In this thread, I was reading the list of factors that control the frequencies of audio feedback screech and it occurred to me that the speed of sound in the room makes a difference - if you’re listening to a comedian in a room completely filled with water, or solid steel, the feedback from his PA system will have different characteristics.
Of course, it’s a completely unrealistic scenario - but it struck me that perhaps here more than almost anywhere else, it is necessary to qualify certain statements to avoid them being nitpicked with scenarios that are technically completely valid, but would just never happen in the real world - I get the impression that there are quite a few of us that regard definitive statements as an invitation to explore exceptions. Or maybe that’s just me.
So, the object of this thread will be for people to make any statement they like, for which they believe they have covered all the exceptions, and for others to nitpick them to death - feel free to do either or both.
For example, the statement: “Light is electromagnetic radiation of a wavelength that is visible to the human eye” can be nitpicked with (amongst probably many other things) “I’m sure you mean ‘…the functional human eye’”
In fact, why don’t we start with that.
Light is electromagnetic radiation of wavelengths visible to the functional human eye (assuming that eye is also part of a properly functioning visual system).
My perspective, in this nitpicky mode, is that it is the light which is visible in and of itself, and not the object directly. Your retinas react to being struck with light, rather than with, say, chairs and trees and things.
No, I’d say that light itself is visible - you’re seeing the light, not the object (in fact in the case of distant objects, they may no longer exist by the time the light reaches you). You can’t see objects, only light. Assuming your eyes and visual system are functional, and you are conscious, and have your eyes open and pointed in the appropriate direction, free of obstruction.
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Light is electromagnetic radiation of wavelengths visible to the functional human eye (assuming that eye is also part of a properly functioning visual system).
Surely you mean ‘detectable’.
And forget about defining a working eye, just go with non-blind human.
Pi is another one. Pi expresses the ratio of a circle’s diameter to its circumference only on a flat plane. (I’m guessing we’re supposed to redden and bolden these.) So, in models of the universe in which space is curved like a saddle, there is no such circle.
Don’t make these too easy. Of course such a circle exists in a model of a universe shaped like a saddle. It would be a little difficult to measure but not impossible. Kind of like doing the geometric construction on the back of a Pringles.
That’s an added complication, certainly, but first let’s get our definitions straight, 'cos as long as we’re defining “light” as “something detectable by the non-blind eye” and “blind” as “adjective pertaining to an eye unable to detect light” we’re plainly getting nowhere.
It would be a circle relative to the rest of the Pringles universe and thus subject to the math of that perspective. It would not be a circle relative to the flat universe*. It could also be that an observer in the Pringle universe views his space as flat and our universe would be viewed as an inverse Pringle.
although it would still be a circle with a functioning ratio of pi only if it were constructed on a two dimentional plane and the plane was then warped. Any third dimention would distort the circumference*.
** note that the warping of the two dimentional plane only provides a third dimention relative to the observer. Within the reality of the plane it is still 2D***.
Could be? How could it be else, assuming that in the P-verse light follows Pringle-shaped lines? They must necessarily appear straight to the local observer.
Indeed, how do we know that we do not already inhabit a P-verse?
No no, that’s backwards. A circle is defined differently for curved surfaces because they are curved. For it to be a circle on a curved surface, its ratio *cannot * be pi.
Think of a round trampoline. Its surface is a circle so long as there is no weight on it. But if you stand at its center, its diameter has increased significantly but its circumference has remained the same.
You’re assuming the saddle curvature suggested is in the third dimension. It’s not - the curvature suggested is an analogy for curvature in the fourth (spatial) dimension, which leaves our ‘regular’ three untouched.