. They have to compromise either network-bottleneck to break it. Actually it surprises me that no one thought of this earlier. It's a simple concept which appears to serve its purpose (at least until empirical evidence finds otherwise).
Thank god the server is encrypted but the laptop isn't. That makes a lot of sense.
Anyone else think this story is just a cover-up for the fact the laptop really is still lost? Falsely claiming it's been recovered is a lot less painful than dealing with the PR consequences.
I actually find this idea interesting. Clearly someone has to seed the network with the whole song, but once more than two people provide it, perhaps they only keep portions of songs on their share folder, so it's not even a whole song. It just so happens that other people sharing have different pieces. The RIAA would come up with an excuse for why this is just as bad, but technically you don't even have a working copy in your share folder to distribute so the legalease around it would be interesting.
but the problem is that it requires a human to seed the questions, which means they will be limited in number. If they're limited in number then the spammers will just go through and keep reloading the screen until they've seen all (or mostly all) of the answers and program their bot with the correct answers.
That is partially a true statement. You can use your limited number of items, and combine them in such a way that you are combinatorically increasing the answer space. For instance, you have 100 items in your limited database -- if you require two things be identified at once, there's 10,000 items in your answer space. Make that 4 things, and it's almost a billion unique captchas. Of course, this is an over simplification, but the concept is there if it's done correctly. I prefer the math word-problems approach. A friend of mine who did his Master's in AI said the best AI can do on true/false kindergarten word-questions (i.e. "A dozen bagels is 12 bagels?") is like 60%. General comprehension of sentences and language constructs is very far behind human abilities, even at the kindergarten level. Of course, though, this requires more time to complete a CAPTCHA, but sounds like there aren't many other options.
I don't remember there being a standards war. There was not two parties competing. It was an established standard (ODF) and MS attempting to corrupt it, dilute it, bribe their way in with their own product. It is amusing that "ODF won" when there wasn't even a competition.
When we do find that guy, we can waterboard him to get the private key. According to the man, that's not torture!
This is really just hype more than anything. Remember that article about like 50% of people with HDTVs think they are viewing in HD but it turns out they're not (b/c of having wrong cables, etc)? It's the same with colors--the eyes just can't distinguish between a display with 10 million colors and a billion colors. Personally I think you're wasting your money buying this thing. But at the very least, maybe the price of "inferior" monitors will go down if this goes mainstream, so I shouldn't complain.
Peer review is the single most important aspect of scientific/mathematical development, and that doesn't exist online, unless it's reprinting the peer reviewed journals. The process for journal publication is what ensures that there is quality being printed and that multiple other scientists agree with the results (or rather, don't find problems with it).
You'll notice http://www.claymath.org/millennium/ has seven, $1million problems and the money won't be awarded until a solution has been published, and survives the peer review process for two years. Without this process, there is no mechanism for separating people who sound like they know what they're talking about, and people who *actually* know what they're talking about.