If a tree falls in the forest, and nobody is there, does it make a sound?
If your answer is, “obviously, yes.” stop reading now. Go out and have a coffee. Talk to a friend. Read a book. Or go for a walk. Because the rest of this post will mean nothing to you.
If, on the other hand, you are willing to pursue the idea that no – if there is no one there to hear it, then there is no sound, then we just might be able to reflect in a way that combines physics, psychology, philosophy, and theology…
So. You’re still here.
Here’s the psychology and some of the physics bit:
Branches and trunks striking the ground create rapid pulses of air. So, what we have in hand, in actuality are rapid air-pressure variations, which spread out at around 750 mph. This, according to simple science, is what occurs even when a brain-ear mechanism is absent—tiny, rapid, puffs of wind. There’s no sound attached to them.
Now if a person is nearby, the air puffs cause the ear drum to vibrate, which then stimulates nerves only if the air is pulsing between 20 and 20,000 times a second (or less for us whose youth included rock concerts). Air that puffs 15 times a second isn’t intrinsically different from air that pulses 30 times, yet the former will never result in a human perception of sound. In any case, nerves stimulated by the moving eardrum send signals to the brain resulting in the cognition of a noise. Only then does human consciousness conjure the noise experience. In short, an observer, an ear, and a brain are every bit as necessary for the experience of sound as are the air pulses. The external world and consciousness are correlative.
When someone dismissively answers, “Of course a tree makes a sound if no one’s nearby” they’re merely demonstrating their inability to ponder an event nobody attended. They’re finding it too difficult to take themselves out of the equation. They somehow continue to imagine themselves present when they are absent.
Yes. Do read the rest of that article if you are enjoying that.
In that article, the author also said:
We’ve accepted the big bang, even though it provides no explanation for why the universe is exquisitely fine tuned to support life.
Let me add more of a physics bit to that: if the strong nuclear force, or the weak nuclear force, or the gravitational constant, or any of the other physics numbers were dialed to be even the slightest, tiniest percentage different to what they are in our actual universe – we would not exist. Sentient beings evolved in this universe because the dials of those constants are set as they are.
[OK. Bracket bit: I often meet people who get confused what the universe is. They think it is our galaxy or whatever. Universe is the whole lot - everything we can see, measure, access via science, instruments, etc. "Other universes", "Parallel universes" are "things" we cannot access, measure, get to, examine scientifically, etc - if we can, then that's still our universe.]
So. The fine tuning of our universe is a bit of pain for atheists. And especially for anti-theists. We end up with an anthropic principle – the universe seems to be designed so that sentient beings evolve.
Most atheists and anti-theists respond with – well there must an infinite number of universes, we just accidentally happen to be in the one in which accidentally sentient life evolved. Fair enough (but wait!) Theists regularly respond to that with Occam’s razor (the simplest solution is best): you believe in multiple universes, I believe in the creating God (and important note – multiple universes existing is a belief. If you can access them scientifically then that is part of this universe). But there is another way than Occam’s razor.
Still here? Because here’s the clincher:
Those other universes don’t exist. Something only exists if there are sentient beings able to observe it.