The only living tissue in the human body that contains no blood vessels is the transparent cornea of the eye. It's the firm, smooth outer shell that arcs across in front of the iris and pupil.
The cornea contains no blood vessels because it must be perfectly clear. Even one tiny capillary would cast the shadow of hundreds of streaming blood cells into the light coming through the pupil.
Without blood to provide oxygen and nutrients, the cornea must get them from somewhere else. Nutrients come from the tears and from the liquid (aqueous humor) that fills the chamber behind the cornea. Oxygen is no problem, since the cornea is in direct contact with the air.
Relative to the planet Earth, the fastest speed humans have achieved was 24,791 miles per hour (39,914 km/hr), by the Apollo 10 astronauts, on their return trip from the moon in 1969.
But the universe is much bigger than the Earth-Moon system, and everything moves. If the Sun is taken as a fixed point, then all the humans on Earth are moving at about 66,660 miles per hour (107,320 km/hr) as the Earth follows its orbit.
If the center of the Milky Way galaxy is a fixed point, then the solar system is moving at about 500,000 miles per hour (800,000 km/hr) in its orbit around the galaxy.
From an even broader reference frame, our entire local group of galaxies is moving at about one million miles per hour toward another galaxy group called Virgo Cluster.
During the 1700s and early 1800s, there were so many lobsters along the coast of New England that one could walk down the beach and pick them up off the sand. Lobsters were so abundant that native Americans used them as fertilizer, and colonists thought of them as food for poor people. Servants complained when they were forced to eat lobster more than three times in a week.
Today, of course, lobsters are prized as an expensive delicacy. They are hunted intensely by humans, and they are no longer so abundant. Today's wild lobsters are puny runts compared to the huge forty- pound, three-foot specimens (18 kg, 1 meter) that were once common along the New England coast.
According to recent estimates, the number of actively spoken languages in the world today is around 6,000. More than 1,400 of those languages belong to the Niger-Congo family from Africa, and about 1,200 are in the Austronesian family from Madagascar, Indonesia, Australia, the Pacific Islands, and New Zealand.
Most of today's active languages are spoken by very few people, and many of them are losing speakers rapidly as the world becomes more and more connected. Half of today's languages have fewer than 10,000 speakers, and a quarter have fewer than 1,000.
Thousands of years ago, there may have been as many as 10,000 active languages in the world. Within the next century, thousands of languages may be lost.