There is an old joke that went something like this.
Out on the Serengeti Plane there is a little knoll. The knoll is a favourite observation point for the senior members of a pride of lions. Close by is a waterhole where many animals come to drink. In the late afternoon the head lions wait for suitable prey to arrive and then go down to attack them and having killed their prey, devour them for their evening meal.
Let us join them on the knoll to see what will happen this afternoon. We have ensconced ourselves in a hide close by and wait to see the afternoon activities. The lions lounge around languidly. But then, of a sudden, their attention is aroused. In the middle distance a small herd of gnus is to be seen approaching the waterhole. The wildebeest make their way slowly to the waterhole grazing a little as they progress. The lions in anticipation slink stealthily down from the knoll and position themselves in some cover close to the waterhole. Unaware of the presence of the senior lions from the pride, three gnus approach the waterhole. They look around cautiously but seeing nothing bend down to drink. Once they are engaged in drinking the lions surge from their cover and quickly slay the poor wildebeest. We watch with some abhorrence as the hunters devour their prey. Finally they have sated their hunger and saunter back to the knoll where we are watching.
So that is the end of the gnus and here again are the head lions!
Last week I wrote about the Universe and how it was seemingly governed by the Laws of Physics (or perhaps as some would title them – the Laws of Nature). This week’s essay is a reprise. So here again are the Laws of Physics.
Of course the Laws of Physics (like Australia and the Americas) had always been there just waiting to be discovered. Before the late seventeenth century mankind had tried to rely on divine revelation to understand the world.
Newton and his successors had prised out certain of the Laws of Nature which helped us to understand some of the enduring characteristics of the physical universe. But what are these laws and in what way can they be said to be Laws? Strangely there seems not to be a consensus in the scientific community nor among those who write about the history and philosophy of science.
There is for example a difficult distinction between what is a Law and what is merely a generalisation. It is conceded that a Law can be disproved by merely finding one exception. What if I were to propose as a Law of Nature “that all dragons are left-handed”? I defy you to present an example which will disprove my Law. Unfortunately this can’t be a Law (although I might wish it to be so) because I can’t provide evidence in support of it just as you can’t provide evidence to refute it.
An article I read recently put an interesting position. It suggested there could be a Law saying that “All gold spheres are less than a mile in circumference.” Whilst this might be true on earth where gold is a rare metal it perhaps might not be so in the Universe at large. But we could confidently predict that “All uranium spheres are less than a mile in diameter.” We know that a uranium sphere a mile in diameter would far exceed the critical mass necessary for a nuclear reaction to occur resulting in a huge explosion destroying the sphere.
How does something qualify as such a Law? David Fayn in his book “The Human Touch” wrote of the disagreement between scientists and the philosophers of science. He produced the following list of possible attributes of the Laws and who supported the particular notion:
• Invented by man (Einstein, Bohr, Popper)
• Not invented by man (Planck)
• Expressions of a real underlying order in the world (Einstein)
• Working models justified only by their utility (von Neumann, Feynman)
• Potentially deterministic (Einstein)
• Inherently probabilistic(Heisenberg, Prigogine)
• A dialogue between man and the world (Prigogine)
• A dialogue between the possible and the actual (Medawar)
• Steps on the road towards complete understanding (Feynman, Deutsch)
• Steps on a road that has no end (Born, Popper, Kuhn)
• Forced upon us by the world (Planck)
• Forced by us upon the world (Popper)
• Potentially all embracing (Feynman, Deutsch)
• Inherently piecemeal (Cartwright)
• Likely in the end to be not only comprehensive but simple (Feynman)
• Accounting for less the simpler they are (Cartwright)
There is even disagreement among the scientists about how one might go about discovering one of these nebulous and difficult to quantify Laws. Traditionally the belief was that scientists needed to be careful observers of the world and from observations trends and relationships could be derived. But Karl Popper (like Albert Einstein) insists that most fundamental discoveries are made when the scientist is looking for something specific, thus concentrating attention and focus on discrete possibilities and trying to find evidence to support or dismiss a hypothesis.
Sir Martin Rees, the British Astronomer Royal states, “One of Einstein’s most hackneyed sayings is, ‘The most incomprehensible thing about the universe is that it is comprehensible.’ What Einstein meant is that the laws of nature seem to apply not just here on earth, but everywhere in the universe. We could imagine a universe where there were no laws at all, completely anarchic, every atom being different. And were that the case, we’d make no progress at all in making sense of the external world.”
Rees makes the point that there would be no point at all in studying science without our confidence that the underlying fundamentals were invariant in time and space over the Universe.
It is interesting to contrast the Laws of Nature with statute laws. If for example we pass into law that stealing is an offence, we do not stop people from stealing we only discourage the practice with punitive measures. If however one of the Laws of Nature prevented people from stealing, try as they may they could not offend. Theoretically the Laws of Nature by definition allow of no exceptions. Every body in the universe is attracted to other bodies by the force of gravity. There is not a single electron in the Universe whose position and momentum can be measured accurately and simultaneously. There exists no electromagnetic wave in the cosmos that can travel faster than the speed of light.
Now as I related last week Stephen Hawking compared the complete set of the Laws of Physics with the “mind of God.” However, initially, the Laws of Physics provided a challenge for the traditional believers. In fact, the idea of laws of nature was rejected by the Islamic philosopher, Abu Hamid al-Ghazali [in The Incoherence of the Philosophers], in the late 11th century on the grounds that the very concept put God in chains. Things happen not because there are laws of nature, but because God wants them to happen that way. Of course, that attitude makes science difficult.
There are many difficult questions here. Do things have to be the way they are? Is it possible to envisage a Universe where the Laws might be different? Scientific observations confirm certain regularities in the way the Universe behaves. And yet, as I pointed out last week there is still a huge amount of chaos, disorder and uncertainty. This leads some philosophers to surmise that the Laws of Nature may not be inherent in the Universe but to be merely human constructs.
Lee Smolin, theoretical physicist, asserts that the Laws of Nature can be understood from two points of view. He asserts that either the laws are timeless or contingent. If they are timeless they are invariant throughout time and space and would apply to any Universe imaginable. They just are! But he favours the notion that they might be contingent. By this he means there is some causal relationship. The preconditions of the “Big Bang” might have set up the conditions that determined what they should be.
In my little sojourn through the Laws of Physics in recent weeks it occurs to me how difficult they are to define. Some so-called Laws are merely derivatives of others. Also they purport to explain the regularity of the Universe but so much of the Universe is irregular. There is debate whether the Laws are naturally inherent in creation or whether they have been causally derived. Scientists trying to extricate these laws lean on qualitative criterion like beauty and symmetry. There is no doubting the usefulness of the Laws of Physics. Their development has helped us improve our understanding of the Universe substantially in the last three of four centuries. With all these issues one can only surmise there is much more yet to be discovered. We are intrigued by the possibilities of “String Theory”, the Higgs boson (sometimes referred to as the “God particle”) and a myriad of other things we mere mortals struggle to understand. I can’t help but come back to Gödel’s Incompleteness Theorem. Just as in mathematics I believe there will always be a gap in our understanding of the physical world as well. I think the Grand Unified Theory of everything is a pipe dream. In physics, just as in mathematics, we are fated to either have an accurate but incomplete understanding or we will derive an all-encompassing theory that will have inconsistencies. But I admire the efforts of our scientists and their work truly fascinates me – so I won’t be discouraging them from trying!
[For those of you interested in this topic, whilst researching my material I found a website that might interest you. If you access www.closertothetruth.com you will find a number of short videos on “Where Do The Laws Of Nature Come From?” They are stimulating viewing.]