I’m strictly an amateur armchair cosmology fanboy. If I wanted to do the math that physicists do, I’d have to spend five or six years studying full-time, and even then it would be a struggle. But it’s fun to think about the questions cosmologists grapple with.
There’s a great deal we don’t know about the universe. Scientists gather masses of data and make brilliant guesses that are well supported by the data … but as most physicists will readily admit, modern physics is tattered around the edges.
For starters, we don’t know why there is something rather than nothing. Our best guess is that the universe began in a titanic explosion (the Big Bang) some 13.5 billion years ago — but what caused the explosion?
One school of thought is that our notions of cause and effect are based on the flow of time, but since time itself came into existence in the Big Bang, it makes no sense to talk about a prior cause. There was no “prior.” That may be a true statement about the nature of time, but I’m afraid it begs the question.
Physicists are now aware of a set of numbers (called constants) that define the way the universe works. If any of those constants was even slightly different, the universe as we know it would not exist. But they’re just numbers! Numbers are not things; they’re abstractions. How could the Big Bang, which was a very physical event, have included abstractions as essential components?
We don’t have a clue about that.
It’s not even clear that the universe is a place where logic is reliable. Logic works very well in our local area: If Bob is in the kitchen, we can deduce that Bob is not also in the bedroom. That’s logical. But logic was invented by Greek philosophers 2,500 years ago — and they did it without performing a single scientific experiment. Dare we assume that they somehow stumbled upon a set of rules that governs the entire universe, rigidly and forever?
Physicists in the 18th and 19th centuries had a hard time with that. It seemed to them that light had to be either particles or waves. It couldn’t be both, because that wasn’t logical! But eventually, in the early 20th century, it became clear that light is both particles and a wave at the same time.
At the very least, the grandiose supposition that logic always works (when speculating about the Big Bang, for instance) would seem to require some sort of proof. Unfortunately, you’d have to use logic to construct the proof, so even if the proof worked, you couldn’t trust it.
I have serious questions about dark matter and dark energy too, but we’ll save those for another time. What I’ve been thinking about lately are electrons.
There are squillions of electrons in the universe, right? There are probably a thousand trillion of them in your body right now, and the universe is vastly larger than you are. So here’s my question:
Why is it that all electrons are exactly alike? Why is it that some of them aren’t, perhaps, a little more massive than others, or a little more highly charged? Why is it that when oscillating around the nucleus of an atom (any atom, anywhere), all electrons exhibit exactly the same behavior? Why shouldn’t the Big Bang have produced a large or infinite variety of different electrons?
To put the question slightly more rigorously, why does the Pauli exclusion principle work? Pauli’s concept works nicely to describe the phenomena that physicists investigate, but why is that the case? Have all of those squillions of electrons taken grad courses in physics in order to learn what they’re supposed never to do? No, clearly we need a better explanation.
It seems to me that it’s a bit too easy, too glib, to look at an electron as a thing. An electron is not a thing. It’s not a little tiny lump of stuff that obeys certain laws. That would require either that the laws be an external force acting on the electron to force it to conform, which is pretty clearly not what’s going on; or, alternatively, that the laws are somehow embedded within the tiny lump of stuff which is an electron, and that makes no sense either.
As far as I can see, an electron simply is the behaviors that it exhibits. There’s nothing at the core of the electron, tucked away somewhere within the whirling cloud of behaviors. An electron has spin, but there’s nothing spinning. An electron has charge, but there’s nothing that has that charge.
As a thought experiment, we might imagine an electron drifting alone in an entirely empty universe. Just one electron, nothing else. In such a situation, the electron would have no mass, spin, or charge. Those characteristics exist only with respect to its interactions with other particles. (Or “particles,” if you prefer.) It’s not just that we can’t define a charge of -1 without adding a proton to this nearly empty universe; I’m saying that there would be no such thing as charge. Charge is a quality that exists only with respect to the interactions in which an electron engages.
Right now I’m leaning toward the idea that our own universe contains only one electron. And, I guess, one quark. And maybe I should say “electronness” rather than “electron.” If there’s only one electronness, and it’s everywhere, there’s no need to explain why all those separate electrons behave in an exactly identical fashion in every experiment we can devise. They’re not separate particles; they’re all the same essential thing (whatever that is). Our universe resonates in a constant state of electronness and quarkness.
If you think this idea has implications for our sense of identity as separate individuals, I won’t argue with you. I suspect it also has implications for the physics of the Big Bang, but I wouldn’t know. I can’t do the math.