I am not sure why this is returning nan and what to do.
g = accelerometer.get_z()
G = (6.67*10)**-11
m = (5.972*10)**24
c = 299792458
r = 38.5*(5.972*10)**24/ g* G
deltatgprime = 5 * math.sqrt(1 - (2 * G * m / r * c**2))
display.scroll(deltatgprime)