life altering for millions of people.
• The axolotl was once an abundant species thriving in the ancient Aztec waters, but today the axolotl’s only remaining natural habitat is Lake Xochimilco (pronounced SO-chee-MILL-koh). The lake has been drained, and it’s now a series of meandering canals, partly comprised of untreated sewage water. (Yuck … that can’t be good for them.)
• Axolotls live up to 15 years (in captivity); average an impressive 12 inches (30.5 cm) long; come in a beautiful array of colors including black, pink, gold, olive, brown, gray, white (albino), and multicolored; and, are the only amphibian that can reach sexual maturity when still a larva.
• Bacteria are single-cell organisms. They’ve been around for billions of years and are the oldest living organisms on Earth.
• While the human body is made up of about one trillion cells, you have about ten trillion bacterial cells in or on your body at any given moment.
• Bacteria are instrumental in keeping us alive, digesting food, making vitamins, and educating the immune system to keep “bad” microbes out—these are “good” bacteria.
• “Bad” bacteria make humans sick, such as cholera, Lyme’s disease, and E. coli.
• Contrary to popular belief, while bacteria are primitive, “simple” organisms, they actually talk to each other via chemical languages!
• In fact, similar bacteria—referred to as intra-species bacteria—communicate with each other in their own language so they know who and how many are in the neighborhood, which dictates what they may or may not do. This is called “quorum sensing.”
• Different types of bacteria—referred to as “inter-species bacteria”—have a universal language (a five-carbon molecule) that allows all bacteria to communicate with each other! This helps them avoid duplicating jobs! (Very cool, and kind of scary.)
Big Bang Theory
• The Big Bang occurred approximately 13.75 (± 0.11) billion years ago.
• It’s believed that it took only an instant (a trillion-trillionth of a second!) after the “big bang” for the universe to go from an infinitely dense point to its ever-expanding astronomical grandeur.
• The first galaxies were created about 500 million years after the Big Bang.
• Our solar system was created about eight billion years after the Big Bang.
• The basic ideas of the Big Bang Theory were first published by Belgian priest and astrophysicist, Monsignor Georges Henri Joseph Édouard Lemaìtre, although these ideas are often inaccurately credited to Edwin Hubble.
• The term “Big Bang Theory” was originally coined by Sir Fred Hoyle as a contrast to his own theory of a steady-state universe.
• The original cause of the Big Bang still eludes scientists.
Black Holes
• Albert Einstein’s Theory of General Relativity predicted that:
• When a massive star dies, it leaves behind a small, dense remnant core.
• According to his equation, if the core’s mass is more than about three times the mass of the Sun, the force of gravity overwhelms all other forces, producing a black hole. He was correct!
• Most black holes form from the remnants of a large star that dies in a supernova explosion.
• As the surface of the star nears an imaginary surface called the “event horizon,” Time on the star slows relative to the time kept by observers far away.
• While a star is in the process of collapsing (under the overwhelming influence of gravity), two very cool things happen, from the perspective of an observer from a distance:
• The passage of Time on the surface of the star will appear to be moving in slow motion as it approaches the “event horizon”.
• Then, once the star’s surface reaches the “event horizon,” Time will appear to totally stand still (no movement, nothing; just frozen).
• However, from the perspective of the star, it just keeps collapsing!
• It’s all relative!
• A Princeton physicist named John Wheeler didn’t coin the term “black hole” until 1967.
• Just for the record—and as predicted by Einstein—smaller stars don’t become black holes. Instead, they become dense neutron stars, which aren’t massive enough to trap light.
Blood
• Blood is formed in your bone marrow, which is the soft, spongy center of your bones.
• Blood is actually one of your connective tissues; it’s a liquid tissue and the only liquid tissue in your body.
• Blood makes up around 7% of the weight of the human body.
• Blood cells circulate in the human body for about 120 days.
• Blood helps your body regulate body temperature. It does this by redistributing heat to skin to facilitate cooling via the evaporation process.
• While blood in the arteries is bright red, blood in the veins is more of a dark maroon shade because it carries impurities back to the kidneys and liver for disposal.
• When looking at our skin, the blood looks bluish because of light refraction and other factors but blood really is a reddish color. And just for the record, our veins are actually white!
Brain
• The average adult human brain weighs about 3 pounds (1.4 kg). For comparison, a whale brain weighs 8 to 15 pounds (3.6 to 6.8 kg); an elephant brain weighs 8 to 11 pounds (3.6 to 5 kg); a chimp brain weighs about 0.75 pounds (0.35 kg); and a dolphin brain weighs about the same as a human brain, about 3.5 pounds (1.6 kg).
• Although it makes up just 2% of the body’s weight, the brain uses around 20% of its energy.
• Albert Einstein’s brain weighed only 2 pounds (0.9 kg)—less than the average adult brain. Einstein’s brain had significantly more neurons—a.k.a. brain cells—packed into those 2 pounds!
• The right side of the human brain thinks in pictures and is “present” focused, meaning it’s focused on what’s going on right here and right now. The left side of the brain—which thinks in language—processes linearly and methodically and is focused on the past and the future.
• Exclusive to Homo sapiens, one of the many responsibilities of the prefrontal cortex of the brain—located just behind the forehead—is
