Howard Barrell spoke to a Cape Town cosmologist who believes there will always be a limit to what science can do
In terms of the age and extent of the universe, the passing of the millennium that many of us are marking with such fervour, fear or superstition is an irrelevance, according to George Ellis, one of South Africa’s leading mathematicians and an internationally prominent cosmologist.
At last count our universe was around 13-billion years old. So a period of 1E000 years does not warrant much attention – except inasmuch as chaos theory tells us that even the smallest thing can, over time, contribute critically to momentous, unpredictable outcomes.
Ellis is more respectful of the past century than the millennium. “It has been an amazing period in terms of science,” he says. “We have made major advances in our knowledge.”
He rattles off the more important among them. Albert Einstein’s two theories of relativity eventually overthrew the notion that our universe was infinite and unchanging. It implied, instead, that it had to be expanding or contracting. The view these days is that it is expanding after a moment of creation called the Big Bang.
Quantum theory, which is concerned with behaviour on the smallest of scales, revealed the random character of some atomic behaviour. Ellis explains: “Although we know [from Einstein] how things are going to work on a large scale, we still can’t predict on a microscopic scale.”
A further advance over the past century is that we now know that deoxyribonucleic acid, or DNA, is the molecule that encodes the features of every living creature. The code for you and me is about 2,5-billion letters long. This knowledge has enabled us to manipulate the make-up of, among other things, food-producing plants.
And Ellis warns against sometimes hysterical opposition to genetic modification of food crops. “The only alternatives,” he argues, “may be pesticides and fertilisers. And they poison the planet.”
We now also know that the continents on which we walk drift about the surface of our planet. And the Hubble space telescope, floating beyond the distortions caused by the Earth’s atmosphere, has in the past few years given us an unprecedented clear visual take on deep space.
“These advances have been almost unbelievable. They amount to a revolution. This set of ideas has transformed our understanding,” says Ellis, who carries the extraordinary title at the University of Cape Town of distinguished professor of complex systems.
He attributes the rapidity of these advances over the past 100 years to, among other things, the “spirit of free inquiry and ability to question authority” that has prevailed in many parts of the world. This reasoning partly explains his liberal activism in politics – both before and since the 1994 watershed.
He adds: “Mathematics is the basic language of science, and it is vital that it be properly taught if a country wants to succeed. But South Africa does not have a proper system of maths instruction.”
To Ellis’s mind, the big change in our mindset over the past thousand years has come in the way we explain why and how things happen. “We now look to cause and effect, as opposed to magic and superstition.
“Among other things, we now see our bodies, including our minds, in a machine- like way.” He adds, however, that he does not believe people can ever be conceived of as “nothing but” machines.
It is a theme to which he returned repeatedly during the interview. Ellis the scientist is also Ellis the Quaker. And he has no difficulty in being both at the same time.
“What is also becoming clear,” he says of this moment 2E000 years after the innocuous event in Nazareth that defines our calendar, “is what will not be achieved by science.”
For one thing, he believes science will not be able to explain or replicate human consciousness adequately – notwithstanding the claims of some people working in the field of artificial intelligence on trying to reproduce the mind using computers.
He also considers it highly unlikely that we will ever be able to time-travel, mind- read at a distance, travel faster than light or issue the instruction, with any expectation of a safe journey, “Beam me up, Scottie.”
So what might our descendants several centuries hence be capable of?
Ellis believes it is realistic to expect them to be able to regenerate limbs by regrowing them from DNA codes. It is also “certainly conceivable” that our descendants will be able to regenerate extinct species of animal. So something like Jurassic Park may not be fantasy after all.
He expects major advances in humans’ understanding of the influence of our minds on our health. Ellis suggests, for example, that it is probably the power of the mind that best explains the continued survival of Stephen Hawking, fellow cosmologist and his friend since their days together as students at Cambridge University in the early 1960s.
Hawking, author of what is probably the best-selling though least-understood science text, A Brief History of Time, has been confined to a wheelchair with motor neuron disease.
Like many of his colleagues, Ellis also expects physics to develop what is popularly, though perhaps misleadingly, referred to as “a theory of everything”. The theory would be likely to entail a radical recasting of our understanding of “everything”, from our universe to sub- atomic particles and their behaviour. It would probably in some sense reconcile the predictability of the gravitational motion of bodies on a large scale outlined by Einsteinian relativity with the unpredictability of very small things revealed in quantum theory.
Our descendants are also likely to make important breakthroughs in understanding how it is that we humans learn to do things. From this knowledge, they will be able to develop, among other things, more effective methods of teaching, and improve the usability and design of various technologies.
The technological spin-offs of these scientific advances will be substantial. But Ellis warns against trying to direct science in such a way as to feed technological development. “The major discoveries are totally unpredictable,” he says.
But Ellis does not believe any technologies our descendants may produce will enable them to communicate effectively with, let alone visit, other life elsewhere in our universe. “There is almost certainly extraterrestrial life, but it is unlikely to be close enough.”
He returns to his broader theme on the limitations of science. “There’s an area into which science simply cannot go. Ethics and aesthetics are beyond science. Not just now, but forever.
“In cosmology, I am probing the origins of our universe. But cosmology cannot tell me why the laws of physics exist or why they are as they are.
“Part of the data about the universe is our own lives. Most of us live lives that are aesthetically or otherwise meaningful. In the end there are two competing hypotheses. You can say that this meaning comes out of nothing and constructs itself. Or you can say that the meaning we see around us – ethics, beauty and the like – is reflective of a deeper, underlying nature of the universe in a way we cannot explain.
“My own view,” says Ellis, “is that there is an underlying reality which we can call ‘transcendence’. Various intimations of it are available to us. Morality, beauty, love – which are all beyond the competence of physics to deal with.”