Near death, explained

[Speck Tater]

86. Google "macroscopic quantum effects"

Science is not about "reality", it's about a simplified, stripped-down version of reality. When you apply simplifying assumptions, which all science does, all the time, for the sake of making "good enough" approximations, that's fine. Just don't mistake the model for the reality it models. Quantum effects influence the universe at all scales.

In most cases you can disregard quantum effects at the macroscopic level, just as in most cases you can pretend that pi is exactly 3.1415926535. That's close enough to compute the circumference of the earth to the nearest 1/300th of an inch. Which is fine. But that's not the real value of pi. It's a simplifying assumption.

From the wikipedia article on QM: "Quantum coherence is not typically evident at macroscopic scales - although an exception to this rule can occur at extremely low temperatures (i.e. approaching absolute zero), when quantum behavior can manifest itself on more macroscopic scales"

Notice that they use the phrase "not typically evident" and not the phrase "non-existent". This is a simplifying assumption. When I taught a freshman class in the philosophy of science back in the early 70's one of the hardest things for some of my students was to break the habit of conflating the model with the thing modeled. As Korzybski famously said "The map is not the territory." An abstraction of a thing is not the thing itself. Science deals in abstractions of reality, not in reality; in maps of the territory, not in the territory. And every time we introduce another simplifying assumption (like "quantum effects don't matter at this level&quot we introduce another layer of error and inaccuracy in the model.

So don't forget those all-important weasel words: for practical purposes quantum effect are not noticeable at macroscopic scales in most cases.