One of the reasons I got interested in physics was because I have always been interested in the “question of free will.” Physicists don’t like to talk about free will much, especially since learning what quantum theory has to say about free will seems to put you smack dab in the middle of the measurement problem in quantum theory. In many ways, what I’m most interested in is not the question of free will, which I find too often to be an overly anthropocentric enterprise, but more the question of the determinism / indeterminism of physics. But the “free will question” has played a major role in shaping why I choose to do physics.
As so the question becomes: why was I interested in free will? Most of it is surely due to my older sister Cathy. You see Cathy is a little person. No one knows exactly what syndrome she has, but it causes her to be lopsided (one arm and leg shorter than the other), she has very poor vision and hearing, and has some mental difficulties. This makes it all sound really bad: which it is definitely not because Cathy is an amazing light in our family. She works at the local library in Yreka, loves to listen to her John Denver tapes, she loves to watch Jeopardy, and is, in general, a very happy person who brightens the lives of her many many friends.
But if you grow up with a sister like Cathy you can not avoid thinking about why you ended up the way you are and why she ended up the way she is? Was it fate and totally out of the hands of human choice? Science, and physics in particular, is the path one is reduced to in order to possibly find any answer to such a question. While we can argue forever whether reductionism to fundamental physics is central to answering this question, there can be no doubt that understanding the role of determinism and indeterminism in physics will have a profound impact on our view of this question.
On the other hand, Richard Feynman said: “Do not ask yourself… ‘how can it be like that?’ because you will lead yourself down a blind alley in which no one has ever escaped.” I don’t think Feynman was talking about science here: scientists spend much of their time answering how it can be like that. I think Feynman was talking about asking for reasons which somehow satisfy us as humans: answers that will give us short sentences explaining why. There are simple important questions which might have simple concise explanations, but finding these explanations seems impossibly difficult. And this is how I find myself coming full circle. Because this point of view, that there are simple questions for which there aren’t answers which can be found in a short time (and once we find them, we’ll know we’ve answered the question) is basically the complexity class NP. Which is computer science. The field, besides physics, which I most deeply admire.
So fate not only made me a physicist, but it also made me a computer scientist.
And the only question left remaining is whether or not it was destiny that I was born at a time when I could participate in the unfolding of the field of quantum computing, which merges physics and computer science like never before?
Time is Change
Random thoughts at 2 a.m.: I have been playing poker all night and it’s 2 a.m., so this post may make no sense when I wake up in the morning…
If we take a single spin 1/2 particle, and put it in a magnetic field, the spin precesses. We can use this to form a sort of clock by preparing the spin in a particular state and then measuring the spin along a particular direction. Of course this clock only has two value 0 or 1. So a universe with a single spin has a single bit clock. But this clearly doesn’t approximate our univerese. What do we need? More spins! So add more spins. Now we get clocks that count in some binary fashion. So we can more accurately measure a time with more spins. Look: if we add more spins we gain accuracy in keeping track of time.
Now look at relativity. If our clock has a very small mass, and it is all that exists in the universe, we will read a time which is nearly that of clocks which are infinitely distant. But add more clocks and the mass increases. Now we have a clock with a larger mass. And the larger mass will cause the clock to run slow compared to a clock at infinity. But this means that such a clock can be used to measure the time at infinity much more accurately.
Are these two effects really one and the same?
**Update** Yep, it’s morning and this makes no sense. Although the two effects scale similarly in the non-relativistic regime.
Bow Down Before Giblets
I will tell you once and only once that Fafblog is the best blog currently running. In fact it is so good that I think it may be written by someone with the last name of Wiggin.
The Book Queue
Packing for the move to Santa Fe has begun! So far I have 28 boxes of books stacked in my room. Everytime I look at them my back hurts.
Beside my bed I keep a queue of books that I am reading or have recently purchased and am planning on reading. Here is the final state of my South Pasadena book queue:
- Cannery Row by John Steinbeck
- Counter-Clock World by Philip K Dick
- Adventures in Group Theory by David Joyner
- Infinite Jest by David Foster Wallace
- The Amazing Adventures of Kavalier & Clay by Michael Chabon
- Quicksilver by Neal Stephenson
- The Metaphysical Club by Louis Menand
- Cosmicomics by Italo Calvino
- A People’s History of the United States by Howard Zinn
- Gravity’s Rainbow by Thomas Pynchon
- The Best Time Travel Stories of All Time edited by Barry Malzberg
- Turing (A Novel About Computation) by Christos H. Papadimitriou
- Modern Elementary Particle Physics by Gordon Kane
- The History of Western Philosophy by Bertrand Russell
- The Year’s Best SF 8 edited by David G. Hartwell
- American Gods by Neil Gaiman
- Great Sky River by Gregory Benford
- Tides of Light by Gregory Benford
- Furious Gulf by Gregory Benford
- Sailing Bright Eternity by Gregory Benford
- A Brief History of Economic Genius by Paul Strathern
- Go To by Steve Lohr
- Earthshaking Science by Susan Elizabeth Hough
- Perdido Street Station by China Mieville
- The Years of Rice and Salt by Kim Stanley Robinson
- Dhalgren by Samuel R. Delany
- Against Infinity by Gregory Benford
- Eyes of the Calculor by Sean McMullen
- Starfarers by Poul Anderson
- Slow Learner by Thomas Pynchon
- The Alchemy of Finance by George Soros
- A Random Walk Down Wall Street by Burton G. Malkien
- Charisma by Steven Barnes
- A Fire Upon the Deep by Vernor Vinge
- Foucault’s Pendulum by Umberto Eco
- Schild’s Ladder by Greg Egan
- Cyteen: The Betrayal by C.J. Cherryh
- The Structure of Scientific Revolutions by Thomas S. Kuhn
- Atomic Physics: an exploration through problems and solutions by Dmitry Budker, Derek F. Kimball, and David P. DeMille
- Ilium by Dan Simmons
- Fahrenheit 451 by Ray Bradbury
- Fire in the Mind: Science, Faith, and the Search for Order by George Johnson
- Prayers to Broken Stones by Dan Simmons
- Are Universes Thicker than Blackberries? by Martin Gardner
- Norstrilia by Cordwainer Smith
Ack! What a queue! Some of these books are in various states of being read, and a few, like Gravity’s Rainbow, I’ve read before, but are on a second read-around.
I have a month off and these all go in two special boxes and will travel with me on my trip around the west. How many will I get through before I start at SFI? Let the betting begin at zero.
What Light Through Yonder Nite Sky Breaks
Last night we went to the boondocks (or as close an approximation as we could get to the boondocks, living in L.A.) to watch the Perseid meteor shower.
“For my part, I know nothing with any certainty, but the sight of the stars makes me dream.” – Vincent van Gogh
Driving back, I was thinking about how amazing it is that we can even do cosmology! What an amazing setup that we can look back in time by collecting light from more and more distance objects. Our universe didn’t have to be this way: it could have been action at a distance, instantaneous transformer of information, etc. And then how would we do cosmology?
Alta Is Not Your Grandpa
Alta has finally built a top-to-bottom high speed quad. I believe this is morally equivalent to the breaking of the Seventh Seal.
If I Were a Censor
Banned: use of the word “final” and “theory” in the same sentence.
Notice the Dates
On arXiv today we find quant-ph/9804008:
from : Andrew Gray [view email]
Date (v1): Thu, 2 Apr 1998 18:51:30 GMT (27kb)
Date (revised v2): Sun, 8 Aug 2004 18:25:20 GMT (0kb,I)
A Design for a Quantum Time Machine
Authors: Andrew Gray
Comments: This paper has been withdrawn
This paper has been retracted, for obvious reasons.
Oye! Harsh!
Elections destroy any positive karma…today I thought of a new bumper sticker:
Reagan died because of research Bush denied.
Ouch! Oye!
Baez Decrypts
John Baez’s description of Hawking’s talk at GR17 is the best scientific commentary on the talk I’ve come across. It’s a notch above all of these descriptions I’ve read which are of the form: I don’t like Euclidean quantum gravity, but I do know [insert other theory of quantum gravity here], and we already knew [insert claim here]. Which is fine for learning about [insert claim here] but doesn’t really tell me anything about what Hawking was trying to say!