2. An individual blood cell takes about 60 seconds to make a complete circuit of the body
Most people have 5 liters of blood in their body. With each beat, the heart pumps around 70 mL of blood and it beats an averagely 70 times per minute, which makes circulation of 4,9 liters per minute.
3. There is enough DNA in the average person's body to stretch from the sun to Pluto and back — 17 times
Each human cell contains 23 chromosomes (DNA molecules), when uncoiled they can reach the size of 1.7 to 8.5 cm long – an average of 5 cm. If you multiply this with the number of cells in the human body (around 37 trillion) it will 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).
4. There are more trees on the planet than stars in the solar system
According to experts from NASA, there are up to 400 billion stars in the milky way galaxy – but the number of trees on Earth is estimated to be more than 3 trillion.
5. Killer whales are actually dolphins
The major physical feature that ensures killer whales or orcas are dolphins is the presence of a melon — a fatty deposit that assists the animals in echolocation and only exists in dolphins.
6. Grasshoppers have ears in their bellies
The grasshopper sound detector is a thin membrane called a tympanum, or "eardrum", and is located beneath the wings.
7. Octopuses have three hearts, nine brains, and blue blood
Ok, let's see that more precisely. One heart is keeping the blood circulation among the organs and the other two are working just to move blood beyond the gills. There is one main brain, which coordinates all processes, and eight ancillary brains at the base of each tentacle. And finally, human blood is red due to the fact that it contains iron-based hemoglobin to transport oxygen to cells, and octopuses, on the other hand, use the copper-based cyanoglobin.
You may think that rain forests produce most of the world's oxygen but in fact, it is plankton, sea weed and other marine plants that do half of the work.
9. The Great Barrier Reef is the largest living structure on Earth
Coral reefs consist of huge numbers of individual coral polyps (soft-bodied, invertebrate animals) that are linked together by tissue. The great barrier reef is more than 2,000 kilometers long.
10. The average human body carries ten times more bacterial cells than human cells
Despite our compulsive attitude towards bacteria and microbes on our hands, there are up to 10 times more bacteria in our bodies than human cells.
11. You can't taste food without saliva
It is only when food is dissolved in saliva that our receptors can detect chemicals and their qualities.
12. A flea accelerates faster than a space shuttle
A jumping flea can reach heights of about 8cm in a milli-second. Acceleration is the change in speed of an object over time as caused by gravity (measured in g's). Fleas experience 100g whereas the Space Shuttle peaks at around 5g.
13. It takes 8 minutes for a photon to travel from the Sun to Earth whereas the distance between the core and the surface of the Sun can take up to 40,000 years.
To travel this relatively small distance (when compared with that to Earth) a photon needs to undergo countless random ricochets inside our star in order to escape into the open space.
14. There are 8 times as many atoms in a teaspoonful of water as there are teaspoonfuls of water in the Atlantic ocean
Each water molecule contains three atoms – two hydrogens and one oxygen. If a teaspoon of water is approximately 5 mL then it contains more than 2×1023 water molecules.