Paul, Paul, Paul

No Paul, you’ve got it wrong. What this downtown property is good for is not a biotech center, but a new research university, a.k.a. the Washington Institute of Technology

Searching for Bobby Fisher

One of the cool results of computer science which I recently learned is Levin’s universal search. Suppose you have a function f from a set X to a set Y. Many problems in computer science ask for you to invert this problem, i.e. given a y in Y, find x such that f(x)=y (there may be multiple such x’s but let’s not worry too much about that let’s just say you want to find an x such that f(x)=y.) Further lets assume that we have an efficient method for evaulating f(x). Thus, we may efficiently test whether a possible solution, x, satisfies the desired f(x)=y. OK, so that’s the problem. How do you solve it?
Well here is what Levin proposed. Consider running all possible programs which can solve this problem. We will do this serial, but with the time spent running each program which is proportional to 2^(-l(p)) where l(p) is the length of the program p. So we will be running shorter programs more often than we are running longer programs. There is a program q, which is the fastest program for solving our problem. This program runs in time T(q). Eventually our program will execute this program and get the correct result. How long does this take? A quick calculation shows that this time is at works 2^(l(q)) (T(q)+Tv) where Tv is the time to verify that the answer is correct (not included in T(q)). Thus, up to 2^(l(q)) the program is the fastest possible. Think about a class of programs now: notice that we will have produced an algorithm for this inversion problem which is, up to this huge multiplicative constant optimal. If we were to use big-O notation, this constant would be hidden and we would say assymptotically we have the most efficient algorithm!
Needless to say, the multiplicative constant DOES matter and in most cases is ridiculously large. But the story doesn’t end here. Recently Marcus Hutter has shown how to make this multiplicative constant 5 (Hutter’s work also solves a broad classes than the one described above.) What’s the catch this time? The catch this time is that there is an additive constant which is huge!

A Strange Candidate

In today’s LA Times there is a strange write in candidate, Gerald Busch.

REPORT FROM THE FRONT:
OSAMA SETTLEMENT AGREEMENT
WHAT HE WILL DO:
HE WILL CALL FOR A STAND-DOWN IN ALL JIHAD. (NO GUARANTEE OF SUCCESS) ON OR BEFORE 10/05/03 OSMA (sic) WILL TRAVEL W/PLANS TO NEW YORK ON 10/07 FOR TRIAL (UNDER USA LAWS) FOR ACCACK ON 9/11.
WHAT HE WANTS
1. ALL USA TROOPS OUT OF AFGHANISTAN AND TALIBAN BACK, IF THAT IS WHAT THE AFGHAN PEOPLE WANT.
2. ALL USA TROOPS OUT OF IRAQ AND SADDAM BACK, IF THAT IS WHAT THE IRAQI PEOPLE WANT.
3. USA ASSISTANCE TO ANY ISLAMIC COUNTRIES BE ONLY WATER AND SEWER PROJECTS FUNDED INTO ISLAMIC BANKS (NO MILITARY OR WEAPONS).
4. SHARIA BANKS BE RECOGNIZED AND ACCEPTED AND SUPPORTED BY BANKING SYSTEM IN THE USA.
(LOANS THROUGH ISLAMIC BANKS=NO INTEREST)
DURING MY MEETING WITH THE OTHER SIDE I DISCOVERED THE SUBLIMINAL SURVIVAL NEED OF THE VAST MAJORITY OF ALL CLASSES OF PEOPLE LIVING IN ISLAMIC 3RD WORLD WANT THE GOD DIRECTED AND DECISIVE DISCIPLINE OF SHARIA LAW, AS AMENDED W/ IMPROVING ECONOMIC CIRCUMSTANCES OF LIVE IN/BY COUNTRY. FREEDOM AS DEFINED IN THE WEST IS NOT WANTED BY THE MAJORITY OF ISLAM AT THIS TIME.
WHAT SAY – GRAY? ARNOLD? GEORGE?
CAN WE END THIS WAR?
CALIFORNIA ELECTION PROMISE:
IF YOU ELECT GERALD BUSCH FOR GOVERNOR I WILL SHARE POWER AND RESPONSIBILITY W/GREAT STATESMAN GRAY DAVIS AND THE EXCEPTIONAL HUMAN BEING ARNOLD SCHWARZENEGGER…EQUALLY

My favorite part is where he has to clarify that Arnold is indeed a human being.

Evolving Evolving … Evolving Evolution

One of my favorite ideas is that the “theory of evolution” is a self-referentially robust. By this I mean that the “theory of evolution” itself can undergo “evolution” and this strengths the theory of evolution (in the sense that theory is more consistent with experiment and history.)
Consider now genetic algorithms where you want to evolve a program to carry out a task. Then we can also talk about evolving the way in which we implement the genetic algorithm which will evolve the program to carry out the task. Well, once you’ve gone to one level of recursion, why not continue on down this path? We can evolve the program which is evolving the genetic algorithm for the program which solves the problem. It seems intuitively clearly (and there are some papers on this, I believe) that (Evo)^(Evo) > Evo, i.e. evolving a program to evolve programs is better than simply evolving a program. So it is interesting to consider (…((Evo)^(Evo))^….^(Evo)). What is the power of evolution recursed?

Rainier Wolfcastle

Clipped from a New Yorker article on Mr. Schwarzenegger (thanks to a tip from Patrick Hayden)

In the “Pumping Iron” series, which chronicles events leading up to and including the Mr. Olympia contest of 1975, there are intimations that Schwarzenegger’s ultimate goal, absurd as it would have seemed at the time, was power. “I was always dreaming about very powerful people—dictators and things like that,” he soliloquizes at one point in the original film. “I was just always impressed by people who could be remembered for hundreds of years or even, like Jesus, being for thousands of years remembered.” In “Raw Iron,” he recounts another dream: “Me being a king and standing on top of a mountain—and there was no room left for anybody else up there, O.K.? Just for me.” Later, a fellow-bodybuilder teases, “Arnold, when are you running for President?” He shoots back, “When Nixon gets impeached.” And in “A Portrait” Butler recounts a conversation he had in a taxi with the actress Candice Bergen a few months after the Whitney show. Bergen is insisting that bodybuilding, and Arnold, has peaked. “I disagree,” Butler replies. “It’s here to stay, and Arnold is going to be the Governor of California one day.” (Bergen, hooting with laughter, retorts, “And one day Ronald Reagan will be President.”)

All Hail King Schwarzenegger!

Who is Watching Who?

Okay. I promise. This will be my last time travel post for a while. But interestingly, the day after my paper appeared I got a hit on this blog from an ARDA internet address. Of course if I were ARDA I would pay attention to any claims of algorithmic speedups. So if I disappear tomorrow, you’ll know what happened. Of course, this could just be my good friend Tom Scott, who does who knows what for the Army, but if it is I’d rather not know so that I can keep my paranoia at a peak level.
Note added: Wired has changed the introductory sentence of this article. Where it now says “futurist” it used to read “time travel believer” (or “time travel afficionado”…well at least it had the words “time travel” in it)

Wesley Clark

Following up on my follow up to my time travel paper, there is an article on Wired describing comments Wesley Clark made about traveling faster than the speed of light. Seems everybody’s favorite four star general believes deep down in his heart that faster than light travel is possible. My first reaction, being a scientist and all, was “Great, Clark is some kind of crazy crank!” But I thought about this a bit and I think I’ve come to completely the opposite conclusion. I mean, does anyone really think George Bush even knows that traveling faster than the speed of light does not appear to be possible according to modern physics? Second, it was impressive that Clark claimed that he has argued about this with “physicists” and realizes that his belief is nothing more than an unsupported faith. My guess is Shrub would think a physicist is someone who is good at making fizzy beverages. Not to mention Shrub and his cohorts rampant political overrunning of scientific oversight (see this page for details.)

Followup on Time Travel

David Deutsch emailed me with nice comments and suggestions about my just posted paper. I told him the funny story behind the paper.
A few years ago I was watching a NOVA program about time travel and closed timelike curves. On watching the program I thought: “hmm, I wonder if quantum circuits always give you self-consistent evolutions?” After thinking about the problem for a few days, I was able to hack out a proof. Only then did I decide to go look in the literature to see what others had done. There I discovered Deutsch’s 1991 paper and found the result I had hacked out. The scary thing was how close our two proof were (I seem to recall even the symbols we used were identitical!) Getting deja vu when writing a paper on time travel is really spooky.