Facts about viruses

          5 Amazing Science Facts That Will Blow Your Mind

1. There is enough DNA in the 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 (called chromosomes), each containing from 500,000 to 2.5 million nucleotide pairs. DNA molecules of this size are 1.7 to 8.5 cm long when uncoiled — about 5 cm on average. There are about 37 trillion cells in the human body, so if you were to uncoil all of the DNA encased in each cell and place the molecules end to end, it would sum to a total length of 2×1014 meters — enough for 17 Pluto round-trips (the distance from the sun to Pluto and then back again is 1.2×1013 meters). As an added bonus, you should know that we each share 99% of our DNA with every other human — just to show that we’re far more alike than different.

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 countertops, or make a grimace when someone sneezes near us, when, in fact, each and every one of us is a walking petri dish! All the bacteria living inside you could fill a half-gallon jug — there are 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 example, 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 despite the fact that they didn’t eat any more than they had before. Gut bacteria is also very important for maintaining immunity. 

3.In an entire lifetime, the average person walks the equivalent of five times around the world

The average moderately active person takes 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.

4. You can’t taste food without saliva

In order for food to have taste, chemicals from the food must first dissolve in saliva. It’s only once they’ve been dissolved in a liquid that the chemicals can be detected by receptors on taste buds. During this process, some salivary constituents chemically interact with taste substances. For example, salivary buffers (e.g., bicarbonate ions) decrease the concentration of free hydrogen ions (sour taste), and there are some salivary proteins which may bind with bitter taste substances.

Here’s a quick science experiment to test this out — get out a clean towel, and rub your tongue dry; then place some dry foods on your tongue, one by one, such as a cookie, pretzel, or some other dry food. After this session, drink a glass of water and repeat. Did you feel a difference?

5. The known universe is made up of 50,000,000,000 galaxies.

There are between 100,000,000,000 and 1,000,000,000,000 stars in a normal galaxy. In the Milky Way alone there might be as many 100 billion Earth-like planets. Still think we’re alone?