Without the hot air

Whether he’s developing a means of communicating in any language with any muscle, debunking energy myths by establishing how the numbers add up, or analysing the fractal Fibonacci spirals of a cauliflower and the internal workings of his Psion organiser, David MacKay, Professor of Natural Philosophy at the Department of Physics Cavendish Laboratory, has an extraordinary diversity of interests.

For the past decade, one of his principal research projects has been Dasher, a machine-learning system that allows individuals to write without a keyboard. The user creates sentences by navigating through letters in a continually unfurling alphabetical display, effectively navigating in the library that contains ‘all conceivable books’. Navigation can be controlled by any muscular movement, even breathing or just gazing, while the software consults an archive of training text to predict what the user might write next. Dasher is available as open-source software free to anyone wishing to use it.

David MacKay’s research group is also developing Opengazer, free software that can use the images from an ordinary webcam to estimate the direction of your gaze. Funding has recently been granted from the European Union as part of AEGIS, a worldwide consortium led by Sun Microsystems to build accessibility support into the next generation of rich internet applications and mobile devices. Combined with Dasher, the aim of Opengazer is literally to allow users to write with their eyes.

Sustainable Energy – Without the Hot Air, David MacKay’s contribution to the energy debate, was driven, as he explained, ‘by outrage at inaccurate statements made about sustainable energy, together with embarrassment that I didn’t know the numbers myself.’ The resulting book provides a straight-talking, honest look at the figures: Can we live on renewables? What are the reasonable options for producing energy? How can we make a big difference to reducing our demand? ‘By helping people understand just how big the energy challenge is,’ he explained, ‘I hope to promote constructive conversations about energy, instead of the perpetual Punch and Judy show of anti-wind and anti-nuclear. We need a plan that adds up.’

What would others be surprised to learn about you?

I love and cherish my 15-year-old Psion 3A Personal Digital Assistant. I have at least five of the same model and when they break down I take them apart and carry out surgery to fix them. I’ve also twice played in the World Ultimate Frisbee Championships (we lost) and the temperature of my home is usually 13°C in winter, although perhaps this isn’t surprising about me, as turning down your central-heating thermostat is one of the best energy-saving things you can do.

Have you ever had a Eureka moment?

My Eureka moment was realising that you could take an existing data compression idea called arithmetic coding, turn it on its head by visualising it on a computer screen, and achieve the goal of helping someone to communicate using a single muscle.

What’s the best piece of advice you’ve ever been given?

‘Friends come and go, enemies only accumulate.’ I’m not sure how good I’ve been at following this advice but I’m hoping that I’m improving with age.

What motivates you to go to work each day?

My main motivation is to understand things. The reason I love this job is I’m free to work on anything I want to. I can choose fun things, often serendipitously. Dasher resulted from a random conversation on a bus with a colleague who was mocking the size of the keyboard on my Psion; we brainstormed on how we could come up with a communication solution that doesn’t assume writing is about pushing buttons or using a pen. By the end of the bus journey, we’d named Dasher (for its effortless speed) and I’d started writing the first prototype.

What is your favourite research tool?

It has to be Google. For all my recent work on energy I’ve learned so much useful and authoritative stuff in a fast and efficient way using this search engine.

What will the future look like in 2050?

One possible future is that we’ll have lots of green, energy-efficient systems. But another possible future is a world of energy wars over the diminishing fossil fuel resources. Realistically, I don’t think we can rely on inventions still to come; the responsible thing is to imagine that today’s technology is what we’ve got to work with. If we go for strong energy efficiency measures and a really big building programme of green energy systems then it will be possible to carry on a lifestyle similar to today’s. It’s possible but it’s not going to be easy.