Tuesday, October 31, 2006

Happy halloween!

Happy Halloween! I have to share this excellent piece of artwork by a PhD student friend of mine with too much time on his hands:

*sniff* There are no more episodes of Six Feet Under for me to watch...

Last night I finished watching the final season of "Six Feet Under". Wow. Does anyone know any other TV series that remotely compares to "Six Feet Under" for quality and quirkiness?

Update: I forgot to mention that Clair has a Sarah Blasko song playing on her stereo in the background in one of the final scenes of the final show of "Six Feet Under". How cool is that?

Monday, October 30, 2006

First snow?

Yesterday I posted some pics that I took last week. According to this weather website, which is pretty reliable, it might snow here on Thursday (Donnerstag). That was a really short Autumn.

Friday, October 27, 2006

QIP 2007

More physics posting! Weird eh?

Michael Nielsen, one of the organizers, has requested that post this info with regard to QIP 2007 conference:

QIP 2007
The tenth QIP (Quantum Information Processing) Workshop is to be held in Brisbane, Australia, from January 30 through February 3, 2007.

QIP covers theoretical aspects of quantum information science, including quantum computing, quantum cryptography, and quantum information theory.

  • The deadline for abstract submission for contributed talks (long and short) and for posters is 4 November, 2006.
  • The deadline for early bird registration is 24 November, 2006.
  • Some partial support available for students and postdocs will be available (see the website).

Full details are available at the workshop website:

Links to past QIP workshops (including programs) are available at the website. Note that this year's program will follow a similar format to QIP 2006, with approximately 10 invited talks, and 30 contributed talks.

Hope to see you in Brisbane in 2007!

I really hope that I can make it to this conference because I'm sure it's going to be a lot of fun and there'll be a lot of great physics and computer science being discussed. Did I mention that Brisbane was my home town so I'm more than qualified to say that it is a great city to visit.

I suggest that you go a few days early or stay on for a few days after the conference and take the opportunity to visit some of the fantastic beaches and islands in the vicinity of Brisbane!

Wednesday, October 25, 2006

Can we make explanations of fault tolerant quantum computing fault tolerant?

Danger! Danger! Physics post ahead!

On the arXiv last week there was a paper written by a well known physicist, Dyakonov, criticizing the idea of fault tolerant quantum computing. Now, the theory of fault tolerance is one of the biggest results in the field of quantum computing. Basically, it is this theory that tells us that a quantum computer might be able to be built even though quantum systems are very hard to control. Recently there has been a fair bit of discussion about this paper over at The Quantum Pontiff's place [see Laugh therapy and A PR battle worth fighting?].

The main idea of fault tolerance goes something like this - if we want to make an ideal quantum circuit of a certain size then it is possible to simulate this circuit using components that are imperfect by constructing a circuit that is a bit more complex than the original, ideal, circuit. Now, the key thing is that there is a tradeoff between how complex this simulation circuit is and how bad its constituent components are. The threshold theorem tells us that if the imperfect components aren't too bad, then it is possible to use them to simulate your desired circuit in such a way that doesn't get so complicated that the whole exercise is a waste of time.

The big question in fault tolerance is how bad can these devices be before quantum computing becomes a waste of time? Which is related to the really big question: whether there are any quantum systems that can be manufactured that satisfy the detail of threshold theorem? At the moment, it seems that there are no physical restrictions that say that we cannot build a fault tolerant quantum computer. However, the technology required to build a fault tolerant quantum computer still seems to be quite a way off.

Now, everything I've said so far seems pretty easy. There is a lot of devil in the detail of all this. The math required to prove that we can build these simulation circuits - or more correctly error correcting circuits - is pretty intense. What's more, I've simplified the language that is normally used to explain the theory of fault tolerance. The literature that one must go through in order to get a thorough understanding of the topic is also very intimidating.

What's more, the theory of fault tolerance seems pretty counter-intuitive to physicists who have spent a lot of time playing with physics. Mostly, quantum systems don't behave nicely. Well, that isn't true, they behave nicely but not in a way that looks immediately nice for quantum computing. You see, quantum computations are made up out of a series of unitary operations. In principle all ideal quantum mechanical systems evolve via unitary operations. In practice, no quantum systems are ideal. The theory of error correction and fault tolerance was derived to show that there should exist quantum systems that have properties that allow us to create ideal operations on a subsystem while generating a whole lot of junk on the rest of the system.

There is a lot of physics underlying why it should be possible to make systems that can perform error correction. The problem is that a lot of it is buried under mountains of math. As a field we need to confront this problem, like Dave mentions here. Most of the language of quantum computing is, with good reason, phrased in the language of computer science. Maybe we need to reach out more to the rest of the physics community by better discussing how quantum computing works and also the implications of things like the fault tolerance theorem for our understanding of physics?

Tuesday, October 24, 2006

Does anyone actually like Clear Type?

So, like the sucka that I am, I downloaded IE7 for my laptop. IE7's default is to use Microsoft's fancy new "cleartype" technology for LCD screens. Cleartype is meant to smooth over all of your fonts and this is meant to look a lot better on LCD screens. On my screen it just looked kinda blurry. Basically, there was no setting that made it look good. What's more, if I could get IE7 to look OK I couldn't get fonts in other programs to look nice, especially in my TeX editor and in Thunderbird.

Did anyone else have this problem or have my eyes just been fried from way too much time in front of my laptop?

Saturday, October 21, 2006

There are some things about the Australian character that I love

This story is one of them. The major off ramp from the freeway into the CBD of Brisbane was shut this week because a stress fracture was found. This caused traffic chaos as one of the major roads in the city was shut down without prior planning.

What do the police union do about this? They take the opportunity to have a Friday lunchtime game of street cricket on one of the affected streets.

I think that's totally awesome.

Friday, October 06, 2006

Funniest thing on the internet ever?

Okay, maybe it isn't. But Iggy Pop's tour rider is pretty damned funny. I personally liked the lighting requirements. This is a must read. Be warned, it is 18 pages long and hard to stop reading...

Wednesday, October 04, 2006

Goddamn "the Lovers" rock

My old ulti team, the UQ Lovers, came second at this year's Australian Uni championships. By all accounts, they not only played well but they played with a lot of spirit and very high blood alcohol levels - thus keeping that Lovers feeling that started back in '04. Well done guys, I wish I could have been there!

What do complexity theorists, snow, and pontiffs have to do with one another?

The answer is Innsbruck. Next week Dave Bacon (the Quantum Pontiff) and Scott Aaronson (Shtetl-Optimized) are coming to visit our institute here in Innsbruck. It will be a lot of fun to see Dave and Scott again. Hopefully I can get the two of them into a half decent stoush!

Oh yea, it snowed in the hills today. This should make Dave happy, if it keeps snowing he might have half a chance of going skiing next week...

Tuesday, October 03, 2006

Rudd on religion and politics

Tim over at Road to Surfdom took a little swipe at Kevin Rudd yesterday for his attempts at selling the ALP as a party that has it's values firmly rooted in Christian philosophy. Tim seems to be mostly concerned with what he perceives to be attempts by politicians from both sides of the aisle to Americanize Australian politics.

Well, I took a little swipe back because I'm not so sure that this is what is happening. While not wanting to strawmanize Tim, I think that he thinks that (God I love that phrase) Rudd's attempts to sell the ALP as a natural choice for Christians will just lead to a war of escalation for the Christian vote between the ALP and the Coalition. I think that there is a real risk of this, but I'm not convinced that it is the only way that this can play out.

I think that over the last 10 years we've seen the right in Australia frequently play the Christian moral card in order to get votes. I think, arguably, that the most blatant proponent of this, at the Federal level, is Tony Abbott. Since the last election we have seen Abbott, and a number of his allies, try to enforce his dogmatic view of Christianity upon the electorate. Most notably through the whole RU486 debate of last year. I fear that if the ALP does nothing about this, and tries to "keep secular" then they will find that the Coalition will not only have moved to the Christian right, but they will have dragged a significant portion of the electorate over to their position.

Kevin Rudd seems to be, quite rightly (sorry, bad pun), pointing out that there are many aspects of Christian philosophy that Tony Abbott, and more generally the Liberal Party, are not a champions for. Christianity is not about the abortion debate. Christianity is about euthanasia. Christianity is not about the War on Drugs, nor the War on Terror. Christianity is a complex religion, with many competing views. Many of these views are held in common with both the Liberal and Labor parties. No single political party can claim absolutely that they represent the "Christian" view, though it is my own personal opinion that the ALP better represents Christian views on social justice than the current Coalition government. This seems to be also where Kevin Rudd is coming from.

I guess the whole point of this post is to say that politics and religion have always been intertwined. Politics is about decision making and that cannot be done in a vacuum. Neither the left nor the right can claim any religion as their own, and any attempt to do so should be blocked by vigorous argument.