If you started the Towers of Hanoi puzzle in the usual state, the minimum solution uses 2^100 - 1 moves. One move per second would take about 4*10^22 years, or about 3*10^12 times the age of the universe.
Sort of. The D is unnecessary, and to be clear C*n is an upper bound on the number of calculations needed. That bound also only has to hold for n larger than some threshold value n0, though this is an unimportant constraint in CS since you can just increase C to cover all positive integer n. The constant C can sometimes be found explicitly in cases like this, though it's often a horrific mess. From the God's Number calculation, one can conclude a lower bound on C, though, to prevent the false contradiction that started this thread:) (if you have it work for all positive integers).
Learn Python "the Hard Way" to me implies an advanced book. It seems they meant "Learn Basic Python Well". I kind of prefer this title, too--it's much friendlier for the apparent target audience, even if it's not as catchy.
1. If 2-bromo-LSD and regular LSD have similar effects, shouldn't there be a very large number of sufferers who have had success with LSD, and wouldn't this have generated a previous study?
2. If they're called "suicide" headaches, are there documented cases of them causing suicide? (The Wikipedia article didn't list any, though the condition sounds horrific enough to cause it.)
3. Did anybody else think of the Star Trek TNG episode where Riker gets a headache, and Crusher mentions something about headaches being very abnormal in that time period? Am I remembering it right?
It's a little extreme, but replacing "study biomolecular chemistry" with "go to culinary school" gives a high quality analogy, both for the person who asked this question and in general. I imagine most good cooks have gone to culinary school, just like most good coders have a degree in CS. To dabble in cooking a nice meal you certainly don't have to go to culinary school either.
My CS program split pretty well into theoretical and practical halves. Also, some of the less useful courses were just specialized--like Compilers, or Computer Graphics. Your med school analogy,
If you want to be a better doctor then going back to med school wont' make any difference.
doesn't hold up: the hypothetical doctor had already been to med school, while the person who asked this question hasn't had a CS education.
In undergrad we once did a project with four CS upperclassmen, and two of us discovered after the project began that the other two really had no idea how pointers worked.
Scary. I know of old VB6 programmers who knew how pointers worked!
See? No serious author minds a $10 fee, as conclusively proven by my (n=1) data!
I think I understand what you're for. I imagine the no-barrier store would just get completely filtered by most people, kind of defeating the purpose of making publishing possible to anyone--even those who don't have $10 for an entry fee. (I maintain no serious author fits that category, but suppose some do.) Establishing an entry fee now wouldn't help filter current spam, unfortunately, but maybe if new spam stopped appearing, existing methods would get rid of existing spam. I really like this "first $10 goes to Amazon" (or to charity, or whatnot; just not the author) idea, since it seems to be the best of all worlds, and it should be extremely simple to implement. It should also have essentially no damaging effect on serious authors. If "spam" books make it past this hurdle, maybe they weren't so awful after all.
No, I'm pretty sure the (erroneous) reaction is just "I'm getting paid because.NET development works on Windows, and you're dropping support?!!!!". It's unclear how much web developer experience with JS/HTML5 will translate to whatever desktop app system Microsoft cooks up. You bring up a good point, but I doubt it's the root of any reaction.
So if they knew they wanted a cross-platform product, why didn't your company select tools that work on all three platforms?
Who says they knew they wanted a cross-platform product? Maybe the program started as Windows-only. It's unclear what decisions went into their current split development and whether or not they were poor ones.
Don't think your.net is better than what your MAC coworkers are doing
You didn't support this statement (which I'm actually interested in, as I've never developed for a Mac)... you just said that.net isn't cross-platform so is worse than the cross-platform GUIs you mentioned.
What money does Microsoft stand to gain by not releasing IE9 on Windows XP? The most recent version of Visual FoxPro will also be supported through 2015. Asking a company to support old versions indefinitely is probably too much.
Your post is essentially a rambling rant against "evil" Microsoft. I suppose that's why you posted AC...?
Peter Bright, an Ars Technica contributor, writes that
Early this month, Microsoft dropped something of a bombshell on Windows developers: the new Windows 8 touch-friendly immersive style would use a developer platform not based on.NET, which Microsoft has been championing for the past decade. Instead, it would use HTML5 and JavaScript.
But he doesn't believe the alarmist hype:
Windows developers want to be able to build immersive applications, and they don't want to have to use HTML5 and JavaScript to do it.
They won't have to. Want to write an immersive application in native C++? That's cool. Want to use C# and Silverlight? That's cool too. Both will be supported. Far from being left behind on the legacy desktop—which was the impression that many took from the presentation—native C++ and managed C# will both be first-class, supported ways of developing immersive, touch-first, tablet-friendly Windows 8-style applications.
(Feel free to write another, better summary. The one given is just completely inadequate for such a long article.)
Yes he did, and his only justification for that (IMO ridiculous) position is:
They suggest Amazon charge a listing fee for each book — perhaps $10 or $20. [...] This would be a huge shame. Through things like KDP and CreateSpace, Amazon is making proper publishing truly democratic and accessible to all. To get a Kindle eBook on sale, all you need is a computer with a word processor. That’s it. You don’t need up-front fees. You don’t need to be a publisher. You don’t need technical knowledge.
Who has a computer, word processor, and the time to write a serious book, but not $10? Amazon could even take the $10 out of the first $10 of profit for each book if this entry fee would otherwise demonstrably be a barrier to serious writers.
I imagine most of congress hasn't met most of congress. Slightly over half of congress is 268 people. If they all just shook hands, there would be 35,778 handshakes.
Unbreakable in principle and unbreakable in reality are two very different claims. One is reasonable, assuming some principles of theoretical physics, while the other is silly to mildly informed people.
People are used to regular crypto, where the task of computing the result of a basic mathematic function can be safely left to hand-waving. You can do RSA with a computer, or longhand on a piece of paper. The properties of the computer aren't an assumed part of the way the system works. With QC, it is assumed that pieces of hardware behave in very specific ideal ways. You can't buy parts that work like that, you have to use real parts. Therefore the system design, and explanations of how a real system works need to account for that.
I still think (from my fuzzy understanding of this attack) that it uses a specific implementation detail that depends upon the system used, and might be relatively easy to patch. Maybe they can use different wavelengths of photons, one for a test and one not--I don't have the expertise to say how much of a redesign is necessary. The article makes it sound like it's not a huge deal, and the Toshiba guys say in one of the other articles that their system isn't susceptible to these attacks when properly operated.
You're exaggerating your point (eg. by talking about dragons and warp drive). One of the articles suggests you might mitigate this attack with a relatively simple extra verification step. This attack depends explicitly upon "blinding" a detector with light "above the intensity threshold" (certainly this is oversimplified). That's an attack on implementation details. Certainly I didn't mean to say that building a QC system is all "implementation details"; that would just be stupid. This one point that was attacked is an implementation detail.
This is an attack on implementation details, not the underlying physics of quantum mechanics. The title could have been a little better. This is (apparently; my only source is the submitter, as he's also the source in the article) the first working exploit of a quantum cryptography system that was able to steal the key without being detected.
He said: 'It would have been hard to prepare for this type of vulnerability.'
Well, yes, actually. It's not saying "it would have been hard to prevent this type of vulnerability", it's saying it would be hard to prepare for hundreds of thousands of customers' information getting stolen. That does sound hard to prepare for.
One expert [...] told The New York Times he wondered how the hackers could have known to breach security by focusing on the vulnerability in the browser.
Maybe he's just being horribly misquoted here. The vulnerability can apparently be triggered using a browser in a very standard way, which to a journalist might sound an awful lot like a "vulnerability in the browser". Still, if it's just shoving different numbers in a query string (which the article really, really makes it sound like it is), there's nothing to wonder at.
Yet again, faced with a news article on a topic I'm somewhat familiar with, shoddy reporting shines through. Disgusting.
I still don't see the point. Even ignoring the fact that there's a "save as PDF" option at the top of the Flash animation, what would be the point of preventing regular people from, say, copy&pasting from this document? It seems like one guy didn't notice the PDF option and wrote a story for the Wall Street Journal about it with an interview from someone not very knowledgeable about this system. This is why I hate journalists, as a rule: shoddy reporting is harmful and prevalent.
(Here's the PDF download link. It's 21.2 MB (lots of pictures) which might explain why they opted for a flash book format. Also, you *can* link to specific pages. Here's page 34.)
Slashdot Mirror
If you started the Towers of Hanoi puzzle in the usual state, the minimum solution uses 2^100 - 1 moves. One move per second would take about 4*10^22 years, or about 3*10^12 times the age of the universe.
Sort of. The D is unnecessary, and to be clear C*n is an upper bound on the number of calculations needed. That bound also only has to hold for n larger than some threshold value n0, though this is an unimportant constraint in CS since you can just increase C to cover all positive integer n. The constant C can sometimes be found explicitly in cases like this, though it's often a horrific mess. From the God's Number calculation, one can conclude a lower bound on C, though, to prevent the false contradiction that started this thread :) (if you have it work for all positive integers).
Learn Python "the Hard Way" to me implies an advanced book. It seems they meant "Learn Basic Python Well". I kind of prefer this title, too--it's much friendlier for the apparent target audience, even if it's not as catchy.
1. If 2-bromo-LSD and regular LSD have similar effects, shouldn't there be a very large number of sufferers who have had success with LSD, and wouldn't this have generated a previous study?
2. If they're called "suicide" headaches, are there documented cases of them causing suicide? (The Wikipedia article didn't list any, though the condition sounds horrific enough to cause it.)
3. Did anybody else think of the Star Trek TNG episode where Riker gets a headache, and Crusher mentions something about headaches being very abnormal in that time period? Am I remembering it right?
It's a little extreme, but replacing "study biomolecular chemistry" with "go to culinary school" gives a high quality analogy, both for the person who asked this question and in general. I imagine most good cooks have gone to culinary school, just like most good coders have a degree in CS. To dabble in cooking a nice meal you certainly don't have to go to culinary school either.
If you want to be a better doctor then going back to med school wont' make any difference.
doesn't hold up: the hypothetical doctor had already been to med school, while the person who asked this question hasn't had a CS education.
In undergrad we once did a project with four CS upperclassmen, and two of us discovered after the project began that the other two really had no idea how pointers worked.
Scary. I know of old VB6 programmers who knew how pointers worked!
See? No serious author minds a $10 fee, as conclusively proven by my (n=1) data!
I think I understand what you're for. I imagine the no-barrier store would just get completely filtered by most people, kind of defeating the purpose of making publishing possible to anyone--even those who don't have $10 for an entry fee. (I maintain no serious author fits that category, but suppose some do.) Establishing an entry fee now wouldn't help filter current spam, unfortunately, but maybe if new spam stopped appearing, existing methods would get rid of existing spam. I really like this "first $10 goes to Amazon" (or to charity, or whatnot; just not the author) idea, since it seems to be the best of all worlds, and it should be extremely simple to implement. It should also have essentially no damaging effect on serious authors. If "spam" books make it past this hurdle, maybe they weren't so awful after all.
No, I'm pretty sure the (erroneous) reaction is just "I'm getting paid because .NET development works on Windows, and you're dropping support?!!!!". It's unclear how much web developer experience with JS/HTML5 will translate to whatever desktop app system Microsoft cooks up. You bring up a good point, but I doubt it's the root of any reaction.
So if they knew they wanted a cross-platform product, why didn't your company select tools that work on all three platforms?
Who says they knew they wanted a cross-platform product? Maybe the program started as Windows-only. It's unclear what decisions went into their current split development and whether or not they were poor ones.
Don't think your .net is better than what your MAC coworkers are doing
You didn't support this statement (which I'm actually interested in, as I've never developed for a Mac)... you just said that .net isn't cross-platform so is worse than the cross-platform GUIs you mentioned.
What money does Microsoft stand to gain by not releasing IE9 on Windows XP? The most recent version of Visual FoxPro will also be supported through 2015. Asking a company to support old versions indefinitely is probably too much.
Your post is essentially a rambling rant against "evil" Microsoft. I suppose that's why you posted AC...?
Early this month, Microsoft dropped something of a bombshell on Windows developers: the new Windows 8 touch-friendly immersive style would use a developer platform not based on .NET, which Microsoft has been championing for the past decade. Instead, it would use HTML5 and JavaScript.
But he doesn't believe the alarmist hype:
Windows developers want to be able to build immersive applications, and they don't want to have to use HTML5 and JavaScript to do it.
They won't have to. Want to write an immersive application in native C++? That's cool. Want to use C# and Silverlight? That's cool too. Both will be supported. Far from being left behind on the legacy desktop—which was the impression that many took from the presentation—native C++ and managed C# will both be first-class, supported ways of developing immersive, touch-first, tablet-friendly Windows 8-style applications.
(Feel free to write another, better summary. The one given is just completely inadequate for such a long article.)
They suggest Amazon charge a listing fee for each book — perhaps $10 or $20. [...] This would be a huge shame. Through things like KDP and CreateSpace, Amazon is making proper publishing truly democratic and accessible to all. To get a Kindle eBook on sale, all you need is a computer with a word processor. That’s it. You don’t need up-front fees. You don’t need to be a publisher. You don’t need technical knowledge.
Who has a computer, word processor, and the time to write a serious book, but not $10? Amazon could even take the $10 out of the first $10 of profit for each book if this entry fee would otherwise demonstrably be a barrier to serious writers.
I imagine most of congress hasn't met most of congress. Slightly over half of congress is 268 people. If they all just shook hands, there would be 35,778 handshakes.
Thank you for the informative reply!
Unbreakable in principle and unbreakable in reality are two very different claims. One is reasonable, assuming some principles of theoretical physics, while the other is silly to mildly informed people.
People are used to regular crypto, where the task of computing the result of a basic mathematic function can be safely left to hand-waving. You can do RSA with a computer, or longhand on a piece of paper. The properties of the computer aren't an assumed part of the way the system works. With QC, it is assumed that pieces of hardware behave in very specific ideal ways. You can't buy parts that work like that, you have to use real parts. Therefore the system design, and explanations of how a real system works need to account for that.
I still think (from my fuzzy understanding of this attack) that it uses a specific implementation detail that depends upon the system used, and might be relatively easy to patch. Maybe they can use different wavelengths of photons, one for a test and one not--I don't have the expertise to say how much of a redesign is necessary. The article makes it sound like it's not a huge deal, and the Toshiba guys say in one of the other articles that their system isn't susceptible to these attacks when properly operated.
You're exaggerating your point (eg. by talking about dragons and warp drive). One of the articles suggests you might mitigate this attack with a relatively simple extra verification step. This attack depends explicitly upon "blinding" a detector with light "above the intensity threshold" (certainly this is oversimplified). That's an attack on implementation details. Certainly I didn't mean to say that building a QC system is all "implementation details"; that would just be stupid. This one point that was attacked is an implementation detail.
This is an attack on implementation details, not the underlying physics of quantum mechanics. The title could have been a little better. This is (apparently; my only source is the submitter, as he's also the source in the article) the first working exploit of a quantum cryptography system that was able to steal the key without being detected.
I think "disclosure" is appropriate. His name appears in several of the articles, and it would be awkward had he not mentioned it in the summary.
Could you say that again, but with more words this time?
There's a list in one of the comments to TFA. I would reproduce it here if I had any reason to trust its authenticity, but I don't.
He said: 'It would have been hard to prepare for this type of vulnerability.'
Well, yes, actually. It's not saying "it would have been hard to prevent this type of vulnerability", it's saying it would be hard to prepare for hundreds of thousands of customers' information getting stolen. That does sound hard to prepare for.
One expert [...] told The New York Times he wondered how the hackers could have known to breach security by focusing on the vulnerability in the browser.
Maybe he's just being horribly misquoted here. The vulnerability can apparently be triggered using a browser in a very standard way, which to a journalist might sound an awful lot like a "vulnerability in the browser". Still, if it's just shoving different numbers in a query string (which the article really, really makes it sound like it is), there's nothing to wonder at.
Yet again, faced with a news article on a topic I'm somewhat familiar with, shoddy reporting shines through. Disgusting.
I still don't see the point. Even ignoring the fact that there's a "save as PDF" option at the top of the Flash animation, what would be the point of preventing regular people from, say, copy&pasting from this document? It seems like one guy didn't notice the PDF option and wrote a story for the Wall Street Journal about it with an interview from someone not very knowledgeable about this system. This is why I hate journalists, as a rule: shoddy reporting is harmful and prevalent.
(Here's the PDF download link. It's 21.2 MB (lots of pictures) which might explain why they opted for a flash book format. Also, you *can* link to specific pages. Here's page 34.)
I think OCR recently matched the accuracy of Home Depot guys, too.