If a tree falls . . .

If a tree falls in the middle of a forest and there is no-one there to hear it, does it make a sound?

I have to say, that question has annoyed me ever since I first heard it more than twenty years ago. Does it mean sound as in the feeling of noise in our ears or does it mean sound as in a disturbance in the air? For many years, it struck me as a semantic hole into which to fall. What exactly was meant by ‘sound’?

I thought, maybe, that the question had first been asked back in ancient times before it was known how sound travels. There might have been some excuse. But, no! The first confirmed sighting of the phrase was in 1883, almost three hundred years after da Vinci discovered sound waves and two hundred years after the speed of sound in air was first measured.

My problem is that the question is wrong, or at the very least, irritatingly vague. Is it asking if ‘sound’ is a perceptual phenomena or is it asking the more fundamental question: are trees perceptual phenomena? Both are entirely valid questions but the lack of qualification of the word sound means that neither is really being asked.

I have a better alternative. Is there a rainbow?

In this case, it is possible to separate the perception of natural phenomena from the physical processes that create them? Asking Google, as I often do,

A rainbow is a meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets resulting in a spectrum of light appearing in the sky. It takes the form of a multicoloured arc. Rainbows caused by sunlight always appear in the section of sky directly opposite the sun.

Correct, but just a little bit vague. The refraction, reflection and dispersion bits are definitely okay by me. They do cause light to be split into a spectrum. However, the ‘appear word leaves something to be desired. Another quick search sorts that out:

appear /əˈpɪə:/ verb come into sight; become visible or noticeable, especially without apparent cause.

That’s better. The reason why? It’s about perception. There is no rainbow.

Imagine yourself standing at the edge of a bóithrín (small road) in the county of Kerry (just because it’s so nice there!). You’re looking over a wall into a field at a beautifully bright rainbow (they get the best I’ve seen there). Two fields over, because fields in Kerry are usually small, there is someone standing – right there at the end of the rainbow. Oh, how you wish you had their number. You could ring them and ask them to stay right where they are so that you could get over and dig for that pot of gold. But you don’t (have their number). And they can’t hear you because the wind is blowing in your face and carrying your voice behind you. Why can’t they see that they’re standing at the end of the rainbow and get digging?

Because they’re not. The beautifully intense rainbow that they are looking at is another two fields over from their perspective. Your rainbow and their rainbow are not the same because neither of them exists up there in the sky. There is only the appearance of a rainbow from each viewer’s perspective. Everyone looking sees a different rainbow and none of them exist in reality. They are only an ‘appearance’ of a rainbow, created from the perspective of the viewer in observing the effects of the reflection, refraction and dispersion of light. If no-one is looking, there is no rainbow. Even when someone is looking, it is something that only exists in their mind and, possibly, eyes.

This allows us to ask two distinctly valid questions in a far clearer fashion than the old chestnut about that tree in the forest:

  1. to what extent are our perceptions of reality created by our perspective? and;
  2. is there any external reality other than what is observed?

And it allows us to rephrase the tree question.

  1. If a tree falls in a forest and there is no-one there to hear it, does it create a noise-like sensation? Obviously not.
  2. If a tree falls in a forest and there’s no-one there to hear it, does it give rise to the air vibrating in the manner of sound waves? Obviously, yes! (The tree falls, therefore it exists and it is a fairly safe bet to say that the air in which it is enveloped exists also.)

It also allows us to separately ask the question the originator of the tree questions was probably driving at in the first place.

  1.  Is there a tree in a forest if there’s no-one there to validate its existence?

Who knows? In both the most advanced physics and the most ancient religions, that question is still up for grabs. Try attacking the question and the only logical conclusion is that the only thing any of us can be really sure of is our own sentience. Sure! It hurts when we stub our toe. But that could be just an over-active disembodied imagination floating around in nothingness looking for the appearance of sensations with which to amuse itself. Whether there is anything external to our own consciousness is something we can probably never prove but it certainly passes the time trying to find out.

So! Is there a rainbow? Only in our own little worlds!

Is there a tree? Maybe, maybe not.

Do the physical phenomena that give rise to a rainbow exist if no-one is looking? Yes, based on the tiny presumption that anything exists other than our own consciousness.

Does this matter in any way? Yes, actually, it does. An example …

It frequently appears to me, as I am helping my youngsters with their maths and maths-concepts homework that a mathematician has never been near the books that are handed out in junior school to teach our young minds mathematical concepts. Here’s a question I saw recently:

Which has a larger surface area – a table or a book?

Would that be a Miffy cloth book with four leaves and numerous shiny, reflective and colourful surfaces for a child of age six months? Or would it, perhaps, be War and Peace? At a mass-market size of 4″ x 7″ coming in at 1,200 pages (without endnotes etc) and with inner and outer covers, that would be 233 square feet. Even allowing for four chunky 4″ x 4″ x 3′ legs, that still leaves a table-top surface of 108′ – say 36 foot x 3 foot (11m2) –  big table! (It might need more legs to hold it up but you get the point by this stage, I’m sure).

The answer the book gives, of course, is that a table has a bigger surface area than a book. How does one explain tactfully, or should one even explain tactfully, to a six-year-old that the people who wrote their maths book don’t understand maths? I went through an entire school career spotting such inconsistencies in what was being taught and was frequently on the receiving end of the, ‘You’ll understand when you’re older’, line. I do! I feel sorry for the younger me, spotting illogic; not having the linguistic equipment to press home my point; not having the opportunity to sort out between what was incorrect and what I just didn’t understand. At times, it was a real disincentive to taking part in school.

And that’s my problem, more than anything. I don’t mind not knowing the answer. My favourite and most quoted movie line is, ‘I’m ignorant, not stupid!’ Ignorance is an opportunity to learn and discover. Trying to find the answer to a badly-phrased question is just annoying!

So there are such things as wrong questions; bad questions. Principally it is a matter of being unclear or not specific. So do your best to ask clear and specific questions. I, at least, will be happier for it.

So glad to get that all off my chest after all these years! 🙂