Free Thought
goodmath | January 26, 2007 Todays pathological language is actually in the form of a challenge for you. (Isn't that
exciting?) It's a very clever numerical programming language in the vein of Conway's
href="http://scienceblogs.com/goodmath/2006/10/prime_number_pathology_fractra.php">Fractran,
called NULL. The author of NULL describes it
as a reaction to 2 and 3 dimensional languages in the Befunge tradition; NULL is a 0
dimensional language - a program is just a single point. It's quite clever in its way; the only
problem is that is that there's only one example program written in it. So the challenge is
to see if…
drorzel | January 26, 2007Matt Leifer doesn't blog all that often, but what he posts is very good. It tends to be extremely high-level stuff about foundational problems in quantum theory, mind, so it's not for the faint of heart, but if you get into that sort of thing, it's fascinating. Wednesday's post on dechoerence is no exception:
[L]et me start by defining two problems that I take to be at the heart of understanding quantum theory:
1) The Emergence of Classicality: Our most fundamental theories of the world are quantum mechanical, but the world appears classical to us at the everyday level. Explain why we do not…
drorzel | January 25, 2007I've been collecting a bunch of little news squibs from the IoP and the APS over the last week or so, and I keep saying that I'm going to do a nice long post explaining each of the experiments. And my actual job keeps eating my life, what with candidate interviews, committee meetings, class prep, and lab set-up. And, of course, those news items are becoming less current with every passing day...
In lieu of a lengthy and detailed explanation of each, then, here's a short list of physics stories that have caught my eye. If there's a great clamor for a more detailed explanation of any of these,…
jrosenhouse | January 23, 2007On the subject of basic concepts, here's an essay I orginally posted back in June. In it I try to explain what infinity is all about. It seems appropriate for this series, so I thought I would bring it back. Enjoy!
________________________________
Think for a minute about basic arithmetic. Addition is something that is done to two numbers. You take two real numbers and add them together to produce another real number. But suppose you had three numbers, x, y, and z? What does it mean to add three numbers together?
Very simple. You would begin by adding x to y. Then, you would take the…
grrlscientist | January 20, 2007The previous story about global warming has an interesting background story regarding how the data were obtained. Basically, these data (pictured, right) were the result of the 250,000 people around the world helping the Intergovernmental Panel on Climate Change scientists by downloading their software onto their home computers so they could compute a single simulation of the future.
The resulting data predict that temperatures in Britain will be about 1.2 degrees Celsius warmer by 2020 than in the 1970s, chosen as the baseline for this project. Since temperatures are already nearly 1 degree…
pharyngula | January 17, 2007This is cool: a team using distributed computing to solve the protein folding problem has put out a promotional video asking for your unused computing cycles…and along the way they explain exactly what it is they are doing.
drorzel | January 17, 2007Scott Aaronson talks sense about religion, in response to an emailer who stopped reading his quantum computing lectures because he made references to "God":
What I'm trying to say, Bill, is this: you can go ahead and indulge yourself. If some of the most brilliant unbelievers in history -- Einstein, Erdös, Twain -- could refer to a being of dubious ontological status as they would to a smelly old uncle, then why not the rest of us? For me, the whole point of scientific rationalism is that you're free to ask any question, debate any argument, read anything that interests you, use whatever…
goodmath | January 8, 2007 Now that we've gone through a very basic introduction to computational complexity, we're ready
to take a high-level glimpse at some of the more interesting things that arise from it. The one
that you'll hear about most often is "P vs NP", which is what I'm going to write about today.
So, what are P and NP?
P and NP are two very broad classes of computational problems. When we're talking about P and NP, we're talking about the intrinsic complexity of a problem - that is, a minimum complexity bound on the growth rate of the worst case performance of any algorithm that solves the problem.
P…
goodmath | January 5, 2007Today, I have something really fun and twisted for you. It's my favorite variation on
BrainF**k, called "BFM", which is short for "BrainFunct-Macro". It's a doubly-Turing-equivalent language - it's got two complete and distinct Turing equivalent computing systems in it: it's
got regular BF on the bottom... But before BF gets going to run the program,
the program is pre-processed by a complete lambda-calculus macro expander.
Basically, you start with a BF interpreter, and you observe, quite logically, that there's a
ton of repetition in a typical BF program - stuff that could be nicely…
catdynamics | January 5, 2007There is a trope in classic science fiction, where humans are "special".
We get out there, into the galaxy, and there's a bunch of aliens, and they're all Really Dumb.
So the clean cut heroic square jawed human takes charge and saves the day. Fini.
What if it is true?
Ok, I've been reading too much Alastair Reynolds recently, trying to catch up on the Conjoiner/Inhibitor series, but there is a serious issue here in looking to resolve the Fermi Paradox.
The basic issue is simple: there are a lot of planets; we think a significant fraction of these are habitable (in the narrow sense of…
goodmath | January 5, 2007 In my discussion with Sal Cordova in this post, one point came up which I thought was interesting, and worth taking the time to flesh out as a separate post. It's about the distinction
between a Turing equivalent computing system, and a Turing complete computation. It's true
that in informal use, we often tend to muddy the line between these two related but distinct concepts. But in fact, they are distinct, and the difference between them can be extremely important. In some sense, it's the difference between "capable of" and "requires"; another way of looking at it is
"sufficient" versus "…
goodmath | January 3, 2007Over at [Dispatches][dispatches], Ed Brayton has been shredding my old friend Sal Cordova.
Ed does a great job arguing that intelligent design is a PR campaign, and not
a field of scientific research. Ed does a fine job with the argument; you should definitely click on over to take a look. But Sal showed up in the comments to defend himself, and made
some statements that I just can't resist mocking for their shallow stupidity and utter foolishness.
[dispatches]: http://scienceblogs.com/dispatches/2007/01/answering_cordova_on_ids_goa…
Let's start with a mangled metaphor from [here][comment-…
clock | January 2, 2007Grand Rounds 3.15 - A Veritable Explosion of Information - now up on Musings of a Distractible Mind
omnibrain | December 30, 2006Alan Turing - the father of computing - as a snowman.
Here's some more angles of the snowturing
Ohh and don't forget the statue (surely not as exciting as the snow sculpture!)
oracknows | December 27, 2006While I am on vacation, I'm reprinting a number of "Classic Insolence" posts to keep the blog active while I'm gone. (It also has the salutory effect of allowing me to move some of my favorite posts from the old blog over to the new blog, and I'm guessing that quite a few of my readers have probably never seen many of these old posts, most of which are more than a year old.) These posts will be interspersed with occasional fresh material. This post originally appeared on January 25, 2006
I hate spammers.
On the scale of Internet scumbags, spammers rank just one notch above pedophiles (barely…
catdynamics | December 26, 2006What's a time in your career when you were criticized extremely harshly by someone you respect? Did it help you or set your career back?...
When I were a lad we used to have to walk to grad school, barefoot through the snow, up-hill both ways.
Not. I actually lived 1.5 blocks from my office, in sunny Pasadena So Cal and had a leisurely stroll through the immaculately groomed Caltech campus.
But...
...bear with me.
How I got there has some relevance to the story.
I did my undergrad in the UK, double honours in Mathemtical Physics ("Q" in the old UCCA classification). I came out of that knowing…
jstemwedel | December 20, 2006On the heels of the Hanukah meme, here's the Christmas meme, as seen at Musings of a Distractable Mind:
1. Hot Chocolate or Egg Nog?
If I must choose, nog with whipped cream (but no bourbon). I also like coffee with a slug of chocolate syrup and a shot of Peppermint Torani's.
2. Does Santa wrap presents or just sit them under the tree?
Unless it's something big and unwieldy, Santa (or his minions) wraps them, usually in paper with pictures of Santa.
3. Colored lights on tree/house or white?
Colored lights on the tree, white outside if we get to it.
4. Do you hang mistletoe?
No. A long…
goodmath | December 18, 2006This week's "Ask a ScienceBlogger" is an interesting one, but *very* tricky to answer.
The question was proposed by fellow SBer [Dave Munger:][munger] **"What's a time in your
career when you were criticized extremely harshly by someone you respect? Did it help you or
set your career back?"**
[munger]: http://scienceblogs.com/cognitivedaily/
I have to tread carefully while answering this one. It's a good question, but it involves people who *could* be reading the blog.
Overall, I've been remarkably lucky in my career. For the most part, I've had excellent
mentors who've been kind and helpful…
cortex | December 13, 2006If I was a smart man, I'd go out and invest in the stock of some robot companies. Bill Gates (yes, that one) is convinced that the 21st century will be the age of the robot:
Imagine being present at the birth of a new industry. It is an industry based on groundbreaking new technologies... But it is also a highly fragmented industry with few common standards or platforms. Projects are complex, progress is slow, and practical applications are relatively rare. In fact, for all the excitement and promise, no one can say with any certainty when--or even if--this industry will achieve critical mass…
j7uy5 | December 12, 2006Spectrolab, Inc. has announced that they have developed a way to nearly
double the efficiency of solar cells. They've done it by
creating semiconductor Dagwood sandwiches, with over 20 layers.
The basic idea is to have different layers that respond to
different wavelengths of light. This way, a greater amount of
the total light energy is captured.
The technology requires the use of a lens, or some other means of
concentrating the light. That may limit its applicability
somewhat. Still it appearto be a major advance. It
could be the one thing we needed to make solar power competitive…