Saturday, July 29

A dose of physics

Karen at Militus, Turkey. 

There's nothing better to heal the stress of current societal turmoil than a dose of physics. To spend an hour in the submicroscopic realm of quarks and photons, of spin clouds and quanta, is to leave the irksome deeds of the macroscopic world far behind.

I've been enjoying just that while reading Reality is Not What it Seems: The Journey to Quantum Gravity, by Italian physicist Carlo Rovelli. The author's first sentence pulled me in, for he describes a journey from Miletus to Abdera in the year 450 BCE. I have stood among the ruins of Miletus, in Turkey, and tried to imagine the great city as it once was. Rovelli's purpose, however, was to introduce us to Democritus of Abdera, the first atomist. Everything, he believed, was made of atoms, indivisible, freely moving in space. 

From there the author introduces, in succession, the great physicists and their ideas, from Isaac Newton, to Einstein, Neils, Werner, and more. It's a very readable book, and I recommend it. You don't need to understand loop quantum gravity or quantum mechanics (no one does) to appreciate that the world is both more complex, and simpler, than what we imagine. In fact quantum gravity predicts that the world is made of only one thing: covariant quantum fields. Try that on for size.

The search for quantum gravity is really the search for a unified theory, a way of understanding how both Einstein's general relativity and quantum mechanics—very different concepts—explain the same universe. Rovelli believes they are close to proving such a theory, but also admits it may never be found. But science progresses, and if you can believe that space is granular, that entangled particles communicate instantaneously across vast distances, and that time exists only when heat is present, you are half way there.

I willingly accept all this, but I'm puzzled most about consciousness. Quantum physics says that quanta exist as both particles and waves in a field of potentiality. That is, it is nowhere until observed, at which time it becomes a particle in a place—an electron in a light bulb for instance. This strange fact has been proven over and over again.

In laboratory experiments it is presumably a human who does the observing. But can the observer also be a machine? An animal? An insect? And how does the wave/particle know that it is or has been observed? Is it conscious? Does it recognize other consciousness? Is consciousness required in order for the world to exist? Is our collective consciousness creating reality around us? And what the heck is consciousness?

No one knows that either, apparently. I once read a book titled The Physics of Consciousness, hoping to learn the secret. Alas, it turns out the author didn't know, though he had a lot of interesting ideas.

I love physics. It's incredibly challenging and I admit I don't comprehend all that I read, but it opens my mind in ways that nothing else does. Rovelli says that physics is like fresh air through an open window. I like that. If you're depressed about the state of the country or the world I can't think of a better antidote. Reach for a physics book and take a deep dive. You may find the world is, instead, a place of endless potentiality. What could be better?

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