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But it’s still wise to change out/boil the sponge periodically? How come some sponges start to smell sour given this phenomena?

More accurately, it’s just that you’ve defined you’re potential to be zero at infinity. You could’ve defined it to be anything (finite) at infinity so long as you remember to add that to the energy you have at radius r too

There’s important distinction between assuming and defining!

Its hard to imagine in between steps of evolution towards "detergent resistance/immunity" that would be selectively advantageous. Is that kinda what you're getting at?

Fantastic, thank you!

Yes. That's why getting soap in an open wound is painful, and why drinking soap is so dangerous.

However, your outer skin is mostly immune to this as it's not made of living cells, but rather a layer of dead cells that made some structures that resist this before they died.

Not easily like with Antibiotics. Antibiotics are like scalpels, they target 1 very specific part of the bacteria and disrupt that part. By changing that part slightly, the antibiotic stops having an effect (or alternatively, they set up systems to pump the molecules of antibiotics out of the bacteria before they can do harm).

Meanwhile, soap is almost like a fire. It simply rips the entire membrane apart. In order to prevent this, they'd need to fundamentally change how the membrane is constructed. Fundamental changes like that are, while not impossible, basically unheard off in evolution.

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The simple answer is it depends how for you are from the source. If you look at big event screens the size of the led pixels and the distance between them is huge by comparison to a mobile phone.

This is probably measurable and more to do with biology and neurology of light perception than the physics. Although arguably everything is physics at some point.

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Link to Wikipedia picture of the dot spacings on blue Ray discs https://en.wikipedia.org/wiki/Blu-ray#/media/File:Comparison_CD_DVD_HDDVD_BD.svg

So that's basically more than the height of the mount everest per second.

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I think the track density is actually more limited by the reading method than the stamping method.

The laser focus is the limiting factor, had to move from a low frequency red laser for a normal CD, to a high frequency blue laser (it’s actually violet) to get the data capacity higher for blue Ray. I believe “multi layer reading” is already being exploited for 4K use on a 5” disc which takes advantage of even finer stamping methods.

I think 25gb is the standard single layer capacity and the current disks in use are dual layer at 50gb… this is expected to rise with XL disk players/writers where the capacity is stretched to 128GB using 4 layers on a single disc using even finer laser targeting/focussing methods.

You're 100% right. I forgot that it wasn't a closed system. I'll sit in the corner with my dunce cap on for a while.

Even if they don’t rupture, they’re getting washed away by magnitudes more water than they can deal with. (In a similar vein, I find general spray cleaners just as effective on unwanted insects as insecticides, but with no awful odors/volatiles, and ready to wipe clean.)

Bacteria can produce biofilms in an attempt to hold position, hence the need for scrubbing to break up their defenses.

Some soaps used to have antibacterials, but that just resulted in resistant bacteria wherever they ended up.

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No, that's not true... If you couple the object to a mechanism that extracts energy while keeping the speed under terminal velocity, then you may recover more energy from the potential energy than this limit you're imposing. For example airplanes (coasting) convert potential energy into kinetic energy by purposefully staying below terminal velocity

Here I'm only counting "useful" energy. But you're ignoring the potential energy converted to air heating and turbulence along the way when the object is at terminal velocity

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Detergents are very similar to soaps which work in the same way. This is why soap and water is an excellent way to kill bacteria and germs compared to alcohol based rubs. Alcohol will kill the germs, but they’ll remain there in almost a nutrient soup for other germs. Washing with soap and water kills it and disposes of the traces.