CCD/CMOS sensors are not nearly as sensitive in the UV as the IR.
Some sensors are more sensitive than others however.
The problem is, the lower the sensitivity the longer the exposure needs to be to create an image. Most webcams can only expose for a few seconds or less. So you'd have better luck with a digital slr camera.
You'd probably still need to modify the camera by removing it's cut/IR/antialiasing filter and replace it with UV pass filter.
There are a few places on the web that will perform this service, but of course you void your warranty. And unless you replace the original filter the camera is not useful for visible photographs.
This isn't really anything new. Amateur astronomers have been doing this with webcams for awhile now. Even in the near IR range, some things look a little different.
There are instances where knowing the instructions will not help you back track, such as certain encryption algorithms.
You're also not taking into acount all the data and sates a piece of software may have traveled through, which is not as simple as just back-traking through the execution.
There are also other fun little things like interrupts, threads, processes, etc. It can get quite complicated very quickly.
In some instances you'd be able to get away with an IP back-trace, but with the complexity of modern software you'd need a lot more than that to reverse execution.
"So the prices of real estate can go up and down, but because there is little speculation involved (unless you're buying undeveloped land in the hope that it will eventually be developed), there is little risk of a sharp downturn."
You're not from around here are you?
There are thousands of people (and many investment firms) who are investing in real estate in the hopes that it goes up. As a matter of fact, there are several funds that do this, if your looking for a way to add to your portfolio.
And in the past there have been big corrections in real estate. The Florida Real Estate Craze in the 1920's is a pretty famous one. There was one not to long ago (in the 90's) that hit southern California pretty hard. Alot of the homes in the area devalued by as much as 50%. And let's not forget those wonderful years of the late '80's when the Japanese used their inflated real-estae properties as collateral for buying stocks (which ultimately led to the biggest economic crash in history). That dragged everything down.
Any and all investments can have bubbles and crashes.
I find it interesting that many on here will claim that open source operating systems are the most stable and can be used in things like medical equipment, rocket systems, massive critical networks, etc. (linux) but would not trust an open source tax program.
Someone who has specialized in a specific field who has not been exposed to other fields will always be doomed to think inside the box.
Sure, you may think it's a complete waste of your time and money, but you'd be really surprised where great ideas come from.
You also never know when certain information may be useful.
I took courses in college that I didn't find particularly interesting, but offered me a wider breadth of knowledge. I've even had opportunity to put alot of what some would call "useless" knowledge to very good use.
It's far better to get the code working first, then go back and analyze where optimizations will be most useful. Most trivial optimizations will be handled by the compiler.
There are some things you can do along the way to help performance, but the serious "thinking" optimizations should come after you have a solid base to work from.
Having worked with both embedded systems and PCs, here's my philosophy.
The first rule of optimization is not to optimize. Get the damn thing working first. After you get it working, don't optimize. Test the damn thing to make sure it doesn't break. After testing, do not optimize. Profile the damn thing to find the choke points. After profiling your code, do not optimize. Analyze the damn profile to determine whether or not optimization will be worth the additional effort.
Establish what you are trying to do, then do it and make sure it works. Once you have something that works you have a baseline to compare against when performing optimizations. You'll also have a much better idea of how long it will take to implement optimizations.
I've seen far too many programmers spend days trying to optimize with incomplete code and doing little more than running around in circles (and not getting much more performance out of their code than what the compiler was doing).
With embedded systems, you are more likely to get a decent performance boost from doing hand optimizations, but only if you fully understand the underlying hardware. You may write your super-leet optimized assembly routine, but if you end up shoving it into the wrong memory section you my find your code runs a hundred times slower.
In general, compilers have come a long way and do a decent job of optimizing most code pretty good.
With embedded systems, that's a little more shakey. I always write some test code and compile to assembler to see if there is anything obviously bad about what the compiler is doing.
So for PC's and the like, I have more faith in the compiler. With embedded systems, I have faith in the compiler...after inspection.:)
It wopuld be considerably more complicated than this. The galactic core is a rotating supermassive black hole with relativistic effects. Taking that into consideration might make the project a bit more challenging.
Think of Earth like a bowling ball with a 1 kg mass that is free to spread out and move around. When the Pangea super-continent existed, that mass was located mostly on one side of the planet, causing exagerated motion in both the horizontal and vertical planes. The land masses spread out over the millions of years, and in doing so stabilized the motion.
The moon likely played an important role in this (the moon had a much stronger influence in the past as it was significantly closer to Earth).
We also can not disregard the shield effect of the moon. Not all asteroid impacts are dead-on. Without something balancing the Earth, a series of strong enough impacts could impart enough momentum to tilt the planet (like some of the impacts on the moon, or the impact that created the Hudson bay).
Did I say that the moon gives us seasons? No. I said the moon acts as a stabilizer.
Oh we would definately have seasons without the moon. But they would not be predictable, and most likely be rather violent, as the tectonic shifting of our planet would lead to some quite interesting axis motion.
Life would be quite different without a moon, with a high probablity that we would have never existed.
I'm sure you've noticed that the three planets you just mentioned are practically devoid of significant geophysical activity?
The Earth's mass distribution is constantly changing. This directly influences the way our planet rotates. Take, for exmple, the tsunami quake which sped up Earth's rotation by about 3 milliseconds.
Over the course of millions of years, tectonic shifts can have a profoud impact on how a planet rotates in 3 dimensional space. Having large enough moons also influences this rotation.
I am fully aware that it is the tilt of the Earth's axis that gives us seasons. I'm fully aware that we have four seasons each year.
What I said was that if you look at a simulation of the Earth's back and forth motion at a fairly decent speed, you'd notice that the tilt is not exactly back and forth. There is a small deviation to either side of the central axis line.
Slashdot Mirror
CCD/CMOS sensors are not nearly as sensitive in the UV as the IR.
Some sensors are more sensitive than others however.
The problem is, the lower the sensitivity the longer the exposure needs to be to create an image. Most webcams can only expose for a few seconds or less. So you'd have better luck with a digital slr camera.
You'd probably still need to modify the camera by removing it's cut/IR/antialiasing filter and replace it with UV pass filter.
There are a few places on the web that will perform this service, but of course you void your warranty. And unless you replace the original filter the camera is not useful for visible photographs.
~X~
This isn't really anything new. Amateur astronomers have been doing this with webcams for awhile now. Even in the near IR range, some things look a little different.
Not recommended when planet imaging.
~X~
Assuming the improbability of something the mass of our sun going supernova?
If the sun did go supernova, there is no place in our solar system that would make us safe. The shockwaves of the blast would rip everything apart.
Just think of the sizeof something like the crab nebula.
~X~
"Saying that no one has the right to publish information that could have been provided only by someone breaking the law."
And exactly how many ludicrous laws do we have now, and how many will we have in the future?
I agree, the judge made a serious error. This leaves a hole big enough to drive a presidential administration through.
~X~
There are instances where knowing the instructions will not help you back track, such as certain encryption algorithms.
You're also not taking into acount all the data and sates a piece of software may have traveled through, which is not as simple as just back-traking through the execution.
There are also other fun little things like interrupts, threads, processes, etc. It can get quite complicated very quickly.
In some instances you'd be able to get away with an IP back-trace, but with the complexity of modern software you'd need a lot more than that to reverse execution.
~X~
"So the prices of real estate can go up and down, but because there is little speculation involved (unless you're buying undeveloped land in the hope that it will eventually be developed), there is little risk of a sharp downturn."
You're not from around here are you?
There are thousands of people (and many investment firms) who are investing in real estate in the hopes that it goes up. As a matter of fact, there are several funds that do this, if your looking for a way to add to your portfolio.
And in the past there have been big corrections in real estate. The Florida Real Estate Craze in the 1920's is a pretty famous one. There was one not to long ago (in the 90's) that hit southern California pretty hard. Alot of the homes in the area devalued by as much as 50%. And let's not forget those wonderful years of the late '80's when the Japanese used their inflated real-estae properties as collateral for buying stocks (which ultimately led to the biggest economic crash in history). That dragged everything down.
Any and all investments can have bubbles and crashes.
~X~
There's a reason why MUD was referred to as "multi-undergraduate destroyer".
3AM, sitting in front of the dull orange glow of a dumb-terminal just to kill one more cave troll for the next level.
It was sad to watch this happen to people.
~X~
I find it interesting that many on here will claim that open source operating systems are the most stable and can be used in things like medical equipment, rocket systems, massive critical networks, etc. (linux) but would not trust an open source tax program.
:P
I'm not sure how I feel about that.
~X~
I agree.
Ban violent videogames, but send 18-year old kids into war where they are shot and killed everyday?
Ban violenent video games, but espouse the virtues of a righteous war?
WTF?
Apparently some people DO NOT HAVE A CLUE.
~X~
In the US, only young people program. :)
~X~
I should have said comfortable, not familiar.
~X~
Loaded question. You are always more productive in the environment you are familiar with.
~X~
People wonder why the US is going downhill? This attitude speaks volumes.
You should get paid to learn? Why, because you actually need to take some time to learn?
I learn because I find things interesting. I learn becuase I want to learn. The fact that it helps me stay on top of my profession is a nice benefit.
I've known plenty of people who have this attitude. "I'm not going to bother to take that course unless I get paid to do it."
It's like momentum. An object at rest tends to stay at rest. It won't kill you to take the initiative once in awhile for self-improvement.
~X~
Someone who has specialized in a specific field who has not been exposed to other fields will always be doomed to think inside the box.
Sure, you may think it's a complete waste of your time and money, but you'd be really surprised where great ideas come from.
You also never know when certain information may be useful.
I took courses in college that I didn't find particularly interesting, but offered me a wider breadth of knowledge. I've even had opportunity to put alot of what some would call "useless" knowledge to very good use.
There is no such thing as useless knowledge.
~X~
I love this country.
Show a tit on TV and get fined. Say shit on the radio and get fined.
But send thousands of 18 year old kids to foriegn country to die horrible deaths for lie, and the fucking country relects you for president.
Morality my ass. This is just fucking stupid.
~X~
"Seriously, if you don't know how to get the answer to the question for yourself, then you don't deserve to know the answer."
Damn, I'd hate to be your kids.
~X~
That's not the best advice.
It's far better to get the code working first, then go back and analyze where optimizations will be most useful. Most trivial optimizations will be handled by the compiler.
There are some things you can do along the way to help performance, but the serious "thinking" optimizations should come after you have a solid base to work from.
~X~
Having worked with both embedded systems and PCs, here's my philosophy.
:)
The first rule of optimization is not to optimize. Get the damn thing working first. After you get it working, don't optimize. Test the damn thing to make sure it doesn't break. After testing, do not optimize. Profile the damn thing to find the choke points. After profiling your code, do not optimize. Analyze the damn profile to determine whether or not optimization will be worth the additional effort.
Establish what you are trying to do, then do it and make sure it works. Once you have something that works you have a baseline to compare against when performing optimizations. You'll also have a much better idea of how long it will take to implement optimizations.
I've seen far too many programmers spend days trying to optimize with incomplete code and doing little more than running around in circles (and not getting much more performance out of their code than what the compiler was doing).
With embedded systems, you are more likely to get a decent performance boost from doing hand optimizations, but only if you fully understand the underlying hardware. You may write your super-leet optimized assembly routine, but if you end up shoving it into the wrong memory section you my find your code runs a hundred times slower.
In general, compilers have come a long way and do a decent job of optimizing most code pretty good.
With embedded systems, that's a little more shakey. I always write some test code and compile to assembler to see if there is anything obviously bad about what the compiler is doing.
So for PC's and the like, I have more faith in the compiler. With embedded systems, I have faith in the compiler...after inspection.
~X~
In Korea only old people have spoilers.
:)
Uh...take that any way you want
~X~
"I have a patent on triangular tires."
No wonder you're piss poor and posting on slashdot.
~X~
It wopuld be considerably more complicated than this. The galactic core is a rotating supermassive black hole with relativistic effects. Taking that into consideration might make the project a bit more challenging.
:P
Like building one in the first place isn't.
~X~
Think of Earth like a bowling ball with a 1 kg mass that is free to spread out and move around. When the Pangea super-continent existed, that mass was located mostly on one side of the planet, causing exagerated motion in both the horizontal and vertical planes. The land masses spread out over the millions of years, and in doing so stabilized the motion.
The moon likely played an important role in this (the moon had a much stronger influence in the past as it was significantly closer to Earth).
We also can not disregard the shield effect of the moon. Not all asteroid impacts are dead-on. Without something balancing the Earth, a series of strong enough impacts could impart enough momentum to tilt the planet (like some of the impacts on the moon, or the impact that created the Hudson bay).
~X~
Did I say that the moon gives us seasons? No. I said the moon acts as a stabilizer.
Oh we would definately have seasons without the moon. But they would not be predictable, and most likely be rather violent, as the tectonic shifting of our planet would lead to some quite interesting axis motion.
Life would be quite different without a moon, with a high probablity that we would have never existed.
~X~
I'm sure you've noticed that the three planets you just mentioned are practically devoid of significant geophysical activity?
The Earth's mass distribution is constantly changing. This directly influences the way our planet rotates. Take, for exmple, the tsunami quake which sped up Earth's rotation by about 3 milliseconds.
Over the course of millions of years, tectonic shifts can have a profoud impact on how a planet rotates in 3 dimensional space. Having large enough moons also influences this rotation.
~X~
Obviously I'm not making myself very clear.
I am fully aware that it is the tilt of the Earth's axis that gives us seasons. I'm fully aware that we have four seasons each year.
What I said was that if you look at a simulation of the Earth's back and forth motion at a fairly decent speed, you'd notice that the tilt is not exactly back and forth. There is a small deviation to either side of the central axis line.
This is the wobble I'm refering to.
~X~