1. There is enough DNA in an average person’s body to stretch from the sun to Pluto and back — 17 times
The human genome, the genetic code in each human cell, contains 23 DNA molecules each containing from 500 thousand to 2.5 million nucleotide pairs. DNA molecules of this size are 1.7 to 8.5 cm long when uncoiled, or about 5 cm on average. There are about 37 trillion cells in the human body and if you’d uncoil all of the DNA encased in each cell and put them end to end, then these would sum to a total length of 2×1014 meters or enough for 17 Pluto roundtrips (1.2×1013 meters/Pluto roundtrip).
2. The average human body carries ten times more bacterial cells than human cells
It’s funny how we compulsively wash our hands, spray our counter tops and grimace when someone sneezes near us—in fact, we do everything we can to avoid unnecessary encounters with the germ world. The truth of the matter is that each and every one of us is a walking petrify dish! All the bacteria living inside you would fill a half-gallon jug or 10 times more bacterial cells in your body than human cells, according to Carolyn Bohach, a microbiologist at the University of Idaho. Don’t worry, though. Most of these bacteria are helpful; in fact, we couldn’t survive without them.
For one thing, bacteria produce chemicals that help us harness energy and nutrients from our food. Germ-free rodents have to consume nearly a third more calories than normal rodents to maintain their body weight, and when the same animals were later given a dose of bacteria, their body fat levels spiked, even if they didn’t eat any more than they had before. The gut bacteria is also very important to maintaining immunity.
3. It can take a photon 40,000 years to travel from the core of the sun to its surface, but only 8 minutes to travel the rest of the way to Earth
A photon travels, on average, a particular distance, d, before being briefly absorbed and released by an atom, which scatters it in a new random direction.From the core to the sun’s surface (696,000 kilometers) where it can escape into space, a photon needs to make a huge number of drunken jumps. The calculation is a little tricky, but the conclusion is that a photon takes between many thousands and many millions of years to drunkenly wander to the surface of the Sun. In a way, the light that reaches us today is energy produced maybe millions of years ago. Amazing!
6. The average person walks the equivalent of five times around the world in a lifetime
The average moderately active person take around 7,500 step/day. If you maintain that daily average and live until 80 years of age, you’ll have walked about 216,262,500 steps in your lifetime. Doing the math; the average person with the average stride living until 80 will walk a distance of around 110,000 miles. Which is the equivalent of walking about 5 times around the Earth, right on the equator.