light travels at precisely 299,792,458 metres every second (abbreviated to 3 x 10^8 metres every second but let's be precise)
There are 60 seconds in every minute (299 792 458 x 60 = 17,987,547,480m)
60 minutes in every hour (17,987,547,480 x 60 = 1,079,252,849,000m)
96 hours in 4 days (1,079,252,849,000 x 96 = 10,360,827,350,000m)
Now let's convert to km to make this number (slightly) more manageable
(10,360,827,350,000 / 1000 = 103,608,273,500km)
Light travels 103,608,273,500km in 4 days - that's the equivalent of going around the equator of the earth 813,124 times!
