Calculate Time Dilation on a Space Trip Using Python

time_dilation.py

"""
This script calculates the time dilation experienced during a space journey given the 
velocity, acceleration, and duration of the journey. 
The script uses the astropy package to handle units and time calculations.

Args:
velocity (float): Velocity of the spaceship as a fraction of the speed of light.
acceleration (float): Acceleration of the spaceship in units of g0.
duration (float): Duration of the journey in years (from the perspective of a clock on earth).

Prints:
Date on Earth at departure
Date on spaceship at journey end
Date on Earth at journey end
Lorentz factor
Time dilation factor
Time interval on spaceship

More Info:
https://samiles.com/blog/2023/02/calculating-time-dilation-in-space-travel-with-python/
"""

import argparse
from astropy import constants as const
from astropy import units as u
from astropy.time import Time
import warnings
from astropy.utils.exceptions import AstropyWarning

# Ingore warnings about odd dates
warnings.simplefilter('ignore', category=AstropyWarning)

# Parse command line arguments
parser = argparse.ArgumentParser(description='Calculate the time dilation experienced during a space journey.')
parser.add_argument('velocity', type=float, help='velocity of the spaceship as a fraction of the speed of light')
parser.add_argument('acceleration', type=float, help='acceleration of the spaceship in units of g0')
parser.add_argument('duration', type=float, help='duration of the journey in years')
args = parser.parse_args()

# Set up input parameters
v = args.velocity * const.c  # velocity of the spaceship
a = args.acceleration * const.g0  # acceleration of the spaceship
duration = args.duration * u.yr  # duration of the journey
earth_time = Time.now() # Define starting time on Earth (as the current time)

# Calculate the Lorentz factor, using the formula γ = 1 / sqrt(1 - v^2/c^2)
gamma = 1 / (1 - (v / const.c) ** 2) ** 0.5

# Calculate the time dilation factor
dilation_factor = 1 / gamma

# Calculate the time interval measured on the spaceship
delta_t = dilation_factor * duration

# Calculate the date on the spaceship
ship_time = earth_time + delta_t

# Calculate the date on Earth after journey ends
earth_time_after = earth_time + duration

print('Date on Earth departure:', earth_time.iso)
print('Date on spaceship at journey end:', ship_time.iso)
print('Date on Earth at journey end:', earth_time_after.iso)
print('Lorentz factor: {:.2f}'.format(gamma))
print('Time dilation factor: {:.2f}'.format(dilation_factor))
print('Time interval on spaceship: {:.2f}'.format(delta_t.to(u.yr)))