xkcd 1017

xkcd-1017.py

from datetime import datetime, timedelta
from math import exp, log

from tqdm import trange
from time import sleep

# https://en.wikipedia.org/wiki/Age_of_the_universe
# age of universe in years
age_of_universe = 13.799e9
offset = 50

now = datetime.today()

def get_past_date( delta_in_years ):
    if delta_in_years > 1e9:
        return "{:.2f} billion years ago".format( delta_in_years * 1e-9 )
    if delta_in_years > 1e6:
        return "{:.2f} million years ago".format( delta_in_years * 1e-6 )
    if delta_in_years > 50000:
        delta_in_years = round( delta_in_years / 5000 ) * 5000
        return "{:,} years ago".format( delta_in_years )
    if delta_in_years > 5000:
        bce_year = -round( ( now.year - delta_in_years ) / 100 ) * 100
        return "{:,} BC".format( bce_year )

    try:
        delta = timedelta( delta_in_years * 365.242199 )
        return str( ( now - delta ).date() )
    except:
        bce_year = -round( now.year - delta_in_years )
        return "{:,} BC".format( bce_year )

def T(x):
    return exp( ( log(age_of_universe) - log(offset) ) * (x**3) + log(offset) ) - offset

bar = trange( 10000, ascii=True )

for i in bar:
    sleep(0.02)
    p = i/10000
    bar.set_description( get_past_date( T(p) ) )