Alternatively, if you are constantly x feet above a spot on Earth, where x is the number of seconds since takeoff, we have a different problem. You’d be in a geostationary orbit above that spot, following the Earth as it rotates, no matter how far away you are. After about 10 860,000 years, you are traveling at the speed of light, and this only increases. Hope your body doesn’t impact Proxima Centauri.

Edit: Oops, I assumed an Earth day is 1 second instead of 86,000 seconds