The article forgot to mention that there was indeed a plausible explanation for the 21 grams lost after each person died. No matter how much one exhales, there is always air left in one's body. However, when you die, your lungs relax and thus expel that final bit of air, hence making your corpse a little bit lighter.
You're missing the point; if a price breaks through the floor, yes, it does go lower and establishes a new floor, but then the old floor becomes a new ceiling.
You know what ticks me off more than people who mess up the meanings of precision and accuracy? People who mess then up but think they're right. If you make a measurement of 165.04452 +/- 50 (say, for example, meters of depth), it (the measurement) is not precise at all. Whether it is accurate or not depends on the actual value of the depth being measured.
To summarize, if the true depth was 165 m:
165.04452 +/- 50 --> not precise, accurate 165.04452 +/-.0005 --> precise, accurate 100 +/- 50 --> not precise, not accurate 100 +/-.00005 --> precise, not accurate
See http://www.geoplace.com/gw/2000/1000/1000gps.asp as a reference, and think before you post next time.
My god. Have *any* of you who are posting your "proofs" and "arguments" *ever* taken a college math class? Listen up, because I'll only explain this once.
A rational number is defined as a pair (p, q), where p is an integer and q is a non-zero natural number. Notice there is *nothing* about decimal expansions or repeading decimals mentioned in this definition.
However, for the sake of convenience, given a rational number (p, q) and a base b (a natural number > 1), one could define a unique b-ary expansion e = {bn...b3b2b1.d1d2d3...dn, r} where bi and di are natural numbers in {0, 1,...,b - 1}, bn != 0, dn != 0, and r = 0 or 1. (r represents whether the last digit dn repeats or not).
The question is, what other conditions do we need to impose on e to make it unique? Guess what: the only time when two decimal expansions arise for the same number is when (p / q) is a whole number w, where the two expansions are {(w - 1).9, 1} (repeating nines) and {w, 0}. So to ensure uniqueness, we *define* the decimal expansion to be (w, 0}.
Simple. Silly-ass questions like HURR DOES.9999... EQUAL 1? can be simply replied to with "That is a stupid and irrelevant question." Equality on rational numbers is defined solely in terms of p and q and it just so happens that for convenience, equality can be considered in terms of the decimal expansions *unless* you try to fuck things up by trying to calculate and "prove" things about meaningless strings of symbols like.99999.... By the way, note that all of the above "proofs" that.9999... = 1 are fallacious, simply because you cannot assume that you can operate on infinite decimal expansions like finite decimal expansions.
So in summary, asking: "Does.9999... = 1?" is just as silly as asking "Does 1 / 0 = infinity?" or "Is the sentence 'All your base are belong to us' passive voice or acive voice?" Why? Because the symbol ".9999..." is meaningless in terms of the analysis of real numbers, just as the symbol "=" has no meaning when combined with the concepts of "1 / 0" (which is also meaningless) and "infinity" (which is also meaningless in this context).
Um...c is not a "man-made" constant. Although you're right that it's simpler to set it to 1 and have all the units change around it, increasing c by 10% would have some noticeable effect.
c is the speed at which electromagnetic waves propagate. calling it the speed of light is somewhat of a misnomer; it might be better to say that light moves at the speed of propagation of electromagnetic waves, since it is, after all, an electromagnetic wave. Furthermore, it turns out that the wave equation implies that c = 1 / square_root(e_naught * mu_naught), where e_naught is the permittivity of free space (ratio of charge to electric flux in vacuum) and mu_naught is the permeability of free space (ratio of current to magnetic flux in vacuum). These two are experimental constants which the speed of light happens to depend on (although now the speed of light is taken to be a fundamental definition). Therefore, an increase the speed of light by 10% would imply an increase in either or both of the fundamental constants, which may have drastic effects, comparatable to G (the universal gravitational constant) being 10% greater.
On balance, do you think being pedantic about the language will make people perceive you as more, or less "professional"?
Come on. This is English and not Latin. Everyone uses "focuses" instead of "foci," unless you're talking about geometry or optics. You can continue to persist in asserting that "foci" is the correct plural, which it may or may not be, but language is one of the few systems which are decided by vox populi. (See "fish"/"fishes")
There is no "centripetal force." There is, however, a centripetal acceleration, which points *inward*. (Look up the word) You're committing the classic mistake of confusing a force with an acceleration. For example, in your example, the ball's centripetal acceleration is inward. By Newton's 2nd law, a force must be acting on it. The force in this case happens to be the tension of the rope.
There IS centrifugal force. It's a fictional force, which is a sort of misnomer. A fictional force is nothing but a force felt by an object in an accelerating frame of reference, like a ball on a string (since velocity is changing direction), or a car getting on a freeway (since velocity is increasing). The fictional force in your example would be the one felt by the ball, radially outward, with magnitude equal to the tension on the rope.
I think it is you who should have paid attention in physics 101.
I'm too lazy to look it up, but this a duplicate from some time ago. You'd think the editors would be able to detect duplicates better than a semi-regular reader, especially since they're getting paid to do it.
> Put a decent text or a good set of notes from such a text in front of me, and I can plow through math with no trouble. Take it away, and I am unable to even handle that pythagorean theorem stuff.
So you're saying that if you had a book in front of you, which, in deriving the relevant theorems and equations, does 99% of the work for you, you can do the (remaining 1% of the) math, but otherwise not. What does that mean? It means you don't know the material. Period.
> I convinced my mom to buy me a TI-85 calculator that I plugged all of my math notes into every day, and used it during ever single test I took.
So, assuming the tests were closed-notes, you cheated.
> If my teachers had been pompous pricks like you, I would have been simply branded a cheater and never finished high school.
But you *were* cheating. You didn't deserve to pass high school.
>If inflexible morons like you were allowed to exist in the business world, programmers would suffer having to work without reference, sysadmins without man pages, et al.
Do you see sysadmins walking around with "Linux for Dummies" under their arms? Do you see programmers walking around with their noses buried in "C++ in 24 days"? Of course not. man pages and such are references, and are not analogous to, say, a math textbook. they would be analogous to a table of integrals or a multiplication table, perhaps. If an unknowledgable "moron" like you was working for me, you'd be out in an instant.
>I only hope that as mankind progresses, we can isolate the gene that produces personalities like yours, and destroy it- and people like you- utterly.
On the contrary, I hope that people like you (lazy, cheaters) will be culled out instead.
>If someone could find a way to turn mercury into gold, [blah blah]
As any chemistry class can tell you, this is practically impossible.
>If a person could find an function f(x) that returns the xth prime number, [blah blah]
Actually, you can. Anyone proficient in a programming language can code one easily enough, and anyone with any math experience can write out a description of said function. I think you meant a "simple" function f(x) (i.e., non-recursive), which I think has been proven impossible (although don't take my word for it).
>If only it was easy to find any decimal of PI with a simple formula, [blah blah]
It is. See other replies to your post.
>"If a person were to find a O(n) solution to an NP complete problem [blah blah]"
What's so different about this question? It's still open! All the examples you posted are either solved or proven unsolvable. This question is neither.
Why do you say that 9.8 m/s^2 is an inaccurate figure? Granted, it may be 9.77 m/s^2 on top of Mt. Everest, but that's a difference of.03, which is less than 1% error.
>The smallpox virus, with only a few thousand base pairs of DNA, could wipe out nearly half the world's population, 2.5 billion people, if released. And that's a virus that doesn't even have intelligence!
You're assuming that the danger varies proportionally to the amount of DNA involved. Well, if that were the case, any fruit fly, with loads of DNA, could destroy the world, based on your "reasoning".
>Now we're talking about creating DNA-based computers. Has anyone even stopped to think about this? What happens if someone runs a neural network or similarly advanced artificial intelligence [sourceforge.net] on one of these computers? What happens if one of them becomes even slightly self-aware?
>That's right, an intelligent virus; a downright apocalypse. Armageddon. We'd just be food for the next life form.
Whoa, there. you went from DNA-based computing to intelligent viruses. That's a non sequitur if I ever saw one. First of all, viruses != DNA. A sentient DNA computer would not be an intelligent virus. By the way, how could anything become *slightly* self-aware? Either it is, or it isn't. There's no middle ground.
>Honestly, I think these "scientists" would create a bomb to destroy the Universe given the opportunity, just to see if they could do it. There's no reason to mess with the designs of our Creator like this. I'm not condemning all biosciences, just the projects that endanger all of Humanity- Viral Genetic Engineering, Human Cloning, and now Sentient Virii.
If only you were born a few hundred years ago -- you'd be one of the people condemning Galileo for his "heretical" theories that "mess with the designs of our Creator". Get a clue. If there are any valid reasons to not pursue human cloning, etc., the "designs of our Creator" is certainly not one of them. And, for God's sake, this is a bunch of scientists trying to build a better computer -- it's not like they're killing baby whales or anything.
>>I cannot imagine any large-scale app being released by a group of "programmers" who designed as they implemented.
>>RedHat Linux 7.2 with current patches.
Ah, I knew someone would cite linux as an example. What I meant when I said "programmers who designed as they implemented", I meant programmers who go
"hey, it would be cool to create my own proprietary movie file format for this game I'm working on instead of using avi" and then scrap it later when they realize it isn't working -- I'm sure red hat programmers aren't so impulsive.
> Actually, getting the aproximate requirements for a bridge involves building a lot of bridges.
By that do you mean a lot of bridges have to be built at first in order to figure out what works and what doesn't? Of course -- this is how engineering develops. But bridge-building is a pretty mature art, to say the least, and I don't think you'd see a bridge being built and then drastically revised later on. My point was that software engineering is also near that point of maturity, in that it is possible to design a program without actually coding it.
> You will find the truth: Software design *is* software implementation. There are no "Software Engineers", there are only Programmers.
I don't know where you've worked, but in my experience, any non-trivial applications requires a huge amount of design and paperwork before a line of code is even written. Why? because you want to find out that something doesn't work in the design phase as opposed to the implementation phase. Hammering out the flaws in the design is cheaper in the long run -- i.e., you can throw away a design, but throwing away an implementation means throwing away that many man-hours of work.
> Getting requirements that fine grained is apparently equivalent to writing the code.
No. To go back to the bridge analogy, that is like saying that getting the exact requirements for a bridge would involve actually building the bridge. I think software engineering has advanced to the point that designing a software project and implementing it are now two different phases. I cannot imagine any large-scale app being released by a group of "programmers" who designed as they implemented.
I did not say you needed pointers to write complicated programs. Perhaps my original comment wasn't clear -- I also did not mean that C-style pointers specifically were needed to write a kernel -- I meant that some sort of memory management mechanism was needed, exemplified by C-style pointers in Linux.
That being said, I realize that one has to write certain portions of the kernel in assembly/C and that the rest can be written in almost any language. However, Java's pointer-less, or memory-management-less, design makes it so that a *significant* amount of other code must be written in order to program the kernel in Java. How exactly would the run-time garbage collector work without some sort of underlying memory management system already in place? How also would it work without some sort of process/thread mechanism? (correct me if i'm wrong, but the garbage collector runs independently of the process, right?) So, in order to program in Java, you'd have to implement memory management and process/thread switching. That's already a significant, or at least a non-trivial, portion of the kernel that has to be written in another language.
> What I'd like to see is a powerful kernel mostly written in a very high level safe language like O'Caml or even Java. That would be a feat with some important consequences.
Ha! A kernel written in Java, a language that does not implement pointers. That would be a feat in and of itself.
> 6/7 to three sig figs. Answer is immediate if the useful 7*11*13==1001 has been memorized.
Actually, there's an easier way to figure out any fraction of 7 to as many places of accuracy as you want. It turns out that all fractions of 7 have the repeating pattern 142857. So to calculate, say, 6/7, you'd only need to calculate the first digit, 8, and follow the pattern: 6/7 =.857 142857...
Slashdot Mirror
nt = no text
The article forgot to mention that there was indeed a plausible explanation for the 21 grams lost after each person died. No matter how much one exhales, there is always air left in one's body. However, when you die, your lungs relax and thus expel that final bit of air, hence making your corpse a little bit lighter.
You're missing the point; if a price breaks through the floor, yes, it does go lower and establishes a new floor, but then the old floor becomes a new ceiling.
You know what ticks me off more than people who mess up the meanings of precision and accuracy? People who mess then up but think they're right. If you make a measurement of 165.04452 +/- 50 (say, for example, meters of depth), it (the measurement) is not precise at all. Whether it is accurate or not depends on the actual value of the depth being measured.
.0005 --> precise, accurate .00005 --> precise, not accurate
To summarize, if the true depth was 165 m:
165.04452 +/- 50 --> not precise, accurate
165.04452 +/-
100 +/- 50 --> not precise, not accurate
100 +/-
See http://www.geoplace.com/gw/2000/1000/1000gps.asp as a reference, and think before you post next time.
My god. Have *any* of you who are posting your "proofs" and "arguments" *ever* taken a college math class? Listen up, because I'll only explain this once.
.9999... EQUAL 1? can be simply replied to with "That is a stupid and irrelevant question." Equality on rational numbers is defined solely in terms of p and q and it just so happens that for convenience, equality can be considered in terms of the decimal expansions *unless* you try to fuck things up by trying to calculate and "prove" things about meaningless strings of symbols like .99999.... By the way, note that all of the above "proofs" that .9999... = 1 are fallacious, simply because you cannot assume that you can operate on infinite decimal expansions like finite decimal expansions.
.9999... = 1?" is just as silly as asking "Does 1 / 0 = infinity?" or "Is the sentence 'All your base are belong to us' passive voice or acive voice?" Why? Because the symbol ".9999..." is meaningless in terms of the analysis of real numbers, just as the symbol "=" has no meaning when combined with the concepts of "1 / 0" (which is also meaningless) and "infinity" (which is also meaningless in this context).
A rational number is defined as a pair (p, q), where p is an integer and q is a non-zero natural number. Notice there is *nothing* about decimal expansions or repeading decimals mentioned in this definition.
However, for the sake of convenience, given a rational number (p, q) and a base b (a natural number > 1), one could define a unique b-ary expansion e = {bn...b3b2b1.d1d2d3...dn, r} where bi and di are natural numbers in {0, 1,...,b - 1}, bn != 0, dn != 0, and r = 0 or 1. (r represents whether the last digit dn repeats or not).
The question is, what other conditions do we need to impose on e to make it unique? Guess what: the only time when two decimal expansions arise for the same number is when (p / q) is a whole number w, where the two expansions are {(w - 1).9, 1} (repeating nines) and {w, 0}. So to ensure uniqueness, we *define* the decimal expansion to be (w, 0}.
Simple. Silly-ass questions like HURR DOES
So in summary, asking: "Does
Um...c is not a "man-made" constant. Although you're right that it's simpler to set it to 1 and have all the units change around it, increasing c by 10% would have some noticeable effect.
c is the speed at which electromagnetic waves propagate. calling it the speed of light is somewhat of a misnomer; it might be better to say that light moves at the speed of propagation of electromagnetic waves, since it is, after all, an electromagnetic wave. Furthermore, it turns out that the wave equation implies that c = 1 / square_root(e_naught * mu_naught), where e_naught is the permittivity of free space (ratio of charge to electric flux in vacuum) and mu_naught is the permeability of free space (ratio of current to magnetic flux in vacuum). These two are experimental constants which the speed of light happens to depend on (although now the speed of light is taken to be a fundamental definition). Therefore, an increase the speed of light by 10% would imply an increase in either or both of the fundamental constants, which may have drastic effects, comparatable to G (the universal gravitational constant) being 10% greater.
On balance, do you think being pedantic about the language will make people perceive you as more, or less "professional"?
Come on. This is English and not Latin. Everyone uses "focuses" instead of "foci," unless you're talking about geometry or optics. You can continue to persist in asserting that "foci" is the correct plural, which it may or may not be, but language is one of the few systems which are decided by vox populi. (See "fish"/"fishes")
There is no "centripetal force." There is, however, a centripetal acceleration, which points *inward*. (Look up the word) You're committing the classic mistake of confusing a force with an acceleration. For example, in your example, the ball's centripetal acceleration is inward. By Newton's 2nd law, a force must be acting on it. The force in this case happens to be the tension of the rope.
There IS centrifugal force. It's a fictional force, which is a sort of misnomer. A fictional force is nothing but a force felt by an object in an accelerating frame of reference, like a ball on a string (since velocity is changing direction), or a car getting on a freeway (since velocity is increasing). The fictional force in your example would be the one felt by the ball, radially outward, with magnitude equal to the tension on the rope.
I think it is you who should have paid attention in physics 101.
I'm too lazy to look it up, but this a duplicate from some time ago. You'd think the editors would be able to detect duplicates better than a semi-regular reader, especially since they're getting paid to do it.
> Put a decent text or a good set of notes from such a text in front of me, and I can plow through math with no trouble. Take it away, and I am unable to even handle that pythagorean theorem stuff.
So you're saying that if you had a book in front of you, which, in deriving the relevant theorems and equations, does 99% of the work for you, you can do the (remaining 1% of the) math, but otherwise not. What does that mean? It means you don't know the material. Period.
> I convinced my mom to buy me a TI-85 calculator that I plugged all of my math notes into every day, and used it during ever single test I took.
So, assuming the tests were closed-notes, you cheated.
> If my teachers had been pompous pricks like you, I would have been simply branded a cheater and never finished high school.
But you *were* cheating. You didn't deserve to pass high school.
>If inflexible morons like you were allowed to exist in the business world, programmers would suffer having to work without reference, sysadmins without man pages, et al.
Do you see sysadmins walking around with "Linux for Dummies" under their arms? Do you see programmers walking around with their noses buried in "C++ in 24 days"? Of course not. man pages and such are references, and are not analogous to, say, a math textbook. they would be analogous to a table of integrals or a multiplication table, perhaps. If an unknowledgable "moron" like you was working for me, you'd be out in an instant.
>I only hope that as mankind progresses, we can isolate the gene that produces personalities like yours, and destroy it- and people like you- utterly.
On the contrary, I hope that people like you (lazy, cheaters) will be culled out instead.
>If someone could find a way to turn mercury into gold, [blah blah]
As any chemistry class can tell you, this is practically impossible.
>If a person could find an function f(x) that returns the xth prime number, [blah blah]
Actually, you can. Anyone proficient in a programming language can code one easily enough, and anyone with any math experience can write out a description of said function. I think you meant a "simple" function f(x) (i.e., non-recursive), which I think has been proven impossible (although don't take my word for it).
>If only it was easy to find any decimal of PI with a simple formula, [blah blah]
It is. See other replies to your post.
>"If a person were to find a O(n) solution to an NP complete problem [blah blah]"
What's so different about this question? It's still open! All the examples you posted are either solved or proven unsolvable. This question is neither.
Why do you say that 9.8 m/s^2 is an inaccurate figure? Granted, it may be 9.77 m/s^2 on top of Mt. Everest, but that's a difference of .03, which is less than 1% error.
>The smallpox virus, with only a few thousand base pairs of DNA, could wipe out nearly half the world's population, 2.5 billion people, if released. And that's a virus that doesn't even have intelligence!
You're assuming that the danger varies proportionally to the amount of DNA involved. Well, if that were the case, any fruit fly, with loads of DNA, could destroy the world, based on your "reasoning".
>Now we're talking about creating DNA-based computers. Has anyone even stopped to think about this? What happens if someone runs a neural network or similarly advanced artificial intelligence [sourceforge.net] on one of these computers? What happens if one of them becomes even slightly self-aware? >That's right, an intelligent virus; a downright apocalypse. Armageddon. We'd just be food for the next life form.
Whoa, there. you went from DNA-based computing to intelligent viruses. That's a non sequitur if I ever saw one. First of all, viruses != DNA. A sentient DNA computer would not be an intelligent virus. By the way, how could anything become *slightly* self-aware? Either it is, or it isn't. There's no middle ground.
>Honestly, I think these "scientists" would create a bomb to destroy the Universe given the opportunity, just to see if they could do it. There's no reason to mess with the designs of our Creator like this. I'm not condemning all biosciences, just the projects that endanger all of Humanity- Viral Genetic Engineering, Human Cloning, and now Sentient Virii.
If only you were born a few hundred years ago -- you'd be one of the people condemning Galileo for his "heretical" theories that "mess with the designs of our Creator". Get a clue. If there are any valid reasons to not pursue human cloning, etc., the "designs of our Creator" is certainly not one of them. And, for God's sake, this is a bunch of scientists trying to build a better computer -- it's not like they're killing baby whales or anything.
>>I cannot imagine any large-scale app being released by a group of "programmers" who designed as they implemented.
>>RedHat Linux 7.2 with current patches.
Ah, I knew someone would cite linux as an example. What I meant when I said "programmers who designed as they implemented", I meant programmers who go "hey, it would be cool to create my own proprietary movie file format for this game I'm working on instead of using avi" and then scrap it later when they realize it isn't working -- I'm sure red hat programmers aren't so impulsive.
> Actually, getting the aproximate requirements for a bridge involves building a lot of bridges.
By that do you mean a lot of bridges have to be built at first in order to figure out what works and what doesn't? Of course -- this is how engineering develops. But bridge-building is a pretty mature art, to say the least, and I don't think you'd see a bridge being built and then drastically revised later on. My point was that software engineering is also near that point of maturity, in that it is possible to design a program without actually coding it.
> You will find the truth: Software design *is* software implementation. There are no "Software Engineers", there are only Programmers.
I don't know where you've worked, but in my experience, any non-trivial applications requires a huge amount of design and paperwork before a line of code is even written. Why? because you want to find out that something doesn't work in the design phase as opposed to the implementation phase. Hammering out the flaws in the design is cheaper in the long run -- i.e., you can throw away a design, but throwing away an implementation means throwing away that many man-hours of work.
> Getting requirements that fine grained is apparently equivalent to writing the code.
No. To go back to the bridge analogy, that is like saying that getting the exact requirements for a bridge would involve actually building the bridge. I think software engineering has advanced to the point that designing a software project and implementing it are now two different phases. I cannot imagine any large-scale app being released by a group of "programmers" who designed as they implemented.
I did not say you needed pointers to write complicated programs. Perhaps my original comment wasn't clear -- I also did not mean that C-style pointers specifically were needed to write a kernel -- I meant that some sort of memory management mechanism was needed, exemplified by C-style pointers in Linux.
That being said, I realize that one has to write certain portions of the kernel in assembly/C and that the rest can be written in almost any language. However, Java's pointer-less, or memory-management-less, design makes it so that a *significant* amount of other code must be written in order to program the kernel in Java. How exactly would the run-time garbage collector work without some sort of underlying memory management system already in place? How also would it work without some sort of process/thread mechanism? (correct me if i'm wrong, but the garbage collector runs independently of the process, right?) So, in order to program in Java, you'd have to implement memory management and process/thread switching. That's already a significant, or at least a non-trivial, portion of the kernel that has to be written in another language.
> You don't need pointers you fucking troll, just need some sort of boot loader to get the thing started.
And implement memory management how?
> What I'd like to see is a powerful kernel mostly written in a very high level safe language like O'Caml or even Java. That would be a feat with some important consequences.
Ha! A kernel written in Java, a language that does not implement pointers. That would be a feat in and of itself.
> 6/7 to three sig figs. Answer is immediate if the useful 7*11*13==1001 has been memorized. Actually, there's an easier way to figure out any fraction of 7 to as many places of accuracy as you want. It turns out that all fractions of 7 have the repeating pattern 142857. So to calculate, say, 6/7, you'd only need to calculate the first digit, 8, and follow the pattern: 6/7 = .857 142857 ...