Category Archives: News

Favicon Added

I know it’s nerdy, but I now have a favicon.  Cool, eh!

Quantum Foundations Resources

Since I get asked a lot, I have added a collection of links to resources on quantum foundations to the About page.  Any suggestions for additions will be gratefully received, especially if you know of any good quality popular talks that can be viewed online.

P.S.  In case you were thinking of asking, neither “The Tao of Physics” or “What The Bleep Do We Know?” are ever going to be added.


OK, it is time to announce some changes that I alluded to in comments to an earlier post.

Firstly, I have decided to take an invitation to blog over at the new FQXi community pages.  At the moment, I’m just doing this on an experimental basis for a couple of months and I am fully intending to bring my foundational musings back over here at the end of it.  One reason for this is that the FQXi blogs currently work a bit more like forums than a regular blog and they are missing a number of key features, e.g. rss feeds, that I think are important.  Still, I think it will be worthwhile as I will potentially be able to reach a wider audience of people working on fundamental physics who would not read this blog.  For now, I will be posting links here when I write a FQXi post, so you can keep track of them.  The first one on ontological vs. epistemic wave-vectors can be found here.

Secondly, I have decided that my strategy to keep this blog purely focussed on foundations and maintain another blog about technology in academia is not really working.  For one thing, I can hardly ever be bothered to write posts on the other blog and it is certainly not the case that I have groundbreaking new things to say about foundations every day.  Therefore, I think it would be an improvement if I allow myself to write about a wider array of subjects in fundamental science and other things that I think are interesting.  Rest assured that foundations will remain the focus, so this will not become just another general physics blog and you will definitely never find me writing any posts about my pet dog.

Site Updated

I have updated my publications and my CV.

Universitas Magistrorum et Scholarium

I have arrived back in Waterloo to start my new hybrid University/Perimeter Institute position.  It’s been quite a long break from posting, because – strangely enough – having two affiliations means I had to do twice the amount of paperwork to get myself set-up this time.  As much as I loved being at PI, it is nice to be back in a university and to have some small role in educating the next generation of quantum mechanics.

Over the break, Andrew Thomas has left a few comments about the role of decoherence in interpretations of quantum theory in my Professional Jealousy post.  There are some who think that understanding decoherence alone is enough to “solve” the conceptual difficulties with quantum theory.  This is quite a popular opinion in some quarters of the physics community, where one often finds people mumbling something about decoherence when asked about the measurement problem.  However, there are also many deep thinkers on foundations who have denied that decoherence completely solves the problems, and I tend to agree with them, so we’ll have a post on “What can decoherence do for us?” later on this week.

To clarify, I’m not going to argue that decoherence isn’t an important and real physical effect, nor am I going to say that it has no role at all in foundational studies, so please hold your fire until after the next post if you were thinking of commenting to that effect.

Swanky New Website

You will have noticed that I have given my website a complete facelift. You can now access it at as well as the old address.

New preprints

I recently posted two new articles on the arXiv.


Visiting CQC Cambridge

I am currently visiting the Centre for Quantum Compuatation at the University of Cambridge.  I’ll be back in  Waterloo on 6th January 2007.

Reorganizing my web empire

I have been busy reorganizing my mini-web empire, as you can see if you look at my swanky new website. Part of this has to do with the fact that I occasionally want to write about things other than the foundations of quantum mechanics, but I don’t want to burden the loyal readers of Quantum Quandaries with such trivia. Therefore, I have started two new blogs.

The first is my announcements blog. This mainly exists to serve the news feed on my website, and it will contain announcements every time I submit a paper to the arXiv, update a paper, get published, visit somewhere for a long time, unify quantum theory with general relativity etc. I won’t announce the details of every paper I write on this blog as well, unless I think the paper is interesting for people into quantum foundations (actually, on that topic you might like this recent paper and also this one). I hope you will appreciate my goal of always keeping this blog strictly on topic, bucking the trend to use blogs mainly for shameless self promotion. Of course, you are welcome to become a regular reader of my announcements blog as well, but I am under no illusions that it will appeal to anyone except maybe my mother.

Secondly, I have started another blog called Academic Tech. This should satisfy my inner geek, as it is about the uses of computers, technology and the net in academia. If you want to know about software and web tools that you can do amazing things with then you might want to read it. However, quantum theory still holds the vast majority of my attention, so articles for this blog will probably be posted much more frequently.

Shameless self-promotion

As is traditional with physics blogs, it is time to indulge in a spot of shameless self-promotion of my own work. I have just posted a paper on quantum dynamics as an analog of conditional probability on the arXiv. This is about a generalization of the isomorphism between bipartite quantum states and completely positive maps, that is often used in quantum information. The main point is that it provides a good quantum analog of conditional probability, so it may be of interest to foundations-types who like to think of quantum theory as a generalization of classical probability theory.

The paper was completed in somewhat of a hurry, to get it out in time for the conference on Foundations of Probability and Physics in Vaxjo taking place this week, where I am due to give a talk on the subject. No doubt it still contains a few typos, so you can expect it to get updated in the next couple of weeks. Any comments would be appreciated.

More on the Vaxjo meeting to follow soon.