THERE is nothing like looking at a galaxy billions of years old or the light from a star that has long ceased to exist as it destroyed itself in a supernova explosion to give you some perspective about your place in the universe.

Since winning the Nobel Prize for physics I've been fortunate to travel the country sharing my passion for the mysteries and beauty of the universe with people from all walks of life.

Last night I conducted one of my more unusual lectures when I invited our federal politicians on to the roof of Parliament House in Canberra for a bit of stargazing.

We set up telescopes on the rooftop and took a tour of the planets, stars, nebulae and galaxies - the awe-inspiring objects that make up our universe.

I talked our political leaders through some of the ideas that have helped build my career, such as what stuff really makes up our universe; what happened to the universe in the past; and what is going to happen in the future.

We pondered the imponderable questions - "what happened before the Big Bang" and "if the universe is expanding, what is it expanding into?" We even considered life on other planets.

But what's really important in explaining my work is not what I think and what I know, it's how I, and other scientists, think.

Last night was a great opportunity for our leaders to leave the structure and constraints of politics and indulge their curiosity. It was a chance to move beyond Question Time, and to imagine, explore and play with ideas - to understand the process of discovery.

You see, science is not about being 100 per cent right and showing other people are 100 per cent wrong - it's about having ideas, putting them to the test and extending our collective understanding of our world. It's our most powerful way of thinking, where the answers to questions are judged by the painstaking collection of evidence, not by our preconceptions and prejudices.

Science and politics do not always have an easy partnership. Politicians talk in absolutes, they use their skills of communication for persuasion - they are often driven by ideology and the short-term imperatives of maintaining public support.

Scientists are different beasts. We question everything, we never prove theories, we just attempt to disprove them until they exist beyond doubt, and even then waves of questioning continue.

Our work is peer-reviewed, analysed, replicated and refined. It is no surprise that science is sometimes deemed 'too hard' for politics - it never gives black-and-white answers.

So science is often sidelined as some abstract concept rather than an essential tool for making better decisions. You only have to look back at the climate debate to see these issues in action. Politicians and the public alike remain confused by the complex debate over the finer points of how we model the Earth's climate.

Despite the vast majority of experts endorsing the view that human activities are causing the Earth's climate to change, there remain scientists who attack this prevailing view, and this will never change, no matter how strong the evidence is. Scientists are trained to challenge everything.

But this does not mean we know nothing, and we cannot afford to have the widely established climate science outcomes treated as just "one side of the argument" against what is often uninformed opinion latching on to the skepticism inherent to our discipline.

Politicians need expert bodies of scientists that they can trust, who can given honest assessments of what we know - and what we don't know.

This week is a big week for science. Science Meets Parliament brings together some 200 of Australia's top scientists and puts them face to face with the country's leaders in Canberra.

It's a much-needed opportunity for our profession to walk the corridors of parliament house and engage with the nation's decision-makers. While last year's Science Meets Parliament was over-shadowed by attacks on science, including death threats against scientists, this year the story is much more positive.

As I've engaged with the public after receiving the Nobel Prize I have been heartened by the enthusiasm of people around the country to understand science and what we scientists do.

The public understands our message to the politicians this week: For the benefit of the nation, Australia needs to have science front and centre in the public debate.

Here are three important things I would like to see:

MORE evidenced-based policy making - each proposal should consider the best available evidence and be nuanced by the political considerations of the day - not the other way around;

MORE scientists in government - we don't have to have a parliament full of lawyers and political practitioners. More diversity of backgrounds would strengthen our democracy, and this does not just include MPs but also advisers and government officials; and

WE need a steady hand when it comes to funding science.

Science is a long-term investment and feeding it one year and starving it the next will lead to a poor return. We need to nurture a love of science in schools, keep students engaged and interested enough to become not just the scientists and Nobel Prize winners of tomorrow, but citizens able to thrive in an increasingly sophisticated world.

I hope last night starts a conversation about getting our leaders to see the world from outside their bubble and better appreciate how science can contribute. Maybe our MPs will continue to reach for the stars years after this night has passed.

Professor Brian Schmidt was awarded the 2011 Nobel Prize in Physics

Originally published as We need fusion of science and politics