The Davey Dialogues - An Exploration of the Scientific Foundations of Human Culture. John C. Madden
fundamental constants were not so constant after all, having changed their values slightly over the life of our universe.
– Well, I told you last time we met that we have no unstable elements in our universe. From that you should have been able to conclude that some of our physical constants must be different, or we would have the same elements and the same chemistry that you have.
– I’m not yet totally certain that you exist. So, I can scarcely use your words as evidence!
You can tell I was feeling a little nettled! Davey noticed and immediately worked to calm me down.
– Quite right. I keep forgetting that the brains of you humans are subject to unbidden thoughts and visions, so you have to be very careful not to believe what you see and hear, unless it can be independently confirmed. Let’s proceed.
– Very soon now I shall address Charles Darwin’s monumental contribution to our quest to understand ourselves. As you almost certainly know already, Darwin believed that we have all evolved from the most primitive life forms through a process of natural selection, in which physical or mental capabilities that have species survival value are likely to be preserved, while changes that reduce the chances of survival have a tendency to die out.
It is difficult to see how understanding the origins of our universe will enhance our ability to survive. So, how could evolution through natural selection bestow on us, for example, the capacity to understand whether or not there are other parallel universes?
One answer is that it is well known that evolution frequently bestows properties that are peripheral to survival. Some genetic changes have no survival benefits, but neither do they materially reduce the odds of survival. Such changes simply alter our genetic makeup. It is to be expected that some such changes will subsequently prove to be advantageous. For example, it seems likely that our ability to write resulted from enhanced mental capacity more generally, combined with our manual dexterity, already a well-established inherited capacity. The upshot of our ability to record our thoughts and our progress has been nothing short of spectacular and has led many of us to view Homo sapiens as being in a class by itself relative to other animals. But we should not let this enormous success blind us to our probable limitations.
Let’s think small for a few minutes.
Consider the ant. Edward O. Wilson, the famous Harvard entomologist, did for many decades and at some length.[25]
It has been estimated that there are at least a million billion (1015) ants alive on Earth at any given point of time, and that there are thousands of different ant species, only some of which attend human picnics. Wilson describes ants as being “. . . in every sense of the word the dominant social insects”. Almost all, if not all, ant species have several different castes in their societies, including a queen, some males, soldiers (which can be much larger than their sisters and brothers), and smaller and medium-sized workers. Wilson describes the morning hunting activities of one particular species of ant, Eciton burchelli, in the following way:
When the light level around the ants exceeds 0.5 foot candle, the bivouac begins to dissolve. The chains and clusters break up and tumble down into a churning mass on the ground. . . . Then a raiding column emerges along the path of least resistance and grows away from the bivouac at a rate of up to 20 metres an hour. No leaders take command of the raiding column. Instead, workers finding themselves in the van press forward for a few centimetres and then wheel back into the throng behind them, to be supplanted immediately by others who extend the march a little farther. As the workers run on to new ground, they lay down small quantities of a chemical trail substance from the tips of their abdomens, guiding the others forward. A loose organization emerges in the columns, based on behavioural differences among the castes. The smaller and medium-sized workers race along the chemical trails and extend them at the points, while the larger, clumsier soldiers, unable to keep a secure footing among their nest-mates, travel, for the most part, on either side. . . . The smaller workers, bearing shorter, clamp-shaped mandibles, are the generalists. They capture and transport the prey, choose the bivouac sites, and care for the brood queen.[26]
Ants are not alone among insects in the highly developed innate nature of their social behaviour. Some species of termites build nests with special tunnels to provide air conditioning and heating as appropriate to keep termite larvae within a prescribed temperature range, and the dance of the honey bees to communicate the direction and distance to promising sources of nectar is now well known.
Change a few words here and there, and the quotation from Wilson could be a description of a raiding party by some remote human society, and yet experiments have conclusively established that almost all ant behaviour is inherited and not learned. It is enough to make us wonder just how many human activities are motivated more by innate behaviour than by our much-vaunted free will.
Ant societies have some definite boundaries to their understanding of the world about them. Exterior (and almost certainly, unimagined) forces can quite suddenly shatter the ant’s world – a bulldozer blade or an elephant’s foot on the nest, a sudden flood or a landslide.
So it is with humans and human societies, though our perception of just where those boundaries of understanding lie has undergone some very significant changes in recent years. We now think we understand how life evolved. We also understand the sources of earthquakes and violent storms. We know what fuels the sun and roughly how long the sun will continue as a benevolent source of energy. But there is still a lot that we don’t know.
For me, as for many others, some of the most perplexing and complex boundaries of our understanding lie in the physics of the universe.
I am almost certain that if my science teacher had not taught me about Newton’s law of gravity, it would never have occurred to me to wonder why it was I walked around on Earth and did not float up into the sky. Just like the vast majority of our ancestors, and, one supposes, all the other mammals and life forms, I would have lived my life without ever imagining such concepts as force and gravity. Furthermore, when I learned about Newton’s equations, they came to me as just another item on a long list of things to learn about, and, if need be, parrot back during an exam.
Now I look at what Isaac Newton discovered in wonder. How is it that he looked about him – perhaps triggered by the famous apple he is reputed to have seen falling to the ground – and asked the simple question I would never have thought to ask: “Why did the apple fall down?” Of course, Newton went even further. He integrated the force of gravity into his laws of motion, identifying the gravitational force as identical in principal to the force felt in one’s back arising from the acceleration of a plane down a runway, or, in his case, more likely a trotter moving a carriage swiftly away from a curb. What a stroke of genius!
Einstein, too, addressed questions it would not have occurred to most human beings to ask. Some famous experiments by distinguished scientists were showing that the speed of light is constant no matter what the relative motion is between the observer and the observed object. This is counterintuitive. If I throw a ball out of a speeding car in the direction of the car’s motion, I expect that the initial velocity of the ball relative to the ground will be the sum of the velocity I give the ball by throwing it, and the velocity of the car. This is true for the ball I throw (though air friction rapidly slows it down), but, as you may know, not for the light in a flashlight beam I point in the direction of travel. In that instance, the speed of the light in the beam as measured by a stationary observer is the same as the speed measured by someone on a passing car going in the opposite direction, or indeed, as measured by me while speeding along in the car. In exploring the consequences of this very strange fact, Einstein evolved the Special Theory of Relativity in 1905.[27]
Figure 6.1 – Two Geniuses, Two Theories of Gravity. Sir Isaac Newton in middle age on the left; Albert Einstein aged sixty-eight at Princeton in 1947 on the right.
Eleven years later, he pushed much further into the realm of questions I would not have thought to ask, in the process adding new meaning and accuracy to Newton’s gravitational equation. Gravity, he concluded, can be thought of as the curvature in space resulting from the presence of mass.
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