The problem with this theory is that in a medium of refractive index n>1, light does not travel at the same speed in all directions: light travels slightly faster in the direction of the flow of the medium, and slightly slower in the opposite direction. As the earth goes round we would pass from one situation to the other, and notice this slight difference in the speed of light. This is basically the Michelson-Morley experiment, which has been repeated to huge precisions over the last century.
Wayne Kerr electronics (http://www.waynekerrtest.com/) made me lough when I saw them in a physics lab. I guess British English counts as a foreign language too...
Hi, I see your point: Python is getting a lot better for scientific use, maybe not so much due to the changes in 3.0 but rather because the community has grown (e.g. Python(x,y), Enthought). There are a few things that make Python what I use most of the time for scientific work:
- The language is better thought out i.e. the Matlab tradition of having one function per file is just annoying.
- The quality of the old Fortran algorithms which scipy wraps is consistently better than that of Matlab functions e.g. Matlab fitting routines are a mess, I get much more accurate results with scipy.
- Compatibility between versions: matlab code from my colleagues always needs some work to run: either because there have been some changes between matlab versions, or they use a function from a toolbox that I don't have, even though there is an equivalent one in standard matlab. Since we changed to Python all is fine.
- When you cannot vectorize a small piece of code, scipy offers a few ways in which compiled code can be added transparently: cython, pyrex, f2py and even pycuda. Much easier than.mex in matlab.
- Python has a large set of very useful libraries for doing scientific work e.g. networkx, vpython...
- Thanks to Python's large set of other libraries, it is trivial to do things such as parsing complex files, interfacing with lab equipment (pyvisa,...) interfacing with the windows/linux/mac GUIs, using databases, sending data over the network etc. All these things are really handy in the lab.
- I don't mind paying for software, but the license management is really a problem: It has happened quite a few times, that Matlab has stopped working because something in the license management had changed. Loosing a day of work of a research group is expensive.
- Of course, the fact that students can just install Python for free, and maybe use it in their future non-scientific job is a plus.
In the early days of webcams I used to work for this tech company, the bos (a techofile) had just set up a webcam from his computer in the London office to his computer in the New York office. He then flow to New York, a cople of guys and I where working quite late, when I see this other junior guy sat in the boss's chair saying with his legs on the boss's desk imitating the boss's voice "I am the boss and I am gay". When suddenly the computer screen turned on and he saw the boss telling him "YOU ARE FIRED". It was so funny to see this guy's face! (in fairness, the boss was gay...)
Thanks for the excellent explanation! Said that way, it just makes perfect sense. I guess it is very often misinterpreted, maybe that could be a good excuse for my confusion:-)
Thanks again!
B.
So, is the BSD license viral too? It seems that if you have to maintain the same license, and cannot re-license under other terms, the BSD license IS viral, In which case, it is quite similar to the GPL, so, what is all the fuss about?
If this is not the case, and you can re-lincese, then, there is no problem either.
I guess Apple, Microsoft etc. do re-license the software taken from BSD, and that is how most people understand the BSD license.
Police actually had to brake in the persons' office to install the keylogger, in order to get their PGP password. This means PGP is at least quite good. However, the article implies that PGP is breakable with a bit of time and effort: Coffey asserted that the DEA needed "real-time and meaningful access" and that's why they monitored for the keys.
In the many worlds interpretation of quantum mechanics the wavefunction does not collapse (that is the copenhagen interpretation). Rather, all the *possible* outcomes of a quantum measurement do happen: each one in a different universe. When you measure one particular outcome, that means that you are in the particular universe where you measure that outcome: by definition.
A measurement consists in an event that translates "quantum information" into "classical information": quantum information is very complex as essentially it means that you are keeping track of what happens in ALL the universes, at some point, you stop doing that, and you become concerned with only what happens in you particular universe: that action constitutes a measurement. And it is from that action that you find out in which universe you happen to be.
I thought that this story came up last year, and it turned out that it was a scam to show how powerful their communications company is: i.e. how much press they can generate about the most obviously stupid idea they could come up with.
A guy I know in Prague did the same thing: he advertised a supermarket that gave away things for free, and all the adverts said "don't come, it's only a dream, it's not actually true" and many many people went! It was only a billboard with a supermarket drawn on it. Very funny actually:-)
you might be onto something: the fermilab statement says:
"Fermilab also assembled into cryostats and shipped to CERN 18 similar KEK-designed magnets that were built in industry in Japan and cold-tested at KEK"
That's exactly right. Here in the UK we are taken as slaves. Before the UK went to Iraq, there were demonstrations with up to 2 million people. Totally ignored.
The British people, who have a long history of democracy, have learned the hard way (Thatcher & Blair)that the government is against them. Something that most other nations have known for a long long time.
The argument of terrorism does not make sense here in the UK: people have experience with the IRA, which were real, and not just an argument to sell weapons and to pass repressive laws.
At least we are not in as bad a position as the US taxpayers, who with the war in Iraq have been conned of hundreds of billions of dollars, which have been "spent" i.e. passed from the government's pockets to the pockets of who is in control (I don't know who that is). How do you judge if a bomb that is thrown was worth 10M or 1M? perfect way of making money disappear.
Exactly! A mate of mine actually did this same sort of thing in the Czech Republic: a massive advertising campaign for "the czech dream", which people were made to believe was a hypermarket with cheap prices. The funny thing was that their entire advertizing campaing was "it does not exist", "don't come", "it's a waste of time", but at least 1000 people came to the "opening" they made a film of it, and of how advertizing companies can really make you believe whatever! It's great!
I am not sure what happened next, knowing the boss I guess he got some kind of compensation. The problem was that for a while no one in my company or at BT knew what was going on: panic everywhere.
The only other time that something as bad happened was when I worked at the ministry of employment (in Egypt) with a microsoft stack which had a licensing cap on the maximum number of connections. Microsoft then gave us access to a great website with all their software that we could use without any license restrictions... There were some really nice programs in there that I never saw on sale anywhere. Bill Gates himself came to visit, and got the Egyptian goverment to standardize on microsoft produts:-(
About 4 years ago, I was working in quite a large company that had many online shops all over the world. We had two connections to BT. One day they did not work anymore, we checked the equipment, all was OK, we phoned BT and they said that we had payd in time and that there was no problem at all. This basically took a lot of our servers down, and we lost a lot of money. The next day, whe phoned BT again and asked what had happened, and they told us that someone had posted a file to a newsgroup, and therefore they disconnected us. (The file in question was a BSD package). So a stupid employee at these companies can really do some damage without a proper legal procedures.
Yes, that is quite an interesting question. From what I recall of General Relativity, it deals with infinitely small reference frames, and as soon as you have an actual extended body (like the Earth) you should be able to detect rotation. A gyroscope or pendulum or satellite (e.g. looking at the moon) should do.
From what I seem to reacall EULAs are not particularly easy to defend in court, and mostly court software piracy cases rely on copyright.
What about adding a term in the EULA saying "this software cannot be used for research on legal cases"
EULAs are just ridiculous. From my grasp of them they are a bit like a contract which means that if only one of the terms is not strictly legal (like this one) the entire EULA is void.
Why can companies not just rely on copyright?
Clustering is great if it's simple, such as web servers. However, removing single point of failure is complex, in terms of software, hardware and network traffic. The solution as a whole can fail, say, because of stupid clustering software. Eg. Microsoft/HP cluster setting same MAC address tothe entire cluster.
Or, Forgetting to put UPS on the air conditioning.
I am all for one big powerful, but simple computer. They are expensive, but at least they don't run Windows.
You are right that zope is very nice to work with, and that most of the time even though Java is much faster than python, you are always limited by the time it takes to access the database. ZODB is good and fast, so no problem there. However somehow I expect a zope server to serve 50-80 pages/s. Which is fine for most applications, but on larger websites I aim to get ~500 pages/s from a server, and for that I use java+tapestry+berkeleydb which is also quite nice, but a lot more work than zope. I consider the two different tools for different jobs, but I might be missing something...
For what I have seen, Java is good for Enterprise development precisely beacuse it eliminates things like multiple inheritance and operator overloading. This results in code that is very understandable, and usually follows standard design patterns. I think Java makes it easier for IDE developers to make very helpful IDEs (IDEA, Eclipse, Netbeans, JBuilder) and promote certain technologies as the 'de facto' standard (eg hibernate). For enterprise apps java is FAST, whereas other languages that you mention, such as python are just too slow (zope/plone). Perl code just gets too messy after a while, and as you say.NET not being cross platform makes it useless.
Pulse tubes make a really annoying high-pitch noise, and they need quite a large compressor too... They also cost 50000$. (Have 2)
I have never been quite sure why the Stirling stuff is not used more, maybe there are implementation problems...
You are right: there is no way that you can use python for any task that requires even the slightest amount of performance. Realistically a zope / plone server can support 10 concurrent users (with write access). With PHP I aim at supporting 100+ concurrent users per server, and with java 1000. For me these technologies are for totally different uses, and I use the 3 of them: python/zope/plone - intranets php/perl - "medium" commercial apps java - "Enterprise" stuff (3+ developers) For each project the right technology: I like all of them!
You are forgetting that if you patent something, it is not a trade secret anymore. You don't need Bnemonic style memory: all you need to do is read the patent, which is your legal right. How would you otherwise know what you are not allowed to copy? Software patents are just ridiculous.
True, Java does have all these disadvantages, whereas C++ has many many advantages. And yes, C++ is very portable across platforms, however heavily optimized code that uses fancy C++ / Compiler features does take some effort to port; particularly when you "inherit" code. A lot of code I have to deal with relies on many libraries, it in not always obvious to track all the dependencies, header files, maybe some inline assembly, threading, graphic libraries, etc. It does take some effort. Even getting a basic application that I built a few years ago on Linux, OpenGL, QT, Blitz; took a bit of playing about, installing the old libraries, recompiling them etc. The exact same application in Java + Java3D is twice as slow, but ran right away. But without a decent numeric library I think it might be quite an effort to make a real numeric application in java even if in some cases extreme performance is not an issue.
It's true that there is no decent java numerical library. However if you implement your own ruotines java isn't that bad: it is maybe 50% slower than carefully optimized Intel Compiler code with SSE3 etc.
But you have the great advantage that you do not have to play around with optimizer flags. This is especially good if you develop on one architecture and run on another (quite common in physics). Another problem with C/C++/FORTRAN (that often get mixed together in projects) is that you end up with a program that for unknown reasons will compile only on one machine (we have a program that compiles only on our SGI onyx2 server only from a particular o2 terminal...). I see that a lot of future work, especially "grid" software is trying to take advantage of the ease of use and reusability of java code. I have not played around with generics yet, but templates are really handy in C++ numerical libraries... Hope someone comes up with a nice java numerics library.
Slashdot Mirror
The problem with this theory is that in a medium of refractive index n>1, light does not travel at the same speed in all directions: light travels slightly faster in the direction of the flow of the medium, and slightly slower in the opposite direction. As the earth goes round we would pass from one situation to the other, and notice this slight difference in the speed of light. This is basically the Michelson-Morley experiment, which has been repeated to huge precisions over the last century.
Wayne Kerr electronics (http://www.waynekerrtest.com/) made me lough when I saw them in a physics lab. I guess British English counts as a foreign language too ...
Hi, I see your point: Python is getting a lot better for scientific use, maybe not so much due to the changes in 3.0 but rather because the community has grown (e.g. Python(x,y), Enthought). There are a few things that make Python what I use most of the time for scientific work: - The language is better thought out i.e. the Matlab tradition of having one function per file is just annoying. - The quality of the old Fortran algorithms which scipy wraps is consistently better than that of Matlab functions e.g. Matlab fitting routines are a mess, I get much more accurate results with scipy. - Compatibility between versions: matlab code from my colleagues always needs some work to run: either because there have been some changes between matlab versions, or they use a function from a toolbox that I don't have, even though there is an equivalent one in standard matlab. Since we changed to Python all is fine. - When you cannot vectorize a small piece of code, scipy offers a few ways in which compiled code can be added transparently: cython, pyrex, f2py and even pycuda. Much easier than .mex in matlab.
- Python has a large set of very useful libraries for doing scientific work e.g. networkx, vpython ...
- Thanks to Python's large set of other libraries, it is trivial to do things such as parsing complex files, interfacing with lab equipment (pyvisa, ...) interfacing with the windows/linux/mac GUIs, using databases, sending data over the network etc. All these things are really handy in the lab.
- I don't mind paying for software, but the license management is really a problem: It has happened quite a few times, that Matlab has stopped working because something in the license management had changed. Loosing a day of work of a research group is expensive.
- Of course, the fact that students can just install Python for free, and maybe use it in their future non-scientific job is a plus.
You are right: for every upload there must be a download, so, by definition, the average seed ratio is exactly 1.
In the early days of webcams I used to work for this tech company, the bos (a techofile) had just set up a webcam from his computer in the London office to his computer in the New York office. He then flow to New York, a cople of guys and I where working quite late, when I see this other junior guy sat in the boss's chair saying with his legs on the boss's desk imitating the boss's voice "I am the boss and I am gay". When suddenly the computer screen turned on and he saw the boss telling him "YOU ARE FIRED". It was so funny to see this guy's face! (in fairness, the boss was gay ...)
Thanks for the excellent explanation! Said that way, it just makes perfect sense. I guess it is very often misinterpreted, maybe that could be a good excuse for my confusion :-)
Thanks again!
B.
So, is the BSD license viral too? It seems that if you have to maintain the same license, and cannot re-license under other terms, the BSD license IS viral, In which case, it is quite similar to the GPL, so, what is all the fuss about? If this is not the case, and you can re-lincese, then, there is no problem either. I guess Apple, Microsoft etc. do re-license the software taken from BSD, and that is how most people understand the BSD license.
Police actually had to brake in the persons' office to install the keylogger, in order to get their PGP password. This means PGP is at least quite good. However, the article implies that PGP is breakable with a bit of time and effort: Coffey asserted that the DEA needed "real-time and meaningful access" and that's why they monitored for the keys.
In the many worlds interpretation of quantum mechanics the wavefunction does not collapse (that is the copenhagen interpretation).
Rather, all the *possible* outcomes of a quantum measurement do happen: each one in a different universe.
When you measure one particular outcome, that means that you are in the particular universe where you measure that outcome: by definition.
A measurement consists in an event that translates "quantum information" into "classical information": quantum information is very complex as essentially it means that you are keeping track of what happens in ALL the universes, at some point, you stop doing that, and you become concerned with only what happens in you particular universe: that action constitutes a measurement. And it is from that action that you find out in which universe you happen to be.
I thought that this story came up last year, and it turned out that it was a scam to show how powerful their communications company is: i.e. how much press they can generate about the most obviously stupid idea they could come up with.
:-)
A guy I know in Prague did the same thing: he advertised a supermarket that gave away things for free, and all the adverts said "don't come, it's only a dream, it's not actually true"
and many many people went! It was only a billboard with a supermarket drawn on it. Very funny actually
here is the link: http://www.ceskatelevize.cz/specialy/ceskysen/en/
you might be onto something: the fermilab statement says: "Fermilab also assembled into cryostats and shipped to CERN 18 similar KEK-designed magnets that were built in industry in Japan and cold-tested at KEK"
That's exactly right. Here in the UK we are taken as slaves. Before the UK went to Iraq, there were demonstrations with up to 2 million people. Totally ignored. The British people, who have a long history of democracy, have learned the hard way (Thatcher & Blair)that the government is against them. Something that most other nations have known for a long long time. The argument of terrorism does not make sense here in the UK: people have experience with the IRA, which were real, and not just an argument to sell weapons and to pass repressive laws. At least we are not in as bad a position as the US taxpayers, who with the war in Iraq have been conned of hundreds of billions of dollars, which have been "spent" i.e. passed from the government's pockets to the pockets of who is in control (I don't know who that is). How do you judge if a bomb that is thrown was worth 10M or 1M? perfect way of making money disappear.
Exactly! A mate of mine actually did this same sort of thing in the Czech Republic: a massive advertising campaign for "the czech dream", which people were made to believe was a hypermarket with cheap prices.
The funny thing was that their entire advertizing campaing was "it does not exist", "don't come", "it's a waste of time", but at least 1000 people came to the "opening" they made a film of it, and of how advertizing companies can really make you believe whatever! It's great!
http://en.wikipedia.org/wiki/Czech_dream
I am not sure what happened next, knowing the boss I guess he got some kind of compensation. The problem was that for a while no one in my company or at BT knew what was going on: panic everywhere. The only other time that something as bad happened was when I worked at the ministry of employment (in Egypt) with a microsoft stack which had a licensing cap on the maximum number of connections. Microsoft then gave us access to a great website with all their software that we could use without any license restrictions ... There were some really nice programs in there that I never saw on sale anywhere. Bill Gates himself came to visit, and got the Egyptian goverment to standardize on microsoft produts :-(
About 4 years ago, I was working in quite a large company that had many online shops all over the world. We had two connections to BT. One day they did not work anymore, we checked the equipment, all was OK, we phoned BT and they said that we had payd in time and that there was no problem at all. This basically took a lot of our servers down, and we lost a lot of money. The next day, whe phoned BT again and asked what had happened, and they told us that someone had posted a file to a newsgroup, and therefore they disconnected us. (The file in question was a BSD package). So a stupid employee at these companies can really do some damage without a proper legal procedures.
Yes, that is quite an interesting question. From what I recall of General Relativity, it deals with infinitely small reference frames, and as soon as you have an actual extended body (like the Earth) you should be able to detect rotation. A gyroscope or pendulum or satellite (e.g. looking at the moon) should do.
From what I seem to reacall EULAs are not particularly easy to defend in court, and mostly court software piracy cases rely on copyright. What about adding a term in the EULA saying "this software cannot be used for research on legal cases" EULAs are just ridiculous. From my grasp of them they are a bit like a contract which means that if only one of the terms is not strictly legal (like this one) the entire EULA is void. Why can companies not just rely on copyright?
Clustering is great if it's simple, such as web servers. However, removing single point of failure is complex, in terms of software, hardware and network traffic. The solution as a whole can fail, say, because of stupid clustering software. Eg. Microsoft/HP cluster setting same MAC address tothe entire cluster. Or, Forgetting to put UPS on the air conditioning. I am all for one big powerful, but simple computer. They are expensive, but at least they don't run Windows.
You are right that zope is very nice to work with, and that most of the time even though Java is much faster than python, you are always limited by the time it takes to access the database. ZODB is good and fast, so no problem there. However somehow I expect a zope server to serve 50-80 pages/s. Which is fine for most applications, but on larger websites I aim to get ~500 pages/s from a server, and for that I use java+tapestry+berkeleydb which is also quite nice, but a lot more work than zope. I consider the two different tools for different jobs, but I might be missing something ...
For what I have seen, Java is good for Enterprise development precisely beacuse it eliminates things like multiple inheritance and operator overloading. This results in code that is very understandable, and usually follows standard design patterns. I think Java makes it easier for IDE developers to make very helpful IDEs (IDEA, Eclipse, Netbeans, JBuilder) and promote certain technologies as the 'de facto' standard (eg hibernate). For enterprise apps java is FAST, whereas other languages that you mention, such as python are just too slow (zope/plone). Perl code just gets too messy after a while, and as you say .NET not being cross platform makes it useless.
Pulse tubes make a really annoying high-pitch noise, and they need quite a large compressor too... They also cost 50000$. (Have 2) I have never been quite sure why the Stirling stuff is not used more, maybe there are implementation problems ...
You are right: there is no way that you can use python for any task that requires even the slightest amount of performance. Realistically a zope / plone server can support 10 concurrent users (with write access). With PHP I aim at supporting 100+ concurrent users per server, and with java 1000. For me these technologies are for totally different uses, and I use the 3 of them:
python/zope/plone - intranets
php/perl - "medium" commercial apps
java - "Enterprise" stuff (3+ developers)
For each project the right technology: I like all of them!
You are forgetting that if you patent something, it is not a trade secret anymore. You don't need Bnemonic style memory: all you need to do is read the patent, which is your legal right. How would you otherwise know what you are not allowed to copy?
Software patents are just ridiculous.
True, Java does have all these disadvantages, whereas C++ has many many advantages. And yes, C++ is very portable across platforms, however heavily optimized code that uses fancy C++ / Compiler features does take some effort to port; particularly when you "inherit" code. A lot of code I have to deal with relies on many libraries, it in not always obvious to track all the dependencies, header files, maybe some inline assembly, threading, graphic libraries, etc. It does take some effort. Even getting a basic application that I built a few years ago on Linux, OpenGL, QT, Blitz; took a bit of playing about, installing the old libraries, recompiling them etc. The exact same application in Java + Java3D is twice as slow, but ran right away. But without a decent numeric library I think it might be quite an effort to make a real numeric application in java even if in some cases extreme performance is not an issue.
It's true that there is no decent java numerical library. However if you implement your own ruotines java isn't that bad: it is maybe 50% slower than carefully optimized Intel Compiler code with SSE3 etc. But you have the great advantage that you do not have to play around with optimizer flags. This is especially good if you develop on one architecture and run on another (quite common in physics). Another problem with C/C++/FORTRAN (that often get mixed together in projects) is that you end up with a program that for unknown reasons will compile only on one machine (we have a program that compiles only on our SGI onyx2 server only from a particular o2 terminal ...). I see that a lot of future work, especially "grid" software is trying to take advantage of the ease of use and reusability of java code. I have not played around with generics yet, but templates are really handy in C++ numerical libraries ... Hope someone comes up with a nice java numerics library.