I’ve heard the word event used for the general concept, but not a term that would be analogous to area and volume.
In the case of sound, I think it would be clarity, as in “loud and clear” or “5x5” in military terms.
In the case of volume as in space, would density be considered the next factor? Or am I missing the whole point of the definition?
later, Tom.
Yes, you’re missing the whole point. This is about the four-dimensional analogue to three-dimensional volume, where you have a fourth spatial dimension orthogonal to the other three, just like how in three dimensions you have a third spatial dimension orthogonal to the other two.
I believe “content” is the general term for “the amount of (N+1)-space bounded by an N-surface”. So, for a 3-sphere, content is 4-volume (the thing that comes after volume)–but for a circle (a 1-sphere), content is area, while for a 5-sphere, content is 6-volume.
But then “hypervolume” can have the same problem, depending on the context, and who you ask.
“Event” usually refers to a point (or vector) in 4D spacetime. At least to physicists; I get the feeling most mathematicians just call it a “point” (or “4-point”) and think physicists are silly for needing an extra word.
Also, I missed this, but it’s also wrong: In signal processing, volume is amplitude and is completely distinct from clarity, which is measured in terms of the signal-to-noise ratio.
I think he might have been making a joke. What comes after volume? Well, in “loud and clear”, clarity comes after volume. Ha ha ha.
Not a great joke. But still, if you really want to show that you have too much density, the best way to ruin it would be to explain why volume and loudness aren’t the same thing, the latter being only the psychoacoustic correlate of the former. It’s very hard to come up with anything funny that uses the phrase "psychoacoustic correlate.*
- And yes, I wrote that sentence only because I figured someone would be perverse enough to make a hilarious joke with that phrase in it, and I want to read that joke.
OK, damn. I did just miss an obvious joke, didn’t I?
Bah!
Don’t have the joke for you, but I did want to say “Welcome to the Straight Dope!”. I think you’ll do well here.
Thanks!
I just remembered that on one of the early raver email lists, someone posted a faux-scholarly paper about whether women respond to bass, as had been claimed by Renegade Soundwaye (the dubby house trio from London, not the giant robot/tape recorder from Cybertron). So, someone may have already made the joke I’m looking for 15-20 years ago. I wonder if I can dig that up anywhere?
In practice, we physicists usually just use “point”, too, or “point in spacetime” if disambiguation is needed. Or, for that matter, “point in phase space”, or “point in Hilbert space”, or whatever: Spacetime is not the only vector space physicists deal with.