Continuity and discontinuity in physics and biology

Abstract

Although classical physicists believed that nature does not make leaps – it is continuous and infinitely divisible – 20th century physicists soon realised that there are indivisible elementary particles (quanta) and that physical space is therefore not continuous and also not infinitely divisible. This state of affairs is also underscored by the duality of particle and wave. Even for Einstein the continuity of the microstructure of ‘space-time’ was still an open question. Therefore considering physical phenomena as literally continuous could be questioned. Moreover it is striking that reflection on the nature of matter gave birth both to an ‘atomistic’ and a ‘continuity’ conception. Faithful to modern nominalism (neo-)Darwinism accepts no universality outside the human mind. Plants and animals are simply positioned in a continuum with the aid of arbitrary names. This continuity postulate – known as ‘gradualism’ – is, nonetheless, confronted from the outset with the dominant stasis pattern of the paleontological record: a type appears abruptly, remains constant for millions of years and then disappears equally abruptly. As a consequence the assumed ‘imperfection’ of the fossil record could be questioned. Prominent biological thinkers still wrestle with the problem of continuity and discontinuity. One of them explains that these stories begin from the same foundational fallacy and then proceed in an identically erroneous way. They start with the most dangerous of mental traps: a hidden assumption, depicted as self-evident, if recognised at all, namely, a basic definition of evolution as continuous flux.