The Beginning of Infinity: Explanations That Transform the World

by David Deutsch

We now know that there can be ‘design without a designer’: knowledge without a person who created it.

‘evolution by variation and selection’.

But the truth is always that knowledge must be first conjectured and then tested.

Thus, it is said, evolution optimizes the good of the species, not the individual. But, in reality, evolution optimizes neither.

For instance, a rule that is expressed in an elegant rhyme may be remembered, and repeated, better than one that is more accurate but expressed in ungainly prose.

The physicist Brandon Carter calculated in 1974 that if the strength of the interaction between charged particles were a few per cent smaller, no planets would ever have formed and the only condensed objects in the universe would be stars; and if it were a few per cent greater, then no stars would ever explode, and so no elements other than hydrogen and helium would exist outside them.

Therefore the existence of an unsolved problem in physics is no more evidence for a supernatural explanation than the existence of an unsolved crime is evidence that a ghost committed it.

another great unsolved scientific mystery, known as ‘Fermi’s problem’, named after the physicist Enrico Fermi, who is said to have asked, ‘Where are they?’

it is overwhelmingly unlikely that any given extraterrestrial civilization is currently at a similar state of technological development to ours: it is likely to be millions of years younger (i.e. non-existent) or older.

it would be statistically certain that our universe is exactly on the edge of the astrophysicist-producing class of universes.

That is because they all address the same underlying problem, and are all easily variable. They are easily interchangeable with each other or with variants of themselves, and they are ‘too easy’ as explanations:

In other words, the problem has been not that the world is so complex that we cannot understand why it looks as it does, but it is that it is so simple that we cannot yet understand it.

So scientific discovery is profoundly unpredictable, despite the fact that it is determined by the laws of physics.

Creationism is really creation denial – and so are all those other false explanations.

The guiding principle is, as always, to reject bad explanations in favour of good ones.

This resolution into explicability at a higher, quasi-autonomous level is known as emergence.

The behaviour of high-level physical quantities consists of nothing but the behaviour of their low-level constituents with most of the details ignored.

For instance, the second law of thermodynamics says that high-level physical processes tend towards ever greater disorder.

All those doctrines are irrational for the same reason: they advocate accepting or rejecting theories on grounds other than whether they are good explanations.

Thus emergence is another beginning of infinity: all knowledge-creation depends on, and physically consists of, emergent phenomena.

The computer scientist Douglas Hofstadter has a nice argument that this sort of explanation is essential in understanding certain phenomena.

Our own brains are, likewise, computers which we can use to learn about things beyond the physical world, including pure mathematical abstractions.

These are not possible objects of any observation. And yet people knew about them – and not just superficially: at the time, such knowledge was the deepest knowledge, of anything, that human beings had ever had.

But it is no mystery where our knowledge of abstractions comes from: it comes from conjecture, like all our knowledge, and through criticism and seeking good explanations.

The growth of knowledge does not consist of finding ways to justify one’s beliefs.

Conversely, advocates of highly immoral doctrines almost invariably believe associated factual falsehoods as well.

The individual scientist has to value truth, and good explanations, and be open to ideas and to change.

The scientific community, and to some extent the civilization as a whole, has to value tolerance, integrity and openness of debate.

The truth has structural unity as well as logical consistency, and I guess that no true explanation is entire...

Since the universe is explicable, it must be that morally right values are connected in this way with true factual theories, and mora...

if you were suddenly the last human on Earth, you would be wondering what sort of life to want. Deciding ‘I should do whatever pleases me most’ would give you very little clue,

In other words, there is an objective difference between right and wrong: those are real attributes of objectives and behaviours.

Beauty, right and wrong, primality, infinite sets – they all exist objectively.

Progress depends on explanation, and therefore trying to conceive of the world as merely a sequence of events with unexplained regularities would entail giving up on progress.

The existence of levels of approximation to true explanations.

Abstract entities are real, and can play a role in causing physical phenomena. Causation is itself such an abstraction.

Also, a writing system based on an alphabet can cover not only every word but every possible word in its language, so that words that have yet to be coined already have a place in it. Then, instead of each new word temporarily breaking the system, the system can itself be used to coin new words, in an easy and decentralized way.

say that it was the system of numerals that performed arithmetic. The human users of the system did of course physically enact those transformations. But to do that, they first had to encode the system’s rules somewhere in their brains, and then they had to execute them as a computer executes its program.

This curious lack of enthusiasm for universality was repeated in medieval Europe: a few scholars adopted Indian numerals from the Arabs in the tenth century

But when it was reinvented by the printer Johannes Gutenberg in Europe in the fifteenth century, using alphabetic type, it initiated an avalanche of further progress.

Here we see a transition that is typical of the jump to universality: before the jump, one has to make specialized objects for each document to be printed; after the jump, one customizes (or specializes, or programs) a universal object

The most momentous such technology is that of computers, on which an increasing proportion of all technology now depends, and which also has deep theoretical and philosophical significance.

The science-fiction authors William Gibson and Bruce Sterling, in their novel The Difference Engine, have given an exciting account of what that might have been like.

In 1936 Turing developed the definitive theory of universal classical computers.

That is because a modern digital computer can be programmed to imitate any of them, and to outperform them in almost any application. The jump to universality in digital computers has left analogue computation behind.

Genes in present-day organisms replicate themselves by a complicated and very indirect chemical route. In most species they act as templates for forming stretches of a similar molecule, RNA. Those then act as programs which direct the synthesis of the body’s constituent chemicals, especially enzymes, which are catalysts.

About four billion years ago – soon after the surface of the Earth had cooled sufficiently for liquid water to condense – the oceans were being churned by volcanoes, meteor impacts, storms and much stronger tides than today’s (because the moon was closer).

At some point, the system switched to replicators made of DNA, which is more stable than RNA and therefore more suitable for storing large amounts of information.

Yet virtually all subsequent organisms on Earth, to this day, have not only been based on DNA replicators but have used exactly the same alphabet of bases, grouped into three-base ‘words’, with only small variations in the meanings of those ‘words’.

In 1994 the computer scientist and molecular biologist Leonard Adleman designed and built a computer composed of DNA together with some simple enzymes, and demonstrated that it was capable of performing some sophisticated computations.