There's a kernel of insight in there somewhere. The sun radiates like a black body, which means that all colors of light are emitted, in varying degrees. There is a peak wavelength, and this peak is in the visible spectrum, IIRC. In any event, by the time the light gets to the surface of Earth, the peak wavelength corresponds to yellow light.
That's the black-body principle, the higher the temperature, the shorter the peak wavelength.
When this light hits, say, a surface painted black, the surface will get hot because the black paint absorbs most of the radiation. Ignoring convection, for the moment, this surface will then re-radiate, more or less as a black body. But since it is much cooler than the sun, its radiation is concentrated in the IR region. So the trick is to find a material which reflects low energy IR, such as that radiated by the black surface, but transmits the higher energy IR and visible light coming from the sun. One such material is ordinary glass.
This principal, which is also called the greenhouse effect, is used in solar water heaters. A simple one would be a black pipe inside a black channel of some sort with a piece of glass closing off the channel. Solar radiation mostly passes through the glass, but the IR coming from the pipe and the inside of the channel is mostly reflected back.
If you have a black roof, you could put glass over it, and your house would probably stay a lot warmer in the winter, at least when it is clear. But then what would you do in summer? You'd have to cover the glass with a reflective material.
Anyway, radiation is only part of the story. An optimal solution would presumably also try to minimize convective loss from the pipe.
The money in question belongs to the taxpayers. If the taxpayers would rather send astronauts to Mars than build a super-conducting super collider, then that is what will happen.
Perhaps geographical frontiers are more attractive to the populace than knowledge frontiers.
"A few billion here, a few billion there. Pretty soon, it starts to add up to real money."
This is a well known quote which, even when first uttered, was meant ironically.
I know jokes aren't funny when you have to explain them but the point of this comment was to call attention to the fact that a billion dollars IS a lot of money all by itself.
My favorite way to look at is that to blow through a billion dollars in a year you would have to spend 2.7 million a day.
Pretty hard to overflow that. strlen() returns a size_t, which is always a very large type.
Oh, to be totally anal and pedantic, unsigned types (which size_t is) don't overflow. The ISO c standard imparts special meaning to "overflow" and specifies that it is only possible for signed types.
But there are plenty of other scenarios where it could be a concern. Chiefly, anywhere that user input directly specifies the length or number of items for which space must be allocated.
As for why malloc(0) doesn't return NULL, I can't say with certainty, but it is clear from the wording of the standard that its writers deliberately left open the door to returning non-NULL. I guess they wanted to support the concept of empty objects. Returning NULL is also allowed, and I'm sure some implementations do this.
Hmmm, yes and no. It is important that the variable on the left hand side of the equals sign be big enough, but the variables on the right side will be promoted.
So if the OP was saying he doesn't care about the left hand side type, then you are right. I get the feeling that he was.;-)
Then again, as the phrack article says, these problems are subtle and much more difficult to exploit than standard buffer overflows (e.g., gets() or scanf("%s",...).
Don't know what things are like elsewhere, but in San Francisco, where I live, foreign movies are never dubbed. No one would watch them. We like to hear the voices of the actors and actresses.
I guess I should add that I'm not too sure about Chinese movies for Chinese-speaking audiences, since I can't read or understnad Chinese. There might, for example, be movies dubbed from Mandarin into Cantonese, for all I know.
Apart from a translation of the title and the DVD logo, there was no English on the box. Worse, the DVD navigation menus were all in Chinese, and none of us speak a word! We had a hell of a time turning on the English subtitles for the movie itself. We just systematically went through every menu and sub-menu until we found it.
They must have either released it with no region encoding, or with US region encoding, I guess, because I had no problems.
Anyway, the movie's not bad. The tone is a bit too earnest for me. And the kung-fu is of the supernatural variety (a bit like Crouching Tiger, Hidden Dragon, which I absolutely loved) which turns off some people. But overall I enjoyed it. Not nearly as much as Crouching Tiger, Hidden Dragon, though.
You shortened it horribly. The version I heard was an engineer vs. business man joke and was more like this:
A man is standing on a foggy hilltop when another man riding in a hot air baloon starts to drift by.
"Can you tell me where I am?" asks the baloonist.
"Yes, you are approximately 50 feet above a small hillock in the fog," replies the man on the hill.
"You must be an engineer," comes the reply.
"How did you know?" asks the man on the hill.
"What you told me is 100% correct, but does not help me at all," replied the baloonist.
"You must be a business man," says the engineer.
"How did you know?" asks the baloonist.
The engineer pauses, briefly, then says "Well, you don't know where you are or where you're going, but you expect me to help. And you're no worse off now than when we met, but now it's my fault."
But isn't it easier to kill your enemy after you disable all his electronics?
So if it's not the perfect weapon, it's still a good tool for an army to have, isn't it?
I'm just afraid that it will be more useful for our enemies to use against us than it is for us to use against our enemies. (as many others have suggested.)
Second, this seems overly paranoid on the safety issue, given that if the FBI is listening in, I'm sure they would be able to hear the person they're tapping scream "Holy [expletive deleted]!" before he hits the semi truck. And I highly doubt the FBI is just gonna sit on their ass wondering why they aren't getting any more sound.
You are dreaming. As many others noted, no one may be listening live. Also, if they respond, they are blowing the surveillance, which may tip off co-conspirators. Furthermore, you may believe that law enforcement has some kind of over-riding duty to respond to emergencies where life is threatened, but they don't. Legally, they don't even have to respond when people call 911. It's a quality of service issue, not a legally enforceable obligation.
...And this is a country filled with half-ignoramus who get all their news from Rupert Murdoch.
The word "ignoramus" is singular, but your sentence is constructed as if it were plural.
...pratically non-existant next to the defense department's big money handout...
You have misspelled both "practically" and "non-existent." Not only that, but you could easily have used actual statistics and provided us with a link instead of using misspelled adjectives.
Perhaps you should learn to spell and to write sentences whose objects and verbs agree in number before you make fun of hypothetical illiterates.
The usage is relatively easy. The hard part is preparing floppies which support the networking cards. If our computers all used the same networking cards, it would be easy, because there'd only be one floppy. But we have about a dozen computers with at least half a dozen different networking cards (or built-in to motherboard).
And I'm not an IT guy, I'm an EE, so they don't want me to spend all my time doing this sort of thing. So we use backup to make backups. So far we haven't had a disk failure that hurt us, so we haven't had to restore, other than once to make sure it works.;-)
I've done this on win2k. You do have to make sure you get the system state. I think there is a checkbox for that.
It is slow, but it's a lot faster than re-installing all of your applications from scratch.
The people at my work don't really like to hear about linux-based solutions, so dd (or tar, for that matter) wasn't an option. We do have ghost, but that is a pain to get working on a network, due to the fundamental limitations of DOS in that regard.
Usually I'm in favor of modding article re-posts as redundant. But in this case, the article really was slashdotted, so I am glad that SunSaw posted it.
Maybe someone can mod the parent back up a bit so people who don't browse at -1 can read it, too?
I don't thing the idea was to make one box able to boot as any processor.
I think the idea was to make one die which could be configured to behave like any processor. But once you pick the one you want, you pretty much are stuck with it.
The architectures of all the different systems are far too varied for one mother board to support them all.
I have never heard a thing about any architecure besides x86. I doubt any work on any other translation layer has even begun. They have their hands full with x86 as it is.
Oh, there are so many reasons for the German failure on the Eastern Front that you and I could probably fill up this board discussing them. My original remarks were based on Speer's figures of keeping at 50% prewar armaments production through the end of the war.
I wasn't aware of that figure. It is indeed impressive!
What I know about the battle for Stalingrad I got from a book my brother loaned me. I don't remember the exact title or author, but it was heavily-referenced and seemed quite well-researched.
Even in World War II the Allies were oft astonished at the recuperative power of the German Army -- they always had plenty of bullets and planes, and in the end, it was an actual lack of fighting age men that did them in.
Actually, on the Russian front, an army of hundreds of thousands gradually ran out of fuel, food, spare parts, uniforms, etc. Those who didn't die of starvation, disease, or cold were forced to finally surrender when they were encircled by one of Stalin's armies. By that time, they were gaunt, dressed in rags, and infested with fleas and lice.
Earlier in the war, when the Germans were winning, the Russian troops were under orders not to surrender or retreat under any circumstances at Stalingrad. It was crazy. People who abandoned their positions were killed by their own commanders. Those who surrendered or defected (and were later recovered when the Germans surrendered) were killed or sent to the gulag. But even without this brutal treatment, the Russians were very brave and determined. There were a lot of tales of heroism on their part.
As an example, Japan has less than 3% of the IPv4 address space. India and China have less than 1% each.
The US already has over half the IP address space.
MM
--
Re:Better served by a standard *nix shell
on
Microsoft's new CLI
·
· Score: 1
From microsoft's perspective, they can't adopt cygwin, because it is "poisoned" by the GPL.
That is, everything in cygwin depends on the cygwin dll which is GPL'd.
Not only that, but a lot of stuff that depends on the cygwin dll runs very slow. Subjectively, gcc seems to run at less than half the speed under cygwin than it does natively on linux.
This apparent slowness of cygwin apps may be an unavoidable consequence of cygwin's providing a somewhat full-featured posix layer to an OS that doesn't really have one.
Parliment issued a prize to John Harrison for developing an accurate chronometer. The guy had zero credentials to do it - he was a cabinet maker - but he beat out everyone else and solved a long standing puzzle because of the prize.
John Harrison wasn't a cabinet maker. He was a clock maker and an unschooled mechanical genius. He was also, apparently, almost impossible to understand. You failed to mention an important constraint: The chronometer had to keep time while at sea, which is what made the task so difficult. The british wanted this because it would give them the ability to determine longitude accurately on long voyages.
What you also don't mention about Harrison is that he was not a member of the Royal Society, and had powerful enemies inside it. This made it very difficult for him to collect his reward. He had to wait many many years.
If Nasa put up a series of substantial prizes for an aircraft capable of reaching LEO, Geostationary Orbit, Lunar Orbit and Lunar landing and Return, I'll bet we'd see a huge surge in space flight for a fraction of what we're spending today for shuttle flights. Nasa may not like the lack of control a prize implies but it would certainly encourage innovation.
The current X-prize task is one thing. Getting a substantial payload into orbit is another. The other goals you mention are even more lofty. I don't think any organization could afford to do it just on the hope of winning a prize.
Well, I will admit to being mixed up on what permafrost is (I was thinking that all permafrost areas were tundra, which is totally wrong). But I won't admit to knowing nothing about Alaska. I've read a bit about it, but never visited.
Anyway, for the record, according to this map
Galena is in "lowland and upland area underlain by discontinuous permafrost."
Slashdot Mirror
There's a kernel of insight in there somewhere. The sun radiates like a black body, which means that all colors of light are emitted, in varying degrees. There is a peak wavelength, and this peak is in the visible spectrum, IIRC. In any event, by the time the light gets to the surface of Earth, the peak wavelength corresponds to yellow light.
That's the black-body principle, the higher the temperature, the shorter the peak wavelength.
When this light hits, say, a surface painted black, the surface will get hot because the black paint absorbs most of the radiation. Ignoring convection, for the moment, this surface will then re-radiate, more or less as a black body. But since it is much cooler than the sun, its radiation is concentrated in the IR region. So the trick is to find a material which reflects low energy IR, such as that radiated by the black surface, but transmits the higher energy IR and visible light coming from the sun. One such material is ordinary glass.
This principal, which is also called the greenhouse effect, is used in solar water heaters. A simple one would be a black pipe inside a black channel of some sort with a piece of glass closing off the channel. Solar radiation mostly passes through the glass, but the IR coming from the pipe and the inside of the channel is mostly reflected back.
If you have a black roof, you could put glass over it, and your house would probably stay a lot warmer in the winter, at least when it is clear. But then what would you do in summer? You'd have to cover the glass with a reflective material.
Anyway, radiation is only part of the story. An optimal solution would presumably also try to minimize convective loss from the pipe.
MM
--
The money in question belongs to the taxpayers. If the taxpayers would rather send astronauts to Mars than build a super-conducting super collider, then that is what will happen.
Perhaps geographical frontiers are more attractive to the populace than knowledge frontiers.
MM
--
"A few billion here, a few billion there. Pretty soon, it starts to add up to real money."
This is a well known quote which, even when first uttered, was meant ironically.
I know jokes aren't funny when you have to explain them but the point of this comment was to call attention to the fact that a billion dollars IS a lot of money all by itself.
My favorite way to look at is that to blow through a billion dollars in a year you would have to spend 2.7 million a day.
MM
--
Woo hoo! I drink 12 cups a day, so my risk should be reduced by 100%!
--
MM
Pretty hard to overflow that. strlen() returns a size_t, which is always a very large type.
Oh, to be totally anal and pedantic, unsigned types (which size_t is) don't overflow. The ISO
c standard imparts special meaning to "overflow" and specifies that it is only possible for signed types.
But there are plenty of other scenarios where it could be a concern. Chiefly, anywhere that user input directly specifies the length or number of items for which space must be allocated.
As for why malloc(0) doesn't return NULL, I can't say with certainty, but it is clear from the wording of the standard that its writers deliberately left open the door to returning non-NULL. I guess they wanted to support the concept of empty objects. Returning NULL is also allowed, and I'm sure some implementations do this.
MM
--
Hmmm, yes and no. It is important that the variable on the left hand side of the equals sign be big enough, but the variables on the right side will be promoted.
;-)
...).
So if the OP was saying he doesn't care about the left hand side type, then you are right. I get the feeling that he was.
Then again, as the phrack article says, these problems are subtle and much more difficult to exploit than standard buffer overflows (e.g., gets() or scanf("%s",
MM
--
Don't know what things are like elsewhere, but in San Francisco, where I live, foreign movies are never dubbed. No one would watch them. We like to hear the voices of the actors and actresses.
I guess I should add that I'm not too sure about Chinese movies for Chinese-speaking audiences, since I can't read or understnad Chinese. There might, for example, be movies dubbed from Mandarin into Cantonese, for all I know.
MM
--
This has been tried and lost.
On appeal, 2600 lost the right to link to deCSS.
MM
--
Apart from a translation of the title and the DVD logo, there was no English on the box. Worse, the DVD navigation menus were all in Chinese, and none of us speak a word! We had a hell of a time turning on the English subtitles for the movie itself. We just systematically went through every menu and sub-menu until we found it.
They must have either released it with no region encoding, or with US region encoding, I guess, because I had no problems.
Anyway, the movie's not bad. The tone is a bit too earnest for me. And the kung-fu is of the supernatural variety (a bit like Crouching Tiger, Hidden Dragon, which I absolutely loved) which turns off some people. But overall I enjoyed it. Not nearly as much as Crouching Tiger, Hidden Dragon, though.
MM
--
You shortened it horribly. The version I heard was an engineer vs. business man joke and was more like this:
A man is standing on a foggy hilltop when another man riding in a hot air baloon starts to drift by.
"Can you tell me where I am?" asks the baloonist.
"Yes, you are approximately 50 feet above a small hillock in the fog," replies the man on the hill.
"You must be an engineer," comes the reply.
"How did you know?" asks the man on the hill.
"What you told me is 100% correct, but does not help me at all," replied the baloonist.
"You must be a business man," says the engineer.
"How did you know?" asks the baloonist.
The engineer pauses, briefly, then says "Well, you don't know where you are or where you're going, but you expect me to help. And you're no worse off now than when we met, but now it's my fault."
MM
--
But isn't it easier to kill your enemy after you disable all his electronics?
So if it's not the perfect weapon, it's still a good tool for an army to have, isn't it?
I'm just afraid that it will be more useful for our enemies to use against us than it is for us to use against our enemies. (as many others have suggested.)
MM
--
You are dreaming. As many others noted, no one may be listening live. Also, if they respond, they are blowing the surveillance, which may tip off co-conspirators. Furthermore, you may believe that law enforcement has some kind of over-riding duty to respond to emergencies where life is threatened, but they don't. Legally, they don't even have to respond when people call 911. It's a quality of service issue, not a legally enforceable obligation.
Mac
--
...And this is a country filled with half-ignoramus who get all their news from Rupert Murdoch.
The word "ignoramus" is singular, but your sentence is constructed as if it were plural.
...pratically non-existant next to the defense department's big money handout...
You have misspelled both "practically" and "non-existent." Not only that, but you could easily have used actual statistics and provided us with a link instead of using misspelled adjectives.
Perhaps you should learn to spell and to write sentences whose objects and verbs agree in number before you make fun of hypothetical illiterates.
Just a thought.
MM
--
The usage is relatively easy. The hard part is preparing floppies which support the networking cards. If our computers all used the same networking cards, it would be easy, because there'd only be one floppy. But we have about a dozen computers with at least half a dozen different networking cards (or built-in to motherboard).
;-)
And I'm not an IT guy, I'm an EE, so they don't want me to spend all my time doing this sort of thing. So we use backup to make backups. So far we haven't had a disk failure that hurt us, so we haven't had to restore, other than once to make sure it works.
MM
--
I've done this on win2k. You do have to make sure you get the system state. I think there is a checkbox for that.
It is slow, but it's a lot faster than re-installing all of your applications from scratch.
The people at my work don't really like to hear about linux-based solutions, so dd (or tar, for that matter) wasn't an option. We do have ghost, but that is a pain to get working on a network, due to the fundamental limitations of DOS in that regard.
MM
--
Heh.
Usually I'm in favor of modding article re-posts as redundant. But in this case, the article really was slashdotted, so I am glad that SunSaw posted it.
Maybe someone can mod the parent back up a bit so people who don't browse at -1 can read it, too?
MM
--
I don't thing the idea was to make one box able to boot as any processor.
I think the idea was to make one die which could be configured to behave like any processor. But once you pick the one you want, you pretty much are stuck with it.
The architectures of all the different systems are far too varied for one mother board to support them all.
I have never heard a thing about any architecure besides x86. I doubt any work on any other translation layer has even begun. They have their hands full with x86 as it is.
MM
--
I wasn't aware of that figure. It is indeed impressive!
What I know about the battle for Stalingrad I got from a book my brother loaned me. I don't remember the exact title or author, but it was heavily-referenced and seemed quite well-researched.
MM
--
Actually, on the Russian front, an army of hundreds of thousands gradually ran out of fuel, food, spare parts, uniforms, etc. Those who didn't die of starvation, disease, or cold were forced to finally surrender when they were encircled by one of Stalin's armies. By that time, they were gaunt, dressed in rags, and infested with fleas and lice.
Earlier in the war, when the Germans were winning, the Russian troops were under orders not to surrender or retreat under any circumstances at Stalingrad. It was crazy. People who abandoned their positions were killed by their own commanders. Those who surrendered or defected (and were later recovered when the Germans surrendered) were killed or sent to the gulag. But even without this brutal treatment, the Russians were very brave and determined. There were a lot of tales of heroism on their part.
MM
--
Here is a URL to back up what you are saying: http://www.caida.org/analysis/geopolitical/bgp2cou ntry/
In particular, check out the prefix space and AS count by country
As an example, Japan has less than 3% of the IPv4 address space. India and China have less than 1% each.
The US already has over half the IP address space.
MM
--
From microsoft's perspective, they can't adopt cygwin, because it is "poisoned" by the GPL.
That is, everything in cygwin depends on the cygwin dll which is GPL'd.
Not only that, but a lot of stuff that depends on the cygwin dll runs very slow. Subjectively, gcc seems to run at less than half the speed under cygwin than it does natively on linux.
This apparent slowness of cygwin apps may be an unavoidable consequence of cygwin's providing a somewhat full-featured posix layer to an OS that doesn't really have one.
MM
--
John Harrison wasn't a cabinet maker. He was a clock maker and an unschooled mechanical genius. He was also, apparently, almost impossible to understand. You failed to mention an important constraint: The chronometer had to keep time while at sea, which is what made the task so difficult. The british wanted this because it would give them the ability to determine longitude accurately on long voyages.
What you also don't mention about Harrison is that he was not a member of the Royal Society, and had powerful enemies inside it. This made it very difficult for him to collect his reward. He had to wait many many years.
The current X-prize task is one thing. Getting a substantial payload into orbit is another. The other goals you mention are even more lofty. I don't think any organization could afford to do it just on the hope of winning a prize.
MM
--
The test only ran for microsecends. Even if the wind-tunnel costs 1,000,000 per second, that's only a dollar per microsecond.
Lighten up.
MM
--
It only broke up after a simulated Space Junk Collision Event (SJCE).
Didn't you read the article?
MM
--
Well, I will admit to being mixed up on what permafrost is (I was thinking that all permafrost areas were tundra, which is totally wrong). But I won't admit to knowing nothing about Alaska. I've read a bit about it, but never visited.
Anyway, for the record, according to this map Galena is in "lowland and upland area underlain by discontinuous permafrost."
MM
--