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Your question is a bit muddy, but I believe the answer to everything is "yes, but..." Here's what's described in the referenced article: The laser produces a small spot on the target and the lens in the camera creates an image of that spot on one (ideally) pixel. By using simple lens equations, or by similar triangles, if you know the lens focal length ...

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As always, a spacetime diagram is crucial for insight. However, this can be dispensed with without one. What am I missing here? The event that Moe's wristwatch reads $1\mu s$ has coordinates, in Joe's frame, of $(2.29\mu s, 618m)$. In other words, according to Joe, Moe's wristwatch reads $1\mu s$ when Joe's clock reads $2.29\mu s$. According to Joe, ...

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According to the generalized uncertainty principle, the Planck length is, in principle, within a factor of order unity, the shortest measurable length – and no improvement in measurement instruments could change that. (Wikipedia) $$1 \text{ Planck length} = 1.61619926 \times {10}^{-35} m$$

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As an engineer I would say $10^{-5}\mathrm{m}$ because for mechanical purposes the smoothest surface finishing does not need to be net as this. As a practical chemist I would say $10^{-10}\mathrm{m}$ is small enough since I will never care about the very real diameter of an electron. I guess physicist would like to get a little bit smaller. Basically ...

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