Slashdot Mirror

A quick bit of searching online reveals the Stanford Virtual Human Interaction Lab website which contains links to a variety of information on the project. Here's a PDF of the paper in The Chronicle of Higher Education on the topic. And although it has a flash video, here's another Stanford article on the same topic.

In response to the bit about logical positivism: Logical positivism would, more than anything I think, label this question as meaningless. However, my understanding is that logical positivism has been mostly discredited, largely thanks to Quine. His "Two Dogmas of Empiricism" attempts to break down the analytic/synthetic distinction that the verification principle so heavily relies upon. Furthermore, it seems impossible to formulate the verification principle in such a way that it gets rid of metaphysical questions such as "What is math?" and hang on to the terminology required to do science.

Carnap gave up on it, convinced by Quine. Wittgenstein, the often cited father of the movement, completely rejected it in his later years.

However, your point with regards to pragmatism I think is important, though not insurmountable. These questions are important for determining what we consider legitimate mathematics and thus how we should proceed in the study of mathematics. Consider the foundational questions in the first half of the 20th century: Frege's, Russel's, Zermelo's, and Hilbert's programs all had wildly different consequences in terms how one should proceed in mathematics (though they all tried to preserve the main body of it). The most concrete example of this is the bizarre machinery that is required to do calculus: have you ever tried to convince anyone that there are have to be different levels of infinity in order to do that which physics takes as central? When Cantor (and Newton for that matter) first came up with their ideas, they were laughed at! What they showed was not considered legitimate mathematics at first, though it turned out to be crucial for modern science.

Furthermore, these questions help decide what mathematics' place in the world: what exactly are we trying to accomplish with it? What is mathematics studying and what predictive powers should we expect from it?

I don't know if this will convince anyone these questions are worth asking, but hopefully they will make people curious. The deeper one goes, the stranger things become. For instance, the Banach-Tarski theorem says that one can break up a ball into a whole bunch of points, and then reassemble them into two balls identical to the first! And this is a theorem, a direct result from ZFC! Or (and this screwed with my head for a long time) Skolem showed that any first order set theory satisfiable by a nondenumerable model is also satisfiable by a coutable one (note: I made that all jargony so that people unfamilar with set theory won't know what I am talking about; dangerous idea if you don't know/believe Cantor's stuff and very easy to misinterpret if you don't know set theory to an okay extent. Even then, takes a while...)

Second, my answer to the question: Mathematical structure is discovered, but such abstractions do not exist as universals/forms/etc. Mathematics is the study of abstract structure. This structure is inherent in/a result of the causal properties of objects in the universe. There are no forms/universals, just systems of objects and causal relations, and isomorphisms between these systems.

(I'm a trope nominalist when it comes to properties: http://plato.stanford.edu/entries/tropes/. Further, I believe that the resemblance classes central to the theory are defined by causal similarity. I think this is possible because causal properties ARE qualitative properties. Sorry, just wanted to answer any phil majors up front :).)

But you never get real numbers that way. Integer, yes. Fractions, yes. Floating point numbers, representation limits and all, yes. But no reals. Reals require additional axioms.

And that is a weakness of your theorem prover. The nq in NQTHM aka Boyer-Moore theorem prover stands for non-quantified. Quoting from the manual:

Nqthm does not support, especially well, attacks on theorems in set theory or about such nonconstructive entities as the real numbers.

Set theoretic formulations for integers exist and no theorem prover is ever going to give you any insight into what is discoverable and what is not. so, please stop spreading that BS around.

Knuth pretty much is a super-genius so you can see why he might have the point of view attributed to him. It's informative to visit his home page... check out his CV http://www-cs-faculty.stanford.edu/~knuth/vita.html

Better yet start here http://www-cs-faculty.stanford.edu/~knuth/index.html Take a look at the number of refereed papers and unrefereed papers. Whatever you do don't click on the link labeled "(don't click here)"!!!

Knuth pretty much is a super-genius so you can see why he might have the point of view attributed to him. It's informative to visit his home page... check out his CV http://www-cs-faculty.stanford.edu/~knuth/vita.html

Better yet start here http://www-cs-faculty.stanford.edu/~knuth/index.html Take a look at the number of refereed papers and unrefereed papers. Whatever you do don't click on the link labeled "(don't click here)"!!!

I have the facts to back it up.

1) The Duelfer Report, clearly stating that there was no connection between the Baathist movement and al Qaeda, and just the dysfunctional remainings of a weapons program.
2) An interview with the Number Two of al Qaeda, al Zawahiri.
3) The history of the Baath Party as a secular, socialist and nationalist Arab movement.
4) The biography of the Number Two of Iraq, Tariq Aziz, who is no muslim at all, but a Chaldean Catholic. So whatever Iraq was, it was surely not ruled by islamistic jihadists.
5) All the alleged evidence brought before the war being debunked, from the Yellow Cake Story to the British dossier on Iraq's WMD program being just a rip of of Ibrahim al-Marashi's doctoral thesis.
6) The fact that Donald Rumsfeld even created his own intelligence unit because the CIA was still unable to uncover anything supporting, what the administration was believing to be true.
7) The fact that Colin Powell's address at the U.N. didn't convince neither Hans Blix, head of the U.N.'s inspectors of Iraq's WMD program nor the "old Europeans", with Germany's Minister for Foreign Affairs, J.Fischer, publicly stating his doubts.

He's still very useful and productive. He's currently churning out new material for The Art of Computer Programming. This includes the new MMIX 64-bit RISC architecture computer that replaces the aging MIX computer and new material on combinatorial algorithms.

I agree with you on unit tests. I find them invaluable to ensure I have a piece of code working properly, and to ensure that I don't introduce errors when I make changes. Probably anyone that didn't write The Art of Computer Programming finds them useful as well.

He's still very useful and productive. He's currently churning out new material for The Art of Computer Programming. This includes the new MMIX 64-bit RISC architecture computer that replaces the aging MIX computer and new material on combinatorial algorithms.

I agree with you on unit tests. I find them invaluable to ensure I have a piece of code working properly, and to ensure that I don't introduce errors when I make changes. Probably anyone that didn't write The Art of Computer Programming finds them useful as well.

There's a relevant quirk of Stanford University employee policy. For Stanford academic employees, software usually is considered "work for hire" and an "institutional work", with Stanford holding the copyright. But books and papers are considered to be the property of the author. (Policy on this changed in the late 1990s; there's a long history here, primarily involving the founding of Sun and Cisco.) However, Stanford permits the creator to place a work in the public domain, unless external funding prohibits this.

Knuth's code is open source. But his books are not.

It predates it.

And the philosophy is different, literate program is essentially embedding the code in the documentation. Doxygen is more about embedding documentation in the code.

So doxygen gives you fancy comments and a way of generating documentation from them and from the code structure itself. CWEB lets you write the documentation and put the code in it deriving the code structure from the documentation, sample cweb program: http://www-cs-faculty.stanford.edu/~knuth/programs/prime-sieve.w

Literate programming is more suited for "dense" programs, which surprise, surprise is the type of stuff Knuth does.

I think that you're misunderstanding the example provided, and literate programming as a result. Literate programming is a language agnostic technique of writing a program essentially as a paper or book, where the book provides a fairly complete description of the behavior of the code, algorithms used, expected input formats, etc. For instance, if you were to use this technique when writing a compiler you could detail the language you'll be compiling alongside the code that will handle that portion of the parsing/interpreting/translating. On his website (Knuth's programs page) he presents a number of programs written using CWEB, C combined with TeX to generate both compilable C code and a fully documented program. He's also written books using this technique, specifically "TeX: The Program" and "METAFONT: The Program", both make use of Literate programming, and both programs are written in Pascal.

Oh come on, the only people on the ARPAnet back in 1978 were the nerdiest of the nerds. What were they going to do, throw their pocket protectors at the guy?

For reference, the people complaining about the spam on that page are her, him, and also this guy

I'm sure the DEC guy was quaking in his boots.

http://www.pamusb.org/ & http://srp.stanford.edu/ndss.html Granted this can be manipulated in other ways but is safe from keyloggers.

Heck, I do it for free.

True for programmers as well: if the system makes it hard to program secure applications, it won't be done. There's a nice paper (pdf) that explains why programmers don't use the principle of least privilege (hint: with the current POSIX API, it's too complex and non-portable, and thus only a few programmers do it, basically in an ad-hoc fashion).

Oh ye of no sense of humor, and no appreciation for a good bit of wordplay....

And if you're really feeling pedantic, it depends on when you learned it and where you learned it from. Even Donald Knuth uses nybble.

Hello iamhigh, Thousands of businesses/schools/organizations are already participating in the FAH project. May I suggest you visit the folding forum where your questions can be viewed and answered by knowledgeable F@h donors. http://foldingforum.org/ Here's the project's main page: http://folding.stanford.edu/ Regards,

http://fah-web.stanford.edu/cgi-bin/main.py?qtype=userpage&teamnum=11108&username=DRAGONWEEZEL

Read Steve Jobs' Stanford commencement address, and then decide if the question is even valid.

No philosopher would have agreed to let this article be published as is. What you might call it is "brain scientists doing naive pseudo-philosophy". Among actual philosophers, there is a lively debate about whether free will and determinism are compatible; this article basically assumes that it's somehow accepted that they aren't, and therefore that if we can prove decisions are deterministic, this disproves free will. That position, termed incompatibilism, is far from universally held. For the opposite, compatibilism, see this article. Famous people to hold that point of view include David Hume, and more recently, Daniel Dennett (along with a lot of less-famous academic philosophers).

The story assumes that everyone agrees determinism (or at least some sort of predictability coming close to determinism) implies lack of free will. This has been debated for centuries, and is far from agreed upon; if anything, the position that free will and determinism (or something like it) are compatible, termed compatibilism, is probably the more widespread position in contemporary philosophy.

See the Stanford Encyclopedia of Philosophy article for more detail than you could possibly want. Among writers likely to be familiar to many Slashdotters, this is the position Daniel Dennett takes.

- I wish neuroscientists would stop getting free press just for saying they observed someone doing something, and (gasp!), there was brain activity. I mean, what did they expect? Unless these people are closet dualists, of course...

- Hume basically killed the silly notion that somehow randomness or chance could give us "extra" free will. Imagine that you have access to some source of perfect randomness, say a radioisotope sample whose individual decays you can observe. This is useful, but basically it just gives you the difference between a pseudo-random number generator and a truly random number generator. This isn't an insignificant difference, mind you, but surely that's not where the difference between volitional and forced deeds lies!

- I think many people who think they object to determinism actually object to lawfulness, or even to the idea of a universe that makes sense. This is why the same problem crops up in theology where people endlessly contrast divine predestination and human free will. What such people really want is magic - just about any problem can be resolved if you allow for mumbo-jumbo and squint hard enough.

- Any chance Hollywood will ever make a film about championing Compatibilism?. In that context, I've always enjoyed Schopenhauer's formulation of human free will:

" you can do what you want, but you can't want what you want"

I am not the type that needs to do big Excel Solver sheets or Matlab simulations while on the go. Why carry more than twice the weight for what amounts to a bigger power draw and little marginal value?

My sentiments exactly. I've got a dual-core desktop at work (which would be idle 90% of the time if I weren't running two instances of Folding@Home). The most intensive thing I do with my laptop is when I remote-desktop to my work box.

I'm beyond low-end. I got an old PII laptop from Retrobox (now Intechra) for under $150 (it would be worth about $10 now, I think), and put Puppy Linux on it. It's a little clunky, but it does everything I need, and it's half the size and weight of any of the new Vista-capable laptops that sell for $1000+.

TCP is mostly controlled by round trip time measurement and window size. Response to packet loss is a backup mechanism. If packet loss were the primary control mechanism, TCP would never work.

It's much better to throttle back before packet loss occurs, since any lost packet has to be resent and uses up resources from the sender to the drop point. Since the main bandwidth bottleneck is at the last mile to the consumer, the drop point tends to be close to the destination.

Don't trust the "Clean Slate Internet" project too much. That started as telco-supported scheme to move more functionality to the telcos so they can add charges for specific services, like cell phone providers.

The tradeoff between the number of examples used and the complexity of the classification algorithm is already a much-explored branch of machine learning known as Computational Learning Theory or PAC (Probably Almost Correct) Learning. Bounds on the expected error rate of a system can be given as a function of the complexity of the classifier and the number of examples seen. Typically, the number of examples needed to guarantee with probability 1 - delta that the error is lower than some threshold gamma is lower bounded by 1/gamma^2 * log(k / delta), where k is (hand-wavingly) the complexity of the classifier family. See http://www.stanford.edu/class/cs229/notes/cs229-notes4.pdf for a more formal treatment.

unless the factors (birthday, clear sky..) are correlated to the explanatory variables they are just noise. something behaves deterministically if somebody can (predict)determine the result in advance. here is an interesting book about propability and (theory of) science: http://csli-publications.stanford.edu/site/1575863332.html .it is also viewable online. don't forget that if you are correct then it simply is not possible to make predictions in this context and this is emirically observable. not in this special case since they are talking about counterfactuals but the principle remains the same. for a treatment of counterfactuals see http://bayes.cs.ucla.edu/BOOK-2K/ .

I don't think Don Knuth would be too willing to hit the road and read "The Art of Computer Programming" to an audience

You might be surprised.

Glad I could be of service. BTW I think your "periodic table" comment is an apt description of the situation. I think what's missing is dynamics.

Rather than google, if you want to keep up with Lisi (or anyone else's) papers, I suggest the SLAC Spires database. For instance, this is Lisi's "exceptionally simple" paper. Click on the "Cited..." to get a list of citations. This is updated daily from journal sources, and more importantly arxiv.org. This database generally has topics of relevance to high-energy physics, astrophysics, and gravity. Another good database is the NASA Astrophysical Data Service, here's Lisi's "exceptionally simple" paper on ADS. I warn you however, everything retrieved this way will be technical in nature.

This is what the web was invented for, by the physics community at CERN no less, and now days all our papers are freely available before they are sent to journals, and the public is welcome to read them. Indeed, I despise the "ivory tower" perception and think we are much better off by having outsiders look at what we're doing. I just with the popular press would wrap their heads around the idea of citing primary sources with a hyperlink....but I digress.

-- Bob

Well, according to this source 9.5kg of H is equivalent to 25kg gasoline which also requires a 17kg container, so you get about 118kg to about 42kg, or almost tipple. Now most of that weight penalty can probably be made up by the fact that Honda has a fuel cell stack that weighs only 67kg which is way less than an IC engine.

Dunno, seems like some earlier research on a similar idea might be more useful - the plenoptic camera. Just one big CCD and a lot of math. CCDs are getting bigger all the time, most people don't really need all the pixels they have already, so sure, why not use some of those pixels for depth. But sticking with one CCD will probably be cheaper. http://graphics.stanford.edu/papers/lfcamera/

Light Field Photography with a Hand-Held Plenoptic Camera. A regular camera with a special lens that emulates the "thousands of tiny lens" from the thing in the article. Includes pictures and a video of how the focus of images taken with the camera can be adjusted as a post processing step.

Cool, but old story.
I can't believe there was no mention of their web site on either this Slashdot posting or the article.

Watch the movie!

http://graphics.stanford.edu/papers/lfcamera/
http://graphics.stanford.edu/papers/lfcamera/lfcamera.avi

Cool, but old story.
I can't believe there was no mention of their web site on either this Slashdot posting or the article.

Watch the movie!

http://graphics.stanford.edu/papers/lfcamera/
http://graphics.stanford.edu/papers/lfcamera/lfcamera.avi

http://graphics.stanford.edu/papers/lfcamera/

For anyone interested in more than the press release, here's a link to their paper, "A 3MPixel Multi-Aperture Image Sensor with 0.7m Pixels in 0.11m CMOS."

The work they've been doing on lightfields is pretty innovative. I first heard about this when Robert Scoble interviewed Marc Levoy and got some cool demos into the video. I've done some lightfield experiments with my trusty Nikon D40, it's interesting to see what new ideas you can come up with for using a camera once you get into it.

I would recommend http://www-cs-faculty.stanford.edu/~knuth/mmix.html

A great way to train your brain.

1. It's on a public website
2. It's 4 1/2 years old
3. On this page(section Crisis in Scientific Publishing), where I found it, Prof. Knuth clearly indicates that he's releasing his letter publicly.
4. I never got as far as the postscript when I read it, or if I did read it, I didn't remember it
5. It's relevant to the point at hand, which is why he released it.

not a physicist, but nearly as clever:
Stanford algorithms expert, Donald Knuth(pdf) doesn't like nasty closed-up journals either. As he said when I asked him about it; "Who are you? How did you get in my house?".

There is little doubt that Turing would have been disappointed by the state of play at the end of the twentieth century.