If a tree fell and no one was around...

[Baby Astronaut]

...it does make a sound.

 

Why?

 

The universe doesn't need our presence for its laws to function. How do I conclude that? Because the universe has existed longer than our fossil record indicates.

 

And sound waves do occur without the presence of a biological listening apparatus. It can be tested: just place a glass chalice along with a machine that emits a high pitched electronic sound deep into the woods away from human ears, come back and observe if the glass shattered. Voilà

[toastywombel]

Yeah. . .good post and interesting experiment. But I think this might be seen as a rather dull topic. I think it is widely known that if a tree falls it makes a noise, even if there are no observers.

[Tugrul]

2 words observer effect

[ydoaPs]

deleted

[JohnB]

I believe your question to be incomplete.

 

The correct phrasing is;

 

"If a tree falls in the forest and hits a mime, does anyone care?"

[iNow]

The correct phrasing is;

 

"If a tree falls in the forest and hits a mime, does anyone care?"

 

Close, but the correct version really is:

 

"If a man speaks in the forest and a woman is not around to hear him, is he still wrong?"

[bascule]

The universe doesn't need our presence for its laws to function.

 

However quantum mechanics has demonstrated that the universe acts differently when we're looking as opposed to when we let it be.

[UC]

However quantum mechanics has demonstrated that the universe acts differently when we're looking as opposed to when we let it be.

 

That depends on how you're observing the system. In this case, intercepting vibrational waves outside of the area of the event and in a time after the event has occured is highly unlikely to alter the state of the tree having made a sound. When you have to directly perturb the system to make a measurement, things get ugly.

 

The real question is "If a quantum mechanical tree falls in a one-dimensional forest and no physicist is around to calculate the expectation values, does anyone care?"

[ydoaPs]

However quantum mechanics has demonstrated that the universe acts differently when we're looking as opposed to when we let it be.

 

It should be noted that any interaction with anything is an 'observation'.

[Baby Astronaut]

The correct phrasing: if someone happened to die by accidentally slipping on a banana peel, will mentioning it cause giggles at their funeral?

 

"If a tree falls in the forest and hits a mime, does anyone care?"

I'm sure the mime's parents care.

 

(we all know mime school's very expensive)

 

(on a side note, wonder if anyone posting on these forums is a mime?)

 

However quantum mechanics has demonstrated that the universe acts differently when we're looking as opposed to when we let it be.

As others have said, the naked eyes without viewing instruments aren't likely to change what's being observed.

Edited November 10, 2009 by Baby Astronaut

[JohnB]

"If a man speaks in the forest and a woman is not around to hear him, is he still wrong?"

 

Mate, I'm married. I know the answer to that one.

[Mr Skeptic]

...it does make a sound.

 

Why?

 

The universe doesn't need our presence for its laws to function. How do I conclude that? Because the universe has existed longer than our fossil record indicates.

 

And sound waves do occur without the presence of a biological listening apparatus. It can be tested: just place a glass chalice along with a machine that emits a high pitched electronic sound deep into the woods away from human ears, come back and observe if the glass shattered. Voilà

 

Oh, but will the glass be broken if nobody comes back to look at it?

[A Tripolation]

Oh, but will the glass be broken if nobody comes back to look at it?

 

Pure Awesome, Mr Skeptic. Props on that one.

[bascule]

Blah, you nitpickers

 

I was referencing the phenomenon of waveform collapse. No need to get all pedantic on me.

[nouusgnostic]

are you talking about another Schrodinger's cat?

[tomgwyther]

This topic has been explored endlessly.

If a tree falls in a forest and there's no body around, it does not make a sound.

In order for it to be a sound, it must be heard by some one.

Sound is described as...

the subjective sensation of hearing something; "he strained to hear the faint sounds"

the particular auditory effect produced by a given cause; "the sound of rain on the roof"; "the beautiful sound of music"

 

When the tree falls, it makes the air around it vibrate. this is not strictly a sound though.

a sound is a subjective personal experience.

 

Another way of putting it

"If someone tells a joke and nobody hears it, do his audience laugh?"

answer no, as there is a false dichotomy in 'nobody' and 'audience'

as there is in 'nobody' and 'sound'

[hermanntrude]

....No need to get all pedantic on me.

 

seriously. You come to a science forum and ask us not to be pedantic???

 

really???

[DrP]

This topic has been explored endlessly.

If a tree falls in a forest and there's no body around, it does not make a sound.

In order for it to be a sound, it must be heard by some one.

Sound is described as...

the subjective sensation of hearing something; "he strained to hear the faint sounds"

the particular auditory effect produced by a given cause; "the sound of rain on the roof"; "the beautiful sound of music"

 

When the tree falls, it makes the air around it vibrate. this is not strictly a sound though.

a sound is a subjective personal experience.

 

Rubbish! Come on Tom! Your dictionary is extreamly poor. Buy a better one.

 

Oxford English Dictionary- Sound:

1 - sensation caused in the ear by vibration of surrounding air or other medium. 2 - a. Vibrations causing this sound. b. similar vibrations whether audible or not 3- what is or may be heard. 4 - idea or expression conveyed by words. 5- mere words. 6. sound produced by regular vibrations - noise. 7.etc.. etc..... it goes on and on for half a page.

 

Of course it makes a sound - this question was invented by philosophers just to annoy scientists with pointless arguments about symantics. In any decent dictionary you get a descent definition of the word.

[Mr Skeptic]

Of course it makes a sound - this question was invented by philosophers just to annoy scientists with pointless arguments about symantics. In any decent dictionary you get a descent definition of the word.

 

Nope, that question was invented by philosophers before there were scientists (as a group using the scientific method anyhow).

[DrP]

Nope, that question was invented by philosophers before there were scientists (as a group using the scientific method anyhow).

 

Yea - I know - philosphy was a kind of science anyhow in those days was it not? To answer this question properly one must know what definition of the word sound is being used. Do we have dictionary dating from around that time? (Not one of those cheap $1.00 dictionaries that tom uses () - a proper one).

 

Am I right in saying (as I come from a science background not philosophy) that the question was designed to encourage intelligent debate, NOT to have an exact answer? (unless you look in a decent modern dictionary - in which case the answer is just yes).

[Sisyphus]

You don't know whether it makes a sound for the same reason you don't know whether the world existed before you were born. There is an apparent consistency in the way the world works - most of our actions are based on this implicitly, and all of science is based on this explicitly and formally. But can you prove the tree makes a sound any other way than observing that sounds are made in similar situations? (And don't say "yes" and talk about mathematical models and whatnot - fundamental physics is empirical too.)

[Mr Skeptic]

Yea - I know - philosphy was a kind of science anyhow in those days was it not?

 

They had natural philosophy, which was rather different. The scientific method did not exist as such, nor did empiricism. Aristotle thought up his laws of motion based on logic alone, just like he decided based on logic alone that women have less teeth than men (they don't, and he didn't bother to look).

 

To answer this question properly one must know what definition of the word sound is being used. Do we have dictionary dating from around that time? (Not one of those cheap $1.00 dictionaries that tom uses () - a proper one).

 

Nope, dictionaries as such came about the same time as the printing press ~1600.

[Sisyphus]

Aristotle loved empirical research, actually. The guy enthusiastically and accurately wrote about many natural phenomenon, including stuff like the embryological development of sharks. He just didn't consistently apply it, and ended up at some of his crazier assertions by extrapolating from "common knowledge." In other words, he didn't have a "scientific method," he was just curious about everything, and sometimes the easiest way to get an answer was to actually look.

[tomgwyther]

Dr P, You quoted...

 

"b. similar vibrations whether audible or not"

 

From the OED.

 

My 1996 version says:

"2: Vibrations causing this sensation" "3: What is or may be heard"

May be heard meaning, it may have been heard by someone we don't now about yet.

Not 'Definitely not heard'.

 

The most current version says:

sound1

 

• noun 1 vibrations which travel through the air or another medium and are sensed by the ear. 2 a thing that can be heard. 3 music, speech, and sound effects accompanying a film or broadcast. 4 an idea or impression conveyed by words.

 

Q.E.D.

Edited November 16, 2009 by tomgwyther

[bascule]

are you talking about another Schrodinger's cat?

 

More or less. To be more specific I'm talking about superposition. When unobserved fundamental particles behave differently than when we observe them (and thus collapse their waveform)

 

2 a thing that can be heard.

 

Can be heard? By who? What if your dog can hear it but you cannot? What if you can hear it, but your grandma cannot?

 

This definition is rather open-ended, and allows for potential perception by any entity capable of hearing.

 

In that regard, longitudinal waves traveling through a medium which would elicit the qualia of sound in some potential perceiver, regardless of whether perceived or unperceived, are still a sound.

Edited November 17, 2009 by bascule
Consecutive posts merged.