>> ^xxovercastxx:

Some of you people seem to really have it out for the guy on the left when you don't even understand the question to begin with. He seems to be the only person on the panel who understands the crux of the question... ultimately it comes down to "What definition of sound do you go by?"
If you define sound as vibrations in the air, then you'd say yes, the tree makes a sound.
If you define sound as the sensory experience of those vibrations, you'd say no, it makes no sound unless someone hears it.
They are both valid definitions of sound. See definitions 1 and 2 here: http://dictionary.reference.com/browse/sound
It doesn't mean the tree doesn't fall if nobody witnesses it.
By the way, light is invisible. You can't see it, only its effect on objects it strikes.
Also, that idiotic tool's name is John Lloyd. He's the creator of the show.


Like Stephen Fry said, given the second definition the point is moot since you can say a mechanical recorder can experience the vibration. If you admit that - and there is no reason you shouldn't except bad faith - then you can take it to the quantum level and say that every object around the falling tree is an observer and thus "hears" (is affected) by the vibrations. In fact, given the first definition, sound cannot exist without affecting something (the molecules in the air) thus by default there must always be at least one observer in order to even conceive of the possibility of the existence and transmission of a sound in the first place. Thus, whether there is a macroscopic observer is moot since there is always a quantum level one in the first place to produce anything (like the tree falling). Its a regression problem and in the end it comes to quantum probabilities: there is a small chance that no sound will be produced, but it is highly unlikely. You'd need an Infinite Improbability Drive to make sure you're there when the sound doesn't happen and be smug.

By the way, light is visible since what is visible is what you can see with your eyes. In fact, technically speaking the only thing you can see with your eyes is light. What you think you "see" (objects) are your interpretations of the light patterns on your retina. What light you can't see are those particles of light that are not converging on your retina, just as you can't see objects that are not in your field of vision or can't hear sounds that don't enter your eardrum. Doesn't mean you can't see anything or hear sounds now does it? Also, you can't ear supersonic vibrations, but your dog can. Thus you can't hear sounds? No, you can't hear supersonic vibrations. The same way you can't see ultraviolet light, but you can still see light. See? It doesn't matter what definitions you take, only that they all be on the same level of abstraction. Now do that with the second definition of sound and you see that you get solipsism. Thus the second definition of sound is not good for any kind of knowledge about the world. Why? Because it cannot explain the exteriority of the sound's provenance. The second meaning can only be a special usage reserved to neurology as a substitute for a more appropriate but cumbersome technical word, just as we still use "heat" to refer to the state of excitation in molecules.

>> ^GeeSussFreeK:

No, he is nearly making the subtle, but logical distinction between phenomenon and noumenon. Have had this conversation here a lot on the sift. The experience of blue is a very different one than the wavelength of 475 nm (which corresponds to blue for most people). "Light" is a subjective experience not related to real properties of photons. Photons appear bright because through the course of a billion years of evolution, interrupting photons as light, and their corresponding wavelengths as colors has better aided that animal that interrupting them as something else. But that says nothing about photons themselves, only the way in which minds are translating reality.
It is the distinction between Empiricism and Intellectualism. One believing that it takes senses to understand truth, the other, that only the power of pure reason can lead knowledge. I, for one, am mostly under the school of intellectualism as it pertains to epistemology. I trust the power of reason and logic to find truth, not eyeballs and olfactories.

No, the distinction between phenomenon and noumenon would more properly apply to colours than to light itself, which was proven by Newton to be a particle (or at least particule-like, and then later a dual particle-wave thingy of course). His conclusions were accepted by Kant, who redefined the distinction between phenomenon and noumenon to not contradict Newton's findings. Goethe disagreed with Kant and Newton, but he was a fool. He thought light and colour were the same thing thus he failed. Schopenhauer rectified Goethe's theory to apply only to the perception of colour but Goethe wouldn't have it thus he failed again and it was up to psychologists to prove Schopenhauer was actually right in a limited sense.

Your distinction of empiricism and intellectualism is also very naive. As far as we know, the only way you can prove the factuality of your knowledge is through experience. That's why modern science works and idle speculation (like most Ancient Greeks did) does not. Being an empiricist doesn't mean you "trust your eyeballs", quite the contrary in fact. That's why David Hume talks a lot of the required skepticism needed to know nature from one's senses. If we could see things as they are (as noumenon), then we would not need our senses nor our reason to interpret what they sense (the phenomenon). That's in fact the basic premise of Kant's whole Critic of Pure Reason. His solution, in a word, was to view reason as recreating it's own idea, in the original Greek sense of "form", of the original noumenon (the thing-in-itself) by interpreting the filtered sense data of phenomenon that passed through the categories of understanding (like substance, causality, etc.). Some call his solution a form psychologism and I think they are right, but Kant certainly didn't think so. In fact, I think it's not psychologistic enough, though one must be wary of going as far as to try founding everything on psychology, a circular dead end if there was one.

Ultimately, it comes to the question of what kind of knowledge you want: absolute knowledge or human knowledge? I purport absolute knowledge is unknowable (irreducible) to human knowledge in the same way the noumenon is irreducible to the phenomenon, not only by its own definition but by the very way knowledge works (at least for us, meaning in a subject-object duality where the subject cannot simply copy the object it wants to know but must make an inherently reduced image of it, i.e. an idea). I think this problem to be related to the P=NP conundrum. Only if P=NP can we ever hope to achieve absolute knowledge and then that is not even guaranteed (we would need to evolve somehow to transcend the P and NP divide which factually exists in our present human knowledge). As Scott Aaronson of the MIT puts it, "If P=NP, then the world would be a profoundly different place than we usually assume it to be. There would be no special value in “creative leaps,” no fundamental gap between solving a problem and recognizing the solution once it’s found. Everyone who could appreciate a symphony would be Mozart; everyone who could follow a step-by-step argument would be Gauss; everyone who could recognize a good investment strategy would be Warren Buffett. It’s possible to put the point in Darwinian terms: if this is the sort of universe we inhabited, why wouldn’t we already have evolved to take advantage of it?" (from his blog).

>> ^deathcow:

> This thread doesn't bode well for the perceived intellect of sifters.
The whole topic is pedantic and stupid.
Now... is the moon still there is nobody is looking at it, we could dig our teeth into that! Is the cat dead AND alive?


*looks up "hypothetical" in the dictionary*

See: "pedantic" and "stupid".

>> ^GeeSussFreeK:

>> ^Yogi:
Hypothetical questions in a "quickfire round" is just madness. No ones just going to let them off with a simple answer and move on.

Is that a statement or a hypothetical!


Is this a hypothetical question?

Your video, QI - Quickfire Hypotheticals - Sound Waves, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.

>> ^GeeSussFreeK:
>> ^DonanFear:
I guess we won't be seeing him again on the show.
According to him, it's perfectly OK for me to break into his house when he isn't there and take a huge dump in the middle of his living room. There is no turd on the carpet if he isn't there to see it.

So your saying that something that can not be verified by any empirical source still exists? You're on a slippery slope of believing in gods.

No, I'm just saying that you can't say it doesn't exist either. Without any evidence there's no way to know.
Saying light and sound (sound waves even) don't exist until someone experiences it is silly. The opposite is equally silly, claiming something exists witout any evidence.

>> ^DonanFear:

I guess we won't be seeing him again on the show.
According to him, it's perfectly OK for me to break into his house when he isn't there and take a huge dump in the middle of his living room. There is no turd on the carpet if he isn't there to see it.


So your saying that something that can not be verified by any empirical source still exists? You're on a slippery slope of believing in gods.

>> ^robbersdog49:

Is it just me or is the bloke far left (viewer's view) an idiot? The whole light is invisible thing is just an irritatingly misguided regurgitation of an error. I'll add arrogant as well.
He should listen to more Scrubius Pip.


No, he is nearly making the subtle, but logical distinction between phenomenon and noumenon. Have had this conversation here a lot on the sift. The experience of blue is a very different one than the wavelength of 475 nm (which corresponds to blue for most people). "Light" is a subjective experience not related to real properties of photons. Photons appear bright because through the course of a billion years of evolution, interrupting photons as light, and their corresponding wavelengths as colors has better aided that animal that interrupting them as something else. But that says nothing about photons themselves, only the way in which minds are translating reality.

It is the distinction between Empiricism and Intellectualism. One believing that it takes senses to understand truth, the other, that only the power of pure reason can lead knowledge. I, for one, am mostly under the school of intellectualism as it pertains to epistemology. I trust the power of reason and logic to find truth, not eyeballs and olfactories.

>> ^Yogi:

Hypothetical questions in a "quickfire round" is just madness. No ones just going to let them off with a simple answer and move on.


Is that a statement or a hypothetical!

Hypothetical questions in a "quickfire round" is just madness. No ones just going to let them off with a simple answer and move on.