Quotes from Martin Rees

Indeed, our everyday world presents intellectual challenges just as daunting as those of the cosmos and the quantum, and that is where 99 per cent of scientists focus their efforts. Even the smallest insect, with its intricate structure, is far more complex than either an atom or a star.

Space and time may have a structure as intricate as the fauna of a rich ecosystem, but on a scale far larger than the horizon of our observations.

There are strong reasons for believing that space goes on beyond the limits of our observational horizon. There are strong reasons because if you look in opposite directions, conditions are the same to within one part in 100,000. So if we are part of some finite structure then, if the gradient is so shallow, it is likely to go on much further.

Indeed, the night sky is the part of our environment that's been common to all cultures throughout human history. All have gazed up at the 'vault of heaven' and interpreted it in their own way.

Scientists habitually moan that the public doesn't understand them. But they complain too much: public ignorance isn't peculiar to science. It's sad if some citizens can't tell a proton from a protein. But it's equally sad if they're ignorant of their nation's history, can't speak a second language, or can't find Venezuela or Syria on a map.

It would be sad if the expertise built up during the 40 years of the U.S. and Russian manned programmes were allowed to dissipate. But abandoning the shuttle, and committing to new launch vehicles and propulsion systems, is actually a prerequisite for a vibrant manned programme.

Space doesn't offer an escape from Earth's problems. And even with nuclear fuel, the transit time to nearby stars exceeds a human lifetime. Interstellar travel is therefore, in my view, an enterprise for post-humans, evolved from our species not via natural selection, but by design.

In future, children won't perceive the stars as mere twinkling points of light: they'll learn that each is a 'Sun', orbited by planets fully as interesting as those in our Solar system.

[On extraterrestrial life:] Absence of evidence is not evidence of absence.

The fine structure constant] ... defines how firmly atomic nuclei bind together and how all the atoms on Earth were made. Its value controls the power from the Sun and, more sensitively, how stars transmute hydrogen into all the atoms of the periodic table.

The Sun contains about a thousand times more mass than Jupiter. If it were cold, gravity would squeeze it a million times denser than an ordinary solid: it would be a 'white dwarf' about the size of the Earth but 330,000 times more massive. But the Sun's core actually has a temperature of fifteen million degrees-thousands of time hotter than its glowing surface, and the pressure of this immensely hot gas 'puffs up' the Sun and holds it in equilibrium.

The atoms that comprise our bodies and that make all visible stars and galaxies, are mere trace-constituents of a universe whose large-scale structure is controlled by some quite different (and invisible) substance. We see, as it were, just the white foam on the wave-crests, not the massive waves themselves. We must envisage our cosmic habitat as a dark place, made mainly of quite unknown material.

The sun has adjusted its structure so that nuclear power is generated in the core, and diffuses outward, at just the rate needed to balance the heat lost from the surface-heat that is the basis for life on Earth.

We, and the visible universe around us, may exist only because of a difference in the ninth decimal place between the numbers of quarks and of antiquarks.

The global village will have its village idiots and they'll have global range.

But it remains a fundamental challenge to understand the very beginning-this must await a 'final' theory, perhaps some variant of superstrings. Such a theory would signal the end of an intellectual quest that started with Newton, and continued through Maxwell, Einstein, and their successors. It would deepen our understanding of space, time, and the basic forces, as well as elucidating the ultra-early universe and the centres of black holes.