5 Myths of the 1920s That Were Debunked—Then Turned Out to be True

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 TruthEven 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. The flashpoint of wood 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.


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 Center 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.


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.

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 color 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 courtesy of the New York Public Library

Women Suffer Worse Migraines Than Men. Now Scientists Think They Know Why

Migraines are one of medicine's most frustrating mysteries, both causes and treatments. Now researchers believe they've solved one part of the puzzle: a protein affected by fluctuating estrogen levels may explain why more women suffer from migraines than men.

Migraines are the third most common illness in the world, affecting more than 1 in 10 people. Some 75 percent of sufferers are women, who also experience them more frequently and more intensely, and don't respond as well to drug treatments as men do.

At this year's Experimental Biology meeting in San Diego, researcher Emily Galloway presented new findings on the connection between the protein NHE1 and the development of migraine headaches. NHE1 regulates the transfer of protons and sodium ions across cell membranes, including the membranes that separate incoming blood flow from the brain.

When NHE1 levels are low or the molecule isn't working as it's supposed to, migraine-level head pain can ensue. And because irregular NHE1 disrupts the flow of protons and sodium ions to the brain, medications like pain killers have trouble crossing the blood-brain barrier as well. This may explain why the condition is so hard to treat.

When the researchers analyzed NHE1 levels in the brains of male and female lab rats, the researchers found them to be four times higher in the males than in the females. Additionally, when estrogen levels were highest in the female specimens, NHE1 levels in the blood vessels of their brains were at their lowest.

Previous research had implicated fluctuating estrogen levels in migraines, but the mechanism behind it has remained elusive. The new finding could change the way migraines are studied and treated in the future, which is especially important considering that most migraine studies have focused on male animal subjects.

"Conducting research on the molecular mechanisms behind migraine is the first step in creating more targeted drugs to treat this condition, for men and women," Galloway said in a press statement. "Knowledge gained from this work could lead to relief for millions of those who suffer from migraines and identify individuals who may have better responses to specific therapies."

The new research is part of a broader effort to build a molecular map of the relationship between sex hormones and NHE1 expression. The next step is testing drugs that regulate these hormones to see how they affect NHE1 levels in the brain.

Vivien Killilea/Getty Images for Caruso Affiliated
A Founder of Earth Day Looks Back on How It Began
Vivien Killilea/Getty Images for Caruso Affiliated
Vivien Killilea/Getty Images for Caruso Affiliated

On the very first Earth Day in 1970, Denis Hayes stood on a stage in Central Park, stunned by the number of people who'd come to honor the planet. Now in his 70s, Hayes remembers it was like looking at the ocean—“you couldn’t see where the sea of people ended.” Crowd estimates reached more than a million people.

For Hayes, who is now board chair of the international Earth Day Network, it was the culmination of a year’s worth of work. As an urban ecology graduate student at Harvard University, he’d volunteered to help organize a small initiative by Wisconsin senator Gaylord Nelson. Nelson was horrified by the 1969 oil spill in Santa Barbara, California, and wanted to raise awareness about environmental issues by holding teaching events similar to those being held by civil rights and anti-war activists.

Senator Nelson saw a growing disconnect between the concept of progress and the idea of American well-being, Hayes tells Mental Floss. “There was a sense that America was prosperous and getting better, but at the same time, the air in the country was similar to the air today in China, Mexico City, or New Delhi," Hayes says. "Rivers were catching on fire. Lakes were unswimmable.”

Nelson's plan for these environmental teach-ins was for speakers to educate college students about environmental issues. But he had no one to organize them. So Hayes, Nelson’s sole volunteer, took control on a national level, organizing teach-ins at Harvard first and then across the U.S. Initially, the response was tepid at best. “Rather rapidly it became clear that this wasn’t a hot issue at colleges and universities in 1969,” Hayes says. “We had a war raging, and civil rights were getting very emotional after the Nixon election.”

Still, both Hayes and Nelson noticed an influx of mail to the senator's office from women with young families worried about the environment. So instead of focusing on colleges, the two decided to take a different tactic, creating events with community-based organizations across the country, Hayes says. They also decided that rather than a series of teach-ins, they'd hold a single, nationwide teach-in on the same day. They called it Earth Day, and set a date: April 22.

Hayes now had a team of young adults working for the cause, and he himself had dropped out of school to tackle it full time. Long before social media, the project began to spread virally. “It just resonated,” he says. Women and smaller environmental-advocacy groups really hooked onto the idea, and word spread by mouth and by information passing between members of the groups.

Courtesy of Denis Hayes

With the cooperation and participation of grassroots groups and volunteers across the country, and a few lawmakers who supported the initiative, Hayes’ efforts culminated in the event on April 22, 1970.

Hayes started the day in Washington, D.C., where he and the staff were based. There was a rally and protest on the National Mall, though by that point Hayes had flown to New York, where Mayor John Lindsay provided a stage in Central Park. Parts of Fifth Avenue were shut down for the events, which included Earth-oriented celebrations, protests, and speeches by celebrities. Some of those attending the event even attacked nearby cars for causing pollution. After the rally, Hayes flew to Chicago for a smaller event.

“We had a sense that it was going to be big, but when the day actually dawned, the crowds were so much bigger than anyone had experienced before,” Hayes said. The event drew grassroots activists working on a variety of issues—Agent Orange, lead paint in poor urban neighborhoods, saving the whales—and fostered a sense of unity among them.

“There were people worrying about these [environmental] issues before Earth Day, but they didn’t think they had anything in common with one another," Hayes says. "We took all those individual strands and wove them together into the fabric of modern environmentalism.”

Hayes and his team spent the summer getting tear-gassed at protests against the American invasion of Cambodia, which President Nixon authorized just six days after Earth Day. But by fall, the team refocused on environmental issues—and elections. They targeted a “dirty dozen” members of Congress up for re-election who had terrible environmental records, and campaigned for candidates who championed environmental causes to run against them. They defeated seven out of 12.

“It was a very poorly funded but high-energy campaign,” Hayes says. “That sent the message to Congress that it wasn’t just a bunch of people out frolicking in the sunshine planting daisies and picking up litter. This actually had political chops.”

The early '70s became a golden age for environmental issues; momentum from the Earth Day movement spawned the creation of the Clean Air Act, the Clean Water Act, the Safe Drinking Water Act, the Endangered Species Act, the Marine Mammal Protection Act, the Environmental Education Act (which was initially passed in 1970 and revived in 1990), and the Environmental Protection Agency.

“We completely changed the framework within which America does business, more than any other period in history with the possible exception of the New Deal,” Hayes says. “But our little revolution was brought entirely from the grassroots up.”

In 1990, Hayes was at it again. He organized the first international Earth Day, with about 200 million participants across more than 140 countries. Since then it’s become a global phenomenon.

Despite its popularity, though, we still have a long way to go, even if the improvements Hayes fought for have made these issues feel more remote. Hayes noted that everything they were fighting in the '70s was something tangible—something you could see, taste, smell, or touch. Climate change can seem much less real—and harder to combat—to the average person who isn’t yet faced with its effects.

Hayes also notes that people have become more skeptical of science. “Historically, that has not been a problem in the United States. But today science is under attack.”

He warns, “This [anti-science sentiment] is something that could impoverish the next 50 generations and create really long-term devastation—that harms not only American health, but also American business, American labor, and American prospects.”


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