Meet the Astronaut Who Discovered Why You Throw Up After Drinking Too Much

motion sickness and alcohol poisoning
The 1978 class of astronaut candidates takes a familiarization flight in a KC-135 zero-gravity aircraft, known as the vomit comet. NASA

Ken Money has one impressive resume. For starters, he's an Olympic high jumper turned astronaut with the Canadian Space Agency. He never made it to space, but he did take several rides in NASA's "vomit comets," giant cargo planes that climb and dive to simulate zero gravity. His research from his first job probably came in handy on those flights. Money also published over a hundred articles as a scientist. His expertise: motion sickness and the inner ear, the understanding of which remains critical to improving virtual reality technology.

One of Money's great discoveries was proving that alcohol sickness is actually a form of motion sickness. That makes sense when you consider how the world seems to spin after you've had too many drinks.

Money isn't a drinker—he had a puritanical upbringing—nor is he prone to get motion sickness, although he admits it happened once, while flying a helicopter. "I [drank alcohol] in an experiment once and that was all," he tells Newsweek from his home outside Toronto where he is now a full-time grandfather. "I got the typical response."

Money knew that motion sickness is tied to the inner ear, or vestibular system, where the body keeps all the tools it needs to feel motion like acceleration and orientation in space. Some people get sick when what they see doesn't match what their inner ear feels. "It's best to call it a poisoning response to motion," Money says. In a famous experiment, scientists discovered that patients without a functioning inner ear (which also means they are deaf) are immune to getting seasick. But Money was curious if there was any connection with motion sickness and throwing up after you binge drink.

It's long been known that people who are drunk are unsteady. "Alcohol not only makes you stupid," Money says, "it gives you sensations of movement that are wrong." It's one of the reasons that pilots are advised not to fly for several hours after having a drink.

But one of the features of stumbling drunks is that their eyes are unsteady, too. It's something police look for at DUI checkpoints. After having too much to drink, people's pupils dart around, but amazingly it's always in the same direction. If you're lying on your right side, your eyes will dart the same way every time you've had too much—down and to the right, down and to the right.

For Money, that motion was a clue. One of the tricks of your ear's vestibular system is keeping your eyes looking straight ahead as you nod "no." You can actually prove this has nothing to do with your vision and everything to do with your inner ear by closing your eyes and placing your fingers lightly on your eyelids and nodding like you're saying no to another round. You'll actually feel your eyes sliding under your eyelids as your head moves.

Soon, Money got another clue. He had a friend who was giving "heavy water"—a naturally occurring type of water where the hydrogen atoms have extra neutrons—to infants as a way to test their level of hydration.

Money's ears perked up when his friend told him that some of the babies who had just taken heavy water drinks were getting sick, just like people who drank too much alcohol, but with one big difference. "After heavy water," Money says, "your eyes move in the opposite direction, up and to the left."

Just as alcohol is a little lighter than water, heavy water is, well, a little heavier. If alcohol, which is lighter than water, makes your eyes dart down, and heavy water, which is heavier, makes them dart up, Money thought the room-spinning effect that makes frat boys puke might be caused by a slight difference in the boyancy of the blood in the delicate parts of their inner ears—the parts that help people look in one place when their head moves.

There's one part of the inner ear in particular, the ampulla, which is full of blood, while the rest isn't. Money reasoned that this part of the ear was actually registering these tiny introductions of fluids lighter and heavier than water in the blood stream, and making the precise inner ear instruments malfunction.

To test this theory, Money got volunteers to drink alcohol and heavy water at the same time and measured their eyes. At just the right ratio, one part alcohol to two parts heavy water by volume, the two balanced each other out. The volunteers drank without becoming dizzy or getting sick.

Before Money's experiment in 1974, most people assumed what was going on was chemical; the brain registered a toxic level of alcohol and ordered a purge. Money showed that you actually throw up from alcohol because of gravity's gentle pull on some tiny blood vessels deep inside your ears.

All of this might seem incredible, but it's less so when you consider the most prevalent theory for why we get motion sick at all.

Thanks in part to Money, most experts think motion sickness evolved as a first, subtle sign that you have food poisoning and need to vomit. If your vision starts to swim after you eat some fresh mushrooms, but your ears aren't registering any motion, it could be the first sign that what you ate was toxic.

So next time you find yourself stumbling from a bar, you could, in theory, reach for glass of heavy water to balance the buoyancy of the alcohol coursing through your veins. Or you could take a moment to consider how gravity, the mysterious force at the center of the universe, just helped you figure out you've had one too many.