Alien Scientist 38: Newton’s Alien Intuition
Stephen Marshall, a former resident of Tsukuba, has been writing Alien Scientist articles for the Alien Times since 2001. Even though he no longer lives in Tsukuba, he is still a regular contributor to the magazine. Here is his latest intergalactic report.
How many eyes since the dawn of time must have gazed at the heavens and wondered how the sun, moon and planets moved about in their wandering paths? According to tradition, it was a falling apple that gave Isaac Newton his insight into the workings of gravity: the idea that the same force that caused ordinary objects to fall to the ground caused the Moon to stay in orbit round the Earth. In effect, Newton’s insight relied on recognising the Earth, the Moon and the apple as similar kinds of things: massive solid objects interacting across space.
Although there is something intuitive about the analogous motion of fruits and satellites, Newton’s insight is not completely obvious, in the sense that the Moon doesn’t seem to be falling at all, but seems to hang miraculously in the sky. It could just as equally be intuitive to believe that the Moon followed some invisible rollercoaster track, or bobbed about on an ethereal whirlpool; or indeed was a celestial beacon that needed no physical explanation at all. It took a scientific mind like Newton’s to turn the intuition into science: to make the physical evidence work mathematically, and to realise the significance of the result. This significance went beyond gravitational mechanics, but helped confirm that the laws of physics applied in the heavens as they did on Earth – a tangible territorial gain for the advance of science. If the view from the telescope was satisfyingly ordered, what about the view from the microscope? Having accounted for the very big, the natural philosopher might naturally turn to examine the very small. One might reasonably intuit that all matter is made up of tiny particles, floating in space. The atom, for example, could be like a miniature solar system, with the electrons orbiting the nucleus like planets orbiting the sun, attracted by electrical rather than gravitational force.
Up to a point, this model of atomic structure can help us visualise what is going on inside an atom. But, the idea is only a rough approximation of reality. In effect, electrons make more sense when thought of as spread-out distributions of electric charge, rather than being specific particles with particular localised presence.
At this point, things start getting a bit slippery, not to say ‘spooky’. At this sub-atomic level, we find ourselves being sucked into the realm of quantum mechanics. On entering this quantum world, what started out as a nice little excursion into speculative mechanics turns into an inquisition into the very nature of matter and the fabric of space-time. We find ourselves contemplating a world where things seems so strange and uncertain that if we weren’t convinced that it worked in practice, we might not believe it could work in principle.
Perhaps we are more comfortable with the classical Newtonian worldview of discrete, solid particles since we live on a fairly solid planet, and we are ourselves fairly solid, and are used to seeing big solid rocky things like moons and planets hurtling around like billiard balls. What could be simpler than thinking that the world was made up of small bits of stuff?
And yet, we could imagine that in some alien environment, there might be no solids to act as our models: no fruits, no moons and definitely no billiard balls. Imagine, indeed, an alien organism inhabiting a fluid world, where the alien and its environment are both fluid and continuous, and where nothing perceptible was as discrete and discontinuous as a solid particle. It might take a very clever alien scientist – or a counter-intuitive one – to imagine that a fluid could be made up of little balls. Perhaps respectable science would consider particles as figments of the imagination; and any corpuscular philosopher would be confined to the very speculative reaches of science. For the more mainstream alien scientist, it must be much more reasonable to think of the universe as a continuous fluid, a spread-out distribution of matter everywhere.
Perhaps, in such a slippery world, things like quantum mechanics would make more sense, whereas a world of isolated solid objects falling in space would seem counter-intuitive, and the idea of being able to measure the position and velocity of an apple unimaginably spooky. The insightful alien scientist might see that the maths was elegant, but could find Newton’s intuitive grasp of the matter quite alien.