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Anatomical quirks: 10 things you didn't know about your body
Bill Bryson's new book, "The Body: A Guide For Occupants," provides important (and funny) lessons in anatomy, neuroscience, physiology, biology, and more.
- American-British scholar, Bill Bryson, has written a fascinating user's guide to the human body.
- The Body: A Guide For Occupants provides important lessons in anatomy, neuroscience, physiology, biology, and more.
- Though we've learn a lot about ourselves in the last two centuries, it's still clear there's much we don't know.
As far as medicine and science have come, we remain ignorant of much of how our body functions. It's a challenge for us, for instance, to wrap our heads around the ecosystems that live within us — that are us. Indeed, even for the self-aware animal that we are, we're still in a nascent phase of understanding what we really are.
That's why we need writers like Bill Bryson. His new book, The Body: A Guide for Occupants, continues the American-British scholar's quest to understand nearly everything — as evidenced by his 2004 book, A Short History of Nearly Everything. Most well-known for travel books such as A Walk in the Woods and Notes From a Small Island, Bryson's nonfiction writing is as enjoyable as his journals galavanting around the globe — not nearly as humorous, but he lets plenty of quips slip into this latest work as well.
Below are 10 factoids about yourself (and, more generally, our species) that you might not have known. If only this book had been available during my high school years, I might have retained more than I did than with those dry biology textbooks. Educators, take note.
To hear Bryson explore his new work, make sure to check out a recent episode of our podcast, Think Again.
Bill Bryson, travel writer, at the Cheltenham Literature Festival on October 10, 2015 in Cheltenham, England.
Photo credit: David Levenson / Getty Images
The Resistance is Growing
Much of our stomach bacteria is healthy, yet for a multitude of reasons our gut ecosystem is becoming infertile. First off, we owe Scottish biologist Alexander Fleming a note of thanks for discovering penicillin, which immediately saved millions of lives. Yet, even in 1945 he warned of the dangers of microbes growing a resistance to this newly discovered medicine known as antibiotics.
As Bryson writes, from the 1950s through the '90s, three new antibiotics were introduced in the U.S. every year; now the number is one every other year. Sadly, pharmaceutical companies would rather focus on drugs that people need to take for decades (like statins and SSRIs) than on low moneymakers that will be obsolete in a few years.
Overuse fattening up farmed animals, C-sections (in which the baby does not pass through the wash of microbes in the mother's vagina), and our own misuse all seem to blame. For example, 20 percent of all antibiotic usage is for sinus problems, yet antibiotics do not help sinus problems. Bryson continues, "Almost three-quarters of the 40 million antibiotic prescriptions written each year in the United Stats are for conditions that cannot be cured with antibiotics."
The human brain is hungry. Weighing just 2 percent of our body weight, it consumes 20 percent of our energy requirements. Whether you're watching TV or doing complex math, your brain burns roughly 400 calories every day. Thinking more doesn't result in a greater calorie burn. In fact, the opposite is true.
"An academic at the University of California at Irvine named Richard Haier used positron emission tomography scanners to find that the hardest-working brains are usually the least productive. The most efficient brains, he found, were those that could save a task quickly and then go into a kind of standby mode."
Our vestibular system is responsible for balance. Located inside of our ears, a gel informs our brains whether we are going left or right, up or down. When spinning in a circle, the gel keeps moving when we stop, resulting in that peculiar disorientation children seem to love. Fascinatingly, our brain isn't interpreting it as merely a pause.
"When loss of balance is prolonged or severe, the brain doesn't know quite what to make of it and interprets it as poisoning. That is why loss of balance so generally results in nausea."
Over the course of your life, you'll secrete roughly 31,700 quarts of saliva. In an interesting comparison, Bryson notes that this is equivalent to "two hundred or so deep baths." As I recently wrote about, salivary diagnostics is an important developing field of medicine. A recent discovery, Bryson writes, is opiorphin, a natural painkiller produced by our saliva. While six times more potent than morphine, we produce very little amounts of it — not enough to avoid the pain of hot pizza on the roof of your mouth, but still, an essential biological feature that helps us manage pain.
Pain in the Head
Speaking of pain management, only our brain — an organ that itself cannot feel pain — can feel pain. Headaches are not even our brain hurting, regardless of how deeply we feel it. Of all the various types of pain there are, some confer evolutionary benefit by warning you to avoid something while others seem to be a design failure. For example, we usually don't feel the pain of cancer until after it's already ravaged our body. Not much of a warning system, that one.
There is not much of a difference between physical and emotional pain. Both can be diminished through a variety of means, such as "pleasant aromas, soothing images, pleasurable music, good food, and sex." Another important factor is expectation. Bryson concludes, "In many ways, we feel the pain we expect to feel."
Bill Bryson on the miraculous human body
Younger is Not Better
Up until relatively recently, children went through puberty around age 16 or 17. That dropped drastically in the last century due to improved nutrition. There's a problem, however: young girls are now menstruating as early as seven or eight, and there is a link between excess estrogen and cancer later in life. You solve one problem — in this case, malnutrition — and suddenly others appear.
While there is no clear reason why we develop allergies at all, between 10 to 40 percent of the world's populations suffer an allergy to something. Strangely, the richer the nation, the more allergies its citizens get. While there is a genetic link, it's only an increased chance that you'll get what your parents have (about 40 percent). Genes are not destiny, unless they are.
One thing is certain, however: babies born through a C-section are eight times more likely to develop allergies (as well as more likely to be struck with diabetes, asthma, celiac disease, and obesity). Today, 60 percent of all births through C-section are because of convenience, not necessity. There's a reason babies are born the way they are. By not allowing for that (unless medically necessary), we're doing our children more harm than the temporary good of reduced pain during childbirth.
Stop Eating So Damn Much
In 1915, an average American spent half of their weekly income on food. Today that number is closer to 6 percent, yet we're eating more than ever. As our biology dictates a hoarding mentality, health care systems pay the price, mostly due to processed foods (almost all of which contain added sugars). As Bryson puts it, "We are in the historically extraordinary position that far more people on Earth suffer from obesity than from hunger."
That Said, Weight Isn't Everything
We know that obesity creates many health problems, but a hyper-focus on "clean eating" and a holistic lifestyle doesn't mean you're going to avoid all of biology's ills.
"Roughly 40 percent of people with diabetes, chronic hypertension, or cardiovascular disease were fit as a fiddle before they got ill, and roughly 20 percent of people who are severely overweight live to a ripe old age without ever doing anything about it."
The body is certainly confusing.
Finally, A Few Myths
It's incredible how easily swayed we are. For example, in 1968 a doctor published a letter (not a study or research) describing how uneasy he felt after dining in Chinese restaurants. He speculated that MSG might be the cause. It wasn't, but for decades we've labeled it as toxic. It's not; it's an essential component of the glorious taste sensation, umami.
Genetically speaking, humans don't reproduce. We recombine.
The marketing ploy that has men taking testosterone supplements to stave off the natural 1 percent yearly decline starting in their '40s? Putting it back in is more likely to harm you: men increase their risk of a heart attack or stroke by taking these supplements.
Ten thousand steps a day? That myth is based on a single study done in Japan in the 1960s that was on shaky ground to begin with. This said, you should be walking. Ten thousand is roughly equivalent to five miles; studies of hunting and gathering societies, which are comprised of generally fit populations, have a "slightly" higher average: 19 miles per day.
Sleep is for the consolidation and transferring of memories? Maybe.
Finally, we don't lose most of our body heat through our heads. Body heat is evenly distributed. If you walk out in winter without a hat, however, you are risking losing body heat through that area because it's exposed. Listen to your mom and put on a hat, dummy.
Physicist Frank Wilczek proposes new methods of searching for extraterrestrial life.
- Nobel Prize-winning physicist Frank Wilczek thinks we are not searching for aliens correctly.
- Instead of sending out and listening for signals, he proposes two new methods of looking for extraterrestrials.
- Spotting anomalies in planet temperature and atmosphere could yield clues of alien life, says the physicist.
For noted theoretical physicist Frank Wilczek, finding aliens is a matter of figuring out what exactly we are looking for. To detect other space civilizations, we need to search for the specific effects they might be having on their worlds, argues the Nobel laureate in a new proposal.
Writing in the Wall Street Journal, Wilczek says that it's a real challenge to figure out which among the over 4,000 exoplanets that we found so far outside of our solar system might host extraterrestrial life. The classic way of listening for space signals is insufficient and inefficient, says the scientist. What might really help are new developments in exoplanetary astronomy that can allow us to get much more precise information about faraway space objects.
In particular, there are two ways we should focus our attention to turn the odds of finding alien life in our favor, argues the physicist.
1. Atmosphere chemistry
Like we found out with our own effect on the Earth's atmosphere, making a hole in the ozone layer, the gases around a planet can be impacted by its inhabitants. "Atmospheres are especially significant in the search for alien life," writes Wilczek "because they might be affected by biological processes, the way that photosynthesis on Earth produces nearly all of our planet's atmospheric oxygen."
But while astrobiology can provide invaluable clues, so can looking for the signs of alien technology, which can also be manifested in the atmosphere. An advanced alien civilization might be colonizing other planets, turning their atmospheres to resemble the home planets. This makes sense considering our own plans to terraform other planets like Mars to allow us to breathe there. Elon Musk even wants to nuke the red planet.
The Most Beautiful Equation: How Wilczek Got His Nobel
2. Planet temperatures
Wilczek also floats another idea - what if an alien civilization created a greenhouse effect to raise the temperature of a planet? For example, if extraterrestrials were currently researching Earth, they would likely notice the increased levels of carbon dioxide that are heating up our atmosphere. Similarly, we can looks for such signs around the exoplanets.
An advanced civilization might also be heating up planets to raise their temperatures to uncover resources and make them more habitable. Unfreezing water might be one great reason to turn up the thermostat.
Unusually high temperatures can also be caused by alien manufacturing and the use of artificial energy sources like nuclear fission or fusion, suggests the scientist. Structures like the hypothetical Dyson spheres, which could be used to harvest energy from stars, can be particularly noticeable.
Similarly, there might be instances when our faraway space counterparts would want to cool planets down. Examining temperature anomalies of space bodies might allow us to pinpoint such clues.
Focusing on the temperatures and atmospheres of other planets might be not only a winning strategy but something specifically encouraged by other civilizations who want us to find them. "An alien species that wants to communicate could draw the gaze of exoplanetary astronomers to anomalies in its solar system, effectively using its parent star to focus attention," expounds the physicist.
You can check out Wilczek's full article here.
Wilczek: Why 'Change without Change' Is One of the Fundamental Principles of the ...
In ancient Greece, the Olympics were never solely about the athletes themselves.
Because of a dramatic rise in COVID-19 cases, the opening and closing ceremonies of the 2021 Olympics will unfold in a stadium absent the eyes, ears and voices of a once-anticipated 68,000 ticket holders from around the world.
Events during the intervening days will likewise occur in silent arenas missing the hundreds of thousands of spectators who paid US$815 million for their now-useless tickets.
After 48 years teaching classics, I can't help but wonder what the Greeks – who invented the Games nearly 3,000 years ago, in 776 B.C. – would make of such a ghostly version of their Olympic festival.
In many ways, they'd view the prospect as absurd.
In ancient Greece, the Olympics were never solely about the athletes themselves; instead, the heart and soul of the festival was the experience shared by all who attended. Every four years, athletes and spectators traveled from far-flung corners of the Greek-speaking world to Olympia, lured by a longing for contact with their compatriots and their gods.
In the shadow of dreams
For the Greeks, during five days in the late-summer heat, two worlds miraculously merged at Olympia: the domain of everyday life, with its human limits, and a supernatural sphere from the days superior beings, gods and heroes populated Earth.
Greek athletics, like today's, plunged participants into performances that pushed the envelope of human ability to its breaking point. But to the Greeks, the cauldron of competition could trigger revelations in which ordinary mortals might briefly intermingle with the extraordinary immortals.
The poet Pindar, famous for the victory songs he composed for winners at Olympia, captured this sort of transcendent moment when he wrote, “Humans are creatures of a day. But what is humankind? What is it not? A human is just the shadow of a dream – but when a flash of light from Zeus comes down, a shining light falls on humans and their lifetime can be sweet as honey."
However, these epiphanies could occur only if witnesses were physically present to immerse themselves – and share in – the spine-tingling flirtation with the divine.
Simply put, Greek athletics and religious experience were inseparable.
At Olympia, both athletes and spectators were making a pilgrimage to a sacred place. A modern Olympics can legitimately take place in any city selected by the International Olympic Committee. But the ancient games could occur in only one location in western Greece. The most profoundly moving events didn't even occur in the stadium that accommodated 40,000 or in the wrestling and boxing arenas.
Instead, they took place in a grove called the Althis, where Hercules is said to have first erected an altar, sacrificed oxen to Zeus and planted a wild olive tree. Easily half the events during the festival engrossed spectators not in feats like discus, javelin, long jump, foot race and wrestling, but in feasts where animals were sacrificed to gods in heaven and long-dead heroes whose spirits still lingered.
On the evening of the second day, thousands gathered in the Althis to reenact the funeral rites of Pelops, a human hero who once raced a chariot to win a local chief's daughter. But the climactic sacrifice was on the morning of the third day at the Great Altar of Zeus, a mound of plastered ashes from previous sacrifices that stood 22 feet tall and 125 feet around. In a ritual called the hecatomb, 100 bulls were slaughtered and their thigh bones, wrapped in fat, burned atop the altar so that the rising smoke and aroma would reach the sky where Zeus could savor it.
No doubt many a spectator shivered at the thought of Zeus hovering above them, smiling and remembering Hercules' first sacrifice.
Just a few yards from the Great Altar another, more visual encounter with the god awaited. In the Temple of Zeus, which was erected around 468 to 456 B.C., stood a colossal image, 40 feet high, of the god on a throne, his skin carved from ivory and his clothing made of gold. In one hand he held the elusive goddess of victory, Nike, and in the other a staff on which his sacred bird, the eagle, perched. The towering statue was reflected in a shimmering pool of olive oil surrounding it.
During events, the athletes performed in the nude, imitating heroic figures like Hercules, Theseus or Achilles, who all crossed the dividing line between human and superhuman and were usually represented nude in painting and sculpture.
The athletes' nudity declared to spectators that in this holy place, contestants hoped to reenact, in the ritual of sport, the shudder of contact with divinity. In the Althis stood a forest of hundreds of nude statues of men and boys, all previous victors whose images set the bar for aspiring newcomers.
“There are a lot of truly marvelous things one can see and hear about in Greece," the Greek travel writer Pausanias noted in the second century B.C., “but there is something unique about how the divine is encountered at … the games at Olympia."
Communion and community
The Greeks lived in roughly 1,500 to 2,000 small-scale states scattered across the Mediterranean and Black Sea regions.
Since sea travel in summertime was the only viable way to cross this fragile geographical web, the Olympics might entice a Greek living in Southern Europe and another residing in modern-day Ukraine to interact briefly in a festival celebrating not only Zeus and Heracles but also the Hellenic language and culture that produced them.
Besides athletes, poets, philosophers and orators came to perform before crowds that included politicians and businessmen, with everyone communing in an “oceanic feeling" of what it meant to be momentarily united as Greeks.
Now, there's no way we could explain the miracle of TV to the Greeks and how its electronic eye recruits millions of spectators to the modern games by proxy. But visitors to Olympia engaged in a distinct type of spectating.
The ordinary Greek word for someone who observes – “theatês" – connects not only to “theater" but also to “theôria," a special kind of seeing that requires a journey from home to a place where something wondrous unfolds. Theôria opens a door into the sacred, whether it's visiting an oracle or participating in a religious cult.
Attending an athletic-religious festival like the Olympics transformed an ordinary spectator, a theatês, into a theôros – a witness observing the sacred, an ambassador reporting home the wonders observed abroad.
It's hard to imagine TV images from Tokyo achieving similar ends.
No matter how many world records are broken and unprecedented feats accomplished at the 2020 games, the empty arenas will attract no gods or genuine heroes: The Tokyo games are even less enchanted than previous modern games.
But while medal counts will confer fleeting glory on some nations and disappointing shame on others, perhaps a dramatic moment or two might unite athletes and TV viewers in an oceanic feeling of what it means to be “kosmopolitai," citizens of the world, celebrants of the wonder of what it means to be human – and perhaps, briefly, superhuman as well.
The ancient Greeks wouldn't recognize some aspects of the modern Olympics.
Vincent Farenga, Professor of Classics and Comparative Literature, USC Dornsife College of Letters, Arts and Sciences
A new brain imaging study explored how different levels of the brain's excitatory and inhibitory neurotransmitters are linked to math abilities.
- Glutamate and GABA are neurotransmitters that help regulate brain activity.
- Scientists have long known that both are important to learning and neuroplasticity, but their relationship to acquiring complex cognitive skills like math has remained unclear.
- The new study shows that having certain levels of these neurotransmitters predict math performance, but that these levels switch with age.
Why do roughly one in five people find math especially difficult?
You might blame teaching methods, which some argue explains why the U.S. lags behind other countries in standardized math test scores. You could point to math anxiety, which affects about 20 percent of students and 25 percent of teachers, according to surveys. And there are also medical conditions that make math difficult, such as dyscalculia, a learning disability that disrupts the normal development of arithmetic skills.
But another explanation centers on neurotransmitters. In a new study published in PLOS Biology, researchers explored how the brain's levels of GABA and glutamate relate to math abilities over time in students of varying ages. The results showed that levels of these neurotransmitters can predict students' performance on math tests. However, this relationship seems to flip as people get older.
GABA and glutamate are responsible for regulating brain activity. In the mature brain, GABA is the brain's main inhibitory neurotransmitter, helping to block impulses between nerve cells in the brain, which can calm feelings of stress, anxiety, or fear. GABA is made from glutamate, the brain's major excitatory neurotransmitter that helps send signals throughout the central nervous system.
Researchers have long known that these neurotransmitters play crucial roles in learning, development, and neuroplasticity. That is partly because they are thought to help trigger developmental windows (or "sensitive periods") during which neural systems become more plastic and better able to acquire certain cognitive skills.
"Importantly, sensitive periods vary for different functions, with relatively simple abilities (e.g., sensorimotor integration) occurring earlier in development, while the sensitive period for acquiring more complex cognitive functions extends into the third decade of life," the researchers wrote.
GABA, glutamate, and math
Still, the exact relationship between GABA, glutamate, and complex cognitive functions has remained unclear. The new study explored that relationship by focusing on associations between the neurotransmitters and math abilities, which "provides a unique cognitive model to examine these questions due to its protracted skill acquisition period that starts already from early childhood and can continue for nearly two decades," the researchers wrote.
For the study, the researchers measured levels of GABA and glutamate in the left intraparietal sulcus (IPS) of 255 students, ranging from primary school to college. The participants completed a math test as their brains were imaged. About a year and a half later, the participants repeated the same process.
"The longitudinal design allowed us to further examine whether neurotransmitter concentration is linked to MA [mathematical abilities] as well as predict MA in the future," the researchers wrote. "Crucially, adopting this design allowed us to discern the selective effect of glutamate and GABA in response to natural (i.e., learning in school) rather than artificial environmental stimulation, thus allowing us to test the knowledge gained from lab-based experiments in high ecological settings."
The results suggest that GABA and glutamate play an important role in math abilities, but that the dynamic switches with age. For the young participants, higher GABA levels in the IPS were associated with higher scores on math tests. The opposite was observed among older students: higher glutamate levels correlated with higher scores. Both results held true on subsequent math tests.
Although the study sheds light on how neurotransmitter levels at different stages of development contribute to learning some cognitive skills, like math, the researchers noted that acquiring other skills may involve different processes.
"Our findings may also highlight a general principle that the developmental dynamics of regional excitation and inhibition levels in regulating the sensitive period and plasticity of a given high-level cognitive function (i.e., MA) may be different compared to another high-level cognitive function (i.e., general intelligence) that draws on similar, albeit not identical, cognitive and neural mechanisms," they wrote.