People such as William Reville, at University College Cork, regularly contemplate such profound issues, although they don't pretend to have all the answers. In his case, he has been putting such questions in The Irish Times since 1995 in a way that brings science to the unscientific. His thoughts were recently published by Irish Times Books, ranging from the origins, nature and future of the universe; whether we are alone; the theory of evolution; modern genetics; the importance of the Sun - even lay people are good on that one; Einstein; science and religion; medicine and disease and diet and nutrition.
So where do we go from here? Is a race of super-intelligent humans about to be cloned in the laboratories by mad scientists? Dr Reville, a senior lecturer in biochemistry and director of the central electron microscopy unit at UCC, thinks the probability is that sometime, somewhere, someone will do it, but that it's not as simple as people imagine.
If I clone you because of your good looks and brilliant mind, what do I get? An exact replica? There's the rub. You were a product of your time, place and environment - these helped to fashion the you that we now know. So if we want an exact clone of you, the laboratory bods will have to consider all the life experiences that made you happen.
However, he believes the super-race concocted in a lab by some nutty professor or tyrant is a long way off.
Are we alone? Dr Reville thinks the life-creating juices that led to our existence must be out there somewhere, so vast is the universe. Who knows, alien life might be as stupid as we are; or vastly more intelligent.
Where will the advances be? Dr Reville has no doubt that genetic engineering is forging a new path for science in disease control and organ regeneration. However, science, he says, is forging ahead so fast that the ethical considerations are being left behind.
He believes it might be no harm if there was some stocktaking in the headlong scientific rush while the ethics dimension took on a new impetus.
The best computer on Earth? It is still the human brain, Dr Reville says, and we haven't yet learned all there is to be known about it - perhaps we're not as clever as we think.
This scientist's mission is to make science available to the public. For more information, fax Dublin 6718446.