# If a tree falls in the forest and no one is there to hear it does it make a sound?

1. Oct 24, 2009

### Monaco

I'm trying to put an end this age old question, but I want to translate it into form of an equation.

SOME SAY: No, because "sound" is ears interpretation of those waves.
I SAY: Yes, because it makes a "sound" (as defined by the vibrations). I'm going by text book definition. It makes sound because sound is a wave vibration of physical matter. Whether or not it gets heard (perceived by ears), that sound still resonates with other medium. (reflects off a tree, hits blade of grass.) To me, that's like End Of Story.

When I read about all the factors of sound being formed, sound in motion, sound being translated through medium... only in the end, in it's final stretch of it's lifespan does the sound get heard or not get heard. To me it's just as cut and dry as the sound wave exists = there is sound. Put a video camera out there. Not only will it give you hard evidence in Dolby stereo, but you can watch the events that caused it.

If y=tree falling and x=sound generated, how would you put into an equation that x is true regardless of the medium of translation?

2. Oct 24, 2009

### rootX

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

I never able to find answer for my question which is similar: What is the Sound of the Single Hand?

3. Oct 24, 2009

### BobG

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Put a window out in the middle of nowhere. Have a remote controlled plane break the sound barrier, creating a sonic boom.

Sound waves transmit energy.

4. Oct 24, 2009

### 27Thousand

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Although I don't agree with this, some will say if you put a video out there, it's making it so it's sound all of a sudden. They say it's putting a human like observer that relays it to humans. (Sounds kind of like a debate between Albert Einstein and randomness) They say without the video camera, you have no way of verifying there's actually sound.

Yes I know this wouldn't make sense based on what we know about sound and thus contradicting what we already know, and in addition to that goes against parsimony, but some would still use that argument.

I wonder if you can evaluate how the leaves/dirt around the fallen tree are moved about and then plug in some equations to see if their design match how sound vibrations would dictate, which is a more naturalistic scientific approach, but then you know what the critics will say. They'll say you observed the leaves and dirt!

5. Oct 24, 2009

### BobG

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

There's only one way to prevent anyone or anything from observing the sound. That's to transmit the sound into a vacuum. In that particular instance, I'd have to agree that there's no sound. Of course, then the tree wouldn't be falling in a forest.

6. Oct 24, 2009

### rootX

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

@OP:
Well, no one is there to observe. I think you cannot put any measuring device.

7. Oct 24, 2009

### 27Thousand

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Here's an idea, have a lab experiment where you drop a tree and observe how the vibrations moves the dirt nearby vs. dropping a tree in a vacuum in the lab to see how only the impact hitting the ground vibrates the dirt. (leaves probably won't be sensitive enough to air vibrations, need dirt) Then you can get a schema for how air vibrations (sound waves) moves the dirt versus when in a vacuum. That wouldn't test for sound waves traveling through solids, but rather would test for it moving through the air. That would be an experimental-control for figuring out sounds traveling through air, and then could be used to test the real life examples.

8. Oct 24, 2009

### NeoDevin

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

If a man says something in the forest, and there's no woman around to hear; is he still wrong?

9. Oct 24, 2009

### 27Thousand

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Good point.

10. Oct 24, 2009

### BobG

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

He was goofing off in the forest instead of home mowing the lawn, wasn't he?

11. Oct 24, 2009

### Monaco

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Ok, tree fall and either makes sound or doesn't make sound. Explain with an equation.

12. Oct 24, 2009

### Topher925

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Yes. Topher = always right.

13. Oct 24, 2009

### Jimmy Snyder

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

It's not a deep philosphical question, it's just asking how you define the word 'forest'.

14. Oct 24, 2009

### Santa1

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Define sound.

15. Oct 24, 2009

### B. Elliott

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

It doesn't become a sound until there is someone or something there to hear it. For it to be a sound, it requires there to be a receiver. Until then, it's just compression waves.

16. Oct 24, 2009

### Pinu7

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

[STRIKE]Define your mom.[/STRIKE]

The tree falling riddle is supposed to be interpreted more deeply, which I thought it would be taken more seriously because this is pertaining to the philosophy of physics. The question can be more directly reworded as

"If we do not observe a specific case of natural phenomena, yet we can predict it based on physical laws we established, does it still follow this law?"

or

"If an electron is not directly observed, does it still have a definite position."

The answer to the latter is commonly answered as No.

17. Oct 24, 2009

### GeorginaS

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

That's my thinking. Compression waves wafting through the air do not become "sound" until they react on an ear drum (human or animal) and all of that complicated stuff happens to transform the waves into electrical impulses that the brain interprets as a sound. Until all of that goes on, you've got nothing but waves.

Anb BobG's sonic boom may break the glass window, but that still doesn't make it a sound.

18. Oct 24, 2009

### Staff: Mentor

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

I'm more curious to know where this forest is that has trees but is devoid of all life.

My question would be "is it possible for a tree to fall in a forest where there is no life capable of hearing it?"

19. Oct 24, 2009

### GeorginaS

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Good point. Do spiders have eardrums?

20. Oct 24, 2009

### TheStatutoryApe

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

The point of the question has nothing to do with an actual scientific explanation. It is a zen koan. It is meant to question the nature of our perceptions and their relationship with reality. Sort of an ontological paradox. Similar ones are "What is the colour of the grass at night?" and as Sorry mentioned "What is the sound of one hand clapping?"

21. Oct 24, 2009

### Monocerotis

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Conservation of energy

/thread.

22. Oct 25, 2009

### Loren Booda

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

If Einstein falls to Bohr, is the Moon still there?

23. Oct 25, 2009

### Dadface

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

If there are no suitable detectors,observations or any other evidence then any assumptions we make are purely speculative.The majority opinion,including my own,is likely to be that a sound is made,the sound one would normally associate with a tree falling over.Somebody else may claim that the tree was singing Zip-A-Dee-Doo-Dah as it fell.Without evidence no assumption can be proved or disproved.
(It's the truth,its actual everything is satisfactual...to be sung to the tune of Zip-A-Dee-Doo-Dah......)

24. Oct 25, 2009

### Monaco

Re: If a tree falls in the forest and no one is there to hear it does it make a sound

There's no need, it's already defined:

Sound is a traveling wave.
Perception of sound is called hearing.

Here's where I'm going with this...

A cat says: "_____" and a dog says: "______". You just played it in your head right? That proves that we don't need ears to "hear". The hearing part of it is something going on in the brain. The ears can serve to assist the translation of sound waves, but the actually hearing is not dependent on them.

Last edited: Oct 25, 2009
25. Oct 25, 2009

### George Jones

Staff Emeritus
Re: If a tree falls in the forest and no one is there to hear it does it make a sound

Sorry for taking this somewhat off topic, but I can't resist posting a variant that I recently came across.

If a man makes a statement in forest, and there are no women around to hear it, is he still wrong?

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