I have to say that this is nearly the best comment I have ever read, certainly the funniest. Thanks! But at the risk of sounding like a bit of a smart-arse, don't you mean "Chemistry is not random, it's not stochastic"...?
OK, I think that it's fair to say that AOP is still very much at the cutting edge of developement in the java community.
Essentially the idea with AOP is that you increase the modularity and decrease the coupling of components in your application. An example of this would be Logging.
Now most (if not all) apps need to have logging code of one sort or another. This means that the code necessary to log to whichever system (commons-logging, log4j etc in the java world) you use tends to touch all of the classes/objects in your application.
Consider a situation where you have a large existing code base that you have refactored using well understood techniques such as extract method and extract superclass until you have a wonderfully clean and consistent application. You will find that even after this refactoring you still have dependencies throughout your code on your logging mechanism that cannot easily be refactored away.
In software engineering terminology this means that your application code is tightly coupled to whichever logging implementation it uses. This is a bad thing. It makes the application brittle - caveat, see 1 below.
Aspect Orientated Programming can help solve these sorts of problem by introducing another conceptual level into traditional OO. You can move the common logging code into one or more Aspects. These are separate from the rest of your codebase. When the application is run, the aspects are used to modify the code in your application to, for example, use your preferred logging implementation - oh, and before someone flames me saying I'm wrong, I know that with java this isn't exactly how it works, but it's a useful lie!
Now the interesting thing about Spring is that it's one of the first widely accepted uses of AOP. I know that even a year ago AOP was mainly of interest to comp-sci academics and bleeding-edge technologists but with Spring incorporating it into the framework it has brought AOP to a lot of people's attention.
Inversion of control, otherwise known as the Hollywood Principle (don't call us, we'll call you), refers to the currently accepted/hyped practice of "telling things what to do" rather than "things inherently knowing what to do". It's obviously a lot more complex than that, and a lot has been written about the technique but that's the basic gist.
As for citing major applications that use these practices, well an awful lot of applications are being written using the Spring framework as their heavy lifter of choice. As for Inversion of Control, well-written/architected applications have been using the hollywood principle for years - it really isn't anything new.
I work in IT as a Software Engineer (java/C++) and have done for 8 years. The product that the company sells is "actually made by me" (sic) and I feel undervalued.
Perhaps things aren't quite as simple as a still dry MBA might otherwise suggest?
"As well as working on airborne gridswarms using UAVs, we are interested in heterogeneous swarms that employ a combination of airborne and terrestrial robots."
GAK! The robots are coming!! RUN FOR THE HILLS! They are coming from the hills! RUN AWAY FROM THE HILLS!
In the best traditions of this site I am posting this at two in the morning. The above has made more sense than most posts I have read.
It appears that a lot of people are unable to distinguish the kind of person who is able to kill innocents from the kind of person who isn't. It has absolutely nothing to do with your religion. It has nothing to do with your ethnic group. Unfortunately it has everything to do with the way you have been treated as a person. Historically or in this moment.
History is full of examples of peoples who have been persecuted turning on their oppressors. It is not racial groups that are to blame for the problems that exist in the world; it is the fundamental social injustices that we should blame.
No educated person (and after reading some of the children of this post I use that term losely) should accept "arabs are to blame"/"islam is to blame". There is no argument that can adequately defend that point of view.
It's easy at the end of the day. WE need to recognise our differences.
"By contrast the light you get off a LASER is coherent - all the waves are synchronised, so they interfere constructively, making the light appear brighter."
Hmm, not actually sure if this is correct. This is going back a bit but I think:
Laser stands for Light Amplification by the Stimulated Emission of Radiation.
A LASER doesn't produce light because of waves contructively interfering. The light is amplified by the absorbtion and emission of photons at specific wavelengths.
There are two types of photon emission, spontaneous and stimulated.
Spontaneous emission occurs when an electron in an atom "jumps" from a higher quantised state to a lower one giving up energy. This energy is emitted as a photon. This is what happens in street lights, electrons fall back to a lower energy level and that corresponds exactly to the wavelength of the orange light we see. The photon can be emitted in any direction.
Stimulated emission occurs when an atom absorbs a photon causing an electron to move to a "higher" state but in this case the electron can immediately jump back to it's lower state. This causes two photons to be emitted in exactly the same direction as the original photon was travelling.
Essentially a LASER works by putting mirrors round a cavity and multiplying the photons by bouncing them back off the mirrors and into the emitting atoms thereby causing a "chain reaction" to take place where two become four etc.
The reason that you get monochromatic light (normally) is that the wavelength of the photons produced is exactly related to the energy levels in the atom producing them.
The reason you get coherent light is because the photons are travelling in the same direction.
IWAPIU (I was a physicist in Uni) and built a Nitrogen LASER for my final year project. That was a good 8 years ago now though.
"then why isn't the universe like something out of Star TRek"(sic)
The author Iain M. Banks has discussed this issue throughout his "Culture" series of books. He suggests that perhaps there are galazy spanning civilisations out there, but that they are evolved enough to leave us alone until we reach a level as a species where we can be considered for inclusion in the galactic community.
Why would they need to do anything as unsubtle as establishing moonbases when they could have invisible ships 30 kms long able to control every single tv screen on this planet from outside the orbit of Jupitor?:)
In fact, one of his short stories from the collection The State of the Art is about what happens when the Culture use Earth as part of a control group. An excellent read.
Of course this is sci-fi but you get the drift. If anyone is interested I would go as far as saying that for thought provoking Sci-Fi, Iain M. Banks is the man to beat at the moment.
Here he is in an interview at scifi.com talking about his writing.
And here is the man with a few introductory notes on the Culture for the unitiated - I just picked this site from the top of google so I hope they don't mind me posting here:P
I've always found that all of this is very well documented. I've never developed an application in anger using it, but have been playing round with the technology as a client for content management on mobile devices e.g. Uploading of photos from camera phones, articles from PDA's etc.
I think you are probably correct about it's usefulness in the future, but dig around a bit further and there is a wealth of information out there.
I have a friend in the UK Armed Forces who had a thing or two to say about the US Army's docrine of mobility.
It's a long story so I'll cut it short; he was involved in training some soldiers from the 101 Airborne whilst they were in the UK and got into a conversation with one of their officers:
Bemused US Airborne Dude: "say, why do you brits spend so much time running up and down mountains in training? Can't you just radio a chopper?" UK Dude: "Well, what happens if it gets shot down?" Bemused US Airborne dude: "We radio for another one." UK Dude: "And if the second one gets shot down?" Even more bemused US Airborne dude: "We radio for another one..."
At the risk of inflaming the issue I think that geologists have a pretty good explanation for:
"the lack of enough silt on the ocean floor"
:plate tectonics.
Essentially the conundrum was that with all the silt being deposited into oceans over aeons the ocean floor should be one thick mass of sh*t. When mankind first got around to investigating this, we found that it wasn't the case. In fact the ocean floor is pretty rich in geography (biggest mountain range on earth etc) with no sign of hundreds of metres of kludge anywhere. So what had happened to it?
Then along came plate tectonics and it nicely explained amongst other things, what was going on here. Plate tectonics accounts for a phenomenon called "Subduction". This process occurs when two plates collide. One of the plates concerned will be subducted under the other. The subducted plate's rock is then returned to the mantle (a load of super-liquid rock underneath the earths crust).
In conjunction with new ocean floor being created, for instance at the mid-atlantic ridge, subduction explains why there is no silt build up on the ocean floor. It's because the ocean floor is always geologically young!
It goes something like:
1. new ocean floor created at mid-ocean ridge.
2. Silt deposited on said new ocean floor.
3. new ocean floor becomes old ocean floor and is subducted. Along with the silt.
4. ?????
5. Profit!
(only joking about the last two)
Much more info is available about this at, for example:
here is an article on the new British high altitude UAV that should be launched pretty shortly.
Apparently it's going to beat that ~96000 record the Helios set, but won't be officially eligable because it's not going to take off under it's own power.
The balloon that launches it is fairly impressive too:
"As tall as the Empire State Building, their manned envelope will be the biggest ever flown."
"Controversy: The computer-enthusiast community does not like using "hacker" to describe malicious people; they prefer "cracker". The security-community restricts the use of the word "cracker" to some who breaks encryption and copy-protection schemes.
Consequently, a journalist who writes about cybercriminals cannot use either word without hate mail from the opposing community claiming they are using the word incorrectly. If a journalists writes about hackers breaking into computers, they will receive hate-mail claiming that not all hackers are malicious, and the that the correct word is "cracker". Likewise, if they write about crackers breaking into computers, they will receive hate-mail claiming that crackers only break codes, but its hackers who break into systems. The best choice probably depends upon the audience; for example one should definitely talk about malicious crackers in a computer-enthusiast magazine like Linux Today."
This is one I've always been confused about too. But I reckon I'm on the side of "Crackers".
Hmm, glad to see that the "Special Relationship" is still very much alive and kicking then.
On a serious note though. In the UK our incidences of domestic terrorism have fallen greatly mainly due to the fact that people bothered to sit down and discuss the issues. They may not have liked it but both the incumbent government and the previous government made it their priority to tackle the diffcult issue of Northern Ireland through peaceful and meaningful democratic debate, although many in NI would no doubt disagree.
Sure there are still terrible tensions in the six counties and a lot of work remains to be done but we live in hope of a lasting peace in the UK.
Once again I would like to reiterate that this was achieved by "talking" and not by bombing the country back into the stone age. Valuable lessons maybe.
Slashdot Mirror
I have to say that this is nearly the best comment I have ever read, certainly the funniest. Thanks! But at the risk of sounding like a bit of a smart-arse, don't you mean "Chemistry is not random, it's not stochastic"...?
OK, I think that it's fair to say that AOP is still very much at the cutting edge of developement in the java community.
Essentially the idea with AOP is that you increase the modularity and decrease the coupling of components in your application. An example of this would be Logging.
Now most (if not all) apps need to have logging code of one sort or another. This means that the code necessary to log to whichever system (commons-logging, log4j etc in the java world) you use tends to touch all of the classes/objects in your application.
Consider a situation where you have a large existing code base that you have refactored using well understood techniques such as extract method and extract superclass until you have a wonderfully clean and consistent application. You will find that even after this refactoring you still have dependencies throughout your code on your logging mechanism that cannot easily be refactored away.
In software engineering terminology this means that your application code is tightly coupled to whichever logging implementation it uses. This is a bad thing. It makes the application brittle - caveat, see 1 below.
Aspect Orientated Programming can help solve these sorts of problem by introducing another conceptual level into traditional OO. You can move the common logging code into one or more Aspects. These are separate from the rest of your codebase. When the application is run, the aspects are used to modify the code in your application to, for example, use your preferred logging implementation - oh, and before someone flames me saying I'm wrong, I know that with java this isn't exactly how it works, but it's a useful lie!
Now the interesting thing about Spring is that it's one of the first widely accepted uses of AOP. I know that even a year ago AOP was mainly of interest to comp-sci academics and bleeding-edge technologists but with Spring incorporating it into the framework it has brought AOP to a lot of people's attention.
Inversion of control, otherwise known as the Hollywood Principle (don't call us, we'll call you), refers to the currently accepted/hyped practice of "telling things what to do" rather than "things inherently knowing what to do". It's obviously a lot more complex than that, and a lot has been written about the technique but that's the basic gist.
As for citing major applications that use these practices, well an awful lot of applications are being written using the Spring framework as their heavy lifter of choice. As for Inversion of Control, well-written/architected applications have been using the hollywood principle for years - it really isn't anything new.
Now, forget all of that and lets talk about Intentional Programming :-P
I work in IT as a Software Engineer (java/C++) and have done for 8 years. The product that the company sells is "actually made by me" (sic) and I feel undervalued.
Perhaps things aren't quite as simple as a still dry MBA might otherwise suggest?
GAK! The robots are coming!! RUN FOR THE HILLS! They are coming from the hills! RUN AWAY FROM THE HILLS!
In the best traditions of this site I am posting this at two in the morning. The above has made more sense than most posts I have read.
It appears that a lot of people are unable to distinguish the kind of person who is able to kill innocents from the kind of person who isn't. It has absolutely nothing to do with your religion. It has nothing to do with your ethnic group. Unfortunately it has everything to do with the way you have been treated as a person. Historically or in this moment.
History is full of examples of peoples who have been persecuted turning on their oppressors. It is not racial groups that are to blame for the problems that exist in the world; it is the fundamental social injustices that we should blame.
No educated person (and after reading some of the children of this post I use that term losely) should accept "arabs are to blame"/"islam is to blame". There is no argument that can adequately defend that point of view.
It's easy at the end of the day. WE need to recognise our differences.
Is this post ironic?
I so so so so so hope so dude.
"mainly cause that is over a mile down"
is that in terms of effect?
Hmm, not actually sure if this is correct. This is going back a bit but I think:
Laser stands for Light Amplification by the Stimulated Emission of Radiation.
A LASER doesn't produce light because of waves contructively interfering. The light is amplified by the absorbtion and emission of photons at specific wavelengths.
There are two types of photon emission, spontaneous and stimulated.
Spontaneous emission occurs when an electron in an atom "jumps" from a higher quantised state to a lower one giving up energy. This energy is emitted as a photon. This is what happens in street lights, electrons fall back to a lower energy level and that corresponds exactly to the wavelength of the orange light we see. The photon can be emitted in any direction.
Stimulated emission occurs when an atom absorbs a photon causing an electron to move to a "higher" state but in this case the electron can immediately jump back to it's lower state. This causes two photons to be emitted in exactly the same direction as the original photon was travelling.
Essentially a LASER works by putting mirrors round a cavity and multiplying the photons by bouncing them back off the mirrors and into the emitting atoms thereby causing a "chain reaction" to take place where two become four etc.
The reason that you get monochromatic light (normally) is that the wavelength of the photons produced is exactly related to the energy levels in the atom producing them. The reason you get coherent light is because the photons are travelling in the same direction.
IWAPIU (I was a physicist in Uni) and built a Nitrogen LASER for my final year project. That was a good 8 years ago now though.
The author Iain M. Banks has discussed this issue throughout his "Culture" series of books. He suggests that perhaps there are galazy spanning civilisations out there, but that they are evolved enough to leave us alone until we reach a level as a species where we can be considered for inclusion in the galactic community.
Why would they need to do anything as unsubtle as establishing moonbases when they could have invisible ships 30 kms long able to control every single tv screen on this planet from outside the orbit of Jupitor? :)
In fact, one of his short stories from the collection The State of the Art is about what happens when the Culture use Earth as part of a control group. An excellent read.
Of course this is sci-fi but you get the drift. If anyone is interested I would go as far as saying that for thought provoking Sci-Fi, Iain M. Banks is the man to beat at the moment.
Here he is in an interview at scifi.com talking about his writing. And here is the man with a few introductory notes on the Culture for the unitiated - I just picked this site from the top of google so I hope they don't mind me posting here :P
Heres the api for starters.
I've always found that all of this is very well documented. I've never developed an application in anger using it, but have been playing round with the technology as a client for content management on mobile devices e.g. Uploading of photos from camera phones, articles from PDA's etc.
I think you are probably correct about it's usefulness in the future, but dig around a bit further and there is a wealth of information out there.
Oooo oooo, more info...
It's a long story so I'll cut it short; he was involved in training some soldiers from the 101 Airborne whilst they were in the UK and got into a conversation with one of their officers:
Bemused US Airborne Dude: "say, why do you brits spend so much time running up and down mountains in training? Can't you just radio a chopper?"
UK Dude: "Well, what happens if it gets shot down?"
Bemused US Airborne dude: "We radio for another one."
UK Dude: "And if the second one gets shot down?"
Even more bemused US Airborne dude: "We radio for another one..."
Train hard, fight easy as they say...
Passing it once was enough, thank you very much.
Now could someone pass the parent a lavatory brush and a dictionary please.
It's still chuffing hard without a docking computer...
"the lack of enough silt on the ocean floor"
Essentially the conundrum was that with all the silt being deposited into oceans over aeons the ocean floor should be one thick mass of sh*t. When mankind first got around to investigating this, we found that it wasn't the case. In fact the ocean floor is pretty rich in geography (biggest mountain range on earth etc) with no sign of hundreds of metres of kludge anywhere. So what had happened to it?
Then along came plate tectonics and it nicely explained amongst other things, what was going on here. Plate tectonics accounts for a phenomenon called "Subduction". This process occurs when two plates collide. One of the plates concerned will be subducted under the other. The subducted plate's rock is then returned to the mantle (a load of super-liquid rock underneath the earths crust). In conjunction with new ocean floor being created, for instance at the mid-atlantic ridge, subduction explains why there is no silt build up on the ocean floor. It's because the ocean floor is always geologically young!
It goes something like:
1. new ocean floor created at mid-ocean ridge.
2. Silt deposited on said new ocean floor.
3. new ocean floor becomes old ocean floor and is subducted. Along with the silt.
4. ?????
5. Profit!
(only joking about the last two)
Much more info is available about this at, for example:
US geological survey
google for the rest.
Someone should explain that to my Project Manager...
Apparently it's going to beat that ~96000 record the Helios set, but won't be officially eligable because it's not going to take off under it's own power.
The balloon that launches it is fairly impressive too:
"As tall as the Empire State Building, their manned envelope will be the biggest ever flown."
However, the US seems to have no problems keeping it's military bases' lights on either when:
Population below poverty line: 13% (2001 est.)
(Src: CIA World Factbook
And it says:
"Controversy: The computer-enthusiast community does not like using "hacker" to describe malicious people; they prefer "cracker". The security-community restricts the use of the word "cracker" to some who breaks encryption and copy-protection schemes.
Consequently, a journalist who writes about cybercriminals cannot use either word without hate mail from the opposing community claiming they are using the word incorrectly. If a journalists writes about hackers breaking into computers, they will receive hate-mail claiming that not all hackers are malicious, and the that the correct word is "cracker". Likewise, if they write about crackers breaking into computers, they will receive hate-mail claiming that crackers only break codes, but its hackers who break into systems. The best choice probably depends upon the audience; for example one should definitely talk about malicious crackers in a computer-enthusiast magazine like Linux Today."
This is one I've always been confused about too. But I reckon I'm on the side of "Crackers".
Hmm, glad to see that the "Special Relationship" is still very much alive and kicking then. On a serious note though. In the UK our incidences of domestic terrorism have fallen greatly mainly due to the fact that people bothered to sit down and discuss the issues. They may not have liked it but both the incumbent government and the previous government made it their priority to tackle the diffcult issue of Northern Ireland through peaceful and meaningful democratic debate, although many in NI would no doubt disagree. Sure there are still terrible tensions in the six counties and a lot of work remains to be done but we live in hope of a lasting peace in the UK. Once again I would like to reiterate that this was achieved by "talking" and not by bombing the country back into the stone age. Valuable lessons maybe.
No messing about. It's time to write a filter that blocks all those evil "1"'s and "0"'s...
Ahhh yes that's right. As Goethe said:
"There is nothing more frightful than ignorance in action."