The Beginning of Infinity - David Deutsch Flashcards
The Reach of Explanations
Transmutation - the conversion of one chemical element into another. For stars to shine, hydrogen is converted into helium.
Although our night sky appears serene and largely changeless, the Universe is seething with violent activity.
A typical star converts millions of tonnes of mass into energy every second, with each gram releasing as much as an atom bomb.
There are several supernova explosions per second. We do not know how many of those explosions are horrendous tragedies. We do know that a supernova devastates all the planets that may be orbiting it.
Supernova - a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
Yet we owe our existence to supernovae: they are the source, through transmutation, of most of the elements of which our bodies, and our planet, are composed.
The physical world proceeds according to elegant laws of physics that we understand in some depth.
Scientific theories are explanations.
It was mistakenly believed (historically) that we derived these explanations from the evidence of our senses. A philosophical doctrine called empiricism.
For example, the philosopher John Locke wrote in 1689 that the mind is like ‘white paper’ on to which sensory experience writes.
In reality, scientific theories are not ‘derived’ from anything. We do not read them in nature, nor does nature write them into us.
Scientific explanations are about reality, most of which does not consist of anyone’s experiences.
Discovering a new explanation is inherently an act of creativity.
Ideas have to be guessed - after which they can be criticised and tested.
The real key to science is that our explanatory theories can be improved, through conjecture, criticism and testing.
Empiricism never did achieve its aim of liberating science from authority.
