A tree falls in a forest...

[Twasbrillig]

Ok. I've been pondering on this timeless question for a while.
If a tree falls in a forest (or anywhere for that matter) and nobody is around to hear it, does it make a sound?

I'm mad that the mods locked this. Even though it's more science than logic.

I was so vehemently taught in science 8 that sound is not sound when it is without any of these 3 things: a creator, whatever may issue the sound; a medium, the way by which the sound travels; and a receiver, something to "hear" the sound.

If said tree was in a vacuum, or even in an air-filled sphere that was completely soundproof or a distance away from any sentient beings, then no, it would not make a sound. QED.

[adlaiff6]

If a tree falls in a forest, it creates vibrations in the air. Whether you call that sound (the alternative being that those vibrations only become "sound" when perceived by a human) is up to you.

[Crane]

Indeed, it's a question of semantics more than logic or science.

[Gordon]

If a tree falls in a forest, it creates vibrations in the air. Whether you call that sound (the alternative being that those vibrations only become "sound" when perceived by a human) is up to you.

Indeed, it's a question of semantics more than logic or science.

Twas, neither HOTkyle nor yourself posited this in such a way to make it a 'Science' question. Can we try to keep this sub-forum for more actual science discussions and not silly debates over old hypotheticals (or whatever you want to call that).

I'll let this stand for a while just so people can get it out of their system and so we don't have a third thread started.

[evilbeanfiend]

id say it was a philosophical question.

the science 8 definition of sound is a little suspicious. generally you would say that without an observation the sound neither exists nor doesn't exist.

[Andrew]

id say it was a philosophical question.

I don't see why.

The tree certainly makes the air vibrate. If you call that sound then the answer is yes. But if nobody hears it then it certainly doesn't cause signals to be sent to someone's brain which could be interpreted as "hearing a sound". So if that's what you call sound then the answer is no. That's semantics.

It only becomes philosophy when you start to get all problem-of-induction on it and say stupid things like "ah, but just because every time we've seen a tree fall over there's been a lot of sound doesn't mean to say that they still do it when we're not listening. They might not bother when there's nobody around to hear it".

And yes, you could argue that point all afternoon and probably nobody could really refute it, because obviously nobody's seen a tree fall over when nobody was around, but I think that would be more of an exercise in stubbornness than in philosophy. For all practical purposes, and all useful theoretical purposes, the tree does exactly the same thing regardless of who is watching (unless it's in a sealed box and was felled by the random decay of a radionuclide), because the tree has no idea we even exist.

[evilbeanfiend]

id say it was a philosophical question.

I don't see why.

really?

The tree certainly makes the air vibrate. If you call that sound then the answer is yes. But if nobody hears it then it certainly doesn't cause signals to be sent to someone's brain which could be interpreted as "hearing a sound". So if that's what you call sound then the answer is no. That's semantics.

It only becomes philosophy when you start to get all problem-of-induction on it and say stupid things like "ah, but just because every time we've seen a tree fall over there's been a lot of sound doesn't mean to say that they still do it when we're not listening. They might not bother when there's nobody around to hear it".

exaclty

And yes, you could argue that point all afternoon and probably nobody could really refute it, because obviously nobody's seen a tree fall over when nobody was around, but I think that would be more of an exercise in stubbornness than in philosophy.

what exactly do you think philosophy is if that isn't it? specifically metaphysics and epistemology seem to be rather relevant.

[Andrew]

what exactly do you think philosophy is if that isn't it?

It just seems like you can do really interesting things with philosophy -- think about really different and novel ways universes could exist and operate, or try to construct consistent and structured codes around morals people generally think of as being disparate rules, or come up with a new way to run a civilisation that may or may not work, whereas this is just saying "yeah, but how do you know?" to anything and everything in what seems to me to be a rather petty and childish way.

I don't think that's what 'philosophy' ought to be about.

The "tree in the woods" thing is only even passably interesting if it's massively generalised, far beyond anything that can be summed up by "if a tree falls in the woods".

[evilbeanfiend]

...whereas this is just saying "yeah, but how do you know?" to anything and everything in what seems to me to be a rather petty and childish way.

that would certainly not get you published . that point is that philosophy, in particluar metaphysics often discusses things you can't know, as opposed to physics, which solely concerns itself with things that you can know (even if you can't conduct an experiment about it yet).

clearly when discussing things you can't find an answer to, you wont find an objective answer but the reasoning may be interesting. (for instance consider this short discussion we had, neither of us can objectively state what the original meaning of the question is, but through debate we have 2 different interpretations).

[Cosmologicon]

It just seems like you can do really interesting things with philosophy -- think about really different and novel ways universes could exist and operate, or try to construct consistent and structured codes around morals people generally think of as being disparate rules, or come up with a new way to run a civilisation that may or may not work, whereas this is just saying "yeah, but how do you know?" to anything and everything in what seems to me to be a rather petty and childish way.

I don't think that's what 'philosophy' ought to be about.

I think you've made up your mind about this, but let me point out that doing this made Descartes famous to people who don't like Cartesian coordinates. He sort of rejected Occam's Razor and inductive reasoning, and decided that he wouldn't conclude anything he didn't know by logic alone.

He wasn't very good at it, though, and it went downhill after Cogito ergo sum: he managed to "prove" Euclid's fifth postulate (which is false in this universe) and also the existence of God.

[Andrew]

that point is that philosophy, in particluar metaphysics often discusses things you can't know, as opposed to physics, which solely concerns itself with things that you can know (even if you can't conduct an experiment about it yet).

Yeah, I know. It's just the whole "how do you know it happens the same way when nobody checks" seems so profoundly pointless it's not worth considering. I mean, there's no actual reason I've ever heard why the presence of an observe should alter anything. It's just pedantry taken to its illogical extreme -- "right, now prove your experiment still works when you don't record the results". It's a scenario constructed specifically so that nobody can ever check the answer directly -- and is in no other way different to the 'normal' scenario where falling trees make noise. And even if you could prove that trees falling in deserted woods were obtusely silent, by definition it wouldn't matter.

I have a feeling this might just be my hangup, and I expect I'll start repeating myself if I haven't already, so unless I see good reason not to I think I'll just quietly duck out of the discussion here. But that's how it always seems to me.

[Fieari]

But isn't the existence of an observer a crucial factor in whether the double slit experiment says light is made of particles or waves?

[simen]

Sorry guys, but this one has pretty much been solved.
http://physicsweb.org/articles/news/11/4/14
The tree DOES NOT FALL when we aren't looking. It simply lays on the ground whenever we check in on it. Thus, no sound.

[oblivimous]

The question here is this: "do phenomen exist independently of observation?" As the previous post says, it is very interesting that modern physics has finally contibuted to this question.

I like this this version: If all humans and animals on earth were instantly and permenantly blinded by a burst of solar radiation, would apples still be red?

Is redness simply the property of reflecting a certain frequency of the EM spectrum or is redness the property of "appearing red to the eye"? I choose the latter. The apples in my dreams are red, even though they don't reflect light, as was Adam's apple, even though it didn't actually exist. If somehow an object was created that didn't actually reflect red light but through some other means stimulated my retinal cells to create a red signal, or even stimulated my optical cortex to interpret red, I say it qualifies as a red thing also.

[Strilanc]

Sorry guys, but this one has pretty much been solved.
http://physicsweb.org/articles/news/11/4/14
The tree DOES NOT FALL when we aren't looking. It simply lays on the ground whenever we check in on it. Thus, no sound.

That's an oversimplification. How do you know whether or not to hear the tree if you're close by but looking in the opposite direction?

[Andrew]

But isn't the existence of an observer a crucial factor in whether the double slit experiment says light is made of particles or waves?

I don't know enought Quantum to answer that, but I'd bet my bottom 50p that the "observer" in question doesn't require a conciousness, which I tend to assume the philosophy version would. I can't see how you could make a physics theory that included the phrase "unless nobody's looking" and not be laughed off the stage.

[HOTkyle]

Thanks everyone.
This gives me more to chew on.

[ZeroSum]

"What color is that house?"
"The side facing us is white."

[TheLordOfPhysics]

Sorry guys, but this one has pretty much been solved.
http://physicsweb.org/articles/news/11/4/14
The tree DOES NOT FALL when we aren't looking. It simply lays on the ground whenever we check in on it. Thus, no sound.

That's an oversimplification. How do you know whether or not to hear the tree if you're close by but looking in the opposite direction?

The tree obviously makes noise. Whether your looking at it or not it doesnt matter becasue you can still hear something if its behind you.

[mrandrewv]

Well Psychology is a science goshdarnit and I've always liked this existential psychological answer the best:

It isn't the sound the tree makes this is important.
It's the hole that is left behind when the tree is gone...

:'(

[knight427]

Well Psychology is a science goshdarnit and I've always liked this existential psychological answer the best:

It isn't the sound the tree makes this is important.
It's the hole that is left behind when the tree is gone...

:'(

Let me, for jut one moment, ignore the fact that your statement in no way addresses the original question. You are making a value judgment in the absence of context. Perhaps the tree was felled by a starving person trying to earn enough money to feed his family (this happens in our world quite often). Would you still say that the important thing is the hole left behind?

Additionally, you are suggesting that the original question has no value and you wish for us to ponder the consequences of deforestation. There is nothing wrong with that, but it certainly belongs in another thread, if not another forum.

knight427

ps I was totally going to Godwin this thread, but thought better of it
pps it was something along the lines of “You know who else left holes behind...â€

[arbivark]

if no one was around to hear it, it wasn't in a forest. actual forests have lots of ears per acre. this doesn't answer the question, but it's relevant somehow.