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Candy
2005-May-05, 07:11 PM
If a tree falls in the forest and there is nobody around does it make a sound?

Iím sure itís been discussed before, but Ö (http://www.badastronomy.com/phpBB/viewtopic.php?p=373008&highlight=atp+made#373008)! :P

Sam5
2005-May-05, 07:17 PM
If a tree falls in the forest and there is nobody around does it make a sound?

I’m sure it’s been discussed before, but … (http://www.badastronomy.com/phpBB/viewtopic.php?p=373008&highlight=atp+made#373008)! :P

A falling tree vibrates the air, but “sound” is only in human and animal brains.

SeanF
2005-May-05, 07:22 PM
If a tree falls in the forest and there is nobody around does it make a sound?

Iím sure itís been discussed before, but Ö (http://www.badastronomy.com/phpBB/viewtopic.php?p=373008&highlight=atp+made#373008)! :P

A falling tree vibrates the air, but ďsoundĒ is only in human and animal brains.
Not necessarily. First definition of sound (http://dictionary.reference.com/search?q=sound):


Vibrations transmitted through an elastic solid or a liquid or gas, with frequencies in the approximate range of 20 to 20,000 hertz, capable of being detected by human organs of hearing.

jfribrg
2005-May-05, 07:23 PM
Before this is answered, lets get some definitions, especially the term "makes a sound". The silly arguments usually go like this:

Person 1: Of course it makes a sound

Person 2: If nobody hears it, how do you know?

Person 2: Because Newton's laws show that some of the Tree's kinetic energy must cause the air to be disturbed. Some of this disturbance is what we perceive as sound.

Person 1: But if nobody hears it, how do you know?

Person 2: Because it has alway happened and the physics describing the situation is well known, and it will happen every time in the future.

Person 1: But if nobody hears it, how do you know?

Nothing progresses after this. Then there are abuses of the Heisenberg uncertainty principle that state that we don't even know that the tree is in the forest, or even if there is a tree.

So before we start, we need a definition of sound: Is the sound defined as the wave energy caused by a falling tree (that would be heard if a person is there), or is the sound the effect of such wave energy on the ear?

farmerjumperdon
2005-May-05, 07:28 PM
This will probably come done to how people define terms like sound, noise, etc. IMO, the requirements for something called sound are an event that is capable of generating energy waves and a medium through which the wave can move.

I've read something somewhere that says the wave must be detected to be a sound, but IMO the medium satisfies the criteria of being detected just as well as an eardrum or microphone does. So where would you draw the line?

Does it have to be heard by a human to be considered a sound? Or will any creature do? Or is having an impact on anything at all, such as causing a surface to vibrate, good enough?

Sam5
2005-May-05, 07:40 PM
This will probably come done to how people define terms like sound, noise, etc. IMO, the requirements for something called sound are an event that is capable of generating energy waves and a medium through which the wave can move.



Those are just vacuum and compression waves in the air. The thing we call “sound” is only inside our brains.

It’s like an old phonograph record. What you see on the record is wiggle lines on a plastic disk. This is not “sound” until it is converted by an amplifier and speaker system into compression and vacuum waves in the air, then converted into biological electrical impulses due to the resonation of cilia in your ear, and then the electrical impulses are converted into “sound” by your brain.

jfribrg
2005-May-05, 07:45 PM
The other argument I hear in this respect is that just because it has always happened in the past, how can you guarentee that it will happen in the future? After all, we don't have perfect knowledge of the system. It is very similar to the doomsday arguments relating to planetary alignments.

WaxRubiks
2005-May-05, 07:55 PM
This can relate to the whole Universe in that up until a certain time there were no Beings(Terrestrial or otherwise) to observe anything that happened in the Universe.
Does a star go nova if there are no astronomers to detect it?

SeanF
2005-May-05, 08:01 PM
Those are just vacuum and compression waves in the air. The thing we call ďsoundĒ is only inside our brains.
I linked to the dictionary definition, Sam - it applies the word to the vibrations themselves. Maybe what you call sound is the perception of those vibrations, but it's not what we call sound. :)

Sam5
2005-May-05, 08:08 PM
Candy asked a specific question and I gave her a scientific answer.

farmerjumperdon
2005-May-05, 08:12 PM
So there you have it. One school of thought says it's the vibrations themselves, and the other school of thought says it's the human detection of the vibrations.

My Office & School Edition of Webster's says it's "stimulation of the auditory nerves by vibrations in the air."

Highly suspect since I can hear underwater. Also somewhat species-centric since some animals detect the vibrations thru means that we probably would not consider as sound.

Guess I did not help much.

WaxRubiks
2005-May-05, 08:15 PM
You sometimes hear sounds in dreams(I think) and that has nothing to do with air vibrating.

Tunga
2005-May-05, 08:16 PM
I think use of a audio tape recorder could resolve issue!

farmerjumperdon
2005-May-05, 08:24 PM
Good point about the dreams. No different in considering a daydream though, heh? So if I have a song going in my head, does that qualify as sound? If no, than neither does the dream.

I still think the best definition is an event that creates energy waves and a medium in which they can move. Any detection device at all is good for me, and the medium serves that role nicely.

I like this best because I came up with it. :roll:

Sam5
2005-May-05, 08:25 PM
A more difficult question to answer is:

“Is the ‘red’ at a car tail light actually at the tail light or is it only in your brain?”

WaxRubiks
2005-May-05, 08:31 PM
does a book have a good end if you don't read it?

Celestial Mechanic
2005-May-05, 08:54 PM
This sounds like the kind of thread Richard J. Hanak would be interested in!
:)

Normandy6644
2005-May-05, 08:57 PM
A more difficult question to answer is:

ďIs the Ďredí at a car tail light actually at the tail light or is it only in your brain?Ē

We define a specific color in the visible light spectrum as "red." A priori it has no name, only physical characteristics. But labelling it something else wouldn't change what it really is. And if your brain doesn't see red, it's an inability to convert those physical properties of the light into electrical impulses to your brain. It's still "red."

Sam5
2005-May-05, 09:17 PM
A more difficult question to answer is:

“Is the ‘red’ at a car tail light actually at the tail light or is it only in your brain?”

We define a specific color in the visible light spectrum as "red." A priori it has no name, only physical characteristics. But labelling it something else wouldn't change what it really is. And if your brain doesn't see red, it's an inability to convert those physical properties of the light into electrical impulses to your brain. It's still "red."

The question is, is the color “red” at the tail light or only in your brain?

mike alexander
2005-May-05, 09:18 PM
http://www.m-w.com/help/faq/words_in.htm

This might help. Or not.

It's a description of how words get into a dictionary. Note that correct or incorrect are fluid notions in dictionaries. Since words are defined by a sort of statistical summary of usage, a dictionary is more of a consensus than, say, a periodic table.

tlbs101
2005-May-05, 09:35 PM
I have another "wrench" to throw into this thread.

First of all, I am in the sound-is-energy-in-the-media(air,etc) camp. Whether someone is there to hear it or not, a sound is made.

Here's something for you other folks to think about. Even if no one is there to hear it, that energy of the falling tree (or even a butterfly flapping its wings) will eventually cause something to happen (maybe rain to fall 100 miles away, where no rain was supposed to fall) -- i.e. the "butterfly effect".

The exact state of the physical parameters of the Earth and the atmosphere will be changed by a tree falling in the woods. Something will be detectable, somewhere, attributible to that event.

Now, how the effect can be attributed to the falling tree (or butterfly) is another matter for the mathemeticians, geologists, and meteorologists to figure out, but at least we have some reason to know the tree fell in the woods when no one heard it.

Lurker
2005-May-05, 09:38 PM
Before this is answered, lets get some definitions, especially the term "makes a sound". The silly arguments usually go like this:

Person 1: Of course it makes a sound

Person 2: If nobody hears it, how do you know?

Person 2: Because Newton's laws show that some of the Tree's kinetic energy must cause the air to be disturbed. Some of this disturbance is what we perceive as sound.

Person 1: But if nobody hears it, how do you know?

Person 2: Because it has alway happened and the physics describing the situation is well known, and it will happen every time in the future.

Person 1: But if nobody hears it, how do you know?




If I drop a hammer in a gravitational field of 1G I need not see it fall to know that it must indeed do so.

eburacum45
2005-May-05, 10:15 PM
Two things; the existence of a forest implies a population of animals, large and small; it would seem to be impossible for a forest to exist without a population of creatures, many of which have sound detection apparatus (they might hear using their ears, or their legs, or their abdomen- but they hear a sound). I have always objected to the anthropocentrism in this thought experiment.

The other thing that occurs to me is; if someone hears a tree fall in the forest does that mean it really has occured? An auditory hallucination of some sort might lead a listener to believe that a tree has fallen when it has not.
In fact it is just possible that trees do not in fact ever make a sound when they fall- it could all be a hallucination.

Just considering all the possibilities...

WaxRubiks
2005-May-05, 10:20 PM
you never hear the tree that hits you......

A Thousand Pardons
2005-May-05, 11:39 PM
ToSeeked (http://www.badastronomy.com/phpBB/viewtopic.php?p=425282#425282) by ToSeek, and uh Nicolas, and maybe others since we lost all the prunes

Maha Vailo
2005-May-05, 11:44 PM
IIRC, the philosopher who orginally came up with that question said: Yes, the tree would make a sound because God would be able to hear it.

- Maha Vailo

Normandy6644
2005-May-05, 11:52 PM
IIRC, the philosopher who orginally came up with that question said: Yes, the tree would make a sound because God would be able to hear it.

- Maha Vailo

Berkeley I believe was his name. That was his explanation for why things don't spontaneously go in and out of existence, because God experiences all things.

Stregone
2005-May-05, 11:57 PM
At the most basic level (quantum mechanics) any interaction is equivilent to measurement or detection. For example, a photon doesn't care if it hits a rock, an air molecule, or a photon detector, in each case it was detected and forever changed. The earth, the moon, and all the planets 'detected' asteroids before there was anything living here. And so on. Sound waves are simply the by product of some gas/liquid (or even solid actualy) 'detecting' something hit or move through it.

Charlie in Dayton
2005-May-06, 03:22 AM
And as a corollary, check the sig...

Enzp
2005-May-06, 04:25 AM
If a tree falls in the woods and no one is around, how do we know it really fell?


The butterfly effect applies to inherently unstable systems, but not to stable ones. He flaps his wings and the tiny displacement will fade away into the noise.

One of my all time favorite science demonstrations - to demonstrate fission - is the floor full of cocked mouse traps, each with a pair of ping pong balls siting on it. Trigger the trap and the balls go flying. Cover the floor with these things, and it sits there until you trigger it. All it takes is one ping pong ball tossed into the pile, and it sets off one trap, which sends two balls out that each trip anothre thrap and so on until in a blink, hundreds of ping pong balls are flying around. All those cocked traps are unstable in the face of stimulation. The first stimulus avalanches the rest.

Now cover the floor with mousetraps but don't cock them. Now there is no instability waiting to fly. Toss in a ball and it will bounce to rest. Any balls it displaces will in turn also roll to rest.

Inferno
2005-May-06, 04:28 AM
If a tree falls in a forest and hits a mime, does anyone care?

Enzp
2005-May-06, 04:48 AM
A mime is a terrible thing to waste...

captain swoop
2005-May-06, 08:37 AM
If a tree falls in the forst, do the other trees laugh at it behind it's bark?

Fram
2005-May-06, 11:11 AM
If you have just enough trees to form a forest, and one tree falls, does it still fall in the forest or is it then a forest no longer? 8-[

Sounds like the beginning of a poor joke: how many trees do you need to make a forest?

Disinfo Agent
2005-May-06, 12:32 PM
IIRC, the philosopher who orginally came up with that question said: Yes, the tree would make a sound because God would be able to hear it.

- Maha Vailo
Berkeley I believe was his name. That was his explanation for why things don't spontaneously go in and out of existence, because God experiences all things.
Isn't the question from Zen philosophy? :-?

Celestial Mechanic
2005-May-06, 12:45 PM
And let's not forget this chestnut:

If Helen Keller falls in the forest, does she make a sound?

Swift
2005-May-06, 12:46 PM
If a tree falls in a forest and hits chef Emeril Lagasse, what sound does it make? :-k

BAM!
#-o :D

mickal555
2005-May-06, 01:00 PM
What is the sound of one hand clapping

captain swoop
2005-May-06, 01:15 PM
Swish?

mickal555
2005-May-06, 01:24 PM
Sort of a kind of vootif vootif noise...

pghnative
2005-May-06, 02:40 PM
If a man speaks in the forest, and no woman is around to hear him, is he still wrong???

Candy
2005-May-06, 03:03 PM
If Kelsey Grammar falls of the stage... #-o

Grey
2005-May-06, 03:12 PM
... would they need a "Crane" to lift him back up?

Swift
2005-May-06, 06:38 PM
I googled around on "tree falls forest" (mostly looking for jokes) and found this (http://www.getodd.com/stuf/treefall.html) strange website.

If a tree falls in the forest and there is nobody nearby, the sound that it makes is very different and often not recognized as the sound of a tree falling.

Even though plants do not show any changes to the naked (or lensed) eye, when a human is in their presence systemic biological changes have been discovered that have grave effects on plant life when a person is within 300 meters. This effect is called "human stress syndrome".

Apparently, when a tree is about to fall, if it senses a human nearby the biological stresses of human presence cause the cell walls in the plant to become brittle and it is the cell brittleness responsible for the familiar sound we know as that of a tree fall. The cell brittleness also has significant effects to the quality of the lumber, making it much more suitable for use in construction (see below).
Trees sense people and get brittle? :roll:

There is also this...

All trees, except the Ohio Buckeye tree, when in the presence of humans, emit a faint cloud of ultraviolet gasses.
My Ph.D. in chemistry somehow didn't cover "ultraviolet gasses".

But hey, go Buckeyes! :lol: