The joy I find in locating a power plug which is not in use at an airport really scares me.
Power! Now I can work on my laptop on the plane AND at the airport. Oh joy!
Words Are Confusing
Stop calling me a buffoon. I am not a buffoon! Oh, what is that word you are saying?
Main Entry: bof·fin
Pronunciation: ‘bä-f&n
Function: noun
Etymology: origin unknown
chiefly British : a scientific expert; especially : one involved in technological research
Quantum Problem
Richard Feynman:
We always have had a great deal of difficulty in understanding the world view that quantum mechanics represents. At least I do, because I’m an old enough man that I haven’t got to the point that this stuff is obvious to me. Okay, I still get nervous with it … you know how it always is, every new idea, it takes a generation or two until it becomes obvious that there’s no real problem. It has not yet become obvious to me that there’s no real problem. I cannot define the real problem, therefore I suspect there’s no real problem, but I’m not sure there’s no real problem.
Whenever I read this, I think, “poor quantum theory.” It seems that many of us have a problem with quantum theory, but quantum theory, it has no problem with us!
"No Country for Old Men" by Cormac McCarthy
Some of you may noticed that I’ve added a little reading list to the sidebar. I’m going to try to blog a little about these books as I finish them, and archive them on the book tab above. The first book I’ve completed on this list is Cormac McCarthy’s new book “No Country for Old Men.”
“No Country for Old Men” is the story of a sherriff, drugs, money, and death. Lots of death. Which might make you think that it’s just some sort of pulp novel, but, no, not even close.
The first thing that strikes you about the book is the writing style. Take, for example, this paragraph from page two:
They say the eyes are the windows to the soul. I don’t know what them eyes was the windows to and I guess I’d as soon not know. But there is another view of the world out there and other eyes to see it and that’s where this is goin. It has done brought me to a place in my life I would not of thought I’d of come to. Somewhere out there is a true and living prophet of destruction and I don’t want to confront him. I know he’s real. I have seen his work. I walked in front of those eyes once. I wont do it again. I wont push my chips forward and stand up and go out to meet him. It aint just bein older. I wish that it was. I cant say that it’s even what you are willin to do. Because I always knew that you had to be willin to die to even do this job. That was always true. Not to sound glourious about it or nothin but you do. If you aint they’ll know it. They’ll see it in a heartbeat. I think it is more like what you are willin to become. And I think a man would have to put his soul at hazard. And I wont do that. I think now that maybe I never would.
(Note that those missing punctuation marks aren’t my typos!) Cormac has a true gift for storytelling and this book is beautiful in its simple use of language. Many times these days you find authors whose entire style seems to be aimed just to shout out “Look at me! Look how many words I know, and how strangely I can construct literary labryths!” Cormac has none of this. Instead the novel is filled with descriptions and turns of phrase and dialogue that are among the best I’ve ever read. No, this is not his greatest novel (I’m comparing it to the Border Trilogy, I’ve not read Blood Meridian.) But it is certainly an excellent book. It has about it an eerie silence, a sort of hush which settles over dramatic horrible events in the novel, in a way which is hard to explain and which is probably worth the price of the novel alone. Highly recommended. But then again, I’m biased 😉
A Serious Version
A resubmission, quant-ph/0507189. Much, much, more serious:
Title: |0>|1>+|1>|0>
Authors: S.J. van Enk
Comments: A more serious version, almost 2.36 pages, but still an unnormalized title
Note: replaced with revised version Thu, 11 Aug 2005 17:17:52 GMT (6kb)
Neither an Analog Guy in a Digital World Nor a Digital Guy in an Analog World
From The Register: Are our brains analog, or digital?.
To which I ask, what are these “analog” and “digital?” Useful approximations, both, but are they really properties that systems can have? Can we scientifically say a system is analog? Analog to me means a continuous parameter space. We can do finer and finer grain experiments, but at each step of the way, is not our best model, one which is digital? And what of digital? Do we really believe that our frothing, complicated world allows states which in discrete states, or are these discrete states but approximations, finite lifetime certainty in an uncertain world? Will we ever know a digital system is really not just a long lived analog system? Both these concepts, to me, are approximations, and debating the difference between them, seems beside the point of science. How, exactly the brain works, and how we think about the nether-land between these two extremes, now that is what I find interesting.
With severe apologies to Frost:
Some say the world is analog
Some say it’s digital
Looking through the physics catalog
I side with those who favor analog.
But if I was a little experimental
I think I know enough of science
To say that of the world digital
Is also possible
And may even be elemental .
Quantum Algorithms People
I’m putting together a talk right now and I was trying to make a list of people who have worked in the past or are now working in the field of quantum algorithms. Below the fold is the list I have right now. If anyone in the know spots someone I miss please let me know (and apologies in advance for those who I’ve left out!) This list is a modified verision of a list of people stolen from Wim van Dam’s home of the homepages. (Thanks for doing the hard work Wim!)
Continue reading “Quantum Algorithms People”
What a Dance
Triple asterodial system reported in Nature.
I'm a Cult/Occult
Pharyngula points to a site where you can enter your url and get your censorship category. According to this authority:
The URL
https://dabacon.org/pontiff
is currently rated as:
Category 7 – Cult/Occult
The real question, of course, is which am I? A cult or occult?
Warning: Negative Information Ahead
The paper quant-ph/050562 has been out for a while now, and I kept meaning to comment on it, but somehow never got around to it. Now it’s hit big time. This month in Nature has the article article, “Partial Quantum Information” by Michal Horodecki, Jonathan Oppenheim and Andreas Winter, along with the a nice intro written by Patrick Hayden. Johnathan Oppenheim also has a really really good popular explanation here . Normally I would write a little explaining this result, but Patrick’s intro and Johnathan Oppenheim’s web page are so good that, well, you should just get your info from the horse’s mouth (so to speak.) But I will tell a story related to this work.
When I was an undergraduate I spent the summer between my junior and senior years working for Nicholas Cerf and Chris Adami. Specifically I was working on trying to find quantum algorithms to efficiently solve NP-complete problems. I call this my summer spent banging my head against the wall. Not a very effective summer, research wise, but I learned a lot about quantum computing over that summer. Anyways, Cerf and Adami worked for Professor Steve Koonin (I think they were both postdocs, but I’m not sure if I remember this correctly.) When I was a freshman at Caltech, I was wandering around campus a few weeks after I showed up on campus, and I saw these two guys having a really animated conversation outside on a bench. One of the guys was really really tall, and the other guy was fairly short and looked EXACTLY like Steve Rick Moranis. I mean exactly. This being Los Angeles, and me being a hick from the sticks, I was only a few feet away from asking the shorter guy for an autograph, when I chickened out. Which is a good thing, because it turns out that this guy was none other than Steve Koonin! (Koonin, by the way, was an undergrad at Caltech. He went to MIT and got his Ph.D. in three years. Three years! Now that’s the power of a Caltech education 😉 ) Some of you will find it funny that the second guy on that bench, I later learned, was Jeff Kimble. Many of you will know Professor Kimble from his demonstration of a quantum logic gate in a cavity QED system in 1995 (as well as a plethora of other cool cavity QED results.)
Back to the story at hand! So I worked for Cerf and Adami. At the time, they had this really strange paper (see here and here) where they talked about negative quantum information. In particular they noticed that if you took the conditional Shannon entropy and converted it over to the quantum mechanical conditional von Neumann entropy, then while the classical conditional entropy was always positive, the quantum mechanical conditional entropy could be negative. For example, a Bell pair had a conditional von Neumann entropy of negative one (bit). This was strange, and one question that their work raised is what exactly this negative number might mean. Another question along these lines arose a little later when the conditional entropy showed up in the quantum channel capacity. Here, however, when the conditional entropy showed up as negative, the capacity was set to zero (creating the so-called mutual information.) Having a negative capacity for a noisy quantum channel didn’t seem like a reasonable thing! What the current work describe above does is to actually given an operational meaning to this mysterious quantity the conditional quantum entropy. By operational, this means that those negative numbers now have an intpretation in terms of a protocl which operates at a rate related to those negative numbers. Read the article to see how this all works out. It is very nice. The author promise a more detail paper (with a date stamp of 2005, so soon) which I’m looking forward to.
(Thanks to Saheli and Grant for pointing me to Johnathan’s web page. Grant, who is a student in the class I am teaching, emailed the class mailing list with links to the negative quantum information web pages, and the comment “It’s possible we may leave this class knowing less than when we started!!!” Hopefully, the same effect hasn’t happened to you after reading this post 😉 )