I said sample it, not use the whole thing. Chop off the header and what is left is a good simulation of random data. In fact to the extent that it is *not* a good simulation of random data, it is further compressible...
The first thing that amazes me is that we don't have a good random number generator in hardware. For various reasons you cannot build a perfect one in software - software has to be deterministic. But you can in hardware.
The trick is that you have to come up with a process that generates a random bit-stream. The classic example is 2 Geiger counters side by side. (Throw away results from both that arrive shortly after the either fires. There is a slight latency and this gets you independence.) There are variations of this that can easily be set up in silicon much more economically.
But, you say, this gives you a biased stream? Yes, but an independent, random one. The next step is to take the output in pairs, drop the pairs that are the same, and then take the first bit. This gives you an independent unbiased bit stream. Well there is a miniscule bias, however it is slight enough that it would not be reliably detectable if the machine operated for several billion years. I consider that acceptable.:-)
This does throw away about 3/4 of the data. Some of this can be recovered and used, after all your "accept, don't accept" is a bit-stream, and so is the set of values from the pairs that agreed. Both are more heavily biased than your original, but a few layers of this will get a lot more information extracted.
Unfortunately no such random number generator done in hardware is widely deployed. If it were then encryption would be a lot better than it is today but...
My other thought was an encryption algorithm that requires lots of random data, but is better than a OTP for transmitting a stream. First of all a common but bad algorithm is to XOR a bit stream with a random block of data, but reuse the block. While a OTP is unbreakable this variation is easy to break. Just XOR the output with itself shifted over, and when you hit the length of the stream you will get a large spike in certain characters. That tells you the length and a good cryptographer can work quickly from there.
A slight variation on this would be to have 2 random blocks of data, of different length, and XOR both of them against the original. This is still breakable but it is harder since each block hides the other.
My idea is to have the 2 random blocks of data, but have the transmitted stream of data be randomly sending the message and replacements for each block. This means that the random blocks of data are each hiding the other and the transmitted changes to the key, while they are themselves getting replaced.
I suspect that if you devote enough of your bitstream to the replacement of the bitstream that this variation is very secure. Unfortunately it needs a large supply of really random bits, and that is not easy to come by...
Regards, Ben
PS One supply of pretty random data is as follows. Compress some large binaries as much as you can, and then sample the result. A well-compressed file looks a lot like random data...
They certainly do NOT expect to be receiving replies from people where both parents have been through multiple marriages and have children from different marriages!
Let me see, if the most studious one is my mother's oldest son, but he is younger than 3 of my father's kids (who he does not necessarily consider family), what is his position in the birth order? Hmmm...
There are many programs in RedHat that source has to be offered for. But they can also distribute non-GPLed software and nobody can make them distribute source for it. They can also tie things together with handy administrative utilities that they wrote, and again source does not have to be distributed.
Now RedHat has been really good about this. But availability of source for the GPLed parts of RedHat does not mean that anything like a working distribution has to be freely available!
And there are solid reasons for it. A brand name company is expected to have an easier time weathering changes, and so people feel more sure that they will get a long-term steady return from the stock. Technology and growth stocks are always trading to some extent on the expectation (hope?) that because their industry is expanding they will have chances to grow and earn more in the future, thereby paying more back. The same holds for small-cap companies which have room to grow just because they are small. (But don't bet too heavily on any one of them!)
By contrast you may find lower ratios in something like power companies that are very stable, but have essentially no growth prospects.
In a stock market with rational long-term investors the market cap is a good proxy for what the market thinks the future profits of said company is.
Why you ask?
The basic principle of value-based investing (as practiced by Peter Lynch and Warren Buffett) is to look at where you think a company is going, compare that to the market cap, and buy when the current market cap is below what you think that the future one will be. The point being that the value of holding a stock is eventually determined by dividends, which in turn depend on earnings (aka profit), and as a rule of thumb the relationship in a stable company is that market cap tends to come out to 20 times earnings. Therefore if your estimate of future profits says that the future market cap should be above what it is today - voila! A long-term investing opportunity.
So a market cap of 5 billion for RHAD would mean that someday it should be making 250 million profit per year in a few years. Analyze the Linux market. If Linux turns the OS market into a commodity market, then RedHat is going to have fairly low profit margins, so that level of profit requires truly impressive revenue streams which, at a low per unit cost, implies very impressive volumes.
As in several orders of magnitude greater than the current OS market.
Now there are other theories of investment than value-based investing. For example George Soros does even better after a speculator, trying to make predictions based on his judgements of the irrationalities of others. (A quote of his, "An investment is a speculation gone bad.") However people who try to imitate Soros are more likely to wind up broke than people who imitate Buffett.:-P
I already gave my basic analysis in another discussion. (Which saw little play because of technical problems with/..)
Basically unless RedHat can get into other lines of business or significantly change the market dynamics upon which their business is based, I don't see them as a long-term investment being worth anything close to what they are currently priced at.
Make that not known to be NP complete. It is clearly NP. The question is whether it is complete. To which I note that if, for instance, P=NP then factoring would trivially be an NP-complete problem.:-P
Although it does seem doubtful that it would be NP-Complete.
First of all STO is not real security. It cannot be your only or primary means of security. But in many cases STO is a convenient solution that should not be ignored.
For instance one problem with scripts is the fact that they often have passwords encoded in everywhere. What to do about it? Well in some random spot under an innocuous name, put a program that when passed a series of semi-open secrets by the appropriate user(s) (and possibly only when called by the appropriate program) will return a password, and log attempts to call it inappropriately. In your scripts you can call on that program.
This means that you no longer have the passwords hanging around everywhere, and it additionally means that when you change passwords, you can just change that one program and all of your scripts will continue to work.
This is not, of course, appropriate for a high-security situation or a broadly used solution, but when your need is a trade-off between convenience and true security this judicious use of STO is a hole, sure. But it is a hole that is reasonably hard to take advantage of. (Although if you know the rules for the program it then becomes trivial!)
But there is a catch. The trick to the DNA "solution" is that it is a massively parallel solution. The time to get the solution may be linear, but the amount of DNA you need grows exponentially. If you simulate this on a single computer, the problem takes exponential time.
However quantum computing offers similar tricks using a superposition of quantum states to do an exponential amount of computing without taking an exponential amount of time. The last that I heard that technology was looking more and more feasible in the long-term. But it is still a good 20 years off even if it can be made to work.
As for P=NP, I honestly believe that they are different. As for a proof, well this post is too short...:-P
The market-cap is defined as it is defined. In one sense you are right, the price of stocks depends upon supply and demand, just like everything else. But in a very real sense you are wrong, commodities and stocks are very different items.
The value of a commodity, like cheese or diamonds, depends upon supply and demand. There is no direct connection where there is a "real" price for that commodity. This is not true of stocks that you buy for the long-term. In the long run there is indeed an intrinsic value to a stock, and that value is the present value to you of the potential future returns. Those future returns come from the dividends and the resale value. In normal markets (which 400 years of experience in many countries say will always come back BTW) you cannot depend on the resale value, and so the value really depends on expectations about dividends. And the potential for that is driven by the (future) size of the company.
Therefore when an experienced investor buys stock for the long-term at a given price, that is an implicit prediction about what that company will do. And the implicit prediction is not hard to determine, it is that the future size of the company will be (order of magnitude) similar to the market cap.
This all applies, of course, to long-term investing. By contrast day-traders and speculators who buy for the short-term are making predictions about the irrationality of other people. In the short term anything can happen and usually does.:-)
Cheers, Ben Tilly
PS In the long-term you cannot depend upon the rest of RHAT remaining forever off of the market...
I am of two minds. I think that parody is OK. However I strongly object to people (for instance) going out, buying celebrity names, and then blackmailing the celebrity by threatening to do things like put up a porn site.
As the saying goes, "Your freedom to extend your fist ends at my face." Cybersquatting does not deserve to be rewarded, but I think that reasonable people can draw the distinction between squatting and deliberate parody.
Let me see, a clear lie about the Paluxy river (hint to the wise, even the ICR has admitted for over a decade that those tracks are fake), a clear (and lame) attempt to try to reverse what I said about Archeopteryx (please note that I was the one who said from the start that it showed both bird-like and dinosaur-like characteristics, and hence classifying it is somewhat arbitrary), and you then blather on about trust.
You have established to my satisfaction that I can trust you to not be fair-minded.
Oh, another point that I let you gloss over before. You claim to be unconvinced that evolution does not contradict the second law of thermodynamics. Unconvinced on a point of basic physics? If you were sincere you would have understood this decades ago!
Here is an explanation in case you really do want to pay attention. The second law of thermodynamics applies to closed systems. The Earth is definitely not a closed system, we get a large influx of energy from the Sun at a high temperature, and radiate it off into outer space. This makes us an open system with a force driving levels of entropy down at an easily calculable rate. That is basic physics.
Now were the Earth to magically become a closed system then evolution would indeed run afoul of the second law of thermodynamics. In fact you don't even need to do any calculations to see that. Cut off the Sun and put us in a reflective shield and rather quickly the plants would die, animals would then quickly starve, and before long evolution would come to a quick and nasty end because there would be nothing living left to evolve.
Luckily for us that outcome is extremely unlikely. We remain an open system, life gets a chance, and evolution can continue as a natural by-product of life continuing to exist in an ever-changing world.
Really, as I said before, this is pretty basic information for anyone who is truly open-minded and investigating the evidence. If you actually understood the science then this would not require any explanation - it is simply obvious. And yet you claim to be "unconvinced" on this basic point after 2 decades? That simply does not wash!
And with that said, I do believe that I am done talking to you.
The question that you are getting at, how life started, is called "abiogenesis" and is properly quite a different topic from evolution. An appropriate analogy would be to think about driving. Figuring out evolution is equivalent to figuring out how the driver controls the car. Figuring out abiogenesis is equivalent to figuring out how the car was being built, except that cars are not being built any more and the factories were long ago torn down and destroyed!
We have very good evidence for the last several hundred million years of evolution. We know that life got started well before that. We have very little evidence of what happened when life got started, and we know much less than we would like to about the processes that were involved.
All of that said, the problem is not absolutely hopeless. While little concrete can be said, there is research progressing, but that said, it all is pretty tenative.
Now I am not positive which professor you are quoting, but you should be aware of common mistakes that are made. The fact that we have much less that is concrete to say about how abiogenesis probably happened is not equivalent to saying that it was an impossible event!
In fact we do have good evidence that the process involved was very long. It turns out that ammino acids can appear in 2 configurations, left-handed or right-handed. On the surface it would appear that the two are (up to a mirror symmetry in what they interact with) chemically equivalent. However there is in physics a very slight asymetry, and theoretically the left-handed version should be slightly more stable.
When I say slightly, I mean slightly! The theoretical difference is too small for us to actually measure. However over millions of years the difference could possibly be significant. It is then potentially significant there there is a strong bias in life towards left-handed ammino acids...
Anyways, the short answer is that we don't really know how abiogenesis happened, but it does not seem (at least to many in the field) to be a fundamentally impossible event. In any case questions around abiogenesis do not compose evidence against evolution per se.
You make it appear that I was saying that few describe themselves as Creationists. In fact in the US over 40% of the population believes that the Bible is literal truth, including its description of Creation and the Flood. Even more believe that what it says is roughly true, and there are more like Jimbo at least feel that Creationism is a belief system that deserves equal consideration with Evolution.
Yes, there is a spectrum, I grant you that. For instance the official position of a number of religions (eg the Roman Catholic faith) involves theistic evolution, which is to say evolution but with some divine prompting. But by and large things are pretty darned polarized. It is difficult for people who have never paid attention to realize how polarized they are. But that does not lessen the real polarization out there.
Given how strong the evidence is against traditional Creationism as believed by these people, is there any reason that we should mince words? It is very easy in ignorance to say that you think that Evolution is implausible. It is much harder for someone with any real knowledge of the processes involved to point to anything implausible in the standard scientific picture in, say, the last 300 million years. Wilful ignorance does not make for an opinion that is worth equal time with an educated one.
And the next time that you quote me, please don't take my sentence so clearly out of context. It really makes you look stupid to anyone who goes back and looks at the original sentence in context.
Unfortunately Dave's comments remind me of the RedHat IPO. Don't get me wrong! RedHat is clearly a company in the right place at the right time. Unlike most "dot com" companies it has a business model that I believe in. Current revenues 10 million/year, doubling each year for 5 years. What is not to like?
The problem is that it is a company in a rapidly growing market with what looks to me to be a fixed horizon. Let us calculate what happens if RedHat has its way and does pretty darned well. 5 years from now suppose that the OS is a commodity market, and RedHat or derivatives thereof is being installed on 100 million computers per year. Let us suppose that they are actually making 5 dollars of revenue per computer (remember, nothing stops people from installing many times for the price of one CD). That is 500 million dollars of revenue/year. (If they double for 5 years in a row they would be at 320 million, so this is a reasonable ball-park.) Assuming that they get a 10% profit margin (about right for a commodity market with low barriers of entry - which is what Linux is trying to be), that is an earnings of 50 million/year.
Long-term in the stock market a sustainable P/E ratio has proven to be about 20 or so. So everything has gone well for RedHat, in 5 years the Linux market stabilizes and they might be justified in having a market cap of 1 billion dollars. That is pretty darned good for a company that last year just about broke even on 10 million in revenue!
However currently 10% of the company is being traded, and that comes to 6 million shares. So the current market-cap is 60,000,000 x 85.25 = 5,115,000,000. That is just over 5 times what I just estimated to be a reasonable market cap in 5 years if all goes reasonably well for the company.
Folks, the investment bankers who calculated $14 as being a reasonable IPO price are not idiots. (Their market cap would be $840 million, which is probably not coincidentally in the same range that my ballpark figures above gave.) They worked out what they thought was a reasonable price for where the company was going. Unless I miss my calculation some people are going to be burned eventually.
Sure, I like RedHat as well. I think that it is going to do really well as a company (although they have to improve their support a lot to meet their goals). But I don't like it as a long-term investment at $85/share!
It seems that you have a common confusion about what macroevolution is and isn't.
Every "ape man" ever found has been proved wrong. The bones that they found where hundreds of feet even miles apart and in different layers of the earth.
You clearly don't have a clue what you are talking about. In a word, "Lucy".
In evolution you only evolve to have what you need. So since we don't need a third arm that is why we don't have a third arm. Well then how come we only use 10% of our brain. Why did we "evolve" to have such a big brain?
Evolution is a theory and all it takes is one thing to prove it wrong and then it should thrown out. There are to many things that prove evolution to be wrong and not enough to back it up.
May I hold Creationism to the same standard?
To me it is easier to beleive that a living God made the earth and it didn't just happen. Have you ever seen a tornado go through a junk yard and assemble a perfectly working car. No! So what makes you think that something as big and complex as the earth and every living thing on it can happen by chance.
If you just look around you you will see that there is someone out there that is bigger than each and everyone of us. Just open your eyes and you will see.
Is closing my eyes also a pre-requisite? So far your batting average is pretty darned pathetic...
Was I unfair? Jimbo asked how one could treat evolution and Creationism fairly. The doctrine of Creationism as espoused by the ICR and other such groups indeed does say that the Earth is about 6000 years old, and there was a global flood about 4000 years ago. This is not a straw-man argument, this is a direct statement of the mainstream Creationist position as believed by a significant portion of the US.
Very few people describe themselves as Creationists and simultaneously do NOT subscribe to this belief system.
I feel that responding this was is, in fact, particularly appropriate in this case when responding to someone who is accusing scientists of changing their theories. Creationism is a well-defined position and it comes with a considerable theological baggage. If scientists are criticized for modifying theories produced by humans, then how much more disingenous would it be to modify theories purportedly laid down by God?
No, I don't feel that I was at all unfair in what I said.
You claim that scientists change the theory to fit the facts. That seems to me to be an excellent straw-man argument. Please come up with concrete examples.
At issue in particular is Darwin's theory of evolution, which states that there is descent with modification where those traits that are beneficial to having plentiful surviving descendants will spread. And this ongoing process, visible today, is responsible over time for the modification and branching of the species.
I maintain that this statement of Darwin's theory has been accurate since The Origin of the Species was published in 1859. Our understanding of that theory has changed significantly. For instance the discovery that inheritance is discrete rather than continuous was a significant change. Likewise there have been ongoing changes in thought about such details at rates, pacing, etc. And there have been many specific examples that have modified, for instance Darwin initially thought that lungs evolved from the swim-bladder of a fish, but later research and fossil evidence shows that the connection is the other way, the swim-bladder of the "higher fishes" evolved from a lung.
But through the entire history of the theory, the basic statement has never changed. Our thoughts and understanding of details have changed, but not the basic theory!
Oh, and do some reading on the history of biology will you? Darwin's theories did not win instant universal acceptance by a long shot. In fact they continued to face serious scientific challenges for 50 years, and I assure you that the critics were not gentle with the theory.
And being fair, we need to examine Creationism fairly. I maintain that Creationism is a belief maintained in spite of all facts and evidence. If you doubt me then explain how one can seriously believe today in a global Flood that purportedly happened 4000 years ago in spite of there being lake bottoms that have been undisturbed in longer than that, Chinese history going back farther than that, ice cores that have survived undamaged for well over 30 times that long, and a distribution of species around the world that is absolutely impossible based on the story of Noah's ark? Wilful ignorance of the facts is not a reason to respect a position!
Moving on to your apparently rhetorical question of mutations, yes, detailed studies have been done on mutation rates. And yes, the numbers do add up. In fact mutation rates have been used to form a "molecular clock" of how long populations have been seperated, and the time-lines that result are in generally good accord with the independent evidence from other lines such as fossil evidence.
Surprised? You should not be! It is characteristic of normal science that it constantly finds new ways to test its basic beliefs with more and more sensitive tests. Evolution is the product of normal science and has survived a century and a half of tests. I strongly doubt that there is any test you can think of which can be carried out in under a decade that has not been performed!
You claim to have been studying this subject for 20 years and have never once encountered the opinion that there are people who think that Archeopteryx is better classified as a dinosaur than a bird? Given that this opinion was stated in 2 out of the 3 links that YOU provided, I do not find that even remotely possible.
Also your ongoing refusal to accept anything about dating is getting simply silly. Your defense essentially comes down to saying, "Well we cannot know anything, no point in trying, and no point in my listening to people who have spent years figuring this stuff out." And then when it comes to uncomfortable facts such as having independent means of dating consistently agree with each other, you just ignore that.
If I wished to take a position that was similarly "open - I just want to see all of the facts" I could happily maintain for years that Bill Clinton is not really President. After all how do the people who tell me that he is know that? They heard it on the TV. Have they met anyone on the TV? Do they know the TV is real? No! The TV could be some evil manipulation plot! They can't prove otherwise! And if they can't prove otherwise, I can ignore them!
Seriously, it really looks like you decided what reality is and cannot hear otherwise. You heard that Archeopteryx is a bird, you cannot conceive of something half-way between a bird and a dinosaur, and so you refuse to hear the constant descriptions of how it is exactly that. Then once you have conveniently made it impossible to accept the common description, you can claim that it is not really a transitional fossil, and there are not really any transitional fossils.
I am seriously beginning to wonder whether there is any point in talking to you. You claim that you would have an open mind, you just want to see all of the facts, but with every word you clearly look at data for just long enough to figure out how there is a possible way that you could theoretically dismiss it, and once you have found that way you then dismiss it. And given that you dismiss everything that you find out of hand, you never have to worry about such alien concepts as, "the preponderance of the evidence".
Please, prove me wrong, but that pattern seems pretty consistent so far.
Slashdot Mirror
Hardware RNG's do exist, but why are they not in more common use?
Ben
I said sample it, not use the whole thing. Chop off the header and what is left is a good simulation of random data. In fact to the extent that it is *not* a good simulation of random data, it is further compressible...
Cheers,
Ben
The first thing that amazes me is that we don't have a good random number generator in hardware. For various reasons you cannot build a perfect one in software - software has to be deterministic. But you can in hardware.
:-)
The trick is that you have to come up with a process that generates a random bit-stream. The classic example is 2 Geiger counters side by side. (Throw away results from both that arrive shortly after the either fires. There is a slight latency and this gets you independence.) There are variations of this that can easily be set up in silicon much more economically.
But, you say, this gives you a biased stream? Yes, but an independent, random one. The next step is to take the output in pairs, drop the pairs that are the same, and then take the first bit. This gives you an independent unbiased bit stream. Well there is a miniscule bias, however it is slight enough that it would not be reliably detectable if the machine operated for several billion years. I consider that acceptable.
This does throw away about 3/4 of the data. Some of this can be recovered and used, after all your "accept, don't accept" is a bit-stream, and so is the set of values from the pairs that agreed. Both are more heavily biased than your original, but a few layers of this will get a lot more information extracted.
Unfortunately no such random number generator done in hardware is widely deployed. If it were then encryption would be a lot better than it is today but...
My other thought was an encryption algorithm that requires lots of random data, but is better than a OTP for transmitting a stream. First of all a common but bad algorithm is to XOR a bit stream with a random block of data, but reuse the block. While a OTP is unbreakable this variation is easy to break. Just XOR the output with itself shifted over, and when you hit the length of the stream you will get a large spike in certain characters. That tells you the length and a good cryptographer can work quickly from there.
A slight variation on this would be to have 2 random blocks of data, of different length, and XOR both of them against the original. This is still breakable but it is harder since each block hides the other.
My idea is to have the 2 random blocks of data, but have the transmitted stream of data be randomly sending the message and replacements for each block. This means that the random blocks of data are each hiding the other and the transmitted changes to the key, while they are themselves getting replaced.
I suspect that if you devote enough of your bitstream to the replacement of the bitstream that this variation is very secure. Unfortunately it needs a large supply of really random bits, and that is not easy to come by...
Regards,
Ben
PS One supply of pretty random data is as follows. Compress some large binaries as much as you can, and then sample the result. A well-compressed file looks a lot like random data...
They certainly do NOT expect to be receiving replies from people where both parents have been through multiple marriages and have children from different marriages!
Let me see, if the most studious one is my mother's oldest son, but he is younger than 3 of my father's kids (who he does not necessarily consider family), what is his position in the birth order? Hmmm...
Cheers,
Ben
There are many programs in RedHat that source has to be offered for. But they can also distribute non-GPLed software and nobody can make them distribute source for it. They can also tie things together with handy administrative utilities that they wrote, and again source does not have to be distributed.
Now RedHat has been really good about this. But availability of source for the GPLed parts of RedHat does not mean that anything like a working distribution has to be freely available!
Cheers,
Ben Tilly
And there are solid reasons for it. A brand name company is expected to have an easier time weathering changes, and so people feel more sure that they will get a long-term steady return from the stock. Technology and growth stocks are always trading to some extent on the expectation (hope?) that because their industry is expanding they will have chances to grow and earn more in the future, thereby paying more back. The same holds for small-cap companies which have room to grow just because they are small. (But don't bet too heavily on any one of them!)
By contrast you may find lower ratios in something like power companies that are very stable, but have essentially no growth prospects.
Cheers,
Ben
In a stock market with rational long-term investors the market cap is a good proxy for what the market thinks the future profits of said company is.
:-P
Why you ask?
The basic principle of value-based investing (as practiced by Peter Lynch and Warren Buffett) is to look at where you think a company is going, compare that to the market cap, and buy when the current market cap is below what you think that the future one will be. The point being that the value of holding a stock is eventually determined by dividends, which in turn depend on earnings (aka profit), and as a rule of thumb the relationship in a stable company is that market cap tends to come out to 20 times earnings. Therefore if your estimate of future profits says that the future market cap should be above what it is today - voila! A long-term investing opportunity.
So a market cap of 5 billion for RHAD would mean that someday it should be making 250 million profit per year in a few years. Analyze the Linux market. If Linux turns the OS market into a commodity market, then RedHat is going to have fairly low profit margins, so that level of profit requires truly impressive revenue streams which, at a low per unit cost, implies very impressive volumes.
As in several orders of magnitude greater than the current OS market.
Now there are other theories of investment than value-based investing. For example George Soros does even better after a speculator, trying to make predictions based on his judgements of the irrationalities of others. (A quote of his, "An investment is a speculation gone bad.") However people who try to imitate Soros are more likely to wind up broke than people who imitate Buffett.
Cheers,
Ben Tilly
Even if someone finds a buffer overflow in a package that you have, finding an exploit becomes a lot harder. :-)
Cheers,
Ben
I already gave my basic analysis in another discussion. (Which saw little play because of technical problems with /..)
Basically unless RedHat can get into other lines of business or significantly change the market dynamics upon which their business is based, I don't see them as a long-term investment being worth anything close to what they are currently priced at.
Sincerely,
Ben Tilly
By Robert L. Forward, (Any sufficiently advanced technology is) Indisinguishable From Magic.
Cheers,
Ben Tilly
Factoring is not NP complete.
:-P
Make that not known to be NP complete. It is clearly NP. The question is whether it is complete. To which I note that if, for instance, P=NP then factoring would trivially be an NP-complete problem.
Although it does seem doubtful that it would be NP-Complete.
Cheers,
Ben
Remember the LinuxPPC challenge? The root password will *not* in general help in getting into a Linux box.
Cheers,
Ben
First of all STO is not real security. It cannot be your only or primary means of security. But in many cases STO is a convenient solution that should not be ignored.
For instance one problem with scripts is the fact that they often have passwords encoded in everywhere. What to do about it? Well in some random spot under an innocuous name, put a program that when passed a series of semi-open secrets by the appropriate user(s) (and possibly only when called by the appropriate program) will return a password, and log attempts to call it inappropriately. In your scripts you can call on that program.
This means that you no longer have the passwords hanging around everywhere, and it additionally means that when you change passwords, you can just change that one program and all of your scripts will continue to work.
This is not, of course, appropriate for a high-security situation or a broadly used solution, but when your need is a trade-off between convenience and true security this judicious use of STO is a hole, sure. But it is a hole that is reasonably hard to take advantage of. (Although if you know the rules for the program it then becomes trivial!)
Cheers,
Ben Tilly
But there is a catch. The trick to the DNA "solution" is that it is a massively parallel solution. The time to get the solution may be linear, but the amount of DNA you need grows exponentially. If you simulate this on a single computer, the problem takes exponential time.
:-P
However quantum computing offers similar tricks using a superposition of quantum states to do an exponential amount of computing without taking an exponential amount of time. The last that I heard that technology was looking more and more feasible in the long-term. But it is still a good 20 years off even if it can be made to work.
As for P=NP, I honestly believe that they are different. As for a proof, well this post is too short...
Cheers,
Ben Tilly
I don't care about whether the stuff works Feb 31, 2000, I don't believe in that day.
What about Feb 29, 2000?
:-P
Ben
The market-cap is defined as it is defined. In one sense you are right, the price of stocks depends upon supply and demand, just like everything else. But in a very real sense you are wrong, commodities and stocks are very different items.
:-)
The value of a commodity, like cheese or diamonds, depends upon supply and demand. There is no direct connection where there is a "real" price for that commodity. This is not true of stocks that you buy for the long-term. In the long run there is indeed an intrinsic value to a stock, and that value is the present value to you of the potential future returns. Those future returns come from the dividends and the resale value. In normal markets (which 400 years of experience in many countries say will always come back BTW) you cannot depend on the resale value, and so the value really depends on expectations about dividends. And the potential for that is driven by the (future) size of the company.
Therefore when an experienced investor buys stock for the long-term at a given price, that is an implicit prediction about what that company will do. And the implicit prediction is not hard to determine, it is that the future size of the company will be (order of magnitude) similar to the market cap.
This all applies, of course, to long-term investing. By contrast day-traders and speculators who buy for the short-term are making predictions about the irrationality of other people. In the short term anything can happen and usually does.
Cheers,
Ben Tilly
PS In the long-term you cannot depend upon the rest of RHAT remaining forever off of the market...
I am of two minds. I think that parody is OK. However I strongly object to people (for instance) going out, buying celebrity names, and then blackmailing the celebrity by threatening to do things like put up a porn site.
As the saying goes, "Your freedom to extend your fist ends at my face." Cybersquatting does not deserve to be rewarded, but I think that reasonable people can draw the distinction between squatting and deliberate parody.
Cheers,
Ben Tilly
Let me see, a clear lie about the Paluxy river (hint to the wise, even the ICR has admitted for over a decade that those tracks are fake), a clear (and lame) attempt to try to reverse what I said about Archeopteryx (please note that I was the one who said from the start that it showed both bird-like and dinosaur-like characteristics, and hence classifying it is somewhat arbitrary), and you then blather on about trust.
You have established to my satisfaction that I can trust you to not be fair-minded.
Oh, another point that I let you gloss over before. You claim to be unconvinced that evolution does not contradict the second law of thermodynamics. Unconvinced on a point of basic physics? If you were sincere you would have understood this decades ago!
Here is an explanation in case you really do want to pay attention. The second law of thermodynamics applies to closed systems. The Earth is definitely not a closed system, we get a large influx of energy from the Sun at a high temperature, and radiate it off into outer space. This makes us an open system with a force driving levels of entropy down at an easily calculable rate. That is basic physics.
Now were the Earth to magically become a closed system then evolution would indeed run afoul of the second law of thermodynamics. In fact you don't even need to do any calculations to see that. Cut off the Sun and put us in a reflective shield and rather quickly the plants would die, animals would then quickly starve, and before long evolution would come to a quick and nasty end because there would be nothing living left to evolve.
Luckily for us that outcome is extremely unlikely. We remain an open system, life gets a chance, and evolution can continue as a natural by-product of life continuing to exist in an ever-changing world.
Really, as I said before, this is pretty basic information for anyone who is truly open-minded and investigating the evidence. If you actually understood the science then this would not require any explanation - it is simply obvious. And yet you claim to be "unconvinced" on this basic point after 2 decades? That simply does not wash!
And with that said, I do believe that I am done talking to you.
Sincerely,
Ben Tilly
The question that you are getting at, how life started, is called "abiogenesis" and is properly quite a different topic from evolution. An appropriate analogy would be to think about driving. Figuring out evolution is equivalent to figuring out how the driver controls the car. Figuring out abiogenesis is equivalent to figuring out how the car was being built, except that cars are not being built any more and the factories were long ago torn down and destroyed!
We have very good evidence for the last several hundred million years of evolution. We know that life got started well before that. We have very little evidence of what happened when life got started, and we know much less than we would like to about the processes that were involved.
All of that said, the problem is not absolutely hopeless. While little concrete can be said, there is research progressing, but that said, it all is pretty tenative.
Now I am not positive which professor you are quoting, but you should be aware of common mistakes that are made. The fact that we have much less that is concrete to say about how abiogenesis probably happened is not equivalent to saying that it was an impossible event!
In fact we do have good evidence that the process involved was very long. It turns out that ammino acids can appear in 2 configurations, left-handed or right-handed. On the surface it would appear that the two are (up to a mirror symmetry in what they interact with) chemically equivalent. However there is in physics a very slight asymetry, and theoretically the left-handed version should be slightly more stable.
When I say slightly, I mean slightly! The theoretical difference is too small for us to actually measure. However over millions of years the difference could possibly be significant. It is then potentially significant there there is a strong bias in life towards left-handed ammino acids...
Anyways, the short answer is that we don't really know how abiogenesis happened, but it does not seem (at least to many in the field) to be a fundamentally impossible event. In any case questions around abiogenesis do not compose evidence against evolution per se.
Cheers,
Ben
You make it appear that I was saying that few describe themselves as Creationists. In fact in the US over 40% of the population believes that the Bible is literal truth, including its description of Creation and the Flood. Even more believe that what it says is roughly true, and there are more like Jimbo at least feel that Creationism is a belief system that deserves equal consideration with Evolution.
Yes, there is a spectrum, I grant you that. For instance the official position of a number of religions (eg the Roman Catholic faith) involves theistic evolution, which is to say evolution but with some divine prompting. But by and large things are pretty darned polarized. It is difficult for people who have never paid attention to realize how polarized they are. But that does not lessen the real polarization out there.
Given how strong the evidence is against traditional Creationism as believed by these people, is there any reason that we should mince words? It is very easy in ignorance to say that you think that Evolution is implausible. It is much harder for someone with any real knowledge of the processes involved to point to anything implausible in the standard scientific picture in, say, the last 300 million years. Wilful ignorance does not make for an opinion that is worth equal time with an educated one.
And the next time that you quote me, please don't take my sentence so clearly out of context. It really makes you look stupid to anyone who goes back and looks at the original sentence in context.
Sincerely,
Ben Tilly
Unfortunately Dave's comments remind me of the RedHat IPO. Don't get me wrong! RedHat is clearly a company in the right place at the right time. Unlike most "dot com" companies it has a business model that I believe in. Current revenues 10 million/year, doubling each year for 5 years. What is not to like?
The problem is that it is a company in a rapidly growing market with what looks to me to be a fixed horizon. Let us calculate what happens if RedHat has its way and does pretty darned well. 5 years from now suppose that the OS is a commodity market, and RedHat or derivatives thereof is being installed on 100 million computers per year. Let us suppose that they are actually making 5 dollars of revenue per computer (remember, nothing stops people from installing many times for the price of one CD). That is 500 million dollars of revenue/year. (If they double for 5 years in a row they would be at 320 million, so this is a reasonable ball-park.) Assuming that they get a 10% profit margin (about right for a commodity market with low barriers of entry - which is what Linux is trying to be), that is an earnings of 50 million/year.
Long-term in the stock market a sustainable P/E ratio has proven to be about 20 or so. So everything has gone well for RedHat, in 5 years the Linux market stabilizes and they might be justified in having a market cap of 1 billion dollars. That is pretty darned good for a company that last year just about broke even on 10 million in revenue!
However currently 10% of the company is being traded, and that comes to 6 million shares. So the current market-cap is 60,000,000 x 85.25 = 5,115,000,000. That is just over 5 times what I just estimated to be a reasonable market cap in 5 years if all goes reasonably well for the company.
Folks, the investment bankers who calculated $14 as being a reasonable IPO price are not idiots. (Their market cap would be $840 million, which is probably not coincidentally in the same range that my ballpark figures above gave.) They worked out what they thought was a reasonable price for where the company was going. Unless I miss my calculation some people are going to be burned eventually.
Sure, I like RedHat as well. I think that it is going to do really well as a company (although they have to improve their support a lot to meet their goals). But I don't like it as a long-term investment at $85/share!
Sincerely,
Ben Tilly
Not that I saw! And you didn't even have the guts to sign it.
Let me take this bit by bit.
There is no proof that Evoltion is true.
You cannot even spell Evolution! As for evidence, you did look in the FAQs that were pointed to above?
Darwin himself later in life admitted that he was wrong.
The infamous Lady Hope story. Known to be a lie.
There is only evolution with in a class.
It seems that you have a common confusion about what macroevolution is and isn't.
Every "ape man" ever found has been proved wrong. The bones that they found where hundreds of feet even miles apart and in different layers of the earth.
You clearly don't have a clue what you are talking about. In a word, "Lucy".
In evolution you only evolve to have what you need. So since we don't need a third arm that is why we don't have a third arm. Well then how come we only use 10% of our brain. Why did we "evolve" to have such a big brain?
Warning, warning, urban legend alert! Do do have a reference?
If Evolution is real then there would be hundreds even thousands of transition fossils and yet there isn't even one!
Funny, the scientists seem to think otherwise.
Evolution is a theory and all it takes is one thing to prove it wrong and then it should thrown out. There are to many things that prove evolution to be wrong and not enough to back it up.
May I hold Creationism to the same standard?
To me it is easier to beleive that a living God made the earth and it didn't just happen. Have you ever seen a tornado go through a junk yard and assemble a perfectly working car. No! So what makes you think that something as big and complex as the earth and every living thing on it can happen by chance.
And that is a straw-man argument.
If you just look around you you will see that there is someone out there that is bigger than each and everyone of us. Just open your eyes and you will see.
Is closing my eyes also a pre-requisite? So far your batting average is pretty darned pathetic...
Sincerely,
Ben Tilly
Was I unfair? Jimbo asked how one could treat evolution and Creationism fairly. The doctrine of Creationism as espoused by the ICR and other such groups indeed does say that the Earth is about 6000 years old, and there was a global flood about 4000 years ago. This is not a straw-man argument, this is a direct statement of the mainstream Creationist position as believed by a significant portion of the US.
Very few people describe themselves as Creationists and simultaneously do NOT subscribe to this belief system.
I feel that responding this was is, in fact, particularly appropriate in this case when responding to someone who is accusing scientists of changing their theories. Creationism is a well-defined position and it comes with a considerable theological baggage. If scientists are criticized for modifying theories produced by humans, then how much more disingenous would it be to modify theories purportedly laid down by God?
No, I don't feel that I was at all unfair in what I said.
Sincerely,
Ben Tilly
You claim that scientists change the theory to fit the facts. That seems to me to be an excellent straw-man argument. Please come up with concrete examples.
At issue in particular is Darwin's theory of evolution, which states that there is descent with modification where those traits that are beneficial to having plentiful surviving descendants will spread. And this ongoing process, visible today, is responsible over time for the modification and branching of the species.
I maintain that this statement of Darwin's theory has been accurate since The Origin of the Species was published in 1859. Our understanding of that theory has changed significantly. For instance the discovery that inheritance is discrete rather than continuous was a significant change. Likewise there have been ongoing changes in thought about such details at rates, pacing, etc. And there have been many specific examples that have modified, for instance Darwin initially thought that lungs evolved from the swim-bladder of a fish, but later research and fossil evidence shows that the connection is the other way, the swim-bladder of the "higher fishes" evolved from a lung.
But through the entire history of the theory, the basic statement has never changed. Our thoughts and understanding of details have changed, but not the basic theory!
Oh, and do some reading on the history of biology will you? Darwin's theories did not win instant universal acceptance by a long shot. In fact they continued to face serious scientific challenges for 50 years, and I assure you that the critics were not gentle with the theory.
And being fair, we need to examine Creationism fairly. I maintain that Creationism is a belief maintained in spite of all facts and evidence. If you doubt me then explain how one can seriously believe today in a global Flood that purportedly happened 4000 years ago in spite of there being lake bottoms that have been undisturbed in longer than that, Chinese history going back farther than that, ice cores that have survived undamaged for well over 30 times that long, and a distribution of species around the world that is absolutely impossible based on the story of Noah's ark? Wilful ignorance of the facts is not a reason to respect a position!
Moving on to your apparently rhetorical question of mutations, yes, detailed studies have been done on mutation rates. And yes, the numbers do add up. In fact mutation rates have been used to form a "molecular clock" of how long populations have been seperated, and the time-lines that result are in generally good accord with the independent evidence from other lines such as fossil evidence.
Surprised? You should not be! It is characteristic of normal science that it constantly finds new ways to test its basic beliefs with more and more sensitive tests. Evolution is the product of normal science and has survived a century and a half of tests. I strongly doubt that there is any test you can think of which can be carried out in under a decade that has not been performed!
Sincerely,
Ben Tilly
At the bottom of my screen:
The bogosity meter just pegged.
Appropriate.
You claim to have been studying this subject for 20 years and have never once encountered the opinion that there are people who think that Archeopteryx is better classified as a dinosaur than a bird? Given that this opinion was stated in 2 out of the 3 links that YOU provided, I do not find that even remotely possible.
Also your ongoing refusal to accept anything about dating is getting simply silly. Your defense essentially comes down to saying, "Well we cannot know anything, no point in trying, and no point in my listening to people who have spent years figuring this stuff out." And then when it comes to uncomfortable facts such as having independent means of dating consistently agree with each other, you just ignore that.
If I wished to take a position that was similarly "open - I just want to see all of the facts" I could happily maintain for years that Bill Clinton is not really President. After all how do the people who tell me that he is know that? They heard it on the TV. Have they met anyone on the TV? Do they know the TV is real? No! The TV could be some evil manipulation plot! They can't prove otherwise! And if they can't prove otherwise, I can ignore them!
Seriously, it really looks like you decided what reality is and cannot hear otherwise. You heard that Archeopteryx is a bird, you cannot conceive of something half-way between a bird and a dinosaur, and so you refuse to hear the constant descriptions of how it is exactly that. Then once you have conveniently made it impossible to accept the common description, you can claim that it is not really a transitional fossil, and there are not really any transitional fossils.
I am seriously beginning to wonder whether there is any point in talking to you. You claim that you would have an open mind, you just want to see all of the facts, but with every word you clearly look at data for just long enough to figure out how there is a possible way that you could theoretically dismiss it, and once you have found that way you then dismiss it. And given that you dismiss everything that you find out of hand, you never have to worry about such alien concepts as, "the preponderance of the evidence".
Please, prove me wrong, but that pattern seems pretty consistent so far.
Ben Tilly