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Aug
30
comment Can a human size object move so fast that it ceases to be observable?
@Jim What do you care whether we say "yes" or "no"? We all agree that the photons will be reflected and that they are observable. THAT is what matters here. Whether you call it a "yes" or a "no" is irrelevant. Some answers like to go beyond that and contemplate whether a human can spot these photons without specialized equipment, that's all.
Aug
30
comment Can a human size object move so fast that it ceases to be observable?
@Jim as long as we agree that you don't know that you see the filter, I don't mind whether it's called "visible" or "invisible"; that's a separate question. Although "observable" seems to be a more accurate term: a camouflaged sniper is definitely observable, and "invisible" doesn't seem appropriate despite being very hard to see, so I see your point.
Aug
29
revised Why aren't all rocks in space orbiting bigger rocks?
False info deleted: Rosetta does not literally orbit the asteroid, presumably because matching the speed to within 8cm per second is too hard at such a distance
Aug
28
awarded  Nice Answer
Aug
27
comment Can a human size object move so fast that it ceases to be observable?
@KyleKanos Fair enough. By your definition, moving fast or slow doesn't matter, obviously the same quantity of photons still get reflected. But I hope you can also see why others find the practical definition of "can a human actually see it" more interesting.
Aug
26
revised Can a human size object move so fast that it ceases to be observable?
added 5 characters in body
Aug
26
awarded  Yearling
Aug
26
revised How do electrons interact if one of them had just exited the two slits of the double-slit experiment?
added 4 characters in body
Aug
26
comment Can a human size object move so fast that it ceases to be observable?
Why do you define "blurred" as "able to see"? Ask the person doing the observation to list all the things they see. If they fail to list the blur, they didn't see it. Simple.
Aug
26
revised Can a human size object move so fast that it ceases to be observable?
added 543 characters in body
Aug
26
comment Can a human size object move so fast that it ceases to be observable?
@KyleKanos Define "invisible". If it's deadly yet someone tries to walk right through it, dying as a result, was it sufficiently invisible? How careful an observation is required to fail to detect the moving object before you would agree to call it "invisible"?
Aug
25
revised What is the closest general-relativistic equivalent of a “time slice”?
removed redundant example
Aug
23
answered Can a human size object move so fast that it ceases to be observable?
Aug
23
comment Can a human size object move so fast that it ceases to be observable?
@Jim you're lucky this is not Skeptics.SE, where claims such as that the brain dumps the light into images 30 times per second need to actually be supported by respectable sources.
Aug
20
comment Is “now” or “the present moment” properly defined in GR?
Somewhat related: what is the closest GR equivalent of a time slice?
Aug
10
comment Where am I confused about force addition?
Agreed with @BMS; easiest way to think about it. Now change the direction a little bit, bit by bit, and it won't seem so counter-intuitive that at 90°, you could still say that the forces kind of cancel out (though, more correctly, don't fully add up).
Aug
7
revised Why aren't all rocks in space orbiting bigger rocks?
added 268 characters in body
Jul
29
answered Why aren't all rocks in space orbiting bigger rocks?
Jul
29
comment Why are the orbits of planets in the Solar System nearly circular?
This is a fascinating answer, however given how little other answers seem to agree with this, a reference would be nice. As for why exoplanets are not quite so circular: perhaps there's a bias in how we detect planets? That would be a pretty simple explanation if true.
Jul
10
comment Why does wavelength affect diffraction?
+1; why does everyone else go into QED and path integrals when the answer applies to classical waves just the same?