The knowledge machine

 That's the title of a book my Michael Strevens, which I recommend. (Liveright, New York, 2020)

Strevens presents his own take on the philosophy of science accessibly and persuasively. If you've even dabbled in this area you've heard of the so-called demarcation problem -- how can we tell science from pseudoscience -- and the two best-known modern conceptions of science, Kuhn's construct of paradigms and paradigm shifts, and Popper's construct of falsfiability. Strevens doesn't think Kuhn or Popper are quite right. However I would say that without quite realizing it, he's pretty close to Popper -- he just notes that falsification is often harder than it might seem. 

I won't back up and try to go machete my way through all that brush in a blog post, but I did want to respond to a comment -- anonymous, so I can't publish it anyway -- to the effect that "Atheism is a belief system. It requires faith." Err, no. On the contrary.

To make this simple enough for a blog post -- and it may actually seem too obvious -- the nature of science, the breakthrough that produced Isaac Newton and the revolution he sparked around the turn of the 18th Century, was that it refers for authority only to observable reality. Newton was actually religious, although he was a heretic. He did not believe in the trinitarian God, a sacrilege he was forced to conceal lest he lose his position at Cambridge. But he kept his religious beliefs entirely separate from his scientific investigations.

In his scientific investigations, he also refrained entirely from speculation. By the way, he also secretly practiced alchemy, in which endeavor he speculated wildly, but again, he kept that separate from science. What is notable about this theory of gravity is that it describes the attraction between massive bodies, but does not try to explain it. The force of attraction is equal to the product of the masses of the objects times a constant, divided by the square of the distance between them. That's it. 

 

He didn't know why this was true, but he did show that it predicted the motion of the heavenly bodies and of falling objects, therefore it was true, and it is true. Einstein later concluded that massive bodies warp space-time, such that bodies following the shortest path through space-time will experience an apparent force of attraction. This may be considered an explanation of the cause of gravity, but obviously that just begs the question of why massive bodies warp space-time, and we can't answer that either. Doesn't matter -- Einstein's theory makes slightly different predictions than Newton's simple equation under extreme conditions, and they turn out to be correct, as far as we can tell within our capacity to measure.

 

Putting together Einstein's theory of gravity with the quantum theory of the other forces of nature, and their associated particles, along with observations of the universe using various sophisticated instruments, scientists have determined what should by now be a familiar story. About 13.8 billion years ago, what had been an unimaginably hot, dense and tiny entity suddenly began to expand and cool, unimaginably quickly, and the particles and forces we know today condensed out of the primordial singularity. I won't go into further details about he we got from there to here, on our 4.54 billion year old planet with our eukaryotic multicellular bodies and our neuron-based minds, but believe me, the story completely hangs together and every attempt to falsify it fails. 

To be sure, there is a whole lot we don't know, including not only the mysterious so-called dark mass and dark energy, but also the even more intriguing questions of why the whole thing happened and why the universe is the way it is. Maybe we'll eventually get some sort of answers to those questions but then obviously there will be the next question, why is that, whatever it may be? A few more important obvious facts are that the stories in the Bible are not true, and that includes the God of the Old and New Testaments who cannot possibly exist. The same goes for whatever sort of god or gods people have believed in throughout history and that some believe in today. The concept is internally contradictory and inconsistent with observable reality.

What scientists, starting with Newton, do not do (at least not as scientists, though they may well do it after they punch out) is a) speculate and b) rely on authority, be it religious or as in the case of medieval scholars ancient writers of any kind be they Aristotle or Galen. 

 

You may want to claim that some vastly powerful intelligent entity brought the universe into being 13.8 billion years ago with the intention of bringing into existence 13.8 billion years later some specific organisms living in a thin coating of slime on one of hundreds of billions of rocks circling hundreds of billions of stars in one of hundreds or maybe thousands of billions of galaxies, but you have absolutely no basis for believing that and it seems to me completely ridiculous. That's not a matter of faith -- show me good evidence and I'll change my mind. It's a matter of empirical reality.