Michael Nielsen

I’ll be speaking about open science at events in Berlin, New York and Boston over the next week. Here’s my current schedule of public and semi-public events:

• Berlin, Friday 16 September, 5pm, event at the Freie Universität of Berlin: more details
• New York, Courant Institute Colloquium, NYU, Monday 19 September, 3:45pm.
• New York, event organized by the Coles Science Center and the NYU Libraries Information Futures Group, Monday 19 September, 6:30pm: more details
• Boston, Harvard, Colloquium at the Institute for Theory and Computation in the Center for Astrophysics, Thursday 22 September: more details.
• Boston, MIT Physics Colloquium (MIT only), Thursday 22 September: more details

I’ll be in Europe for the next couple of weeks, and will be giving several talks about open science. Here’s a rough schedule of where I’ll be and when:

• London (Aug 30 – Sep 6): The Royal Society, Nature, Science Online London, Imperial College, and (TBC) the London Hackspace.
• Manchester (Sep 6-7): U Manchester School of Computer Science
• Oxford (Sep 8-9): Oxford Internet Institute, and Oxford University Scientific Society
• TBA (Sep 10-13)
• Barcelona (Sep 13-14): Universitat Pompeu Fabra
• Berlin (Sep 14-15): TBA

Please come and say hello if you’re at one of the events!

I’m interested in adding more events to my schedule, so if you’re interested in having me speak, or would like to arrange for me to attend some sort of meetup (perhaps with a group), please let me know (mn@michaelnielsen.org).

I’ll add more details over the next couple of days, as details become available.

I’m pleased to say that I’ll be giving a public talk about open science in San Francisco, next Wednesday, June 29, at 6pm. The talk is being hosted by the Public Library of Science, and there will be wine, beer and cheese after the event.

The talk is entitled “Why the net doesn’t work for science – and how to fix it” [*]. Here’s my abstract for the talk:

The net is transforming many aspects of our society, from finance to friendship. And yet scientists, who helped create the net, are extremely conservative in how they use it. Although the net has great potential to transform science, most scientists remain stuck in a centuries-old system for the construction of knowledge. I will describe some leading-edge projects that show how online tools can radically change and improve science (using projects in Mathematics and Citizen Science as examples), and will then go on to discuss why these tools haven’t spread to all corners of science, and how we can change that.

The talk will be thematically similar to my recent talk about open science for TEDxWaterloo, but will go much deeper into the challenge and promise of open science.

For more details on the talk, including the address and a map, please see the PLoS blog. Please RSVP to rshah@plos.org if you plan to attend.

Hope to see you there!

[*] The title is a riff on the wonderful phrase “making the web work for science”, which I believe originated with James Boyle. For a recent talk on the subject by Boyle, see here (see also Creative Commons’ work on science).

I’ve started a new blog, on data-driven intelligence. In future, this is where technical posts like my Google Technology Stack posts will go. There are two posts up:

• A post describing Pregel, Google’s system for implementing graph-based algorithms on large clusters of machines. In addition to describing how Pregel works, I give a toy single-machine Python implementation which can be used to play with Pregel. The code is up on GitHub.
• Sex, Einstein, and Lady Gaga: what’s discussed on the most popular blogs. I crawled 50,000 pages from Technorati’s list of the top 1,000 blogs, and determined the percentage of pages containing words such as “sex”, “Einstein”, “Gaga”, and many others. The results were entertaining.

The blog, of course, has an RSS feed.

I’ve posted to YouTube a series of 22 short videos giving an introduction to quantum computing. Here’s the first video:

Below I list the remaining 21 videos, which cover subjects including the basic model of quantum computing, entanglement, superdense coding, and quantum teleportation.

To work through the videos you need to be comfortable with basic linear algebra, and with assimilating new mathematical terminology. If you’re not, working through the videos will be arduous at best! Apart from that background, the main prerequisite is determination, and the willingness to work more than once over material you don’t fully understand.

In particular, you don’t need a background in quantum mechanics to follow the videos.

The videos are short, from 5-15 minutes, and each video focuses on explaining one main concept from quantum mechanics or quantum computing. In taking this approach I was inspired by the excellent Khan Academy.

The course is not complete — I originally planned about 8 more videos. The extra videos would complete my summary of basic quantum mechanics (+2 videos), and cover reversible computing (+2 videos), and Grover’s quantum search algorithm (+4 videos). Unfortunately, work responsibilities that couldn’t be put aside meant I had to put the remaining videos on hold. If lots of people work through the existing videos and are keen for more, then I’ll find time to finish them off. As it is, I hope the incomplete series is still useful.

One minor gotcha: originally, I was hoping to integrate the videos with a set of exercises. Again, time prevented me from doing this: there are no exercises. But as a remnant of this plan, in at least one video (video 7, the video on unitary matrices preserving length, and possibly elsewhere) I leave something “to the exercises”. Hopefully it’s pretty clear what needs to be filled in at this point, and viewers can supply the missing details.

Let me finish with two comments on approach. First, the videos treat quantum bits — qubits — as abstract mathematical entities, in a way similar to how we can think of conventional (classical) bits as 0 or 1, not as voltages in a circuit, or magnetic domains on a hard disk. I don’t get into the details of physical implementation at all. This approach bugs some people a lot, and others not at all. If you think it’ll bug you, these videos aren’t for you.

Second, the videos focus on the nuts-and-bolts of how things work. If you want a high-level overview of quantum computing, why it’s interesting, and what quantum computers may be capable of, there are many available online, a Google search away. Here’s a nice one, from Scott Aaronson. You may also enjoy David Deutsch’s original paper about quantum computing. It’s a bit harder to read than an article in Wired or Scientific American, but it’s worth the effort, for the paper gives a lot of insight into some of the fundamental reasons for thinking about quantum computing in the first place. Such higher-level articles may be helpful to read in conjunction with the videos.

Here’s the full list of videos, including the first one above. Note that because this really does get into the nuts and bolts of how things work, it also builds cumulatively. You can’t just skip straight to the quantum teleportation video and hope to understand it, you’ll need to work through the earlier videos, unless you already understand their content.

The basics

• The qubit
• Tips for working with qubits
• Our first quantum gate: the quantum NOT gate
• The Hadamard gate
• Measuring a qubit
• General single-qubit gates
• Why unitaries are the only matrices which preserve length
• Examples of single-qubit quantum gates
• The controlled-NOT gate
• Universal quantum computation

Superdense coding

• Superdense coding: how to send two bits using one qubit
• Preparing the Bell state
• What’s so special about entangled states anyway?
• Distinguishing quantum states
• Superdense coding redux: putting it all together

Quantum teleportation

• Partial measurements
• Partial measurements in an arbitrary basis
• Quantum teleportation
• Quantum teleportation: discussion

The postulates of quantum mechanics (TBC)

• The postulates of quantum mechanics I: states and state space
• The postulates of quantum mechanics II: dynamics
• The postulates of quantum mechanics III: measurement

Thanks to Jen Dodd, Ilya Grigorik and Hassan Masum for feedback on the videos, and for many enjoyable discussions about open education.

If you enjoyed these videos, you may be interested in my forthcoming book, Reinventing Discovery, where I describe how online tools and open science are transforming the way scientific discoveries are made.

Continuing the theme of my last post, I’ve now put my old survey notes on fermi algebras and the Jordan-Wigner transform up on GitHub.

The Jordan-Wigner transform is an amazing tool. It let’s you move back and forth between two seemingly very different ways of describing a physical system, either as a collection of qubits, or as a collection of fermions. To give you an idea of the power of the Jordan-Wigner transform, in his famous 1982 paper on quantum computing, Richard Feynman wrote the following:

could we [use a quantum computer to] imitate every quantum mechanical system which is discrete and has a finite number of degrees of freedom? I know, almost certainly, that we could do that for any quantum mechanical system which involves Bose particles. I’m not sure whether Fermi particles could be described by such a system. So I leave that open.

As shown in the notes, once you understand the Jordan-Wigner transform, the answer to Feynman’s question is obvious: yes, we can use quantum computers to simulate systems of fermions. The reason is that the Jordan-Wigner transforms lets us view the fermi system as a system of qubits which is easy to simulate using standard simulation techniques. Obviously, the point here isn’t that Feynman was silly: it’s that tools like the Jordan-Wigner transform can make formerly hard things very simple.

The notes assume familiarity with elementary quantum mechanics, comfort with elementary linear algebr, and a little familiarity with the basic nomenclature of quantum information science (qubits, the Pauli matrices).

I’m releasing the notes under a Creative Commons Attribution license (CC BY 3.0). That means anyone can copy, distribute, transmit and adapt/remix the work, provided my contribution is attributed. The notes could be used, for example, to help flesh out Wikipedia’s article about the Jordan-Wigner transform. Or perhaps they could usefully be adapted into course notes, or part of a review article.

Several years ago I wrote a set of introductory notes (pdf) about expander graphs, an exceptionally useful concept from computer science. I’m not an expert on expanders, but the notes were more popular than I anticipated, and still get a surprising amount of traffic. As an experiment, I’ve put the LaTeX source for the notes up on GitHub, under a Creative Commons Attribution license. That makes it trivial for anyone interested to fork, remix and adapt the notes. I don’t imagine a sudden outbreak of expander graph remixes, but maybe they’ll be useful to someone.

Many people have contributed striking logos for the Polymath wiki. It seems to me that there’s now enough suggestions to have a good conversation about which logo to use, and (perhaps) how the logos could be improved, if that’s what people want. I suggest having that conversation at the talk page for the logo.

Over the next few months, I’ll be giving talks to help raise awareness of open science in many cities in North America and Europe: what open science is, what the benefits are, what the obstacles are, and how we can overcome those obstacles.

If you’re interested in having me speak in your city, I’d like to hear from you. Please drop me an email at mn@michaelnielsen.org.

As a sampler of the kind of talk I can give, see my talk at TEDxWaterloo. That talk was for a general audience – I’m also interested in speaking to audiences of scientists in all disciplines, to librarians, to people in technology companies and organizations, to people in government. I’d also love to meet people everywhere who are working on open science projects!

My speaking is being supported through a generous grant from the Information Program of the Open Society Institute, with assistance from York University.

As a result of this support, there will be no speaker’s fee. Furthermore, if your organization does not have a budget to support travel, that should not be a barrier.

The following talk gives a short introduction to open science, and an explanation of why I believe it’s so important for our society. The talk is intended for a general audience, and was given at the very stimulating and enjoyable TEDxWaterloo event held in the Waterloo region, just outside Toronto, in March of 2011.