Paul Davies

Is there anything science should not try to explain? Science is knowledge and knowledge is power - power to do good or evil. Sometimes ignorance is bliss.

Cancer touches every family in one way or another. As other diseases are brought under control, cancer is set to become the number one killer, and is already in epidemic proportions worldwide.

In science, a healthy skepticism is a professional necessity, whereas in religion, having belief without evidence is regarded as a virtue.

General relativity is the cornerstone of cosmology and astrophysics. It has also provided the conceptual basis for string theory and other attempts to unify all the forces of nature in terms of geometrical structures.

Scientists are slowly waking up to an inconvenient truth - the universe looks suspiciously like a fix. The issue concerns the very laws of nature themselves.

Cosmologists have attempted to account for the day-to-day laws you find in textbooks in terms of fundamental 'superlaws,' but the superlaws themselves must still be accepted as brute facts. So maybe the ultimate laws of nature will always be off-limits to science.

For me, science is already fantastical enough. Unlocking the secrets of nature with fundamental physics or cosmology or astrobiology leads you into a wonderland compared with which beliefs in things like alien abductions pale into insignificance.

Science, we are repeatedly told, is the most reliable form of knowledge about the world because it is based on testable hypotheses. Religion, by contrast, is based on faith. The term 'doubting Thomas' well illustrates the difference.

Imagine a civilisation that's way in advance of us wants to communicate with us, and assist us in our development. The information we provide to them must reflect our highest aspirations and ideals, and not just be some crazy person's bizarre politics or religion.

Man-made computers are limited in their performance by finite processing speed and memory. So, too, the cosmic computer is limited in power by its age and the finite speed of light.

To expect alien technology to be just a few decades ahead of ours is too incredible to be taken seriously.

Clearly, some creative thinking is badly needed if humans are to have a future beyond Earth. Returning to the Moon may be worthy and attainable, but it fails to capture the public's imagination. What does get people excited is the prospect of a mission to Mars.