3 ms·
An interesting quirk of this, is that the description of the path of a particle under constant proper acceleration in special relativity is mathematically very
by messe 5y ago
An interesting quirk of this, is that the description of the path of a particle under constant proper acceleration in special relativity is mathematically very close to that of a simple harmonic oscillator.
Now, just as you can use rotation in the complex plane (i^2 = -1) to describe a simple harmonic oscillator in 2D space,
x + iy = e^(it)
It's possible to use a rotation in the split-complex plane[1] (j^2 = 1) to describe the motion of a particle undergoing constant proper acceleration,
x + jt = e^(ajτ)/a - 1 [2]
This is because multiplying by e^(jτ) preserves the split-complex modulus (|x+jt|^2 = (x + jt)(x - jt) = x^2 - t^2), which is equivalent to the Minkowski norm. Expanding the above gets you,
x = cosh(aτ)/a - 1
t = sinh(aτ)/a
which are the more traditional expressions you would typically see.
[1]: https://en.wikipedia.org/wiki/Split-complex_number https://en.wikipedia.org/wiki/Split-complex_number
[2]: There's a line of reasoning that allows you to write this down almost immediately, or in maths-speak makes it trivial, but I can't remember it at the moment. I spent a good deal of time thinking about this for a university assignment years ago in order to avoid spending 2 minutes doing an integral.