The human brain uses about 200 kilocalories per day, which equates to approximately 10 watts of power. For comparison's sake, that's about 10 percent of the power that it takes to run a 100-watt light bulb. So the cartoon image of a light bulb over your head when a great thought occurs isn't too far off the mark. Your brain generates as much energy as a small light bulb even when you're sleeping.
25,000,000 of your cells died while you read this sentence. It's okay though, your body made more than 300 billion new ones today.
The cells that make up your body are dying and being replaced all the time. This happens so often that about every 7 years you have a completely new body of cells. While this is true for most cells, such as the cells lining the stomach, some of the most important cells in your body (those of your bones, your brain, and your heart) don't regenerate much at all, so treat them with care.
The speed of nerve impulses varies enormously but the fastest travel at about 250 mph. That's as fast as a Formula 1 racing car! However this demand for speed uses a lot of energy and is found only in neurons that need to transfer information urgently. For example, if you burn your fingers it is important that your brain gets the message to withdraw your hand very quickly.
Your entire body is made up of around 75 trillion cells. Each one of your cells is like a small city with thousands of different types of complex molecules interacting with each other to keep you alive and conscious. When you compare this to the 400 billion stars in our galaxy, you can understand just how magical your existence really is. So the next time you are feeling down or insignificant, simply remember, you are made of 75,000,000,000,000 cells, and that's far from “insignificant”!
If you took all of the blood vessels out of an average child, and laid them out in one line, the line would be over 60,000 miles long. An adult's vessels would be closer to 100,000 miles long! That means an adult's blood vessels could go around the circumference of the world more than 4 times!
Ancient Chinese philosopher Lao Tzu once said: “Watch your thoughts; they become words. Watch your words; they become actions”. Your mind is a powerful machine and controls every function of the body. But the good news is you have the power to control your mind. Experiencing positive thoughts leads to more positive thoughts and an even broader view of everything around us. For example, positive thoughts can strengthen your immune system while negative thoughts can bring it down.
As Carl Sagan used to say, we are made of “star stuff”. It sounds like a line from a poem, but there is some concrete science behind this statement: almost every element on Earth was formed at the heart of a star. The carbon, nitrogen and oxygen atoms in our bodies, as well as atoms of all other heavy elements, were created in previous generations of stars over 4.5 billion years ago. So next time you're out gazing at stars twinkling in the night sky, remember, we are all made of star dust, we are all one!
Astrophysicist Dr. Neil DeGrasse Tyson was asked by a reader of TIME magazine, "What is the most astounding fact you can share with us about the Universe?" This is his answer.