IMO it would be better for the compiler to identify and tag the calls internally - obviously it can do so, or it couldn't give compilation errors in the way you describe. Then it could allow you to mark a function as pure, for your own information, and give a compilation error if it wasn't.
That would give you the advantages that the compiler can give for pure functions, without the hassle of updating whole trees of functions when one impure call is made, but it would still let you ensure that critical calls are pure.
I'm not sure about the quotes - is that intended to be sarcasm? Your sentence reads fine without them, and including them seems to be intended to imply that I'm stupid, which I'm not;-)
I am, unfortunately, not an expert in functional languages. I do remember that LISP isn't pure functional.
The main point still stands - functional languages do already address this issue. You're absolutely right that LISP doesn't do all it needs to out of the box to address the issue properly.
I honestly have no idea if Erlang, Scala or Haskell do allow the compiler to identify pure functional calls, although I tend to believe the other AC response that Haskell, at least, does.
Seriously, no one has brought up functional programming, LISP, Scala or Erlang? When you use functional programming, no data changes and so each call can happen on another thread, with the main thread blocking when (& not before) it needs the return value. In particular, Erlang and Scala are specifically designed to make the most of multiple cores/processors/machines.
See also map-reduce and multiprocessor database techniques like BSD and CouchDB (http://books.couchdb.org/relax/eventual-consistency).
I fail to see how monitoring my body automatically and being informed when my lifestyle leads to risk of serious ill health is "constantly try to eliminate every imaginable element of risk".
I put on a wrist strap, forget about it, and then I get a notice every few months that I need more exercise, or I need to cut out saturated fats. Or, I even get a couple of notices daily to tell me to go eat a banana to maintain a blood sugar level that will keep me feeling good.
That sounds pretty damn good to me. Most adults are killed by cancer or heart disease, and most cancer and heart disease are curable if caught early. It sounds to me like a system only an idiot would turn down.
Seriously, if you live the way you're proposing, you would ride your motorcycle helmet-less back & forth to work every day, dine on bacon cheeseburgers and chili cheese fries, and only ever exercise if it was fun. I'm all for your right to live that way, but I refuse to let your snide commentary on people who choose to put a little work into living happy, long lives stand without refutation.
(Note: this commentary is really directed as much at moderators as at the parent. A +5 Insightful comment naturally gets a more visceral reaction than the same comment at 2.)
We have a convenient source of fusion already - the sun.
I think molecular manufacturing (nanotech) is going to give us cheap, automated ways to make the materials for a space elevator and dirt-cheap solar cells. Once putting solar power satellites into orbit is cheap, it seems to me that beaming power to earth that would otherwise have dissipated out into the galaxy is the way to go.
And I think this will come long before practical fusion.
Um, I don't know about you, but I *live* in the environment. It's in everyone's interest to be an environmentalist, particularly if you have children.
And just because one person who holds a belief uses a bit of conspiratorial hyperbole doesn't invalidate the belief.
I could go into all kinds of discussions of human psychology, non-conspiracy theory ways in which one can profit or avoid criminal penalties by manipulating people's beliefs, etc. but I wouldn't want to paint myself as a nutjob.
(I should say that I generally don't give much credence to people who talk about what "they" want us to believe. But there's a difference between not giving credence and treating a crazy argument as evidence against its point.)
To fail at basic info like that, shows a disregard for scientific knowledge. And that is foundation of critical thought (together with some philosophy in it).
I would certainly consider doing mathematics critical thought, and mathematics is not founded on scientific knowledge. Nor is mathematics a science - a theorem in mathematics has a proof that is (or at least can be represented as) a set of symbolic manipulations that demonstrate that the given absolutely imply the conclusion. There is no possibility that future work will find the theorem to be false (if the mathematical system is consistent), unless the proof has an error in it, and since they can be mechanically verified, that basically doesn't happen after a proof has been around for a few months.
A theorem in science means that your model represents the data under all known conditions, possibly with some known exceptions. The theorem can be disproven (or, rather, demonstrated to be inapplicable in some domains) by finding a single counterexample. A mathematical proof demonstrates incontrovertibly that a counterexample doesn't exist.
I would expect you to counter by saying that mathematics requires scientific knowledge, but I disagree. Certainly what mathematics we do is impacted to some degree by what we know of the real world, but lots of mathematics is done that has no known relationship to reality. And in fact, sometimes that mathematics becomes the foundation of a new scientific model, even though the math was a "pure" pursuit for a long time. For an example, look up Group Theory.
I said "use large scale features" which is very misleading in context. I meant the "gift" was going to be very big, so errors in gps coordinates wouldn't be too noticable.
That's great - I wanted to do almost exactly the app he's doing with the "treasure hunt" for a mobile platform.
The only difference was that I wanted to make it more of a large scale thing, and use gps to get you close. I didn't think about using features to guide you once you get close... I was going to use large scale features for which the error in gps coordinates wouldn't be an issue. The thing that prevented me from doing the app is that I would need a digital compass in the phone to be able to tell direction. In fact, unless he has the whole environment they're likely to be in encoded and lots of computing power, he would need one too.
Oh, and I didn't think of the cool "bubbles" animation. I planned to do some futuristic, fantasy magic and steampunk skins for a locator.
I don't think phones have the computing power to do dynamic features now, and in fact I think it will be a terrible way to calculate location other than in very limited circumstances for a very long time. I do agree that augmented reality will be huge in 10 years, I just think other ways will be used of calculating location, except for landmarks (fixed location items of interest to lots of people).
Vernor Vinge invented cyberspace (although I don't think he coined the term) in True Names.
If you haven't read it, I highly recommend it. Read True Names to get a notion of the profound visionary Vernor Vinge is. (Remember it was published in 1981).
Then read Rainbows End with your newfound respect for Vinge's powers of prognostication, and recognize that you're seeing into the near future.
(This post is a blatant copy of an old post of mine.)
We put out Pharce (an app to let you create mocking or cute videos from pictures on your iPhone) a few weeks ago. (Video here). We sent out a press release, and got about 140 downloads a day for several days after the press release went out.
This slowly dwindled to 40, then to 20, then lower. We expected that people sending the videos to one another would lead to notable growth over time, but that appears not to be the case. (The app lets you email the video or post it on YouTube from the phone).
I am working on a small update to the app, then we're going to buy some ads. I'm just curious if your app took off on its own, or if not, where you're advertising;-)
It was obvious that his was going to happen to anyone with one brain cell 5 years ago, and to anyone with two brain cells a decade ago.
Oh, in that case could you loan me a 30 or 40 thousand dollars from the millions you made by short selling stocks?
Or are you one of the many people with less than one brain cell?
I agree that this *should* have been obvious before to anyone who knew what financial instruments were being created, or to whom home loans were being given, but obviously it wasn't, or the market would have corrected itself as people moved money out of the foolish investments and into smart ones.
I read and enjoyed "Mathematics for the Million" by Lancelot Hogben. It covers a lot of different mathematical areas, and provides some historical context. I generally don't like history, but he (and Isaac Asimov) does a great job of using it to make the math, and the process by which the math was discovered, more interesting.
The Fermi paradox doesn't have much to do with radio waves.
In less than 100 years (probably much less), we will be capable one way (mature molecular manufacturing) or another (bioengineering + advanced technologies based on biological byproducts) of building tiny autonomous systems that can reproduce themselves given sufficient raw materials of the right basic sorts (carbon, hydrogen, oxygen, nitrogen, and trace amounts of other materials). This would allow exponential expansion, using tiny ramjets or laser driven lightsail seeds.
If *just one* civilization developed that capability, and *just one* member of that civilization got the inclination to cover the galaxy/universe once the technology is trivially cheap, then a sphere expanding at near light speed would be consumed. In a mere 150,000 years, the galaxy would be consumed by "smart matter" which could be programmed to do the will of the originator. In less than 3 million years, a seed starting in the Andromeda Galaxy would consume all suitable matter in the Milky Way.
(By the way, it gets trivially cheap pretty damn quickly for technology that can reproduce itself autonomously - one prototype means an indefinite, dirt-cheap supply.)
Radio waves aren't the issue. The question is why there's a solar system here instead of a Dyson sphere supporting a quadrillion copies of Joe the Plumber in his own personal heaven.
I agree with all of your opinions expressed here, but it's based on rationalization, which I *know* is often wrong. I see that you don't give any references for these "good books out there", which leads me to believe you are doing the same thing.
Can you list some of these good books that you have read?
I agree that what we're charged for the births that go smoothly is crazy, but look at infant (and mother) mortality rates from 70 years ago and tell me that birth is a normal process that shouldn't happen in a hospital.
I say this as a father who paid $8,0000 each for the births of my three sons (I had a very high deductible on my insurance; I'm a software contractor). All went smoothly, or it would have cost at least triple that.
From the perspective of what services we got, it was insanely expensive, although less so than the $1,000 we paid to get *one stitch* in my son's lip through the ER. But from the perspective of my wife and children having the support they needed to survive the process in case of a problem, it was a fantastic bargain.
That all said, we're moving somewhere with national health care, although our actual primary motivation is to get somewhere with clean air, a good educational system, and good public transportation. (We live in the US now.)
I don't get your point about information being stored in the black hole's horizon. What do you mean, the information is stored? The object is there, near-ish to the horizon...
And two other points about black holes. Firstly, the object doesn't "appear" to get stuck at the event horizon. From the POV of an outside observer, the object *in fact* never falls into the black hole. Part of Special Relativity is that what you see about the objects subject to relativistic effects is representative of what you'll measure about the object in any way, and hence is in every meaningful way representative of reality. The same is true of General Relativistic effects.
Secondly, objects falling towards the horizon are (usually) eventually going to fall into the hole from the POV of an outside observer, because the hole's horizon will expand as more matter gets densely packed around it. Once the neighborhood around the hole which includes the object has an escape velocity greater than light (due to more matter accreting around the hole), then the object is inside the event horizon.
Er, my phone certainly does have essentially an ever-present connection to the worldwide network. And my phone is a linux machine I would have been proud to have on my desktop 7 years ago.
I'm sure there are lots of other ways to make movies without copyright protection (another poster mentions consignment), but product placement seems the most obvious to me.
I'm not arguing that copyright should be done away with, although I agree with the people pointing out that it will be insupportable within a decade or two anyway. I do think a 5 or 15 year copyright would be MUCH more beneficial to society (which is supposed to be the point, at least in the US) than our current 120 year copyright.
Of course, my opinion on what copyright should be like is irrelevant - your argument was that moviemaking is insupportable without it, which is just not true.
Well, that is our #1 concern. We have two homeschool groups that we get together with on a regular basis, and they have several friends with whom they spend the night or have over several times a week.
In fact, my oldest is approaching 9th grade. I believe he should go to public school for high school, to prepare him to deal with other people more and so he can benefit on higher level topics from hopefully mostly learning from people who really care about their subject and can convey that interest.
I'm not sure what kind of public school you went to, but I don't remember many great experiences... how much time do you waste sitting in a classroom with nothing to do, or nothing but busywork to do? My kids go to the zoo, go to museums, the library, etc. in addition to regular desk time.
I definitely agree that it's a tradeoff, but we feel like we can manage the downsides so that the upside far outweighs it.
Slashdot Mirror
IMO it would be better for the compiler to identify and tag the calls internally - obviously it can do so, or it couldn't give compilation errors in the way you describe. Then it could allow you to mark a function as pure, for your own information, and give a compilation error if it wasn't.
That would give you the advantages that the compiler can give for pure functions, without the hassle of updating whole trees of functions when one impure call is made, but it would still let you ensure that critical calls are pure.
I'm not sure about the quotes - is that intended to be sarcasm? Your sentence reads fine without them, and including them seems to be intended to imply that I'm stupid, which I'm not ;-)
I am, unfortunately, not an expert in functional languages. I do remember that LISP isn't pure functional.
The main point still stands - functional languages do already address this issue. You're absolutely right that LISP doesn't do all it needs to out of the box to address the issue properly.
I honestly have no idea if Erlang, Scala or Haskell do allow the compiler to identify pure functional calls, although I tend to believe the other AC response that Haskell, at least, does.
Seriously, no one has brought up functional programming, LISP, Scala or Erlang? When you use functional programming, no data changes and so each call can happen on another thread, with the main thread blocking when (& not before) it needs the return value. In particular, Erlang and Scala are specifically designed to make the most of multiple cores/processors/machines.
See also map-reduce and multiprocessor database techniques like BSD and CouchDB (http://books.couchdb.org/relax/eventual-consistency).
I fail to see how monitoring my body automatically and being informed when my lifestyle leads to risk of serious ill health is "constantly try to eliminate every imaginable element of risk".
I put on a wrist strap, forget about it, and then I get a notice every few months that I need more exercise, or I need to cut out saturated fats. Or, I even get a couple of notices daily to tell me to go eat a banana to maintain a blood sugar level that will keep me feeling good.
That sounds pretty damn good to me. Most adults are killed by cancer or heart disease, and most cancer and heart disease are curable if caught early. It sounds to me like a system only an idiot would turn down.
Seriously, if you live the way you're proposing, you would ride your motorcycle helmet-less back & forth to work every day, dine on bacon cheeseburgers and chili cheese fries, and only ever exercise if it was fun. I'm all for your right to live that way, but I refuse to let your snide commentary on people who choose to put a little work into living happy, long lives stand without refutation.
(Note: this commentary is really directed as much at moderators as at the parent. A +5 Insightful comment naturally gets a more visceral reaction than the same comment at 2.)
We have a convenient source of fusion already - the sun.
I think molecular manufacturing (nanotech) is going to give us cheap, automated ways to make the materials for a space elevator and dirt-cheap solar cells. Once putting solar power satellites into orbit is cheap, it seems to me that beaming power to earth that would otherwise have dissipated out into the galaxy is the way to go.
And I think this will come long before practical fusion.
Um, I don't know about you, but I *live* in the environment. It's in everyone's interest to be an environmentalist, particularly if you have children.
And just because one person who holds a belief uses a bit of conspiratorial hyperbole doesn't invalidate the belief.
I could go into all kinds of discussions of human psychology, non-conspiracy theory ways in which one can profit or avoid criminal penalties by manipulating people's beliefs, etc. but I wouldn't want to paint myself as a nutjob.
(I should say that I generally don't give much credence to people who talk about what "they" want us to believe. But there's a difference between not giving credence and treating a crazy argument as evidence against its point.)
To fail at basic info like that, shows a disregard for scientific knowledge. And that is foundation of critical thought (together with some philosophy in it).
I would certainly consider doing mathematics critical thought, and mathematics is not founded on scientific knowledge. Nor is mathematics a science - a theorem in mathematics has a proof that is (or at least can be represented as) a set of symbolic manipulations that demonstrate that the given absolutely imply the conclusion. There is no possibility that future work will find the theorem to be false (if the mathematical system is consistent), unless the proof has an error in it, and since they can be mechanically verified, that basically doesn't happen after a proof has been around for a few months.
A theorem in science means that your model represents the data under all known conditions, possibly with some known exceptions. The theorem can be disproven (or, rather, demonstrated to be inapplicable in some domains) by finding a single counterexample. A mathematical proof demonstrates incontrovertibly that a counterexample doesn't exist.
I would expect you to counter by saying that mathematics requires scientific knowledge, but I disagree. Certainly what mathematics we do is impacted to some degree by what we know of the real world, but lots of mathematics is done that has no known relationship to reality. And in fact, sometimes that mathematics becomes the foundation of a new scientific model, even though the math was a "pure" pursuit for a long time. For an example, look up Group Theory.
I said "use large scale features" which is very misleading in context. I meant the "gift" was going to be very big, so errors in gps coordinates wouldn't be too noticable.
That's great - I wanted to do almost exactly the app he's doing with the "treasure hunt" for a mobile platform.
The only difference was that I wanted to make it more of a large scale thing, and use gps to get you close. I didn't think about using features to guide you once you get close... I was going to use large scale features for which the error in gps coordinates wouldn't be an issue. The thing that prevented me from doing the app is that I would need a digital compass in the phone to be able to tell direction. In fact, unless he has the whole environment they're likely to be in encoded and lots of computing power, he would need one too.
Oh, and I didn't think of the cool "bubbles" animation. I planned to do some futuristic, fantasy magic and steampunk skins for a locator.
I don't think phones have the computing power to do dynamic features now, and in fact I think it will be a terrible way to calculate location other than in very limited circumstances for a very long time. I do agree that augmented reality will be huge in 10 years, I just think other ways will be used of calculating location, except for landmarks (fixed location items of interest to lots of people).
Vernor Vinge invented cyberspace (although I don't think he coined the term) in True Names.
If you haven't read it, I highly recommend it. Read True Names to get a notion of the profound visionary Vernor Vinge is. (Remember it was published in 1981).
Then read Rainbows End with your newfound respect for Vinge's powers of prognostication, and recognize that you're seeing into the near future.
(This post is a blatant copy of an old post of mine.)
We put out Pharce (an app to let you create mocking or cute videos from pictures on your iPhone) a few weeks ago. (Video here). We sent out a press release, and got about 140 downloads a day for several days after the press release went out.
This slowly dwindled to 40, then to 20, then lower. We expected that people sending the videos to one another would lead to notable growth over time, but that appears not to be the case. (The app lets you email the video or post it on YouTube from the phone).
I am working on a small update to the app, then we're going to buy some ads. I'm just curious if your app took off on its own, or if not, where you're advertising ;-)
It was obvious that his was going to happen to anyone with one brain cell 5 years ago, and to anyone with two brain cells a decade ago.
Oh, in that case could you loan me a 30 or 40 thousand dollars from the millions you made by short selling stocks?
Or are you one of the many people with less than one brain cell?
I agree that this *should* have been obvious before to anyone who knew what financial instruments were being created, or to whom home loans were being given, but obviously it wasn't, or the market would have corrected itself as people moved money out of the foolish investments and into smart ones.
I read and enjoyed "Mathematics for the Million" by Lancelot Hogben. It covers a lot of different mathematical areas, and provides some historical context. I generally don't like history, but he (and Isaac Asimov) does a great job of using it to make the math, and the process by which the math was discovered, more interesting.
The Fermi paradox doesn't have much to do with radio waves.
In less than 100 years (probably much less), we will be capable one way (mature molecular manufacturing) or another (bioengineering + advanced technologies based on biological byproducts) of building tiny autonomous systems that can reproduce themselves given sufficient raw materials of the right basic sorts (carbon, hydrogen, oxygen, nitrogen, and trace amounts of other materials). This would allow exponential expansion, using tiny ramjets or laser driven lightsail seeds.
If *just one* civilization developed that capability, and *just one* member of that civilization got the inclination to cover the galaxy/universe once the technology is trivially cheap, then a sphere expanding at near light speed would be consumed. In a mere 150,000 years, the galaxy would be consumed by "smart matter" which could be programmed to do the will of the originator. In less than 3 million years, a seed starting in the Andromeda Galaxy would consume all suitable matter in the Milky Way.
(By the way, it gets trivially cheap pretty damn quickly for technology that can reproduce itself autonomously - one prototype means an indefinite, dirt-cheap supply.)
Radio waves aren't the issue. The question is why there's a solar system here instead of a Dyson sphere supporting a quadrillion copies of Joe the Plumber in his own personal heaven.
Great, thanks for the pointers!
I agree with all of your opinions expressed here, but it's based on rationalization, which I *know* is often wrong. I see that you don't give any references for these "good books out there", which leads me to believe you are doing the same thing.
Can you list some of these good books that you have read?
Thanks!
I agree that what we're charged for the births that go smoothly is crazy, but look at infant (and mother) mortality rates from 70 years ago and tell me that birth is a normal process that shouldn't happen in a hospital.
I say this as a father who paid $8,0000 each for the births of my three sons (I had a very high deductible on my insurance; I'm a software contractor). All went smoothly, or it would have cost at least triple that.
From the perspective of what services we got, it was insanely expensive, although less so than the $1,000 we paid to get *one stitch* in my son's lip through the ER. But from the perspective of my wife and children having the support they needed to survive the process in case of a problem, it was a fantastic bargain.
That all said, we're moving somewhere with national health care, although our actual primary motivation is to get somewhere with clean air, a good educational system, and good public transportation. (We live in the US now.)
Thank you! I was going to log in to make this point, and then I saw you've already made it, better than I would have.
Well, I just built an iPhone app (http://www.pharceapp.com) and I had to buy a MacBook Pro to do it.
I agree there's a correlation between people using Macs and people writing code for iPhones, but it's nowhere near 100%.
I don't get your point about information being stored in the black hole's horizon. What do you mean, the information is stored? The object is there, near-ish to the horizon...
And two other points about black holes. Firstly, the object doesn't "appear" to get stuck at the event horizon. From the POV of an outside observer, the object *in fact* never falls into the black hole. Part of Special Relativity is that what you see about the objects subject to relativistic effects is representative of what you'll measure about the object in any way, and hence is in every meaningful way representative of reality. The same is true of General Relativistic effects.
Secondly, objects falling towards the horizon are (usually) eventually going to fall into the hole from the POV of an outside observer, because the hole's horizon will expand as more matter gets densely packed around it. Once the neighborhood around the hole which includes the object has an escape velocity greater than light (due to more matter accreting around the hole), then the object is inside the event horizon.
Do you have any references, or even verifiable assertions, to back that up?
Er, my phone certainly does have essentially an ever-present connection to the worldwide network. And my phone is a linux machine I would have been proud to have on my desktop 7 years ago.
I'm sure there are lots of other ways to make movies without copyright protection (another poster mentions consignment), but product placement seems the most obvious to me.
I'm not arguing that copyright should be done away with, although I agree with the people pointing out that it will be insupportable within a decade or two anyway. I do think a 5 or 15 year copyright would be MUCH more beneficial to society (which is supposed to be the point, at least in the US) than our current 120 year copyright.
Of course, my opinion on what copyright should be like is irrelevant - your argument was that moviemaking is insupportable without it, which is just not true.
I'm running Debian, and all the programs built for any normal debian release are there.
Well, that is our #1 concern. We have two homeschool groups that we get together with on a regular basis, and they have several friends with whom they spend the night or have over several times a week.
In fact, my oldest is approaching 9th grade. I believe he should go to public school for high school, to prepare him to deal with other people more and so he can benefit on higher level topics from hopefully mostly learning from people who really care about their subject and can convey that interest.
I'm not sure what kind of public school you went to, but I don't remember many great experiences... how much time do you waste sitting in a classroom with nothing to do, or nothing but busywork to do? My kids go to the zoo, go to museums, the library, etc. in addition to regular desk time.
I definitely agree that it's a tradeoff, but we feel like we can manage the downsides so that the upside far outweighs it.