style="font-size:15px;"> • In 1943, work began on the Electronic Numerical Integrator and Computer (ENIAC), which was the first general-purpose programmable electronic computer and was used to solve ballistics problems during World War II.
• The ENIAC contained over 18,000 vacuum tubes.
• ENIAC was displayed to the public on February 14, 1946, at the Moore School of Electrical Engineering at the University of Pennsylvania.
• In 1964, the IBM 360 became the first computer to be mass-produced.
Corals
• While people tend to think of coral as hard, stonelike inanimate rock formations that sometimes gets turned into pretty jewelry, corals are actually living, breathing marine animals. Their class is Anthozoa, their phylum is Cnidaria).
• Almost all corals are colonial organisms, meaning they’re composed of thousands of tiny, individual invertebrate animals called polyps—which are tubular saclike animals.
• Polyps are also related to sea anemones and jellyfish. They’re amazing little creatures that secrete the mineral calcium carbonate, which, over time, accumulates and becomes the amazing reefs we know and love.
• One of the largest corals is the Fungia—the mushroom coral—which is a solitary coral that can grow to be 10 to 12 inches (25 to 30 cm) in diameter. Colonial corals are much smaller; their polyps range between 0.04 and 0.12 inches (1 to 3 mm) in diameter.
• Similar to our sense of smell and taste, coral polyps can detect certain substances like sugars and amino acids, which enable corals to detect their prey, such as plankton and small fish.
• Most corals get the majority of their nutrition via their symbiotic relationship with single-celled algae called zooxanthellae—which live within the coral polyp’s tissues. [See Zooxanthellae.]
• Polyps are generally nocturnal feeders, and the stomach cavities of colonial corals are interconnected, meaning food obtained by one polyp can be passed to other polyps in the colony!
• While corals don’t have “brains,” they do have a simple nervous system called a nerve net that extends from their mouth to their tentacles.
• Corals can reproduce both sexually and asexually. Some corals are hermaphroditic, meaning they have both male and female reproductive cells, and others are either male or female. Both sexes can occur in a colony, or a colony may consist of individuals of the same sex. Progressive little creatures!
Coriolis Effect
• Earth’s rotation causes objects moving over its surface—like missiles or hurricanes—to veer to the right in the Northern Hemisphere and to the left in the Southern because Earth is constantly moving beneath these objects in the direction of its daily rotation. This is the Coriolis effect.
• The Coriolis effect can be observed in any rotating frame of reference such as the spinning Earth or a merry-go-round.
• It is a myth that the Coriolis effect causes bathtubs or sinks to drain one direction in the Northern Hemisphere and the other in the Southern. The power of the effect is far too small to overcome the other factors involved in such events, such as residual currents or the vessel’s shape.
• The mathematical expression for the magnitude of the Coriolis effect appeared in an 1835 paper by French scientist Gaspard-Gustave Coriolis, as part of the explanation of the theory of water wheels.
• The Coriolis effect influences left or right movement, but it also influences up and down. This is known as the Eötvös effect.
• With the Eötvös effect, eastward-traveling objects are deflected upward because they feel lighter, and westward-traveling objects are deflected downward because they feel heavier.
• The Coriolis effect has a strong influence on air circulation in a developing tropical cyclone. These rarely form along the equator because the Coriolis effect is very weak there.
(Deoxyribonucleic Acid)
• DNA is our genetic blueprint, the fundamental building block for an individual’s entire genetic make-up.
• Nearly every cell in your body has the same DNA. Most DNA is located in the cell nucleus—where it is called nuclear DNA—but a small amount of DNA can also be found in the mitochondria, where it is called mitochondrial DNA or mtDNA.
• Since human red blood cells don’t have a nucleus, they don’t contain DNA.
• In 1953, James Watson and Francis Crick became famous for their accurate description of DNA’s double-helix model.
• Not so famous is Johann Friedrich Miescher, who, shortly after graduating from medical school, actually discovered DNA—which he called “nuclein”—while researching white blood cells in the pus of used hospital surgical bandages. The year was 1869.
• What people tend not to know about DNA is that DNA actually has three naturally occurring structures: A-DNA, B-DNA, and Z-DNA. The double helix of A-DNA and B-DNA twists to the right, and the Z-DNA twists left!
Dodo Birds
• The dodo (Raphus cucullatus) is a now-extinct, flightless bird related to pigeons and doves. The last confirmed sighting occurred in 1662, on an islet off Mauritius.
• The origin of the name is unclear. One theory suggests that in 1598, Portuguese sailors discovered the previously unknown species, which displayed no fear of humans. They called it douda—simpleton in Portuguese.
• The dodo was a character in Lewis Carroll’s Alice in Wonderland. In the 1865 book, the dodo is said to be a self-caricature of Carroll, whose real name was Charles Lutwidge Dodgson. Purportedly, because of a stutter, he was known to introduce himself as “Do-do-dodgson.”
• It’s a commonly held belief that dodos weighed over 50 pounds/23 kg (thanks to a 17th-century report) but fossil evidence suggests that dodos ranged in size from 24 to 46 pounds (10.6 to 21.1 kg)—the size of a large wild turkey.
• Research suggests that classic illustrations of fat dodos were either exaggerations or were based on overfed specimens. Pictures of fat dodos may also have been based on the dodo’s tendency to puff out its feathers.
• In the 1977 publication Plant-Animal Mutualism: Coevolution with Dodo Leads to Near Extinction of Plant, the author wrongly suggests that since there were almost no Calvaria trees younger than 300 years (around the same time period as the dodo became extinct), the seeds must have passed through the digestive tract of the dodo to germinate. This is a good example of how correlation and causation are not the same thing.
Dogwood Trees
• The Dogwood (Cornus florida) is an unusually hard wood and a beautiful
