Growing up in Highland Park, in high school, I had some very influential teachers: I had a math teacher who taught calculus that helped me learn to be in love with mathematics; I had a chemistry teacher who inspired us to work what was in the class and to go beyond.

As a young boy growing up on the South Side of Chicago, I was inspired by the nascent space age.

I see no difference between scientific exploration and human exploration.

I think that space exploration as a broad activity is the most important things that humans can do. I've always found it fascinating, interesting, compelling, and I have a drive to go out into space.

When it comes to climate and energy, Gates is a radical consumerist. In his view, energy consumption is good - it just needs to be clean energy.

We seriously have to question the motivation of those people referred to as climate change sceptics, who are denying the evidence of human-caused climate change and preventing us from moving forward by spreading disinformation and supporting unchecked carbon pollution.

America must not abdicate its global leadership role in the climate crisis to countries like China.

But Australia faces additional regional and global challenges also crucial to our nation's future - climate change, questions of energy and food security, the rise of China and the rise of India. And we need a strong system of global and regional relationships and institutions to underpin stability.