Legge di Natura

Are the Laws of Nature Fixed? The Science Delusion: Feeling the Spirit of Enquiry by Rupert Sheldrake

Esistono leggi di natura immutabili? Lo si dà per assodato ma il campione da cui si ricava l’inferenza è esiguo…

… On the basis of two or three hundred years of earthbound research, how can we be sure that the laws were always the same and always will be, everywhere?…

L’evoluzionismo è il paradigma delle scienze naturali. Perché mai non dovrebbero evolvere anche le leggi stesse della natura?…

… For most of science’s history, eternal laws of nature made sense. Either the universe was eternal and had needed no God to create it, or it had been made by God and stayed the same thereafter, guaranteed by God’s eternity. But in an evolutionary cosmos, does the theory of fixed laws make sense?…

Ma l’uomo sembra ossessionato con l’idea di legge fissata per sempre…

… First, the very idea of a law of nature is anthropocentric. Only humans have laws. For the founders of modern science, the metaphor of law was appropriate because they thought of God as a kind of cosmic emperor whose writ ran everywhere, and whose omnipotence acted as a cosmic law-enforcement agency…

Ma l’inclinazione non è unanime, c’è chi respinge questa presenza trascendentale…

… Some philosophers of science avoid these awkward questions by denying that scientific laws are transcendent, eternal realities; they argue instead that they are generalisations based on observable behaviour. But this amounts to an admission that the laws of nature evolve and may not be fixed for ever…

Anche se la stragrande maggioranza di noi porta incorporata questa idea…

… Nevertheless, whatever some philosophers may say, eternal laws are deeply embedded in the thinking of most scientists. They are implicit in the scientific method… Observations should be replicable. Why? Because the laws of nature are the same at all times…

***

Il nostro bisogno di eterno nasce già con i greci

… The materialists thought that changeless atoms of matter were eternal, while Pythagoras and his followers believed that the entire universe, especially the heavens, was ordered according to eternal non-material principles of harmony…

Platone e la matematica lo riflettono in modo chiaro…

… Plato (428–348 bc) was strongly influenced by the Pythagoreans but went further. He generalised the notion of eternal mathematical truths to a wider vision of Forms or Ideas (Platonic Forms and Ideas are traditionally written with initial capitals), or archetypes or universals, including not only mathematics…

Il cosmo è ordinato e la matematica lo descrive trascendendolo.

L’esperienza diretta è ingannevole quanto un’ombra intravista dall’uomo imprigionato nella caverna. E’ questa la famosa metafora prescelta da Platone…

… Plato famously compared the objects of sense experience to shadows in a cave experienced by prisoners, permanently chained so they can watch only the blank cave wall, with their backs to a fire…

I cristiani ereditarono questa visione nel Vangelo di Giovanni: “in principio fu il Logos”…

… Many elements of Platonic philosophy were incorporated in Christian theology, and are implicit in the opening of St John’s gospel, which, like the rest of the New Testament, was written in Greek. ‘In the beginning was the Word.’ ‘Word’ with a capital W is the translation of logos…

Filone d’ Alessandria: Dio è un giardiniere…

… He compared God to a gardener forming the world according to the pattern of the logos…

I fondatori della scienza moderna? Tutti neoplatonici…

… The founding fathers of modern science, Copernicus, Galileo, Descartes, Kepler and Newton, were all essentially Platonists or Pythagoreans. They thought that the business of science was to find the mathematical patterns underlying the natural world…

Platone e la teoria della relatività

… Albert Einstein’s general theory of relativity was firmly in this tradition, and Arthur Eddington, who provided the first evidence in favour of the theory, concluded that it pointed to the idea that ‘the stuff of the world is mind stuff…

Platone e la meccanica quantistica

… Werner Heisenberg, one of the founders of quantum mechanics:   [M]odern physics has definitely decided for Plato. For the smallest units of matter are not physical objects in the ordinary sense of the word: they are forms, structures…

***

Oggi, il mondo immaginato dai fisici è soggetto alle costante universali

… Some constants are considered to be more fundamental than others, including the velocity of light, c, the Universal Gravitational Constant, known to physicists as Big G, and the fine-structure constant, ?, which is a measure of the strength of interaction between charged particles, such as electrons, and photons of light…

Si tratta di parametri fissi calcolati in laboratorio…

… Unlike the constants of mathematics, such as ?, the values of the constants of nature cannot be calculated by mathematics alone: they depend on laboratory measurements…

Ma quanto sono fissi questi parametri fissi? Una cosa è certa: vengono aggiustati periodicamente.

Gli aggiustamenti di Paul Dirac

… However, some physicists, notably Paul Dirac (1902–84), speculated that at least some of the fundamental constants might change with time. In particular, Dirac proposed that the Universal Gravitational Constant might decrease slightly as the universe expands… he was merely proposing that a mathematical law might govern the gradual variation of a constant…

La costante gravitazionale di Newton sembra crescere, per esempio…

… the disparity in measurements of G by different laboratories increased, rather than decreased.10 Between 1973 and 2010, the lowest value of G was 6.6659, and the highest 6.734, a 1.1 per cent difference…

La causa dei cambiamenti? Si ipotizza vagamente l’ambiente astronomico

… What if G really does change? Maybe it does so because measurements are affected by changes in the earth’s astronomical environment, as the earth moves around the sun and as the solar system moves within the galaxy. ..

Uno studioso che si è speso molto in queste materie: Mikhail Gershteyn del MIT.

Tipi di variazione: giornaliere, di lungo periodo e di lunghissimo periodo…

… Gershteyn’s team looked only for daily fluctuations, but G may well vary over longer time periods as well…

La velocità della luce sembrerebbe in calo…

… Finally, what about the speed of light, c? According to Einstein’s theory of relativity, the speed of light in a vacuum is an absolute constant, and modern physics is based on this assumption. Not surprisingly, early measurements of the speed of light varied considerably, but by 1927, the measured values had converged to 299,796 kilometres per second. At the time, the leading authority on the subject concluded, ‘The present value of c is entirely satisfactory and can be considered more or less permanently established.’20 However, all around the world from about 1928 to 1945, the speed of light dropped by about 20 kilometres per second.21 The ‘best’ values found by leading investigators were in impressively close agreement with each other…. How can the drop in c between 1928 and 1945 be explained?…

Implicazioni: se le costanti non sono costanti il corso della natura evolve ed evolvono anche le leggi che la governano…

… The implications of varying constants would be enormous. The course of nature would no longer seem blandly uniform; there would be fluctuations at the heart of physical reality…

***

Il miracolo della vita: niente vita se le costanti del nostro universo fossero state differenti…

… According to the Anthropic Cosmological Principle, the fact that the ‘laws’ and ‘constants’ of nature are just right for human life on this planet requires an explanation. If these laws and constants had been even slightly different, carbon-based life would not exist…

Una simile considerazione supporta il teismo: non può essere un caso se la vita esiste…

… One response is to suggest that an Intelligent Designer fine-tuned the laws and constants of nature at the moment of the Big Bang so they were exactly right for the emergence of life and human beings. This is a modern version of deism…

L’alternativa dei molti universi

… many cosmologists prefer to think that there are innumerable actually existing universes besides our own, each with different laws and constants. In these ‘multiverse’ models the fact that we occupy a universe that is just right for us is explained very simply. This is the only universe that we can actually observe precisely because it is the only one right for us…

Le teorie inflazionistiche come ipotesi per la nascita di molti universi

… The multiverse model is popular among cosmologists for two other reasons. First, models of an ultra-rapid period of inflation in the earliest stages of the Big Bang suggest that if this period of inflation could generate one universe, our own, it could also generate many others, and go on generating them…

Altre speculazioni sui molti universi: le superstringhe

… The other theoretical reason for the popularity of the multiverse is superstring theory. This ten-dimensional theory and the related eleven-dimensional M-theory generate far too many possible solutions, which could correspond to different universes, as many as 10500…

Mark Tegmark e l’universo matematico…

… Some theorists go even further. The cosmologist Max Tegmark proposes that any mathematically possible universe must exist somewhere: ‘Complete mathematical democracy holds – mathematical existence and physical existence are equivalent, so that all mathematical structures exist physically as well…

Sia chiaro: si tratta di mere speculazioni non testabili

… Some physicists and cosmologists are unhappy with these speculations. A vast number of unobserved universes violates the canon of scientific testability…

Lee Smolin: nessuna evidenza a supporto…

… Lee Smolin summarised the situation in 2006:   Hundreds of careers and hundreds of millions of dollars have been spent in the last 30 years in the search for signs of grand unification, supersymmetry, and higher dimensions. Despite these efforts, no evidence for any of these hypotheses has turned up…

Altra ipotesi: l’universo in serie, o ciclico

… Another class of speculative theories suggests that the universe is part of a series of universes, the progeny of a previous one and the progenitor of the next… In modern cosmology, this ancient cyclic theory takes the form of the ‘bouncing universe’ model. After the Big Bang the universe expands for billions of years until its expansion slows down; it finally stops, and then begins to contract again under the force of gravity, finally collapsing in on itself in a Big Crunch. This in turn is the beginning of a new universe – a Big Bounce…

L’elemento comune: in tutte le ipotesi la matematica è messa al centro. Platone domina.

***

Esiste un approccio alternativo? Sì, il panevoluzionismo…

… The alternative to Platonism is the evolution of the regularities of nature…

Precursori: Pierce…

… In the late nineteenth century, the American philosopher Charles Sanders Peirce (1839–1914; pronounced ‘purse’) pointed out that fixed laws imposed upon the universe from the outset are inconsistent with an evolutionary philosophy. He was one of the first to propose that the ‘laws of nature’ are more like habits, and suggested that the tendency to form habits grows spontaneously…

Nietzsche…

… The German philosopher Friedrich Nietzsche (1844–1900), writing around the same time, went so far as to suggest that the ‘laws of nature’ underwent natural selection…Ma merita una citazione anche William James (1842–1910)…

Più di recente va segnalata l’opera di Whitehead…

… Likewise, Alfred North Whitehead suggested, ‘Time is differentiated from space by the acts of inheriting patterns from the past.’ This inheritance of pattern meant that habits built up. Whitehead said, ‘People make the mistake of talking about “natural laws”. There are no natural laws. There are only temporary habits of nature.’…

Tuttavia, negli anni sessanta, la teoria del Big Bang divenne la prevalente.

***

Un’ipotesi alternativa: la risonanza morfica. La materia ha una memoria, delle sue abitudini…

… My own hypothesis is that the formation of habits depends on a process called morphic resonance.41 Similar patterns of activity resonate across time and space with subsequent patterns. This hypothesis applies to all self-organising systems, including atoms, molecules, crystals, cells, plants, animals and animal societies. All draw upon a collective memory and in turn contribute to it…

Esempio…

… A growing crystal of copper sulphate, for example, is in resonance with countless previous crystals of copper sulphate, and follows the same habits of crystal organisation, the same lattice structure…

E’ come se la materia avesse delle abitudini che conserva e trasmette nel vuoto quantico…

… resonance may pass through the quantum-vacuum field, also known as the zero-point energy field, which mediates all quantum and electromagnetic processes…

Un esempio concreto: la cristallizzazione. E’ difficile ottenere nuovi composti ma una volta ottenuti, i tentativi successivi sono più semplici. E’ come se la materia si abituasse…

… The hypothesis of morphic resonance predicts that when chemists make a new compound for the first time, it might be difficult to obtain crystals of this compound because a morphic field for this crystal-form does not yet exist. When the crystals appear for the first time, a new pattern of organisation comes into being. The second time the compound crystallises, there will be an influence from the first crystals by morphic resonance all over the world. The third time, there will be an influence from the first and the second crystals, and so on…

 

Ma per avere evoluzione occorre qualcosa che produca cambiamento, occorre anche un elemento creativo

… Habits alone cannot explain evolution. They are by their very nature conservative. They account for repetition, but not for creativity. Evolution must involve a combination of these two processes: through creativity, new patterns of organisation arise; those that survive and are repeated become increasingly habitual…

Dove reperire creatività autentica? Mistero fitto…

… Creativity is a mystery precisely because it involves the appearance of patterns that have never existed before…

Nella concezione platonica la creatività è una novità preesistente che viene scoperta. Una creatività per modo di dire, una creatività già implicita…

… Our usual way of explaining things is in terms of pre-existing causes: the cause somehow contains the effect; the effect follows from the cause. If we apply this way of thinking to the creation of a new form of life, a new work of art, or a new idea, we infer that the new pattern of organisation was already present: it was a latent possibility. Given the appropriate circumstances, this latent pattern becomes actual. It is discovered rather than created…

Occorre una concezione più radicale.

Il filosofo della creatività: Henri Bergson.

… Bergson (1859–1941) was an evolutionary philosopher…

La sua concezione di creatività è ben più radicale

… Bergson argued that we need not attribute to these possibilities, which are unknowable until they actually happen, a pre-existent reality transcending time and space… Henri Bergson attributed this creativity to the élan vital or vital impetus. Like Darwinians, Marxists and other believers in emergent evolution, he denied that the evolutionary process was designed and planned in advance in the mind of a Platonic God…

Big Bang: l’unico momento creativo è all’inizio, il resto è svolgimento…

… The Big Bang theory locates cosmic creativity at the beginning. In the original miracle, all the laws of nature and all the matter and energy in the universe suddenly arose from nothing, or from the wreckage of a previous universe…

Bergson: creatività e menti ovunque, anche la materia ha una sua coscienza e una sua libertà…

… By contrast, a radically evolutionary view of nature implies an ongoing creativity, establishing new habits and regularities as nature evolves….

COMMENTO PERSONALE

L’Autore discrimina due partiti: quello platonico (per la legge di natura fissa) e quello panevoluzionsta (per la legge di natura mutevole). C’è davvero bisogno di dividersi filosoficamente per preferire la legge fissa? A me pare di no: basta preferire la semplicità alle complicazioni. La soluzione della “legge fissa” è più semplice: basta enunciarla. Una legge mutevole è più complessa: bisogna enunciarla e poi anche spiegare come cambia. Se facciamo della semplicità un criterio guida della scienza, allora la legge fissa s’impone come soluzione ottimale (a parità di capacità esplicativa).

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