How the modern world arose from imaginary numbers

Re:How the modern world arose from imaginary numbers by vishnugupta on Friday February 11, 2022 @02:02AM (#30297999)

> You can't have -5 rocks. Negative numbers are just the solution to equations of the form x + n = 0.

The best mental model of negative numbers that works for me is to treat it as direction.

In your example, if I have "-5" rocks it means I owe +5 rocks to someone else, let's say John. If, after a few days Rachel were to give me +5 rocks and then you square it off with John you are left with no rocks. Directionally Rachel → (5 rocks) You → (5 rocks) John;

So +/- stand for things flowing into and away from you respectively.

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Re:How the modern world arose from imaginary numbers by CamperBob2 on Friday February 11, 2022 @03:50AM (#30298907)

Exactly. Signed numbers for direction, complex numbers for 2D rotation, quaternions for 3D rotation (if you want to stretch the analogy to the breaking point.)

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Re:How the modern world arose from imaginary numbers by Qem on Friday February 11, 2022 @07:49AM (#30300801)

Octonions?

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Re:How the modern world arose from imaginary numbers by CamperBob2 on Friday February 11, 2022 @05:57PM (#30308018)

Over my pay grade.

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