jadero

I'll give it a crack.

As others have hinted at, it's mostly about noise. The author puts noise in quotes when referring to those qualities of sound (and lyrics?) that are normally considered noise but are exploited for aesthetic purposes.

Thus, extreme volume and heavy distortion might normally be undesirable noise when trying to faithfully reproduce a sound, they are exploited by rock music in general and, in their extreme forms, by heavy metal in particular.

A metaphorical or all-inclusive understanding of noise can be applied to the various other aspects of music (rhythm, repetition, tempo, key changes, and even lyrics). The more of these aspects are affected (the more "noisy"), the "heavier" the result.

This was not addressed in the paper, but I think that the noise has to be introduced during the creation or performance of the music. If you play back a recording in ways that distort the signal or sound, you are probably getting noise, not "noise".

As a non-geologist living next to Lake Diefenbaker (the reservoir formed by damming the South Saskatchewan River), I also like geological history.

I have a standard reply for when I'm asked why we chose to move to this "treeless wasteland". "I look out at the flat horizon and see how the glaciers planed the earth the way a woodworker flattens a board. I look around me at the river breaks and see how the meltwater from retreating glaciers carved the earth away into shapes that defy imagination." I don't know accurate any of that is, but it fits my mental model of what I was taught in high school.

(What we call the river breaks are twisted and braided networks of coulees, some with sides so steep as to require mountaineering equipment. Most still run with meltwater in the spring.)

Is there a site that does a variety of energy comparisons

Yes! Thank you. It's always nice to see other perspectives.

When I'm figuring the buoyancy of a 20 litre pail or, alternatively, how much it'll weigh when filled with sand, 3 is easier to work in my head for off-the-cuff estimates so I know about how many pails I need.

That said, I do typically use the π button on my calculator when it comes time to actually execute on the project. :)

I get it now. I was taking exception to your characterization of 3 and 5 being equally inaccurate in the sense of how close they are to the actual true value, which, of course, can never be known, except in every more accurate approximations.

In that case, I guess we still have a difference of opinion. I think that using approximations that are closer to their true value are more useful in teaching, despite (and maybe because of) the greater difficulty. If the student is not yet ready for that level of difficulty, then perhaps a different problem should be presented.

To that end, I actually think that there are several things to teach. That PI is not 3 or 3.14 or any other decimal expansion. That 3 is close enough for most casual encounters outside school. That 3.14 is close enough for most engineering work. That 3.1416 is close enough for most scientific work. That 15 decimal places is close enough for rocket scientists. That 37 decimal places are enough to calculate the circumference of the universe to within the diameter of a hydrogen atom. (https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimals-of-pi-do-we-really-need/ is my reference for the last two items. The others are just wild-ass guesses.)

I would draw your attention to the difference between mathematics and reality. Although mathematics is extremely useful in modeling reality, it's important to remember that while all models are wrong, some are nonetheless useful.

Thus, a household gardener or storage tank owner or a builder of small boats can choose the appropriate diameter of hose, tank, or pontoon very effectively by rounding PI to 3 but cannot do so when "rounding" to 1 or 5. In these cases, it literally doesn't matter how many decimal points you use, because the difference between 3 and any arbitrary decimal expansion of PI will be too small to have concrete meaning in actual use.

Under the philosophy you are promoting, it would be impossible to act in the physical world whenever it throws an irrational number at us.

I don't know, but I suspect that there is a whole branch of mathematics, engineering, or philosophy that describes what kinds of simplifications and rounding are acceptable when choosing to act in the physical world.

The real world in which we act has a fuzziness about it. I think it's better to embrace it and find ways to work with that than to argue problems that literally have no numerical solution, at least when those arguments would have the effect of making it impossible to act.

Not necessarily. Calculating the flotation of a cylindrical pontoon using pi=5 will leave you with a boat that sinks!

Just an ordinary person doing ordinary things :)

Especially given that using π=3 is accurate enough for most daily use by ordinary people for ordinary things.

As long as nobody is using drinking water for irrigation, the output does pretty closely match the input.

But my point was that we can treat that water for use and reuse. That way, the desalination is kept to a minimum.

It's not quite that simple. After extracting water, matching salinity would require extracting salt or adding water. It's not that there aren't sources of water that can be used for salinity matching, including the output of sewage treatment, the reality is that it probably makes more sense to treat that water than to desalinate in the first place.

Extracting the salts might be a source of valuable minerals and metals, but there is still no free lunch.

As far as I know, we still would be putting stuff back that doesn't make a good match for what we took. That means depending on the natural environment for dilution and "treatment". That has been an ongoing problem for humanity. We're very good at exceeding the capacity of the environment to cope with our wastes.

I completely understand the comment about perpetual motion machines, but tend to think that it's more of a scale management problem than a strict prohibition.