3 ms·

Doesn't help for the "older question." That's just used as an intuitive example for how imprecision can arise from subtraction. Rearranging helps when you can

• majormajor 6y ago
  I see. I might quibble that here the imprecision isn't just from the subtraction, but because we originally just have very rough estimates for the dates (though 'mam2 brings up a very interesting point about correlation if estimates are based on each other and using them like that isn't the ideal way of answering the question). It threw me off enough that I didn't get the original point of it re: floating point numbers until your comment - in our floating point formats, the imprecision is often an accidental effect of the limits of the format, vs a true unknown, and then magnifying the relative size of that arbitrary limitation is a problem.
  • skybrian 6y ago
    Wether it's imprecise measurements or imprecise calculations, there are still things you can do if you're aware of the problem. When measurement is imprecise, it might be possible to improve accuracy by using a different measurement. For geology, it's often easier to put things in the right order due to rock layers rather than to figure how long ago they were from present. In this case, obviously, the Earth is older than the oceans, even if the estimated ages were even rougher and the error bars implied they could be in the opposite order. For history, you may be able to figure out the relative order of events without knowing what year they were on our calendar.