A light-year ... 225 million years of walking

If your walk begins before the dinosaurs appear on Earth, then to complete the journey of a light-year, it has just finished recently.

A light-year - the distance that light travels in a year, is used as the basic unit of measuring the distance between planets - about 5.9 million miles. If you walk at an average speed of 20 minutes a mile, then it takes 225 million years to complete your journey (not eating or sleeping at all).

If you hitch a ride on a NASA X-43A supersonic aircraft with a 9.68 Match speed (the fastest aircraft in the world today), you will spend about 97 thousand years to cross this gap.

You also need to carry a huge bag of supplies. On average, an adult consumes 80 calories per mile on foot, so you'll need 2 trillion energy bars to refuel your trip. You also need a pile of shoes to replace the torn ones. An average pair of shoes lasts 500 miles, so you will spend about 11.8 billion pairs.

And most of all, no matter how much effort you make, you won't get far in the vast galaxy: the star closest to the Sun, Proxima Centauri, is also 4.22 light-years away.