Quotes from Paul Davies

Astonishingly, in spite of decades of research, there is no agreed theory of cancer, no explanation for why, inside almost all healthy cells, there lurks a highly efficient cancer subroutine that can be activated by a variety of agents - radiation, chemicals, inflammation and infection.

Most research into life's murky origin has been carried out by chemists. They've tried a variety of approaches in their attempts to recreate the first steps on the road to life, but little progress has been made. Perhaps that is no surprise, given life's stupendous complexity.

The vast majority of terrestrial species are in fact microbes, and scientists have only begun scratching the surface of the microbial realm. It is entirely possible that examples of life as we don't know it have so far been overlooked.

I always look on the black side of life. That way, you won't be disappointed and I'm cheerful if it doesn't work out. I'm a cheerful pessimist.

Astronauts have been stuck in low-Earth orbit, boldly going nowhere. American attempts to kick-start a new phase of lunar exploration have stalled amid the realisation that NASA's budget is too small for the job.

When I was a student, the laws of physics were regarded as completely off limits. The job of the scientist, we were told, is to discover the laws and apply them, not inquire into their provenance.

Searching for alternative life on Earth might seem misconceived, because there is excellent evidence that every kind of life so far studied evolved from a common ancestor that lived billions of years ago. Yet most of the life that exists on Earth has never been properly classified.

The laws of physics ... seem to be the product of exceedingly ingenious design... The universe must have a purpose.

The birth of science as we know it arguably began with Isaac Newton's formulation of the laws of gravitation and motion. It is no exaggeration to say that physics was reborn in the early 20th-century with the twin revolutions of quantum mechanics and the theory of relativity.

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.

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

The way life manages information involves a logical structure that differs fundamentally from mere complex chemistry. Therefore chemistry alone will not explain life's origin, any more than a study of silicon, copper and plastic will explain how a computer can execute a program.

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.

Should we find a second form of life right here on our doorstep, we could be confident that life is a truly cosmic phenomenon. If so, there may well be sentient beings somewhere in the galaxy wondering, as do we, if they are not alone in the universe.

Perhaps the best motivation for going to Mars is political. It is obvious that no single nation currently has either the will or the resources to do it alone, but a consortium of nations and space agencies could achieve it within 20 years.

Traditionally, scientists have treated the laws of physics as simply 'given ' elegant mathematical relationships that were somehow imprinted on the universe at its birth, and fixed thereafter. Inquiry into the origin and nature of the laws was not regarded as a proper part of science.

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

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.

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.

The origin of life is one of the great outstanding mysteries of science.

A permanent base on Mars would have a number of advantages beyond being a bonanza for planetary science and geology. If, as some evidence suggests, exotic micro-organisms have arisen independently of terrestrial life, studying them could revolutionise biology, medicine and biotechnology.

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.

We will never fully explain the world by appealing to something outside it that must simply be accepted on faith, be it an unexplained God or an unexplained set of mathematical laws.

Recent discoveries about the primeval cosmos oblige us to accept that the expanding universe has been set up in its motion with a cooperation of astonishing precision.