Can the Dalai Lama enlighten Western science, asks Michael Brooks
As the spiritual leader of Tibetan Buddhism, the Dalai Lama is accustomed to seeking enlightenment over deep philosophical issues. Recently, however, he had a new experience to contemplate as he watched a demonstration of the bizarre world of quantum physics.
Anton Zeilinger, professor of experimental physics at the University of Innsbruck, showed him an experiment proving that photons can simultaneously exist as both particles and waves.
Zeilinger has accomplished some of quantum physics’ most remarkable experimental feats. Last year, for instance, he teleported a photon across his laboratory – the first time this had been done. He now says that his research could make new progress with the Dalai Lama’s help.
“As a scientist you have to be opportunistic,” says Zeilinger. “The tradition the Dalai Lama represents is very rational, very logical and very welcoming to scientific ideas. For me, anything goes if it might lead to a new idea.”
The two men first met last October when Zeilinger, with four other Western scientists, was invited to discuss physics at the Dalai Lama’s home in Dharamsala, northern India. In the discussions, it emerged that quantum theory and Buddhist thought have a great deal in common.
“There seem to be a lot of interesting parallels,” says Zeilinger. “We ended up discussing things like `what can we know?’ and `when do we agree that we know something?’ – things that are central to our understanding of quantum mechanics.”
The concept of knowledge is possibly the hottest issue in quantum physics. To find out about quantum systems they have to be measured, but the theory puts limitations on what can be known about them. You can’t precisely know both the position and the momentum of a photon, for example. Add that to the fact that measuring a system changes its characteristics, and you can begin to understand the Dalai Lama’s fascination.
There were, however, aspects of quantum theory that the Dalai Lama refused to accept. When Zeilinger told him that a quantum particle’s spin is randomly clockwise or anticlockwise – that there is no cause that determines the outcome – he was told to keep looking. “I think you will find a cause some day,” the Dalai Lama suggested.
“To him, everything is part of a chain where cause and effect follow each other,” says Zeilinger.
So, while cosmological ideas of life in other galaxies coincided nicely with the Buddhist belief in myriads of inhabited world systems, the birth of the universe remained a problem; the idea that time and space came into existence only with the Big Bang was inconceivable.
But the Dalai Lama admits not all Buddhist ideas can be retained in the light of recent scientific discoveries. Early Buddhist texts contain discussions about the evolution of the universe, some of which are in direct conflict with modern cosmology.
“He argues that under such circumstances it is the traditional Buddhist cosmology that needs to be modified,” says Thupten Jinpa, a Tibetan Buddhist monk.
Zeilinger is most excited about showing the Dalai Lama the “double slit” experiment that demonstrates the paradoxical nature of quantum particles. When standard waves pass through two neighbouring slits, the emerging waves combine to produce a characteristic “interference” wave pattern. Particles show no such interference effects – firing bullets through the double slit, you simply get twice the number of bullets.
However, firing quantum particles, like photons, is different. Close off one slit, and they behave like the bullets. But open both slits, and interference occurs. The quantum particles are also quantum waves.
This is more of a problem to the Western mind than it is to those who are accustomed to Eastern thought. “They have a logic where they claim that opposites can be true at the same time,” says Zeilinger. “When we talked about this last year it took a couple of hours to make the Dalai Lama understand why it had us so puzzled.”
Thanks to Zeilinger, the Dalai Lama is beginning to get a feel for the intellectual challenges faced by scientists researching quantum theory. The enlightenment even had visible effects, Zeilinger recalls: “I actually saw his face brighten up when he understood why we were so confused.”