Brass is an alloy of copper and zinc. Bronze is a more durable mixture of copper and tin.
Named for the patron saint of sailors, Saint Elmo’s fire is actually discharges of electricity that occur during storms. These discharges are seen as blue or bluish white lights at the tips of masts and bowsprits of ships at sea, as well as on church steeples and building spires on land.
The orbit of the moon around the earth is tilted at an angle of about 6 degrees from the plane of the earth’s orbit around the sun. As a result, the moon is usually above or below the line between the earth and the sun, except on certain predictable occasions.
The term noble gas refers to the lack of chemical reactivity in these inert gases. For the record, there are six noble gases: helium, neon, argon, krypton, xenon, and radon.
In our galaxy alone, there are about 100 billion stars. In the universe that we can see, the number of stars is estimated at 10^22.
The moon’s diameter is 2,160 miles. The earth’s diameter at the equator is 7,926.68 miles.
The prefrontal lobotomy was invented by Portuguese surgeon Antonio Caetano de Abreu Freire Egas Moniz (1874-1955) for patients with incurable mental disturbances. Moniz, who also served as the foreign minister of Portugal from 1918 to 1919, was awarded the Nobel Prize in physiology or medicine in 1949.
There are 10 types of clouds: cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus, cumulonimbus. Each of these clouds has a different shape and internal structure.
There are about 6,000 to 10,000 species of “true” grasses, members of the family Poaceae. They are the most widespread and numerous of all the flowering plants.
Actually called Newton’s law of gravitation, it describes the degree to which one body of matter attracts another. That attraction is in direct proportion to the product of the bodies’ masses, and in inverse proportion to the square of the distance between them. This law can be expressed in a formula first set forth in […]
A cosmic year is the length of time it takes the sun to complete one revolution around the center of the Milky Way galaxy. A cosmic year is about 225 million earth years. The sun is between 20 and 21 cosmic years old.
To galvanize steel means that a zinc coating is applied, either by “hot-dipping” the steel in molten zinc or by electroplating it in an electrolytic process. Thus protected against exposure, galvanized iron or steel is less liable to rust.
Close encounters of first kind is the sighting of UFOs. Close encounters of the second kind is the finding of physical evidence of UFOs. A close encounter of the third kind is actual physical contact with UFOs.
American physicist Murray Gell-Mann (b. 1929) named the quark in 1964. He took the name from James Joyce’s Finnegans Wake. A quark, a subatomic particle with a fractional electric charge, is believed by physicists to be the fundamental unit of matter.
Plastics are only one kind of polymer, a substance composed of very large chain-like molecules that consist of smaller, repeating chemical units. Natural polymers include proteins, cellulose, diamonds, and quartz. Besides plastics, man-made ones include concrete, glass, and paper.
Mercury, Mars, Venus, Jupiter, and Saturn were known from ancient times. Uranus was discovered in 1781, Neptune in 1846, and Pluto in 1930.
Quicksand doesn’t work by pulling you down. Quicksand is nearly always found above a spring, which creates a supersaturated condition that makes the sand frictionless and unable to support weight. In addition, quicksand is airless, which creates suction as you struggle to get free. The most effective way to escape quicksand is to position yourself […]
Neutrinos are objects produced by the decay of certain subatomic particles. They have energy but little or no mass, and they travel almost at the speed of light.
A quasar is another name for a quasi-stellar object. It looks like a star but emits as much radiation as an entire galaxy, with a volume far smaller than that of our Milky Way galaxy. No one knows what a quasar is; recent evidence suggests it might be a galaxy with a big black hole […]
Avoirdupois weight is the system we use whenever we measure a grain, dram (27.3 grains), ounce (16 drams), or pound (16 ounces).
Glass is generally made of three components: silica, in the form of sand; an alkali flux, such as soda or potash, which promotes fusion; and lime, which stabilizes the mixture. In the process of being heated and then cooled, glass loses its crystalline nature and becomes an amorphous but rigid substance. Like a solid, it […]
Shooting stars are not stars but meteorites, particles from space entering and burning up in the earth’s atmosphere.
The earth moves at 66,641 miles per hour around the sun.
Both stalagmites and a stalactites are elongated deposits of minerals at points where slowly dripping water enters a void. Stalagmites build from the bottom of such a cavity; stalactites hang from the ceiling. When the same dripwater source creates both a stalactite and a stalagmite, the two may meet and form a column.
Yes, if you heat them to somewhere between 1,400 to 1,607 degrees Fahrenheit, diamonds will burn. A blowtorch will do the trick. Diamonds are composed of pure carbon and will convert into graphite under such temperatures.
It was brought on by the awarding of the 1932 Nobel Prize in physics to Werner Heisenberg for his uncertainty principle. The principle states that you cannot accurately know both the position and momentum of an atomic particle at the same time. Einstein believed that the principle made a mockery of cause and effect.
When a new drug is being tested, what is the difference between a blind test and a double-blind test?
In a blind test of a new drug, the subject does not know if he or she is receiving the drug or a placebo, but the physician administering the test does know. In a double-blind test, neither the subject nor the physician knows.
No, typhoid fever is not the same thing as typhus. Typhus is caused by microbes called rickettsiae and is carried by fleas, mites, and ticks, which in turn are carried by rats and other rodents. Typhoid (also called typhoid fever or enteric fever) resembles typhus in its symptoms but is caused by a different microbe, […]
If 32 degrees is the freezing point of water on the Fahrenheit scale, what does 0 degrees represent?
German physicist Gabriel Daniel Fahrenheit (1686-1736) took the temperature of an equal ice-salt mixture as the zero for his scale.
Hailstones begin as frozen raindrops or pellets of snow in a thunderstorm cloud. These “hail embryos” are carried by updrafts to a part of the storm where droplets of water exist in a supercooled state (that is, in liquid form at temperatures below freezing). These supercooled droplets freeze into ice when they strike the surface […]
Sometimes likened to the shell that covers an egg, the layer of rock or crust that covers the surface of the earth is, on average, 22 miles thick.
Man evolved in the Pleistocene epoch, which began about 2.5 million years ago and ended about 10,000 years ago. We now live in the Recent (or Holocene) epoch, beginning about 10,000 years ago.
The earliest era of geologic time is the Precambrian age. It began when the earth’s crust formed, 4.6 billion years ago, and ended with the dawn of the Cambrian period, 570 million years ago. About seven-eighths of earth’s history since the formation of the crust took place during the Precambrian age.
An average bolt of lightning raises the air temperature along its way to about 50,000 degrees Fahrenheit.
Bird guano is the accumulated excrement and remains of birds such as cormorants, pelicans, and gannets. Guano is 11 to 16 percent nitrogen, 8 to 12 percent phosphoric acid, and 2 to 3 percent potash. The excellent fertilizer is harvested from islands off Peru, Baja California, and Africa. Bat and seal guano is also highly […]
The oldest moon material brought back to earth by the Apollo program crews has been soil-dated to 4.72 billion years.
Twentieth-century American physicist John Archibald Wheeler (b. 1911) coined the term black hole to describe a collapsed star whose gravitational field is so intense that not even light can escape from it.
The continental shelf is an underwater ledge around the coastline of the world’s oceans. The edge of the shelf lies at depths of between 360 and 480 feet. The width may vary from a few feet to several hundred miles.
The Greek word heureka, meaning “I have found it,” was made famous by Archimedes, a Sicilian philosopher (c. 287-212 B.C.). Archimedes was given the task of finding out whether a crown presented to the ruler of Syracuse was really pure gold or alloyed with an inferior metal. The philosopher was baffled until he stepped into […]
Growth hormones called auxins makes houseplants turn toward the light. When light falls on one side of a plant, the auxins tend to concentrate on the shaded side, causing the cells on that side to grow longer. As a result, the plant gradually leans toward the light. This bending movement in response to an outside […]
The first to approximate the speed of light roughly was French physicist Armand Fizeau (1819-1896). In 1849 Fizeau obtained a value for the speed of light that was about 5 percent too high. Fizeau’s contemporary Jean Foucault (1819-1868) obtained the first accurate measurement (within 1 percent of the correct speed) in 1862.
Charles Darwin did not come up with the phrase survival of the fittest. The British philosopher and scientist Herbert Spencer introduced the phrase in Principles of Biology (1864-1867) as a way of describing Darwin’s theory of natural selection.
Astronomers once believed that a planet called Vulcan existed between the planet Mercury and the sun. Its existence, first proposed by French astronomer Urbain Jean Joseph Leverrier in 1845, was hypothesized to explain a discrepancy in Mercury’s orbit. Vulcan was even reported to have been observed once, but the observation was never confirmed. Einstein’s general […]
At any given time on a clear night in a dark place with no obstructions on the horizon, 2,500 stars are visible to the naked eye.
The plates (solid segments of the earth’s crust and upper mantle) that consist mostly of continents move at an average speed of about 2 centimeters per year. Europe and North America are moving apart at about this speed. The plates that are mostly under the oceans move faster, at an average speed of about 10 […]
A common ingredient in many laundry detergents, optical bleaches (“fabric brighteners”) act by reflecting blue light. The blue light combines with the yellow discoloration in a fabric to produce white light that makes the fabric seem brighter.
Most of the world’s non-Muslim countries use the Gregorian calendar, introduced by Pope Gregory XIII in 1582 as a reform of the Julian calendar. The latter, instituted by Julius Caesar, had been in use since 46 B.C. Americans have used the Gregorian calendar since 1752. What’s the difference between the the Julian or the Gregorian […]
The explosion of a star is called a supernova and is estimated to release 10^49 ergs or 1 followed by 49 zeros. By comparison, pronouncing an average syllable releases 200 ergs, and the first atom bomb produced 1021 ergs.
The term plasma to a physician means the fluid part of blood, lymph, or milk as distinct from suspended matter. The term plasma to a physicist means a collection of negatively charged electrons and positively charged ions, existing in about equal numbers in a neutral state; plasma is considered a fourth state of matter, distinct […]
Sigmund Freud’s original term for the unconscious mind was not id but es, the indefinite pronoun it in German. Freud borrowed that term from a physician, Georg Groddick, who in turn had borrowed it from his teacher Ernst Schweninger. As Freud’s ideas became popular in English-speaking countries, translators felt that simply calling the unconscious it […]
In 1900, a hurricane in Galveston, Texas, with 15- to 20-foot waves swept over Galveston Island and drowned 6,000 people.
Contrary to dormitory fears, it does not inhibit sexual desire. Instead, saltpeter, or potassium nitrate (KNO3), is a diuretic. Another form of saltpeter is Chile saltpeter, or impure sodium nitrate (NaNO3). Lime, or Norwegian saltpeter, is calcium nitrate. It is used to make explosives.
A wave breaks when the water that supports a wave is only about 1.3 times as deep as the wave is high. At that point, the water at the crest is moving faster than the water below. This condition commonly occurs in shallow water at the shore, but it may occur farther off if the […]
According to Albert Einstein’s law on the equivalence of mass and energy, the energy (E) of a quantity of matter is equal to the product of the quantity’s mass (m) and the square of the velocity of light (c).
Dinosaurs lived during the Mesozoic era, 225 million to 65 million years ago. By the end of that era, all Archosauria (or “ruling reptiles”), except crocodiles, had died.
The light from a firefly comes from an area on the sides of its stomach. Fatty tissue located there contains air tubes and nerves that when stimulated give off oxygen. The oxygen combines with a pigment in the fat called luciferin, producing the familiar heatless light.
The colors red, orange, yellow, green, blue, indigo, violet make up a rainbow.
The largest plant in the world is said to be the General Sherman Tree, a giant sequoia in Sequoia National Park, California. The tree is about 272 feet tall and more than 100 feet in circumference. It is about 3,500 years old.
The first leap year was 46 B.C. It was then that the Julian calendar of 365.25 days was adopted. The calendar required that an extra day be added every fourth year.
At the Pacific Ocean’s greatest depth-36,198 feet (in the Marianas trench southwest of Guam), the pressure is 16,124 pounds per square inch, more than 1,000 times the atmospheric pressure at sea level (14.7 pounds per square inch).