The reason why these materials didn’t burn is because of pyrolysis -the breakdown of of organic material at elevated temperatures in the absence, or under a shortage, of oxygen. Smoke is an airborne collection of little particles of these unburned materials. However, when most materials are burned, they undergo incomplete combustion, which means that the fire isn’t able to completely burn all of the fuel. In complete combustion -what occurs when you light a gas stove -the fire produces no smoke. So for a fire to ignite and be sustained, it needs heat, fuel and oxygen -denying a fire any of these three things will extinguish the fire attempting to start a fire without one of three things will be futile. But let’s step back-do you always have to have fire if you see smoke?Īnswering that first requires defining “fire.” Merriam-Webster’s first definition of fire is “the phenomenon of combustion manifested in light, flame, and heat.” Combustion is the chemical reaction that occurs when fuel is burned in the presence of oxygen. Where there’s smoke, there’s fire: The phrase means that if something looks wrong, it likely is wrong. If this were to occur every blue moon, we’d soon be awash in blue creatures three apples high!Ĭan there be smoke with no fire? Photo by Flickr user Maarten TakensĢ. Readers may recall that baby Smurfs are delivered to the Smurf village during blue moons. In such a case, one of the four full moons in that season was labeled “blue.” Typically, 12 full moons occur from winter solstice to the next winter solstice (roughly three per season), but occasionally a fourth full moon in a season could be observed. But prior to that, blue moons meant something slightly different. The usage of “blue moon” as the second full moon in a month dates back to a 1937 Marine Farmer’s Almanac. The problem with the phrase, however, is that blue moons are not so rare-they happen every few years at least, and can even happen within months of each other when the 29.5-day lunar cycle puts the full moon at the beginning of any month but February. A blue moon is the term commonly used for a second full moon that occasionally appears in a single month of our solar-based calendars. Once in a blue moon: This poetic phrase refers to something extremely rare in occurrence. Thus, the darkest hour of the night (in the absence of the Moon) is midway between sunset and sunrise.Ī few phrases, however, have less obvious scientific inaccuracies. Or the person who utters the placating phrase that “the darkest hour is just before dawn,” meant to give hope to people during troubled times, probably knows that well before the Sun rises, the sky gets progressively lighter, just as how well after the Sun sets, light lingers until the Earth rotates beyond the reach of the Sun’s rays. A person who sagaciously shakes her head and says “A watched pot never boils” while you are waiting second after agonizing second for test results to arrive or job offers to come in knows that if she sat down and watched a vessel containing water on a stove over high heat for long enough, the water will eventually boil. Some are obvious, yet we use them anyhow. Yet certain well-used phrases from science are misrepresentations of what they’re trying to express. These colorful expressions bring spice to our language. “Tuning in” to someone’s message has its origins in the slight turns of a dial needed to focus on a radio signal. Someone as “ mad as a hatter” exhibits behavior similar to 18th and 19th century hat makers who stiffened felt cloth with mercury-an ingredient that after continued exposure causes dementia. To be “in the limelight”-at the center of attention-harks back to how theater stages used to be lit by heating lime (calcium oxide) until it glowed a brilliant white, then focusing the light emitted into a spotlight. The incredulous expression” Well, I’ll be a monkey’s uncle” stems from sarcastic disbelief over Darwin’s writings on evolution. Are blue moons really that rare? Photo by Flickr user bilbord99Ĭoncepts from science and nature pervade our language’s common phrases, idioms and colloquialisms.
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