Medium Sized Objects moving at Medium Speed

May 10th, 2007 Fred McVittie

We are, as Richard Dawkins memorably put it, ‘Medium sized objects moving at medium speed’. The scales at which all of creation operates stretches in size from the Planck length to the horizon of visible space, a scale of some 40 or so powers of magnitude, and as Joel Primack and Nancy Abrams relate in ‘The View from the Centre of the Universe’ , we occupy a tiny proportion of this scale somewhere in the middle. From an evolutionary perspective we have been medium sized objects for a very long time, since before we had an opposable thumb, since before we had language, since before we had consciousness, since before we had the complex unconscious we have today. We were medium sized objects moving at medium speed when our entire psychophysical repertoire was limited to flight or fight, breeding and eating. It is as medium sized objects that our being asserted itself such that our physiology, and indeed our psychology has designed itself to operate within that particular range and scale of operation, to solve problems and exploit opportunities offered within that range and scale. To our distant ancestors these problems would be ones of basic survival, of hunting, gathering, avoiding predators and identifying prey. Driven by the attractions of pleasure (nature’s reward for survival-enhancing behaviour) and the distress of pain (the stick that nature holds in her other hand), those of our ancestors who were best able to respond to these coaxings would be those who survived the longest, and therefore were most likely to leave their imprint in the genetic record.

The processes of evolution are contingent and conservative, and there is no place within its mechanism for wild experimentation and flights of fancy. Should nature occasionally have the urge to assert herself as revolutionary artist, the beautiful mutants that result from such bohemianism, less well equipped to solve the problems of medium sized objects moving at medium speed, never make it into the museum of natural history we carry in our genome. For this reason we have never evolved eyes capable of seeing into the heart of the atom, or into the reaches of outer space; in survival terms we have nothing to fear and nothing to gain from such extended sight. We can hear the roar of a lion and the wimpering of a potential next meal, but not the background hum of the universe. We can hold apples in our hands, and we can hold the hand of a lover, but have never had need to grasp a quark.

Posted in Dawkins, Richard, Evolution, Pain, Pleasure, Primack, J. & Adams, N. | No Comments »

The Earth is Flat

August 20th, 2007 Fred McVittie

As Primack and Adams not in ‘View from the Centre of the Universe’, the model by which scientific revolutions proceed by large scale ‘paradigm shifts’ is flawed. Kuhn’s model, postulated that occasionally there are major changes in the way that science understands (all or part of) the world. At these times, and the most commonly-cited example is the Copernican revolution from an Earth-centred solar system (or universe) to one centered on the Sun, the old order of theories, models, diagrams, and mechanisms, is dismissed in favour of the new. In Kuhn, it is a necessary consequence of this revolutionary overturning that what went before it becomes wrong and that apostles of the new, (after moving through a brief period of being heretics) become keepers of the new flame and upholders of the new truth. Old is wrong, new is right.

According to Primack and Adams, a more accurate understanding of what happens during these times is not a replacement of one truth by another, but rather the re-interpretation of the data of the world such that it applies to a wider set of circumstances and covers a larger set of phenomena. So, by this understanding, the Ptolomaic model of the Earth-centered universe is not ‘wrong’, it is instead a special limited case of the Copernican model. It is worth noting in passing that the Copernican model tends to promote an understanding of the universe which is as partial in its own way as the Ptolemaic which preceded it. A casual interpretation of the Sun-centered model seems to indicate a stationary star orbited by moving planets, but of course, in relativity, nothing is stationary in absolute terms and by most accounts the Sun itself is hurtling at several thousand miles an hour in the direction of Andromeda, with the planets around it like the loose reins of a horse. Copernicus put his thumb on the Sun and momentarily arrested its wild flight and, in doing so, revealed a pattern in the relationship of the movement of the planets, but the Copernican map is not of the real solar system, any more than a 2-dimensional map of the Earth is an accurate rendition of the real globe. It is more a graph or schematic showing the pattern of relations he discovered.

In many cases it is preferable to work with the assumption that the Earth is stationary and central rather orbital and peripheral. When we make appointments or set or watches we do not consider this as stating the location of the Earth in its orbit around the Sun, or the number of degrees through which it has rotated. We refer to sunrise not Earthfall and we watch the Sun go down over the ocean, not the Earth turning its face away into the darkening night. For most purposes the Ptolemaic model of the universe in which Earth is the centre of attention is sufficient. This is not to say that when we use such Earth-centered concepts we are using a kind of lazy shorthand, or are being inaccurate. When the application of the Ptolemaic paradigm is limited to specific uses such as these it is as accurate, and more efficient, that the Copernican.

On the even more local scale of vernacular or ‘folk’ experience, we can even extend this notion of overlapping or simultaneous paradigms to include the apparently self-evident wrong-headedness of flat Earth theory. The Earth in its entirety is not usefully considered flat, and any depiction of the Earth which too closely resembles a 2-dimensional map is demonstrably inaccurate. However, in day to day life we routinely work with the assumption that it it indeed flat, and are rarely proved wrong. When we measure a room prior to fitting a carpet, or stake out the foundations of a building, we do not take the spherical nature of the Earth into account. It would be perfectly possible to include the curvature of the Earth in our calculations but since this difference would be insignificant (smaller by far than the variations in the landscape itself) it would be foolish to do so. It is at this level that ‘folk knowledge’, or Naive Physics, and the paradigms which make it up, become available as accurate, relevant theory.

Posted in Knowledge, Naive Physics, Paradigm, Primack, J. & Adams, N., Science, Space | No Comments »