12 Fascinating Facts About Ivan Pavlov

Wikimedia Commons // Public Domain
Wikimedia Commons // Public Domain

Thanks to Ivan Pavlov, we’re all familiar with classical conditioning and the Pavlovian response (ring a bell before giving a dog a plate of food enough times, and he'll eventually begin to salivate at the sound of the bell rather than the sight of the meal). But if you want to know more about the man himself, from his side gig selling canine gastric juice to his couch-surfing days, it's time to examine these 12 drool-worthy facts about Ivan Pavlov.

1. A LOT OF WHAT WE THINK WE KNOW ABOUT HIM IS WRONG.

Pavlov’s biographers point out that most people have misconceptions about the Russian physiologist. For example, instead of ringing a bell to train dogs, Pavlov actually used a variety of tools such as a metronome, buzzer, whistle, light, harmonium, and even electric shock. And Pavlov’s concept of the conditioned response is, in reality, not exactly what he pioneered. He discussed the conditional response, but a mistranslation of the original Russian word uslovnyi gave us the phrase conditioned response, which is still used today.

2. HE PLANNED TO BECOME A PRIEST.

Pavlov was born in Ryazan, Russia in 1849. His father was a priest, and Pavlov enrolled in a theological seminary. But after reading the works of Russian physiologist Ivan Sechenov, Pavlov decided to change course. In 1870, he left the seminary and enrolled at what is now known as St. Petersburg University to study natural science, physics, and math.

3. HIS CHEMISTRY PROFESSOR WAS A BIG DEAL.

During Pavlov’s first year of university, one of the classes he took was inorganic chemistry. His professor, Dmitri Mendeleev, was a big deal in the world of science. In 1869, Mendeleev published the first periodic table of elements and is credited as the father of the periodic table. Not too shabby.

4. HIS EARLY WORK DEALT WITH PANCREATIC NERVES AND ANIMAL DIGESTION.


Wikimedia Commons

Throughout the 1870s and early 1880s, Pavlov studied the natural sciences and physiology, conducting research and working on his doctorate thesis. Specifically, he wrote about the function of the nerves in the pancreas and the heart. In 1890, Pavlov was asked to develop and direct a physiology department at the Institute of Experimental Medicine, where he studied the interplay between the nervous system and digestion.

5. HE WAS SO POOR THAT HE COUCH-SURFED FOR A FEW MONTHS.

Russian scientists worked in modest labs and were paid very little, so Pavlov struggled with finances. In 1887 he couldn’t afford his apartment anymore, so he spent a few months away from his wife Serafima (or Seraphima) Karchevskaya and young son. Pavlov crashed with friends or slept in his lab, and he took on extra jobs; he taught physiology and worked on a medical journal to earn more money.

6. HE FINANCED HIS LAB BY SELLING CANINE GASTRIC JUICE AS A CURE FOR INDIGESTION.

Pavlov kept his physiology lab running by selling something that he had easy access to: canine gastric juice. While conducting experiments on dogs’ digestive systems, Pavlov collected gastric juice from hungry dogs that stared at a big bowl of meat all day. Pavlov paid an assistant to run the gastric juice collection operation, and he sold thousands of containers of the juice each year to people around Europe, who drank it daily to treat dyspepsia (indigestion). Yum!

7. AFTER HIS FIRST SON DIED, HE NAMED ALL HIS FUTURE CHILDREN WITH “V” NAMES.

If you think Pavlov and the Kardashians have nothing in common, think again. After the sudden death of their first child, Wirchik, at a very young age, the Pavlovs had four more children: three sons and a daughter, whom they named Vladimir, Victor, Vsevolod, and Vera.

8. HE WON A NOBEL PRIZE FOR REMOVING DOGS’ ESOPHAGI.

Ivan Pavlov with students
Wellcome Images Gallery, Wikimedia Commons // CC BY 4.0

Although Pavlov’s best-known work—showing how an environmental stimulus can influence a behavioral response—was groundbreaking, he won a Nobel Prize in 1904 for something different. He earned the honor for his research into the animal digestive system. After surgically removing a dog’s esophagus, Pavlov fed the animal and observed how the process of digestion worked, measuring the digestive secretions of the stomach and pancreas.

9. H.G. WELLS WROTE ABOUT PAVLOV FOR THE NEW YORK TIMES MAGAZINE.

In November 1927, science fiction writer H.G. Wells wrote an essay about Pavlov for The New York Times Magazine. Because Wells didn’t fully understand the science behind one of Pavlov’s articles about reflexes, he ignored the heavy-duty science and focused on Pavlov the man. Wells wrote about Pavlov’s "vastly heroic" nature and devotion to advancing science in the face of poverty, war, and revolution. After a 23-year-old B.F. Skinner read Wells’s article on Pavlov, he became a fan and grew up to be one of history’s most influential behavioral psychologists.

10. HE HAD A BAD TEMPER.

Ivan Pavlov
Wikimedia Commons

According to his biographer, Daniel Todes, Pavlov had issues with anger management. Beginning in childhood, his mood could change suddenly, and as an adult, he hit aggressive dogs in his lab and was known for his uncontrollable outbursts of anger. Pavlov himself described his angry outbursts as “morbid, spontaneous paroxysms.”

11. HE SPOKE OUT AGAINST SOVIET COMMUNISM.

In 1921, Vladimir Lenin publicly praised Pavlov for his scientific contributions, and the Soviet government funded his research and offered him increased food rations (he didn’t accept). But Pavlov spoke out against communism, requesting in 1922 that he be allowed to move his lab to another country. Lenin refused. Pavlov said, “For the kind of social experiment that you are making, I would not sacrifice a frog’s hind legs!” Pavlov also decried his government’s persecution of political dissidents and clergymen; in a letter, Pavlov told Joseph Stalin that he was "ashamed to be called a Russian." Pavlov wasn’t killed for his contrarian views because the government determined that his scientific work was too valuable for Russia.

12. HIS HOME AND APARTMENT WERE CONVERTED TO MEMORIAL MUSEUMS.

Pavlov’s estate in Ryazan, Russia is now a museum where visitors can explore his life and achievements. If you visit, be prepared to see stuffed dogs (and even a monkey) that Pavlov used in his experiments. And if you find yourself in St. Petersburg, you can check out The Pavlov Memorial Museum, where Pavlov lived for almost two decades before he died on February 27, 1936.

The Reason Our Teeth Are So Sensitive to Pain

This woman's tooth pain is actually helping her avoid further damage.
This woman's tooth pain is actually helping her avoid further damage.
champja/iStock via Getty Images

On a good day, your teeth can chew through tough steak and split hard candy into pieces without you feeling a thing. But sometimes, something as simple as slurping a frosty milkshake can send a shock through your tooth that feels even more painful than stubbing your toe.

According to Live Science, that sensitivity is a defense mechanism we’ve developed to protect damaged teeth from further injury.

“If you eat something too hot or chew something too cold, or if the tooth is worn down enough where the underlying tissue underneath is exposed, all of those things cause pain,” Julius Manz, American Dental Association spokesperson and director of the San Juan College dental hygiene program, told Live Science. “And then the pain causes the person not to use that tooth to try to protect it a little bit more.”

Teeth are made of three layers: enamel on the outside, pulp on the inside, and dentin between the two. Pulp, which contains blood vessels and nerves, is the layer that actually feels pain—but that doesn’t mean the other two layers aren’t involved. When your enamel (which isn’t alive and can’t feel anything at all) is worn down, it exposes the dentin, a tissue that will then allow especially hot or cold substances to stimulate the nerves in the pulp. Pulp can’t sense temperature, so it interprets just about every stimulus as pain.

If you do have a toothache, however, pulp might not be the (only) culprit. The periodontal ligament, which connects teeth to the jawbone, can also feel pain. As Manz explains, that sore feeling people sometimes get because of an orthodontic treatment like braces is usually coming from the periodontal ligament rather than the pulp.

To help you avoid tooth pain in the first place, here are seven tips for healthier teeth.

[h/t Live Science]

Arrokoth, the Farthest, Oldest Solar System Object Ever Studied, Could Reveal the Origins of Planets

NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko
NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko

A trip to the most remote part of our solar system has revealed some surprising insights into the formation of our own planet. Three new studies based on data gathered on NASA's flyby of Arrokoth—the farthest object in the solar system from Earth and the oldest body ever studied—is giving researchers a better idea of how the building blocks of planets were formed, what Arrokoth's surface is made of, and why it looks like a giant circus peanut.

Arrokoth is a 21-mile-wide space object that formed roughly 4 billion years ago. Located past Pluto in the Kuiper Belt, it's received much less abuse than other primordial bodies that sit in asteroid belts or closer to the sun. "[The objects] that form there have basically been unperturbed since the beginning of the solar system," William McKinnon, lead author of one of the studies, said at a news briefing.

That means, despite its age, Arrokoth doesn't look much different today than when it first came into being billions of years ago, making it the perfect tool for studying the origins of planets.

In 2019, the NASA spacecraft New Horizons performed a flyby of Arrokoth on the edge of the solar system 4 billion miles away from Earth. The probe captured a binary object consisting of two connected lobes that were once separate fragments. In their paper, McKinnon and colleagues explain that Arrokoth "is the product of a gentle, low-speed merger in the early solar system."

Prior to these new findings, there were two competing theories into how the solid building blocks of planets, or planetesimals, form. The first theory is called hierarchical accretion, and it states that planetesimals are created when two separate parts of a nebula—the cloud of gas and space dust born from a dying star—crash into one another.

The latest observations of Arrokoth support the second theory: Instead of a sudden, violent collision, planetesimals form when gases and particles in a nebula gradually amass to the point where they become too dense to withstand their own gravity. Nearby components meld together gradually, and a planetesimal is born. "All these particles are falling toward the center, then whoosh, they make a big planetesimal. Maybe 10, 20, 30, 100 kilometers across," said McKinnon, a professor of Earth and planetary sciences at Washington University. This type of cloud collapse typically results in binary shapes rather than smooth spheroids, hence Arrokoth's peanut-like silhouette.

If this is the origin of Arrokoth, it was likely the origin of other planetesimals, including those that assembled Earth. "This is how planetesimal formation took place across the Kuiper Belt, and quite possibly across the solar system," New Horizons principal investigator Alan Stern said at the briefing.

The package of studies, published in the journal Science, also includes findings on the look and substance of Arrokoth. In their paper, Northern Arizona University planetary scientist Will Grundy and colleagues reveal that the surface of the body is covered in "ultrared" matter so thermodynamically unstable that it can't exist at higher temperatures closer to the sun.

The ultrared color is a sign of the presence of organic substances, namely methanol ice. Grundy and colleagues speculate that the frozen alcohol may be the product of water and methane ice reacting with cosmic rays. New Horizons didn't detect any water on the body, but the researchers say its possible that H2O was present but hidden from view. Other unidentified organic compounds were also found on Arrokoth.

New Horizon's flyby of Pluto and Arrokoth took place over the course of a few days. To gain a further understanding of how the object formed and what it's made of, researchers need to find a way to send a probe to the Kuiper Belt for a longer length of time, perhaps by locking it into the orbit of a larger body. Such a mission could tell us even more about the infancy of the solar system and the composition of our planetary neighborhood's outer limits.

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