Is that correct? Spinning implies rotation implies acceleration, which I'd always thought could be detected without external reference points.
This is addressed later in the article, very well IMHO. Let me just give the relevant excerpts:
If you tried to visualize [the entire universe moving together], it seems like you can imagine it. If the universe is standing still, then you imagine a little swirly cloud of galaxies standing still. If the whole universe is moving left, then you imagine the little swirly cloud moving left across your field of vision until it passes out of sight.
But then, ... you can't always trust your imagination. [...]
Suppose that you pick an arbitrary but uniform (x, y, z, t) coordinate system. [... Y]ou might say:
"Since there's no way of figuring out where the origin is by looking at the laws of physics, the origin must not really exist! There is no (0, 0, 0, 0) point floating out in space somewhere!"
Which is to say: There is just no fact of the matter as to where the origin "really" is. [...]
[...]
And now—it seems—we understand how we have been misled, by trying to visualize "the whole universe moving left", ... The seeming absolute background, the origin relative to which the universe was moving, was in the underlying neurology we used to visualize it!
But there is no origin!
I worry I'm missing something obvious, but that EY quote doesn't seem to address my belief (namely, that detecting accleration doesn't need an external reference point). It just argues there's no absolute origin to use as an external reference point.
In an erratum to my previous post on Pascalian wagers, it has been plausibly argued to me that all the roads to nuclear weapons, including plutonium production from U-238, may have bottlenecked through the presence of significant amounts of Earthly U235 (apparently even the giant heap of unrefined uranium bricks in Chicago Pile 1 was, functionally, empty space with a scattering of U235 dust). If this is the case then Fermi's estimate of a "ten percent" probability of nuclear weapons may have actually been justifiable because nuclear weapons were almost impossible (at least without particle accelerators) - though it's not totally clear to me why "10%" instead of "2%" or "50%" but then I'm not Fermi.
We're all familiar with examples of correct scientific skepticism, such as about Uri Geller and hydrino theory. We also know many famous examples of scientists just completely making up their pessimism, for example about the impossibility of human heavier-than-air flight. Before this occasion I could only think offhand of one other famous example of erroneous scientific pessimism that was not in defiance of the default extrapolation of existing models, namely Lord Kelvin's careful estimate from multiple sources that the Sun was around sixty million years of age. This was wrong, but because of new physics - though you could make a case that new physics might well be expected in this case - and there was some degree of contrary evidence from geology, as I understand it - and that's not exactly the same as technological skepticism - but still. Where there are sort of two, there may be more. Can anyone name a third example of erroneous scientific pessimism whose error was, to the same degree, not something a smarter scientist could've seen coming?
I ask this with some degree of trepidation, since by most standards of reasoning essentially anything is "justifiable" if you try hard enough to find excuses and then not question them further, so I'll phrase it more carefully this way: I am looking for a case of erroneous scientific pessimism, preferably about technological impossibility or extreme difficulty, where it seems clear that the inverse case for possibility would've been weaker if carried out strictly with contemporary knowledge, after exploring points and counterpoints. (So that relaxed standards for "justifiability" will just produce even more justifiable cases for the technological possibility.) We probably should also not accept as "erroneous" any prediction of technological impossibility where it required more than, say, seventy years to get the technology.