"A motion simulator has 2 axes of rotation. For any single axis, if the simulator is capable of spinning at a rate of 400 degrees per second or faster around that axis, then the simulator is military grade."

Now, is "For any single axis" equivalent to "For every axis" (i.e. both axes should fulfill the condition simultaneously to make it a military grade), or is it "For any axis separately" (i.e. it is enough that even one axis fulfills the condition to make the simulator military grade)?

Looks pretty ambiguous to me, wouldn't you say?

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    To be military grade, the simulator must be able to spin at 400 degree per second or faster around both axes but it is not necessary that the spin be that fast around both axes at the same time. – deadrat Sep 26 '15 at 23:24
  • I would read it as firmly ambiguous. – Hot Licks Sep 26 '15 at 23:24
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    I don't see an ambiguity -- I think, as written, it has only the second of the two interpretations you mention: for any axis separately. Probably the intent was to put the "for any single axis" inside the "if" clause, but that's not what it says. – Greg Lee Sep 26 '15 at 23:30
  • I wonder why they didn't express the rotation speed as 66 2/3 rpm. Interestingly, that's exactly twice the speed of an LP phonograph record, which rotates around only one axis. Earlier "drum" recordings also rotated around one axis, as do the more recent CDs and DVDs. Who knows what levels of audio and video density might be achieved with a recording medium rotating around two (or three) axes? – Brian Hitchcock Sep 27 '15 at 4:37
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    If I put myself in the shoes of the author of the passage... I think the author put the word single in there to convey what deadrat said. – aparente001 Sep 27 '15 at 13:58

I think it is clear that the second is meant. "For any single axis" is clear to me.

If the author had intended the first meaning she would have written: "A motion simulator has 2 axes of rotation. The simulator is military grade if it is capable of spinning at a rate of at least 400 degrees per second simultaneously around both axes."


I read it as "any" meaning either of them. Meaning that they don't have to be identical and that only one axis has to fulfil the specification to qualify the product as being of x quality.

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