This really has the sound of a 'pet theory' to me (no pun intended:-p). This guy really, really, likes hyenas, and therefore concludes that they are the solution to a significant archeological mystery. I mean, really, hyenas aren't the only predators around; why didn't (say) the lions in Africa kill off humans there?
Nothing wrong with pet theories... he's just gonna need more evidence than a dog skull in a hyena cave to prove it.
Um. Yes. It would. I think. As long as the level of incoming light exceeds the level of the black-body radiation (which is probably very low). I don't think that the black-body radiation is really relevant to the physics of the situation.
However, if you're hot enough for there to be a meaningful amount of black-body radiation in the visible range where many solar cells operate, you're probably hot enough to damage the solar cell anyway.
There's a wrapper for GTK in OCaml. LablTK or something like that. There's also a very primitive set of graphics routine in the standard library, but if you try to write a GUI with that you're insane.
OCaml is a member of the ML family of languages. Caml, I guess, probably refers to OCaml and its predecessor Caml Lite. 'OCaml' is to 'ML' in approximately the same way 'Common Lisp' or 'Scheme' is to 'Lisp'.
Couldn't it be that this person's immune system is so compromised that no AB would cure him?
Nope. Antibiotics have nothing to do with the immune system.
Well, sort of. Antibiotics, in their original form, were essentially the 'immune system' of various types of molds and other such creatures. Antibiotics act by ripping holes in the cell walls of bacteria, or otherwise directly interfering with them- not by supplementing the existing immune system.
>I'm wondering: how did life survive the other dozens of other times the pole flipped?
The article strikes me as very sensationalistic. And your comment seems to be taking it the the wrong way. I'd be inclined to flip it around:
If life survived all the previous pole reversals, why wouldn't it survive the next one?
As for migrating animals- I'd imagine it will cause problems. But then again, many migratory animals rely on other cues in addition to the magnetic field (eg, position of the sun in the sky, etc)
As for radiation, a quick google got me this. So we would probably be in for some impressive northern lights, but no great danger.
A common mistake I've seen is people assuming that key size == keyspace size. For nearly all cyphers this isn't true. Suppose, for example, that your key requires a large prime number. The Prime Number Theorem says that the fraction of numbers up to N that are prime is approximately 1/lg(N) (that's base e, not base 2). So if we are using a k-bit prime number as the key, the keyspace size would be 2^k/(k*lg(2)), not 2^k. This isn't a huge reduction in keyspace size, but then again most codes have much stronger restrictions on valid keys.
The point is, a code with, say, 1024-bit keys may only give you, say, a 700-bit keyspace.
A couple tricks you can do with a gallon bottle (like apple cider often comes in)
Get a peeled, hard-boiled egg. Take a scrap of paper, light it on fire, and drop it in the jug. While it's still burning set the egg on the opening of the bottle. After a bit, the paper will burn out, and shortly thereafter the egg will be sucked into the bottle, as the air inside cools and shrinks.
Equally good is the trick of getting the egg back out again. Tip the bottle upside down so the egg comes to rest in the neck of the bottle. Put the bottle to your mouth and blow into it, hard. As soon as you take your mouth away the egg should pop right out. Careful, or you'll get a mouthful of sooty egg:-)
A second trick. You'll need a small piece of window screen, cut a bit larger than the bottle's mouth. It needs to be screen with pretty small holes. Make sure both the bottle and the screen are scrupulously clean- any bit of soap on anything will break surface tension and get you very wet.
Now, fill the bottle clear to the brim with water, and set the screen over the top. Hold it in place, and flip the bottle. You should be able to take your hand away and the screen will stay in place, and the water will stay in the bottle. This is a very impressive demonstration of both surface tension and air pressure.
(explanation: the air can't go through the holes because the surface tension of the water across the hole is high enough to prevent a bubble from forming; thus the water can't leak out)
Piplining.
You make the chip such that it does only part of the computation each cycle, and sucessive parts of the computation are adjacent to each other on the chip.
You (theoretically) get the same throughput as without pipelining, just the latency is longer- as soon as one instruction passes on to the second stage of the pipeline, you can stuff another one into the first.
A passive component is one that does not require power- something like a resistor or a capacitor. It is particularly difficult to make decent-size capacitors on a computer chip, thus almost any system will have at least a handful of external passive compontents. But that's okay, since they are usually quite small (a few millimeters square).
Sorry folks, that's not good enough. Do a search for Arrow's Impossibility Theorem. It states that there's no such thing as a 'fair' election between more than two candidates. The fairness conditions are very sensible (for example, if everyone prefers A to B, then B cannot win); the conclusion is that the only electoral system that satisfies all the conditions is a dictatorship.
Instant runoff voting might work a little better (I don't know), but the point is that there's no perfect solution to the voting problem.
This sounds like it's based on the same technique used to make filters in the microwave band. By creating a transmission line with several appropriately spaced steps in the impedance, you can create a low-pass filter. With some more sophisticated branching of the line, you can make a high-pass or a band-pass filter. The technique relies on interference and reflection effects from the boundaries between the transmission line sections. I think they're doing the same sort of thing here; introducing fluid into the center of the line will change its refraction coefficient, which takes roughly the same role in the fiber that impedance does in a transmission line.
If they are generating the key with a program, then by definition it's not random. The best they could be doing is getting something poly-time indistinguishable from randomness. And, given that that is (IIRC) equivalent to proving P!=NP, I doubt they've done that.
Furthermore, if you have to exchange the keys by electronic means, you've defeated the whole point of a one time pad.
So, in other words, it sounds like just another attempt to dress up security through obscurity in fancy language.
Here's a point I don't think I've heard argued before. Article I, section 8 of the U.S. Constitution states:
The Congress shall have the power to... [a few other things]... To promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries;...
Hm. Now, it seems to me that a lot of the copyright and patent mess we've seen lately is definitely not intended to 'promote the progress of science'. So, I wonder, could someone get this law, the DMCA, and all the other wonderful legislation we've been seeing recently, declared unconstitutional, on the grounds that this copyright system does not fulfill the original purpose of the institution?
Well, it ain't ever gonna happen, but it's an interesting thought...
Slashdot Mirror
This really has the sound of a 'pet theory' to me (no pun intended :-p). This guy really, really, likes hyenas, and therefore concludes that they are the solution to a significant archeological mystery. I mean, really, hyenas aren't the only predators around; why didn't (say) the lions in Africa kill off humans there?
Nothing wrong with pet theories... he's just gonna need more evidence than a dog skull in a hyena cave to prove it.
Um. Yes. It would. I think. As long as the level of incoming light exceeds the level of the black-body radiation (which is probably very low). I don't think that the black-body radiation is really relevant to the physics of the situation.
However, if you're hot enough for there to be a meaningful amount of black-body radiation in the visible range where many solar cells operate, you're probably hot enough to damage the solar cell anyway.
There's a wrapper for GTK in OCaml. LablTK or something like that. There's also a very primitive set of graphics routine in the standard library, but if you try to write a GUI with that you're insane.
OCaml is a member of the ML family of languages. Caml, I guess, probably refers to OCaml and its predecessor Caml Lite. 'OCaml' is to 'ML' in approximately the same way 'Common Lisp' or 'Scheme' is to 'Lisp'.
Nope. Antibiotics have nothing to do with the immune system.
Well, sort of. Antibiotics, in their original form, were essentially the 'immune system' of various types of molds and other such creatures. Antibiotics act by ripping holes in the cell walls of bacteria, or otherwise directly interfering with them- not by supplementing the existing immune system.
The article strikes me as very sensationalistic. And your comment seems to be taking it the the wrong way. I'd be inclined to flip it around:
If life survived all the previous pole reversals, why wouldn't it survive the next one?
As for migrating animals- I'd imagine it will cause problems. But then again, many migratory animals rely on other cues in addition to the magnetic field (eg, position of the sun in the sky, etc)
As for radiation, a quick google got me this. So we would probably be in for some impressive northern lights, but no great danger.
If you can move your mouse to a precision of 700nm, I'm very impressed :-)
A common mistake I've seen is people assuming that key size == keyspace size. For nearly all cyphers this isn't true. Suppose, for example, that your key requires a large prime number. The Prime Number Theorem says that the fraction of numbers up to N that are prime is approximately 1/lg(N) (that's base e, not base 2). So if we are using a k-bit prime number as the key, the keyspace size would be 2^k/(k*lg(2)), not 2^k. This isn't a huge reduction in keyspace size, but then again most codes have much stronger restrictions on valid keys.
The point is, a code with, say, 1024-bit keys may only give you, say, a 700-bit keyspace.
A couple tricks you can do with a gallon bottle (like apple cider often comes in)
:-)
Get a peeled, hard-boiled egg. Take a scrap of paper, light it on fire, and drop it in the jug. While it's still burning set the egg on the opening of the bottle. After a bit, the paper will burn out, and shortly thereafter the egg will be sucked into the bottle, as the air inside cools and shrinks.
Equally good is the trick of getting the egg back out again. Tip the bottle upside down so the egg comes to rest in the neck of the bottle. Put the bottle to your mouth and blow into it, hard. As soon as you take your mouth away the egg should pop right out. Careful, or you'll get a mouthful of sooty egg
A second trick. You'll need a small piece of window screen, cut a bit larger than the bottle's mouth. It needs to be screen with pretty small holes. Make sure both the bottle and the screen are scrupulously clean- any bit of soap on anything will break surface tension and get you very wet.
Now, fill the bottle clear to the brim with water, and set the screen over the top. Hold it in place, and flip the bottle. You should be able to take your hand away and the screen will stay in place, and the water will stay in the bottle. This is a very impressive demonstration of both surface tension and air pressure.
(explanation: the air can't go through the holes because the surface tension of the water across the hole is high enough to prevent a bubble from forming; thus the water can't leak out)
Piplining.
You make the chip such that it does only part of the computation each cycle, and sucessive parts of the computation are adjacent to each other on the chip.
You (theoretically) get the same throughput as without pipelining, just the latency is longer- as soon as one instruction passes on to the second stage of the pipeline, you can stuff another one into the first.
That's 70GHz, folks. And no, this isn't vaporware, I've worked with a chip fabricated using this tech.
A passive component is one that does not require power- something like a resistor or a capacitor. It is particularly difficult to make decent-size capacitors on a computer chip, thus almost any system will have at least a handful of external passive compontents. But that's okay, since they are usually quite small (a few millimeters square).
Sorry folks, that's not good enough. Do a search for Arrow's Impossibility Theorem. It states that there's no such thing as a 'fair' election between more than two candidates. The fairness conditions are very sensible (for example, if everyone prefers A to B, then B cannot win); the conclusion is that the only electoral system that satisfies all the conditions is a dictatorship.
Instant runoff voting might work a little better (I don't know), but the point is that there's no perfect solution to the voting problem.
This sounds like it's based on the same technique used to make filters in the microwave band. By creating a transmission line with several appropriately spaced steps in the impedance, you can create a low-pass filter. With some more sophisticated branching of the line, you can make a high-pass or a band-pass filter. The technique relies on interference and reflection effects from the boundaries between the transmission line sections. I think they're doing the same sort of thing here; introducing fluid into the center of the line will change its refraction coefficient, which takes roughly the same role in the fiber that impedance does in a transmission line.
From my college coursework on crypto:
If they are generating the key with a program, then by definition it's not random. The best they could be doing is getting something poly-time indistinguishable from randomness. And, given that that is (IIRC) equivalent to proving P!=NP, I doubt they've done that.
Furthermore, if you have to exchange the keys by electronic means, you've defeated the whole point of a one time pad.
So, in other words, it sounds like just another attempt to dress up security through obscurity in fancy language.
Hm. Now, it seems to me that a lot of the copyright and patent mess we've seen lately is definitely not intended to 'promote the progress of science'. So, I wonder, could someone get this law, the DMCA, and all the other wonderful legislation we've been seeing recently, declared unconstitutional, on the grounds that this copyright system does not fulfill the original purpose of the institution?
Well, it ain't ever gonna happen, but it's an interesting thought...