5 MYTHS OF THE 1920S THAT WERE DEBUNKED - THEN TURNED OUT TO BE TRUE

5 Myths of the 1920s That Were Debunked - Then Turned Out to be True
By Therese Oneill, Mental Floss, 24 March 2015.

In the 1920s, Lambert & Butler English Cigarette cards set out to debunk common myths. Some are just bizarre (hold burned skin closer to a fire to “draw off” the burn), some are things teachers have the audacity to say to this day (“In summer, the earth is nearer the sun than in winter”) - and some, like these five, weren't actually myths at all, as 95 additional years of scientific research has shown.

1. Fallacy: Drinking hot tea will cool you down

Lambert & Butler Truth: It’s obvious that drinking hot tea causes your body heat to increase, though eventually you’ll return to normal, which may account for your brain “tricking” you into think you’re cooling down.

Twenty-first Century Truth: When an NPR executive producer told one of her writers to find out why hot tea cooled the body, the writer balked, saying that couldn’t possibly be true. The producer, Madhulika Sikka, replied, “Trust me. I’m Indian, I’m English. One billion Indians can’t be wrong. They drink hot tea in hot weather.” The journalist found out that receptors on the tongue tell the brain that the body is hot, which triggers the body’s cooling systems, particularly sweating. In fact, you sweat disproportionately to the amount of heat you’ve ingested, resulting (as long as that sweat can comfortably evaporate) in a cool down.

2. Fallacy: Artillery Fire Causes Rain

Lambert & Butler Truth: This long-held superstition was applied to rains that coincidentally accompanied such famous battles as Waterloo and English battles with the Spanish Armada. But this was disproved by a New Zealand scientist in 1907, who fired all sorts of bombast into the air to no result. It was determined that no explosion could generate the amount of energy required to make rainfall.

Twenty-first Century Truth: At the time these cards were printed, the theory of how big “artillery fire” would have to be to change the weather must have only existed in the nightmares of a handful of scientists. In 1945, theory became fact. Nuclear explosions can cause rain, as they did within a half hour of detonation at both Hiroshima and Nagasaki. It’s called “black rain,” caused by extreme atmospheric thermal changes and millions of particles of airborne debris becoming condensation vessels. It falls to earth like black sludge, and is highly radioactive.

3. Fallacy: The sun can cause prairie and forest fires

Lambert & Butler Truth: Even the hottest deserts in North Africa only reach temperatures of 140 degrees Fahrenheit, which is far below the temperature needed for forest debris to combust. Sun can dry out tinder, making a spark more likely to catch, but cannot start the fire.

Twenty-first Century Truth: It is extremely hard for sunshine to start a forest fire. But under perfect circumstances, it can. Wood’s flashpoint is 572 degrees Fahrenheit, and that’s a mighty high temperature for sunlight - unless that sunlight is concentrated by something, and/or directed onto tinder that doesn’t have as high a flashpoint, such as dry grass or pine needles. When paired with the most innocent of debris - a concave soda can bottom, a dog’s water dish or even a drop of water - the temperature soars and spontaneous sparks can fly.

4. The weather changes with the changing moon

Lambert & Butler Truth: The moon has no effect on weather. Although this has been repeated as truth for ages, studies since 1774 comparing weather changes and the phase of the moon have consistently had the result that “no connection whatever has been traced” (emphasis theirs).

Twenty-first Century Truth: This belief has been around in various forms since the Romans. And it turns out that they may have been on to something. In 2010, researchers from Arizona and the National Climactic Data Centre noticed that there was a slight increase in stream flow around the quarter moon, so they went back and looked at rainfall data from as far back as 1895. What they saw was that there was an increase in rainfall around the quarter moon. It’s a small effect - at the most it increases rainfall by 5 percent - but it is there.

5. Fallacy: Ozone is present in the air at the sea-side

Lambert & Butler Truth: The bracing smell of the seaside isn’t ozone, it’s probably just decaying seaweed. Analyses of seaside air versus air from other regions shows that the variation in ozone levels is very small.

Twenty-first Century Truth: This is a strange case in that it was probably true when the card was written, but now isn’t. Seasides probably do contain more ozone than other areas for one reason: shipping. Diesel engines produce a lot of nitrogen oxides that react with chloride (as is found in sea salt spray) to form nitryl chloride, which encourages the production of ozone. And around Miami and Houston, nitryl chloride levels were 20 times higher than models suggested. In Houston, a NOAA researcher has said that 10 to 30 percent of morning ozone production is probably thanks to sea air. So the Victorians were just a little ahead of their time.

There is one major difference between then and now, however. Back then, people felt that the ozone was a great curative that made people healthy. Now the exact opposite is believed.

BONUS: Fallacy: All Bats Are Blind

Lambert & Butler Truth: Bats have eyes, they are just very small. And they can hardly be blind because they eat very tiny things at night. And there you have it. Argue with that, if you can.

Twenty-first Century Truth: L&B weren’t wrong, really, but it’s a lot more complicated than that. There are many different species of bats, and they “see” in a variety of ways, often as well as humans. Some bats can only see black and white, but the fruit bat can see colour and has eyes adaptable to low light, like cats. But the real proof that bats are not blind didn’t show up until 1939, when Harvard student Donald Griffin began blindfolding, gagging, and covering the ears of bats. After discovering that bats made a great deal of noise too high for humans to hear, he then discovered they used that noise to “see.” Echolocation occurs when the noise a bat makes bounces off an object back to him, telling him where it is, how large, and if he can eat it.

All images (except top image) courtesy of the New York Public Library.

Top image: Bat echolocation. Credit: Stephen Burnett/Clayton State University.

[Source: Mental Floss. Edited. Top image added.]