#!/usr/bin/python3
# ====================================================================
# Calculate time dilation by comparing a moving clock and a
# and a stationary clock
# ====================================================================
import math
import user_interface as ui
light_speed = 186000.0 # speed of light (miles/sec)
print()
print('Time dilation compaired to a stationary observer')
while True:
print()
ans = ui.get_user_input('Enter the percentage speed of light: ')
if not ans: break
tf,percent = ui.is_float(ans)
if not tf:
print()
print(f'Illegal percentage entered ({ans})')
continue
if percent >= 100.0:
print()
print(f'Can not go faster than the speed of light ({ans})')
continue
speed = light_speed * (percent/100.0) # moving speed
time_dilation_factor = 1 / math.sqrt(1.0 - (speed**2/light_speed**2))
print()
print(f'time dilation factor = {time_dilation_factor:.4f}')