Faster than light

Question

Fou Lu what if you are so tall, that every step you take would be the equivalent of the diameter of our galaxy?

Would you need 100 K light years (or even longer) to perform this step, or would it just seem for us as an observer, but to the reality of the giant, it would only take a few seconds? If so, how? He’d be way faster than light,

Answer 1

Hi Danou,

The limitation of movement of an object to <= c is independent of the frame of reference. So, if the galaxy diameter were to be 106, 000 light years (as it approximately is), then Fou Lu would need that (as 106,000 years, your time), plus a little, for his/her step (let alone the mechanics of accelerating feet, etc.). We assume here that Fou Lu does not exist as a tachyonic object. Because time dilation depends in a complicated way on acceleration and velocity, it is not possible to say that all portions of Fou Lu would undergo the same perceived passage of time during the step; however, on the average he/she would perceive somewhat less than 106,000 years (NOT light-years!) elapsed.

We additionally hope that Fou Lu doesn't drag a foot through the central black hole of the galaxy; if so, a piece of his/her foot might NEVER arrive at the other side of the galaxy. How do you average in a small portion of infinite duration into your calculation, should give you pause for thought.

If Fou Lu is successful at the step, might the appropriate quote be, "One big step for giant-kind, one small leap over man(kind)!"?