Getty Images
Getty Images

What Causes Morning Sickness?

Getty Images
Getty Images

Buckingham Palace has confirmed what the British tabloids have suspected for a while: The Duchess of Cambridge is expecting. Unfortunately, Kate has also been admitted to the hospital due to hyperemesis gravidarum, or acute morning sickness—so severe that no food or liquid can be kept down. This is much different than the morning sickness that affects 50 to 80 percent of pregnant women, starting around the sixth week of their pregnancy. What is it about pregnancy that gives women the constant urge to purge?

It seems contradictory—in the early stages of pregnancy, when a mother needs to nourish her growing fetus, her stomach refuses to keep anything down. And many pregnant women will state categorically that “morning sickness” is a misnomer; the nausea likely lasts all day and night.

For many years, doctors attributed morning sickness to the plethora of hormones that race through the body during early pregnancy. These hormones heighten the sense of smell, making a woman far more sensitive to aromas than she was prior to pregnancy.

New Theories

However, in the late 1970s, scientists—including Ernest Hook, an endocrinologist at Albany Medical College—began floating a new theory: That morning sickness protected the fetus from toxins that could hinder or derail its development (the period between six and 18 weeks is crucial in a fetus's development). And in 1992, Margaret Profet argued that morning sickness was part of an evolutionary adaptation. Potential toxins nauseated the mother, so she avoided them and didn’t hurt her baby—or herself. (A woman's immune system is compromised during pregnancy.)

In 2000, researchers at Cornell University found evidence that supported this theory. They studied 79,000 pregnancies in 16 countries, and found that 65 percent of the women had an aversion to at least one food. Twenty-eight percent couldn’t tolerate animal products (meat, eggs, fish), 16 percent avoided caffeinated drinks, and eight percent disdained strong-flavored vegetables such as broccoli. All of the aforementioned items contain secondary compounds which are natural toxins. "Our study ... shows that nausea and vomiting in pregnancy is beneficial by expelling such foods as meat and strong-tasting vegetables that historically and still may contain harmful toxins and microorganisms that could potentially sicken the woman and damage her fetus just when its organs are developing and are most vulnerable to chemicals," said Paul Sherman, Cornell professor of neurobiology and behavior. The study also found out that women in societies that eschewed animal products and subsisted mainly on corn, rice, and tubers rarely suffered from morning sickness.

There are some scientists who disagree with this idea, though, because, among other things, sickness during pregnancy doesn't necessarily equal a better pregnancy outcome (i.e., healthier babies).

There is another theory that gained some attention earlier this year: SUNY-Albany psychologist Gordon Gallup believes that the cause of morning sickness is actually unfamiliar semen. Because half of the fetus's DNA comes from the father, he says the mother's body treats it as an infection, which triggers nausea and vomiting.

AFP, Getty Images
Big Questions
What Happened to the Physical Copy of the 'I Have a Dream' Speech?
AFP, Getty Images
AFP, Getty Images

On August 28, 1963, Martin Luther King Jr. stood on the steps of the Lincoln Memorial and gave a speech for the ages, delivering the oratorical masterpiece "I Have a Dream" to nearly 250,000 people.

When he was done, King stepped away from the podium, folded his speech, and found himself standing in front of George Raveling, a former Villanova basketball player who, along with his friend Warren Wilson, had been asked to provide extra security around Dr. King while he was speaking. "We were both tall, gangly guys," Raveling told TIME in 2003. "We didn't know what we were doing but we certainly made for a good appearance."

Moved by the speech, Raveling saw the folded papers in King’s hands and asked if he could have them. King gave the young volunteer the speech without hesitation, and that was that.

“At no time do I remember thinking, ‘Wow, we got this historic document,’” Raveling told Sports Illustrated in 2015. Not realizing he was holding what would become an important piece of history in his hands, Raveling went home and stuck the three sheets of paper into a Harry Truman biography for safekeeping. They sat there for nearly two decades while Raveling developed an impressive career coaching NCAA men’s basketball.

In 1984, he had recently taken over as the head coach at the University of Iowa and was chatting with Bob Denney of the Cedar Rapids Gazette when Denney brought up the March on Washington. That's when Raveling dropped the bomb: “You know, I’ve got a copy of that speech," he said, and dug it out of the Truman book. After writing an article about Raveling's connection, the reporter had the speech professionally framed for the coach.

Though he displayed the framed speech in his house for a few years, Raveling began to realize the value of the piece and moved it to a bank vault in Los Angeles. Though he has received offers for King’s speech—one collector wanted to purchase the speech for $3 million in 2014—Raveling has turned them all down. He has been in talks with various museums and universities and hopes to put the speech on display in the future, but for now, he cherishes having it in his possession.

“That to me is something I’ll always be able to look back and say I was there,” Raveling said in the original Cedar Rapids Gazette article. “And not only out there in that arena of people, but to be within touching distance of him. That’s like when you’re 80 or 90 years old you can look back and say ‘I was in touching distance of Abraham Lincoln when he made the Gettysburg Address.’"

“I have no idea why I even asked him for the speech,” Raveling, now CEO of Coaching for Success, has said. “But I’m sure glad that I did.”

Big Questions
How Are Rooms Cleaned at an Ice Hotel?

Cleaning rooms at Sweden’s famous ICEHOTEL is arguably less involved than your typical hotel. The bed, for example, does not have traditional sheets. Instead, it’s essentially an air mattress topped with reindeer fur, which sits on top of a custom-made wooden palette that has a minimum of 60 centimeters of airspace below. On top of those reindeer hides is a sleeping bag, and inside that sleeping bag is a sleep sack. And while it’s always 20ºF inside the room, once guests wrap themselves up for the night, it can get cozy.

And, if they’re wearing too many layers, it can get quite sweaty, too.

“The sleep sack gets washed every day, I promise you that. I know it for a fact because I love to walk behind the laundry, because it’s so warm back there," James McClean, one of the few Americans—if not the only—who have worked at Sweden's ICEHOTEL, tells Mental Floss. (He worked on the construction and maintenance crew for several years.)

There isn’t much else to clean in most guest rooms. The bathrooms and showers are elsewhere in the hotel, and most guests only spend their sleeping hours in the space. But there is the occasional accident—like other hotels, some bodily fluids end up where they shouldn’t be. People puke or get too lazy to walk to the communal restrooms. Unlike other hotels, these bodily fluids, well, they freeze.

“You can only imagine the types of bodily fluids that get, I guess, excreted … or expelled … or purged onto the walls,” McClean says. “At least once a week there’s a yellow stain or a spilled glass of wine or cranberry juice … and it’s not what you want to see splattered everywhere.” Housekeeping fixes these unsightly splotches with an ice pick and shovel, re-patching it with fresh snow from outside.

Every room has a 4-inch vent drilled into the icy wall, which helps prevent CO2 from escalating to harmful levels. Maintenance checks the holes daily to ensure these vents are not plugged with snow. Their tool of choice for clearing the pathway is, according to McClean, “basically a toilet brush on a stick.”

When maintenance isn’t busy unstuffing snow from that vent hole, they’re busy piping snow through it. Every couple days, the floor of each room receives a new coat of fluffy snow, which is piped through the vent and leveled with a garden rake.

“It’s the equivalent of vacuuming the carpet,” McClean says.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at


More from mental floss studios