The nature of existence or the future of the universe are questions that scramble the brain of most of us, but Gerry Gilmore grapples with these mysteries every day.
The Christchurch-born professor of experimental philosophy at Cambridge University's Institute of Astronomy, has one of the top astronomy jobs in the world
and is in New Zealand on a lecture tour.
Professor Gilmore left in 1979 after graduating from Canterbury University with the first astronomy doctorate awarded in this country.
His work is to try to define the nature of dark energy, a force scientists now believe is accelerating the universe and which, if we can one day get a handle on it, will reveal our ultimate fate.
Dark energy makes up about 70 per cent of the universe. About 25 per cent is an unknown, transparent matter and the remaining 5 per cent of matter we recognise, such as planets, the moon, the sun - and us.
"Dark energy is really weird. It's acting against gravity and all mass and it's really only become clear in the last year just how much of this stuff there is," Professor Gilmore says. "We don't know what it is but it is a force ripping apart space and time. It's speeding up the universe."
As a scientist, he believes the millions of dollars being spent on things like the troubled Discovery mission grounded through technical problems, are just "an expensive form of tourism" and the money would be better spent on space-travelling robots.
"You don't have to feed them or bring them home when the batteries go flat," he says.
So, what is the latest thinking on the biggest question of all: are we alone?
In another decade or so, we may start to get some answers to that, he says, because we are searching in a much cleverer way.
The next generation of telescopes, based on Earth, are designed to seek out Earth-like planets about 20 light years away and measure their colour over a period of time.
"We will see whether there are seasons, with spring growth they will change colour and we'll know whether there is life."
Professor Gilmore will give the 2005 Einstein Lecture at Victoria University tomorrow.
