If you think about a number line, multiplying 2 by -1 takes you to -2. Multiply it again by -1 and its back at 2.
If you think of the arrow from 0 to 2, all you did was rotate that arrow by 180 degrees to point along the negative axis and back again.
Multiplication by -1 is already a rotation of 180 degrees!
All were doing now is extending that concept to 90 degrees by imagining a second line perpendicular to the original number line.
Two 90 degree rotations need to get to -1 to complete the 180 degree rotation we already expect in normal multiplication.
Giving it the symbol i, this means definitionally i * i = -1. It has to because -1 flips us around the other way on the number line.
That means i is the square root of negative 1.
Any values that use i to store information, even time, could be called “imaginary time”. Really it’s just constantly oscillating between the real and imaginary spaces like a constantly spinning arrow.
If you think about a number line, multiplying 2 by -1 takes you to -2. Multiply it again by -1 and its back at 2.
If you think of the arrow from 0 to 2, all you did was rotate that arrow by 180 degrees to point along the negative axis and back again.
Multiplication by -1 is already a rotation of 180 degrees!
All were doing now is extending that concept to 90 degrees by imagining a second line perpendicular to the original number line.
Two 90 degree rotations need to get to -1 to complete the 180 degree rotation we already expect in normal multiplication.
Giving it the symbol i, this means definitionally i * i = -1. It has to because -1 flips us around the other way on the number line.
That means i is the square root of negative 1.
Any values that use i to store information, even time, could be called “imaginary time”. Really it’s just constantly oscillating between the real and imaginary spaces like a constantly spinning arrow.
Thanks for this! I think it’s the clearest visualization explanation I’ve ever heard for i