2005-08-12
Math Games
The Mathematical Association of America has a monthly column about Math Games which they publish on the internet. I heartily recommend a visit there. The variation is very good and span from discussing 64K intro demos to block sliding puzzles to prime numbers. There are lots of interesting puzzles and links to fun pages. Everything is very accessible. Enjoy!
2005-08-04
Sojourner Quote of the Week
Every week I receive Sojourner's weekly newsletter. This week's newsletter featured the following quote which I found rather worrying:
- Author Bill McKibben, in his Harper's magazine essay, "The Christian Paradox"
"Three quarters of Americans believe the Bible teaches that 'God helps those who help themselves.' That is, three out of four Americans believe that this uber-American idea, a notion at the core of our current individualist politics and culture, which was in fact uttered by Ben Franklin, actually appears in Holy Scripture. The thing is, not only is Franklin's wisdom not biblical; it's counter-biblical. Few ideas could be further from the gospel message, with its radical summons to love of neighbor."
- Author Bill McKibben, in his Harper's magazine essay, "The Christian Paradox"
2005-07-29
Numb3rs
I've been watching the TV show Numb3rs lately and I enjoy it immensely. But me being a math geek and this show being obviously meant to appeal to such I'd like to explain why I like it.
But let me first give a brief review of Numb3rs. Numb3rs is a crime show about an FBI agent solving cases. To his aid he has a mathematician who tries to explore various patterns in the crimes and can help solve the cases. Hence the name Numb3rs.
I started watching the show mid-season and watched about two episodes when I sort of decided that I didn't quite like the show. I thought the math part was pretty dull and this whole thing with the mathematician trying to explain the mathematics pedagogically was pretty lame. But then I thought I should give the show a second chance and started to watch it from the beginning. And all of a sudden I was hooked.
I had the wrong expectations on the show when I started watching it. I hoped the math part would be really savvy but I was greatly disappointed. The real strength in this show is the characters and how they develop. As it turns out the FBI agent and the mathematician is not only colleagues, they're also brothers with the FBI agent being the older brother. This in itself makes for a very interesting relationship between them. Add to this couple their father who's another important character in the show. He has seldom anything to do with the cases, he's just there as a part of the brothers lives. On top of this we have two other FBI agent working together with our main character and a rather eccentric physicist who is a friend of the mathematician. All of this makes for a very good mix of characters and the show is really about the lives of the two brothers who happens to be colleagues. The focus being of course on their work together. So I think that the thing I like about the show is this very well-balanced mix of character development and crime solving. The math part is just a bit of extra spice which makes it even better.
So what about comparing this show to, say, CSI? I think it is difficult because they are rather different. Numb3rs is better on the character development and gets interesting because one cares about the lives of the characters. CSI is better on the crime solving part and excels in the juicy details about the crime. I like the atmosphere in Numb3rs better but I also really like the really slick production of CSI. So I'm not going to pick a winner between these two.
Well. All in all I can very much recommend Numb3rs. Even to non-geeks.
But let me first give a brief review of Numb3rs. Numb3rs is a crime show about an FBI agent solving cases. To his aid he has a mathematician who tries to explore various patterns in the crimes and can help solve the cases. Hence the name Numb3rs.
I started watching the show mid-season and watched about two episodes when I sort of decided that I didn't quite like the show. I thought the math part was pretty dull and this whole thing with the mathematician trying to explain the mathematics pedagogically was pretty lame. But then I thought I should give the show a second chance and started to watch it from the beginning. And all of a sudden I was hooked.
I had the wrong expectations on the show when I started watching it. I hoped the math part would be really savvy but I was greatly disappointed. The real strength in this show is the characters and how they develop. As it turns out the FBI agent and the mathematician is not only colleagues, they're also brothers with the FBI agent being the older brother. This in itself makes for a very interesting relationship between them. Add to this couple their father who's another important character in the show. He has seldom anything to do with the cases, he's just there as a part of the brothers lives. On top of this we have two other FBI agent working together with our main character and a rather eccentric physicist who is a friend of the mathematician. All of this makes for a very good mix of characters and the show is really about the lives of the two brothers who happens to be colleagues. The focus being of course on their work together. So I think that the thing I like about the show is this very well-balanced mix of character development and crime solving. The math part is just a bit of extra spice which makes it even better.
So what about comparing this show to, say, CSI? I think it is difficult because they are rather different. Numb3rs is better on the character development and gets interesting because one cares about the lives of the characters. CSI is better on the crime solving part and excels in the juicy details about the crime. I like the atmosphere in Numb3rs better but I also really like the really slick production of CSI. So I'm not going to pick a winner between these two.
Well. All in all I can very much recommend Numb3rs. Even to non-geeks.
2005-07-28
Harry Potter and the Half Blood Prince
A few days ago I finished reading the latest Harry Potter book; Harry Potter and the Half Blood Prince. It is the sixth of the seven previously promised books in the series. For those of you who haven't read it yet: don't worry, I'm not going to have any spoilers in this post.
To begin with and somewhat off topic I should say that I didn't stand in line to get this book in the day it was released. I preordered it from Amazon UK which turned out to be a real bargain. I paid 130 SEK including shipping when the price for the book in Swedish bookstores was 199 SEK. I'm finding it very hard to go to a bookstore to buy a book these days when it's that much cheaper to buy over the net.
Okay. What about the book then? I must say I didn't find it as exciting as the previous books. The book was still an easy and fast read but it lacked some magic which the other books had. Maybe this is just because I'm getting to know the format of the books. All the books have pretty much the same general chain of event and it's getting a little too familiar. But the end of the Half Blood Prince promises that the seventh book will be quite different.
As to my theory about Draco Malfoy which I posted about earlier, the Half Blood Prince had some very interesting turnes of events. I think the events in the very end of the book and Draco's behavior there shows that I might be on the right track. But it is by no means certain. It has occurred to me that Rowling (the author of the HP books) uses Draco as the antithesis of Harry Potter and maybe she wants to maintain that all the way to the end. It'll be exciting to see what she does in the last book.
One theme which has been constant throughout the books has been the mystery surrounding Severus Snape. I have long though that he is one of the most interesting and mysterious character in the books. It was a little surprising to me to see that the secrets surrounding Snape, why Dumbledore trusts him, the reasons for his various behavior and his true allegiance was revealed already in the sixth book. But I don't say it is a bad decision, I was just surprised. One of the reasons for the early disclosure of this mystery is perhaps that there are a great many things which need to be explained and finalized in the seventh book that it was more or less necessary to get this particular thing out of the way. It also gives room for some exciting drama in the final book.
So despite the fact that I wasn't overly thrilled with the Half Blood Prince I am (as you probably can tell by now) already looking forward to the seventh and final Harry Potter book. The way the Half Blood Prince builds up to the finale in the last book shows great promise.
To begin with and somewhat off topic I should say that I didn't stand in line to get this book in the day it was released. I preordered it from Amazon UK which turned out to be a real bargain. I paid 130 SEK including shipping when the price for the book in Swedish bookstores was 199 SEK. I'm finding it very hard to go to a bookstore to buy a book these days when it's that much cheaper to buy over the net.
Okay. What about the book then? I must say I didn't find it as exciting as the previous books. The book was still an easy and fast read but it lacked some magic which the other books had. Maybe this is just because I'm getting to know the format of the books. All the books have pretty much the same general chain of event and it's getting a little too familiar. But the end of the Half Blood Prince promises that the seventh book will be quite different.
As to my theory about Draco Malfoy which I posted about earlier, the Half Blood Prince had some very interesting turnes of events. I think the events in the very end of the book and Draco's behavior there shows that I might be on the right track. But it is by no means certain. It has occurred to me that Rowling (the author of the HP books) uses Draco as the antithesis of Harry Potter and maybe she wants to maintain that all the way to the end. It'll be exciting to see what she does in the last book.
One theme which has been constant throughout the books has been the mystery surrounding Severus Snape. I have long though that he is one of the most interesting and mysterious character in the books. It was a little surprising to me to see that the secrets surrounding Snape, why Dumbledore trusts him, the reasons for his various behavior and his true allegiance was revealed already in the sixth book. But I don't say it is a bad decision, I was just surprised. One of the reasons for the early disclosure of this mystery is perhaps that there are a great many things which need to be explained and finalized in the seventh book that it was more or less necessary to get this particular thing out of the way. It also gives room for some exciting drama in the final book.
So despite the fact that I wasn't overly thrilled with the Half Blood Prince I am (as you probably can tell by now) already looking forward to the seventh and final Harry Potter book. The way the Half Blood Prince builds up to the finale in the last book shows great promise.
2005-07-27
Quote day
The Second Law of Thermodynamics:
If you think things are in a mess now, just wait!
-- Jim Warner
Seen in a sig.
To refuse awards is another way of accepting them with more noise than is normal.
- Peter Ustinov
Appeared on my personal google page.
2005-07-20
Death Star Subwoofer
I haven't been blogging for quite a while now. It has its reasons. First of all I've been working my (insert appropriate part of body) off trying to write up my thesis. Then I hit the wall. Now I'm currently on sick leave, and the thesis is nowhere done. But that should leave me with more time to blog shouldn't it?
Anyway, ./ had a link to the most awesome piece of HiFi equipment currently being sold on eBay. A Death Star subwoofer. It's truly impressive. Check it out at eBay.co.uk.
Anyway, ./ had a link to the most awesome piece of HiFi equipment currently being sold on eBay. A Death Star subwoofer. It's truly impressive. Check it out at eBay.co.uk.
2005-06-28
Another Google Beta
Google just released Google earth, a program to view pretty much the whole of the earth. Some parts of earth even come in 3D. Here is a picture of southern manhattan:
Of course there is a lot of search features in the program linking it to Google. Pretty cool application if you ask me. I find it a bit slow though and I hope that will improve. Otherwise it will be unbearable to use.
Again here is a picture of where I live, together with a little placemark to give a more precise position:
Of course there is a lot of search features in the program linking it to Google. Pretty cool application if you ask me. I find it a bit slow though and I hope that will improve. Otherwise it will be unbearable to use.
Again here is a picture of where I live, together with a little placemark to give a more precise position:
Quote By Edward Nelson
I've been reading stuff by and about the Princeton Mathematics professor Edward Nelson lately. And I'll be reading more when I get the time. Here's a beautiful quote by prof. Nelson:
The reason why I've been reading Nelson is that I've been thinking about my own philosophical standpoint with respect to mathematics lately. Nelson is pretty radical but I find his opinions interesting. I will have more to write about that soon (I hope).
Perhaps infinity is not far off in space or time or thought; perhaps it is while engaged in ordinary activity - writing a page, getting a child ready for school, talking with someone, teaching a class, making love - that we are immersed in infinity.
The reason why I've been reading Nelson is that I've been thinking about my own philosophical standpoint with respect to mathematics lately. Nelson is pretty radical but I find his opinions interesting. I will have more to write about that soon (I hope).
Inorder traversal in Haskell
How many ways can you write a function that performs inorder traversal of a tree? On the whiteboard in my office there is currently five different versions. One has quadratic complexity, one is higher order, one uses an accumulator and three of them needs a helper function to do all the work.
All these variations sprang from a discussion with David Wahlstedt about which versions his termination analysis could handle. It happens that my preferred version of the function, which is linear, first order and doesn't need any accumulator nor a helper function is little more difficult to prove to be terminating. And David's termination analysis cannot handle it.
As a little programming exercise I suggest you try to write my preferred version. To make it a challenge make sure you write it in a functional language. It takes a tree (defined in the obvious way) and returns a list of all the internal node in the order they would be visited by an inorder traversal. Remember, the function must be first order, have linear time complexity with no need for an accumulator or a helper function.
All these variations sprang from a discussion with David Wahlstedt about which versions his termination analysis could handle. It happens that my preferred version of the function, which is linear, first order and doesn't need any accumulator nor a helper function is little more difficult to prove to be terminating. And David's termination analysis cannot handle it.
As a little programming exercise I suggest you try to write my preferred version. To make it a challenge make sure you write it in a functional language. It takes a tree (defined in the obvious way) and returns a list of all the internal node in the order they would be visited by an inorder traversal. Remember, the function must be first order, have linear time complexity with no need for an accumulator or a helper function.
2005-06-26
Welcome to my place
Google has now added satellite images over most of Europe and a bunch of other places to Google Maps. In the center of this map you can see where I live.
2005-06-16
Web based applications
OK, since I cannot get anything written on my thesis right now anyway I might as well do some blogging. What I'd like to write a bit about is web based applications.
I believe Web based applications is the applications of the future. By a web based application I mean an application that you download from the internet when you run it. It typically also communicate over the internet a lot while running. The advantages are clear: You don't have to do anything to get the latest version, you automatically get it when downloading the program. It is the same with the data you're going to handle in the program, it will always be up-to-date. If the company providing the application is storing your personal data for you on their servers you can access it anywhere there is an internet connection. You don't have to worry about backups or transferring files when you get a new computer. This is their problem and they're most likely a lot better at it than you are.
Google is currently the leading company on this. I use GMail for all my emailing nowadays and it is perhaps the best email application I have ever used. (For the record I've used the following email programs: I started using the text based elm and pine. When I got my windows laptop I started using Outlook. I tried to use Netscape once but didn't like it. GMail beats them all.) Another cool Google app is Google Maps. I think it is pretty amazing that it can run so smoothly! Still, there are room for improvements. But the possibilities for Google Maps are simply huge if you imagine adding all kinds of localized information to that program.
One niche which I think could benefit a lot from this is games. The gaming industry has already realized the new posibilities with web based game play which make the games a lot more fun. For small games such as card games and puzzles I think web based deployment is ideal. If you're only after some minutes of diversion you don't want to bother with downloading and installing an application. This has already happened to some extent with site like Shockwave. I list other links below.
The current technology is to use the web browser as an "operating system" to host web based applications. The "machine code" is java script. But the browser comes equipped with a lot of technology for displaying information graphically such as rendering HTML and using CSS. These things together with interaction with the web server from the java script code is usually called AJAX and is currently very hyped. And it IS cool in the sense that it allows us to enjoy these new cool web based applications.
But this need not be the only technology and if it is going to take of seriously it should be integrated with the standard operating system in my opinion. An alternative technology is Java Web Start. Java Web Start has a little ordinary application which can be seen as the start button in windows. It has a list of programs that is available to you for download. The platform used here is not the browser but the Java Virtual Machine. In my opinion Java is a much more mature platform for web based applications but it hasn't received much attention since the applets went out of fashion. (I should add that I think that applets were the wrong thing. It was difficult to get an "application feeling" from them. They were restricted to a little box inside a web page. But they clearly paved way for cooler things.)
I understand perfectly if you're a bit skeptic about this idea. Especially if you have no experience with web based apps. And of course there are drawbacks. There are security issues all over the place and so it can never be the case that all programs are web based. And one needs to be connected to internet pretty much all the time to use them. In some cases this could be circumvented by caching the application locally. That would restrict the user to only use the data available locally on the machine. How much of a problem this is will vary between applications.
Finally I wish to list some cool links to some pretty amazing demos as to what is possible with these new technologies. Some of those things aren't very useful but they sure give a taste of the enormous potential of web based apps.
I believe Web based applications is the applications of the future. By a web based application I mean an application that you download from the internet when you run it. It typically also communicate over the internet a lot while running. The advantages are clear: You don't have to do anything to get the latest version, you automatically get it when downloading the program. It is the same with the data you're going to handle in the program, it will always be up-to-date. If the company providing the application is storing your personal data for you on their servers you can access it anywhere there is an internet connection. You don't have to worry about backups or transferring files when you get a new computer. This is their problem and they're most likely a lot better at it than you are.
Google is currently the leading company on this. I use GMail for all my emailing nowadays and it is perhaps the best email application I have ever used. (For the record I've used the following email programs: I started using the text based elm and pine. When I got my windows laptop I started using Outlook. I tried to use Netscape once but didn't like it. GMail beats them all.) Another cool Google app is Google Maps. I think it is pretty amazing that it can run so smoothly! Still, there are room for improvements. But the possibilities for Google Maps are simply huge if you imagine adding all kinds of localized information to that program.
One niche which I think could benefit a lot from this is games. The gaming industry has already realized the new posibilities with web based game play which make the games a lot more fun. For small games such as card games and puzzles I think web based deployment is ideal. If you're only after some minutes of diversion you don't want to bother with downloading and installing an application. This has already happened to some extent with site like Shockwave. I list other links below.
The current technology is to use the web browser as an "operating system" to host web based applications. The "machine code" is java script. But the browser comes equipped with a lot of technology for displaying information graphically such as rendering HTML and using CSS. These things together with interaction with the web server from the java script code is usually called AJAX and is currently very hyped. And it IS cool in the sense that it allows us to enjoy these new cool web based applications.
But this need not be the only technology and if it is going to take of seriously it should be integrated with the standard operating system in my opinion. An alternative technology is Java Web Start. Java Web Start has a little ordinary application which can be seen as the start button in windows. It has a list of programs that is available to you for download. The platform used here is not the browser but the Java Virtual Machine. In my opinion Java is a much more mature platform for web based applications but it hasn't received much attention since the applets went out of fashion. (I should add that I think that applets were the wrong thing. It was difficult to get an "application feeling" from them. They were restricted to a little box inside a web page. But they clearly paved way for cooler things.)
I understand perfectly if you're a bit skeptic about this idea. Especially if you have no experience with web based apps. And of course there are drawbacks. There are security issues all over the place and so it can never be the case that all programs are web based. And one needs to be connected to internet pretty much all the time to use them. In some cases this could be circumvented by caching the application locally. That would restrict the user to only use the data available locally on the machine. How much of a problem this is will vary between applications.
Finally I wish to list some cool links to some pretty amazing demos as to what is possible with these new technologies. Some of those things aren't very useful but they sure give a taste of the enormous potential of web based apps.
2005-06-13
2005-06-10
Regexp humor
Niklas Broberg told me a hilarious thing he'd seen in irc. There was a guy who had erroniously spelled the word "wrong" like this: "worong". When noting his mistake he wrote the following thing in the hope of correcting his mistake:
s/worong/worng
2005-06-09
Wittgenstein was a genius
If people never did silly things nothing intelligent would ever get done.
--Ludwig Wittgenstein
2005-06-08
Things said in court
Here a link to a hilarious page with quotes from court. My personal favourite:
Q: Doctor, before you performed the autopsy, did you check for a pulse?
A: No.
Q: Did you check for blood pressure?
A: No.
Q: Did you check for breathing?
A: No.
Q: So, then it is possible that the patient was alive when you began the autopsy?
A: No.
Q: How can you be so sure, Doctor?
A: Because his brain was sitting on my desk in a jar.
Q: But could the patient have still been alive nevertheless?
A: It is possible that he could have been alive and practising law somewhere.
2005-06-07
The Insanity on Internet
Apparently there is no end to the crazy things you can find on Internet. I thought I'd seen many strange things but this page takes it to a new level.
2005-05-29
Revenge of the Sith
I suppose I should have written about this earlier. Being in the middle of my dissertation-writing-swamp I joined up with my friends to go see Star Wars Episode III, Revenge of the Sith on its premiere. I must say the movie was spectacular and very good. But it was also a tough movie to see. As someone put it, it is really a movie about sin and turning to the dark side. Seeing Anakin's being sucked up by all the hate, anger and confusion was difficult to watch.
I should also note that I have a difficult time to watch and judge star wars movies like other movies. To me they are more like historical documents and it is difficult to have an opinion such things. (Before you think I am a total freak I should say that I do realize the these films are fiction and doesn't relate to reality whatsoever.) When the first prequel came out and turned out to be a not so good movie it really didn't matter to me. I just wanted to see what happened to the characters and what their history was. I guess you can call me a star wars fan...
I was a little disappointed with the premiere though. I thought there would be more people being dressed up and a more tense atmosphere around the whole happening. Part of the reason was because we didn't choose the geek cinema, but still it was the premiere and I would have expected more.
The real reason I started writing this entry is because of a page I saw at starwars.com listing a bunch of easter eggs which appeared in the film. I am a little disappointed with the list, I would have guessed it to be longer. Some of the stuff I noticed but I missed most of it. Lisa, my fiance managed to spot the millennium falcon though which made me a little jealous.
I should also note that I have a difficult time to watch and judge star wars movies like other movies. To me they are more like historical documents and it is difficult to have an opinion such things. (Before you think I am a total freak I should say that I do realize the these films are fiction and doesn't relate to reality whatsoever.) When the first prequel came out and turned out to be a not so good movie it really didn't matter to me. I just wanted to see what happened to the characters and what their history was. I guess you can call me a star wars fan...
I was a little disappointed with the premiere though. I thought there would be more people being dressed up and a more tense atmosphere around the whole happening. Part of the reason was because we didn't choose the geek cinema, but still it was the premiere and I would have expected more.
The real reason I started writing this entry is because of a page I saw at starwars.com listing a bunch of easter eggs which appeared in the film. I am a little disappointed with the list, I would have guessed it to be longer. Some of the stuff I noticed but I missed most of it. Lisa, my fiance managed to spot the millennium falcon though which made me a little jealous.
2005-05-24
Boole's law of thought
I was browsing in Amazon the other day. The book "An Investigation of the Laws of Thought" by George Boole came up. This is a real classic and I was considering buying it. But was I happy to find that the whole text is available by Project Gutenberg. Now I just need to print the 328 pages...
P.S. I really like Amazon because you can really go shopping there, browsing through there product by various means. They have good recommendation lists and people can set up their own lists of favorite items. I think it works really well and I like it.
P.S. I really like Amazon because you can really go shopping there, browsing through there product by various means. They have good recommendation lists and people can set up their own lists of favorite items. I think it works really well and I like it.
2005-05-23
Measured my brain
I just saw this test on a friends blog. It is said to measure what kind of thinking one does. My result can be seen below. That third advice really disturbs me...
| Your brain: 40% interpersonal, 60% visual, 80% verbal, and 220% mathematical! |
| Congratulations on being 400% smart! Actually, on my test, everyone is. The above score breaks down what kind of thinking you most enjoy doing. A score above 100% means you use that kind of thinking more than average, and a score below 100% means you use it less. It says nothing about how good you are at any one, just how interested you are in each, relatively. A substantial difference in scores between two people means, conclusively, that they are different kinds of thinkers. Matching Summary: Each of us has different tastes. Still, I offer the following advice, which I think is obvious:
|
 |
My test tracked 4 variables How you compared to other people your age and gender:
|
| Link: The 4-Variable IQ Test written by chriscoyne on Ok Cupid |
2005-05-22
A Group Is Its Own Worst Enemy
I just read a nice article called "A Group Is Its Own Worst Enemy" about group psycology and social software. It has an abundance of nice quotes:
Go on and read it!
Humans are fundamentally individual, and also fundamentally social
So there's this very complicated moment of a group coming together, where enough individuals, for whatever reason, sort of agree that something worthwhile is happening, and the decision they make at that moment is: This is good and must be protected.
The external enemy -- nothing causes a group to galvanize like an external enemy.
People who work on social software are closer in spirit to economists and political scientists than they are to people making compilers.
And the worst crisis is the first crisis, because it's not just "We need to have some rules." It's also "We need to have some rules for making some rules."
The tyranny of the majority.
The user of social software is the group, and ease of use should be for the group. If the ease of use is only calculated from the user's point of view, it will be difficult to defend the group from the "group is its own worst enemy" style attacks from within.
Go on and read it!
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