The 18 Coolest Things I Ever Learned!

1. Why is the Mona Lisa’s smile such a big deal?

Today, the Mona Lisa is one of the most famous paintings in the world; everyone has seen the image. And everyone’s heard the question of whether or not the woman in the picture is smiling. But if you’re like me, you may have looked at the picture and wondered what the fuss was about. It turns out there’s a pretty cool reason for this debate!

The Mona Lisa painting, by itself, is notable primarily because it was painted by Leonardo Da Vinci. He was an extraordinary person if there ever was one—and he only created about a dozen paintings in his entire life! He clearly thought the Mona Lisa was special, because the evidence suggests that he worked on it for about 15 years, and even took it with him when he moved to France from Italy.

Interestingly, the painting wasn’t popular with the public until the 20th Century, even though art experts began calling it a Renaissance masterpiece in the mid-1800s. It didn’t really catch the public’s attention until it was stolen from the Louvre museum in Paris in 1911 and went missing for about two years. (It was eventually recovered in Florence, Italy, in the possession of a man who’d worked at the Louvre.) That generated so much publicity that everyone became aware of the painting, and its popularity soared.

But what about Mona Lisa’s smile? It turns out it is kind of a big deal, because Leonardo was a student of anatomy and human perception. He was aware that our central vision perceives things very sharply and clearly, but even a little bit away from the center of our vision, everything is fuzzy and out of focus. We have the impression that everything in our field of vision is in focus because our brains compensate for this. The moment we shift our gaze to look at something, it’s back in focus…so it must have been in focus the whole time, right?

Why does this matter? Because Leonardo used this knowledge to create a smile that looks different when we stare directly at it and when we look away a little bit! When looking directly at Mona Lisa’s mouth, she’s barely smiling at all. But when we look at other parts of the painting and see her mouth through our off-center, fuzzier vision, she appears to be smiling!

It’s very unlikely that this is a coincidence. Although he didn’t leave any notes saying so, Leonardo almost certainly knew what he was doing; this might even be part of the reason he worked on the painting for so long. An Italian Renaissance optical illusion! Pretty cool.

2.  How do spiders build a web between two objects that are high up and not very close to each other?

Most of us don’t think about spiders too often, even though we’re surrounded by them. (In the average house there’s always a spider within a few feet of you, no matter where you are!) Most of us imagine a spider sitting on a web, or scurrying across a surface. But there’s more going on here than meets the eye. When we’re not looking, spiders are doing some pretty amazing things.

I’ve often noticed that spiders can build webs between two objects that are quite high up and several feet apart. (Nothing’s more fun than walking through a web built across a walkway…) The question is, how do spiders manage that? It seems very impractical for a spider to drop from a high place, crawl across the ground and climb to a parallel high space a few feet away, all the while dragging a sticky silk thread. So how do they do it?

The answer is that spiders can fly—even though they don’t have wings. Those well-versed in spider-lore know that spiders can travel great distances; that’s how they spread across a continent. The way they travel those great distances is by air. (Darwin famously once noted that a massive infestation of spiders appeared on the boat he was traveling on—the HMS Beagle—when it was anchored 60 miles from land.) Basically, spiders exude a short line of thread and the thread lifts them into the air. This is known as “ballooning,” and it’s very effective; spiders have been found two and a half miles high in the air and 1,000 miles out to sea.

For many years, scientists assumed that it was wind that made spider ballooning possible, once a line of silk was dangling from the spider’s body. Clearly, wind does have something to do with spiders traveling a long distance using this modality. However, spiders actually do ballooning mostly when the wind is light.

Today, it’s become clear that what’s actually lifting the spiders up is the electromagnetic field of the earth, which shifts over time in a given spot (thanks in part to the weather, including thunderstorms). Researchers have now shown that when a magnetic field appears or strengthens where a spider is sitting, a specific type of hair on the spider’s body stands up (shades of Spiderman’s “spidey sense”!), and the spider then starts positioning for a lift-off by putting out a thread. Even in an enclosed, wind-free box, spiders can lift off using the magnetic field. No crawling required! So that’s how they build a web between two objects high above the ground; they “balloon” across the open space to place the first filaments of the web.

3. The full moon is six times as bright as a half-moon, and twice as bright as it is three days before or after the full moon. Why?

Every sighted person has seen the moon in the night sky, and we all know about the moon’s phases, going from no moon at all to a crescent moon, to a half moon, to a full moon, and then reversing that pattern back to no moon at all. But we don’t often notice the little details—including the fact that the moon is significantly brighter when it’s full than even a few days before or after the peak of the full moon and six timesas bright as a half moon, not twice as bright.

To understand why, two facts are particularly important: First, the moon is lit by sunlight, and the phases of the moon are caused by the position of the sun when we’re looking at the moon. Second, the moon has a bumpy surface full of craters and rocks, although they’re not visible to the naked eye. Both of these facts affect how bright the light reflected off the moon is at different times of the month.

When the moon is full, the sun is behind us, shining directly on the moon. The side of the moon we’re looking at is completely illuminated. When we see a half-moon, the sun is more or less at a right angle to our line of sight. That means the light we see at the half moon is light reflecting off the moon’s surface at an angle. Most light shining on an object tends to reflect directly back toward the source of the light, so when the light source (the sun) is directly behind us during the full moon, we’re getting the direct reflection. At the half moon, when the sun is shining on the moon from the side, we’re just seeing the scattered light, not the directly reflected light.

Imagine shining a flashlight on an object at night; if you’re holding the flashlight, the object will appear brightly lit. If someone off to the side is shining the flashlight instead of you, you’ll only see part of the object lit up, of course, but the light you see will also be much dimmer, because you’re just seeing scattered light. Most of the light is being reflected back to the person holding the flashlight.

However, that doesn’t explain why the reflected light is so much brighter on the day of the full moon than a few days before or after, when the sun is still more-or-less behind you while you look at the moon. The reason for that is something called “shadow hiding.” The moon’s surface isn’t smooth—it’s covered with craters and rocks, all of which create shadows when the sun shines on them. When the light of the sun is directly behind us (at the full moon), all of those shadows disappear, from our perspective. But when the light isn’t directly behind us—even a few days before or after the full moon—shadows start to be part of what we’re seeing, reducing the brightness pretty dramatically, even though we couldn’t make out those shadows without a telescope. (In fact, if you don’t believe this, get hold of a good telescope and compare what you see on the night of the full moon to a few days before or after. If the telescope is strong enough, you’ll see that the shadows only disappear from view when the moon is completely full.)

So if the light from a full moon seems especially bright, lighting the ground below in a particularly beautiful way, it’s not your imagination!

4. What makes one piece of art evoke an emotional reaction, while a seemingly similar piece of art leaves us flat?

This may seem like a question that’s nearly impossible to answer, but in fact, part of the answer lies in a very interesting attribute of human perception that few people are aware of. It was written about extensively by a scientist, musician and inventor named Manfred Clynes. (Among other things, he was a good friend of Albert Einstein, and among his many inventions is the CAT computer for electrical brain research.) Clynes observed that human beings all seem to unconsciously associate specific “shapes” with emotions. He calls these “sentic forms,” although I find it helpful to think of them as shapes. We associate a certain type of curve with joy, for instance; a different shape is associated with anger, or hatred, or grief, or reverence.

So what?, you may ask. The strange thing is that human beings recognize these shapes unconsciously, react to them, and also make them with our bodies, faces and voices, without necessarily realizing it. For example, our bodies tend to assume positions that form the curve associated with whatever mood we’re in! If we’re happy, our body tends to position itself in ways that make the shape humans unconsciously associate with happiness, which helps other people know how we’re feeling. Furthermore, when we create art, the result automatically captures the shapes that reflect the emotion we’re feeling when we create it.

For example, paintings and drawings containing these shapes evoke the corresponding emotion in people viewing the art. (Picasso was really good at drawing these shapes. Many of the simple, strong lines in his paintings form the curve or shape associated with the emotion the painting is supposed to capture.) The movements of a dancer may “draw” the shapes in the air, or create them with the position of the body. Sculpture, and even architecture, can provoke an emotional response by featuring these shapes.

These “shapes” can also be expressed through music—especially through melody. As a melody moves up and down, it makes an emotional “shape” in the listener’s mind, and if it makes the right shape, the listener will feel the corresponding emotion. (In fact, if an emotional melody is written down in standard music notation, you can often see the sentic shapes on the page.) So when someone says a melody—or a singer—has a lot of feeling, what they’re really saying is that the melody and/or the singer’s presentation is full of the “shapes” that we associate with intense emotions!

Remarkably, these associations between shapes and emotions have been found to be identical in everyone who has been tested, regardless of age or cultural background. For example, Clynes got individuals to express different emotions through the way they applied pressure to a touch pad. He translated the resulting “sentic forms” into sound, and played those recordings for people in vastly different cultures. In one trial, Australian Aborigines correctly identified the emotions that had been expressed in this way by Caucasian Americans. Apparently the connection between the shapes and our emotions is encoded in our genes.

The presence or absence of these “sentic shapes” seems to be one of the main things that leads us to decide that something is “great art.” Picasso’s use of lines is extremely effective at capturing the right emotional “shape” to match his subject matter. Likewise, a great dancer’s body and movements “draw” the shapes for us, while a dancer who is less interesting to watch doesn’t. And the great classical composers were all expert at capturing these “shapes” in their music.

So, the presence or absence of “sentic forms” in art, whether it’s a painting, a song, a dance or any other kind of art, seems to be a key factor in whether or not the art moves us emotionally. And—artists take note—whether those “sentic forms” end up in the art you’re creating may depend on whether or not you’re feeling the emotion you want the art to convey while you’re creating it!

5. Why does a mirror image appear to flip a reflection left to right?

It’s a common belief that when we look at our reflection in a mirror, it reverses the image from left to right. Actually, that’s an illusion. People believe it’s true for three reasons: First, we alter the position of things so that we can see them in the mirror. Second, what we call “left” and “right” are totally relative. And third, it is possible to get a mirror to reverse an image (either left-to-right or upside down) by turning it away from you to reflect something else.

The most common evidence people offer that mirrors reverse things from left to right is that when we hold up something written so that we can see it in the mirror, it’s reversed. But let’s look at this more carefully. Find a piece of clear plastic and a magic marker; write a few words on the clear plastic sheet. Now, WITHOUT TURNING THE PLASTIC SHEET AROUND, stand in front of a mirror and hold it up in front of you so you can still read it. What do you see in the mirror? The same words, in the same direction, not reversed at all. The words in front of you are being reflected back exactly as you see them held up in front of you.

Most of the time when we want to see something in a mirror, we have to turn it around to face the mirror. In relation to us, we’re reversing it from left to right by doing that; then the mirror faithfully reflects that turned-around message back at us. If this is still puzzling, write some words on a regular piece of paper and stand in front of a mirror. But this time, instead of turning it around to face the mirror, FLIP IT OVER to face the mirror. Now, what you’ll see reflected back is the words reversed up-to-down, not left-to-right. Again, the reason you’re seeing that is because YOU flipped over the words to face the mirror. The mirror is simply reflecting back what you’re holding up in front of it.

The second thing confusing this question is the relativity of left and right. Most designations of direction are based on non-relative things; if you look into a mirror when you’re facing east, north is on one side and south is on the other side, and north and south are on the same sides in the reflection. Left and right, however, are based on location relative to the person. So if you raise your left hand, you can claim that the person in the reflection is raising his right hand. But if you’re facing east and you raise your left hand, it’s the “north” hand; and your reflection is raising his “north” hand as well. Left and right are reversed because they’re arbitrary; they’re based on the perspective of the person, not an external reference.

Finally, it is possible to get an image to flip in a mirror by turning it away from you and using it to reflect something other than yourself. That’s why, for example, the surface of the water in a calm lake reflects the trees or buildings on the other side of the lake upside down. But if you’re looking directly into the reflective surface, whether it’s a lake or a mirror, the appearance of left-too-right reversal is an illusion.

6. During the Middle Ages the Arab world was far more culturally and scientifically advanced than Europe for almost 500 years. Why was that, and what caused Europe to finally pull ahead?

Most people who grow up in the West know at least a few basic things about history. We all know at least a little about the ancient Egyptians, Greeks and the Roman Empire, and that there was a long period of time after the Roman Empire fell when progress more-or-less ground to a halt, often referred to as “the Dark Ages.” And most Westerners know that this period ended, more-or-less, with the Italian Renaissance, when art and science finally got back on track and progress resumed, eventually leading to the world we live in today.

However, not many people wonder WHY history unfolded this way. Understanding some of the reasons for these changes can give you a very different perspective about how we got here.

It turns out that progress on a large scale depends on being able to write ideas down and share them with other people. In today’s digital age, sharing ideas and information is a no-brainer. But hundreds of years ago, being able to do that depended on having some basic resources that many people didn’t have, especially paper. The rate of progress in the West turns out to be intimately connected with the availability of paper. And then, once movable type and the printing press were invented—giving people a way to share information on a far greater scale than ever before—it turned out that the design of the alphabet in a given culture had a profound effect on whether that culture could take advantage of those advances.

The ancient Egyptians and Romans wrote with ink on papyrus, which could be rolled into scrolls; it was easily made in Egypt from the papyrus plant. But after Rome fell, papyrus became hard to get. Eventually, Europeans switched to writing on parchment, a writing surface made from animal skins. This surface was extremely difficult and time-consuming to prepare, and very expensive, with the result that European books in Medieval times were slowly and painstakingly hand-copied—and very rare. The transfer of information became severely limited. You couldn’t even jot down an idea!

This was also true for a while in the Islamic Arab world—but not in China during this time. The Chinese figured out how to make paper from mulberry tree bark, resulting in plentiful paper and plentiful writing. However, the emperors managed to keep their paper-making method a secret for hundreds of years, leaving communication stifled in the rest of the world. That changed when the Arabs captured a group of Chinese paper-makers who were traveling with the Chinese army during a battle at the Talas River in 751 A.D. After that, the secret was out. Now, having plenty of paper to spread ideas via the written word, the Islamic world leapt ahead of Europe in art, science, math and astronomy. That was true for about 500 years, a period known as the Islamic Golden Age.

It took a long time for the use of paper to spread from the Islamic world to Europe. When it did, sharing information became easier and Europe began to catch up with the Arab world. But then, something remarkable happened that threw the balance very much in Europe’s favor: in 1450 Johannes Guttenberg invented movable type and the printing press. Within a few years, this technology was spreading like wildfire.

You might expect that this would have spread rapidly into the Islamic world as well—but it didn’t. The reason was simple: The Latin alphabet, used in European languages, consisted of compact letters that were not joined together when assembled into words; they were simply put next to each other. That made the Latin languages perfect for movable type, where the individual letters could simply be lined up next to each other to make printable words and sentences.

This wasn’t true of the Islamic languages: Their writing was artistic and flowing, with extensions from each letter interacting with the letters around it. There was no way to recreate that in movable type. People tried chopping the Arabic letters apart to make the language amenable to movable type, but it was barely recognizable to Arab readers.

As a result, Europe suddenly had an easy and relatively inexpensive way to spread ideas far and wide, a culture-changing technology that was of no use in the Islamic world because of the way Arabic words and sentences were written. Within a few decades, Europe’s art, science, math and astronomy caught up with that of the Islamic world and then surpassed it. (After a few hundred years, ways of printing Arabic using movable type did become acceptable to readers, but by then Europe had become the new center of culture and knowledge.)

7. Where did Groundhog Day, May Day and Halloween come from?

These holidays represent the midpoints of their respective seasons; they originated with the Celts in the British Isles. The Celts divided the year into four parts, each beginning with a “Quarter Day”—the winter solstice, the spring equinox, the summer solstice and the fall equinox. They went further, however, and divided each quarter-year into halves, marked by days they called “Cross-quarter Days.” February 2nd, the mid-point of winter, was Candlemass (a Christian holiday); May first, the mid-point of spring, was Beltane; August 1st, the mid-point of summer, was Lammas; and October 31st, the mid-point of fall, was Samhain. Some believe the Celts thought the Cross-quarter Days were more significant than the solstices and equinoxes.

On February 2, Candlemass, marked the mid-point of winter; it has now evolved into our Groundhog Day. This day was an occasion to predict how the weather would be during the weeks leading up to planting season; if it was bright and sunny, that was a bad omen for early planting, but if it was dark and cloudy, people thought the planting season would begin early. Today, that has translated into a weather prediction based on whether or not a groundhog sees his shadow. But the idea remains the same!

On May 1, Beltane (now referred to as May Day) was considered by the Celts to be the beginning of summer, although it was technically the mid-point of spring. It was an occasion for dancing and singing to celebrate the fields being sown. It was also a traditional time for couples to pair up, leading to the popularity of June weddings!

August 1st, the mid-point of summer, was Lammas, which marked the beginning of the wheat and corn harvests. This day is still celebrated in some countries with a feast for friends and family. (We should bring this one back in the United States — we can always use another holiday!)

October 31st was Samhain; it represented summer’s end. Many historians believe the Celts also thought of this day as the end of the old year and beginning of the new. This could explain the stories about ghosts wandering the countryside as the old year ends…now a key part of Halloween lore!

 8. Why are the Hawaiian Islands in a chain with a large, volcanic island at one end and progressively smaller islands as you go up the chain?

As most everybody today knows, the surface of the Earth isn’t solid and unmoving; it consists of a number of tectonic plates—about 20—that are slowly but continually shifting. The interactions between the plates (for example, as one pushes into another) are a common cause of earthquakes. But these slow-moving plates are also responsible for other phenomena, including the existence and characteristics of the Hawaiian Island chain.

Although the tectonic plates are moving, what’s underneath them may not be. There’s an unmoving “hot spot” beneath the Pacific Plate at the location of the Hawaiian Islands. This is a point at which hot magma, or lava, pushes up from the layers of the Earth below the plates. It pushes up with great force, sufficient to break through the plate, forming a volcano as the hot magma hits the cold ocean water above. The hot magma solidifies into a cone shape around the opening, gradually growing in size as more of it pushes up through the center of the cone. Eventually the volcano gets large enough to break the surface of the water, and as it continues to grow, it becomes an island.

However, the tectonic plate continues to slowly move, while the hot spot beneath remains stationary. The result is that after a while, the volcano formed above the hot spot moves away from the hot spot; eventually it stops erupting. Since the magma is still being pushed upwards, the process repeats; the magma breaks through the plate at a new location and starts to form a new volcanic island.

This process has been occurring in the area of Hawaii for millions of years. The result is a chain of volcanic islands, lined up in a row. But nature has another force at work: erosion. Once a volcano goes dormant, it stops growing and the forces of wind, rain and ocean tides begin to erode it away. Thus, over time, the existing islands gradually get smaller. The overall result is a chain of islands, smaller islands on one end, with a large island with an active volcano at the other end.

In Hawaii, the Big Island is still an active volcano. The popular tourist attraction, Diamond Head, near Honolulu on the island of Oahu, is one of the extinct volcanos further up the chain. The parts of the island chain that have already eroded enough to be underwater extend for thousands of miles, up to Alaska. Meanwhile, a new volcanic island is already building up beneath the water next to the Big Island (it’s already been named Loihi, although it won’t grow tall enough to break the surface for at least another 10,000 years).

If you’ve never been to Hawaii, it’s worth going at least once in your life. And if you have to wait a few years for that to be feasible, well, the islands aren’t going anywhere! (At least not very fast!)

9. What advantage do zebras gain by having stripes?

There are three species of zebras in Africa, and they’re the only striped members of the horse family. Their eye-popping black and white stripe patterns vary from one species to the next, as well as from one location to the next. Over the past 100 years, at least 18 different explanations have been suggested to explain why zebras have stripes, including camouflage, unique individual identifiers and temperature control in the hot Savannah. However, the suggested answers were not holding up well when closely examined or tested in the wild.

Recently, one explanation has stood out: Flies that bite rarely land on a striped surface! These flies often suck the blood of the animals on which they land and transmit disease, so having a physical characteristic that prevents the flies from biting is a significant advantage to have in the wild. In fact, biologists have analyzed tsetse fly bodies and found no traces of zebra blood. (Scientists are still trying to determine what it is about stripes that throws off a fly’s ability to land on a surface.)

While other theories—like regulating temperature or fooling predators—have some supporting evidence, that evidence is inconsistent. In contrast, there are two strong pieces of evidence that keeping flies at bay is probably the explanation for the stripes:

  • Striping is more pronounced in areas in Africa that have more of the biting flies. In contrast, the intensity of the stripes didn’t parallel temperature differences or danger from predators in several studies.
  • Placing zebra-stripe coats on horses (their version of a Halloween costume, no doubt) caused far fewer flies to land on the horses.

Of course, more than one factor could have caused zebras to evolve those catchy stripes. But it seems likely that warding off dangerous fly bites is likely a key piece of the equation.

10.  Who almost single-handedly shaped much of the modern English language?

They say that whatever language we speak not only allows us to communicate, but also limits us, depending on the nature and extent of its vocabulary. So it would be fair to say that expanding the number of words in a given language also expands the universe of those who speak the language and allows for greater innovation in thinking. In the case of modern English, one person above all others deserves credit for expanding the language: William Shakespeare.

Shakespeare was not only one of history’s greatest playwrights and poets, he was one of the greatest word and phrase inventors of all time. He took nouns and turned them into verbs, and vice versa, and created new words by combining other words. Furthermore, his multi-word “turns of phrase” were so brilliant that they remain in use to this day. (I’m reminded of the joke about the high school student assigned to read a Shakespeare play. When the teacher asked what she thought of it, she said, “It was OK, but it was full of clichés!”)

Here’s just a small sample of the approximately 1,700 words Shakespeare has been credited with creating: jaded; fortune-teller; pander; widowed; employer; bloodstained; bandit; domineering; mountaineer; advertising; manager; excitement; skim milk; academe; accused; addiction; softhearted; alligator; amazement; watchdog; anchovy; hint; arouse; fashionable; assassination; auspicious; farmhouse; eyeball; sanctimonious; lackluster; hush; deafening; tightly; buzzer; zany; glow; gnarled; hobnob; gossip; traditional; eventful; hoodwinked; and the popular name “Jessica.”

That may seem like a long list, but the complete list of words attributed to Shakespeare is 40 TIMES as long!

Shakespeare’s original multi-word expressions include: It’s Greek to me; salad days; vanished into thin air; refused to budge; green-eyed jealousy; playing fast and loose; a tower of strength; knitted your brows; fair play; slept not a wink; stood on ceremony; laughed in stitches; short shrift; cold comfort; too much of a good thing; seen better days; fool’s paradise; a foregone conclusion; as luck would have it; high time; the long and short of it; the game is up; the truth will out; flesh and blood; foul play; teeth on edge; one fell swoop; without rhyme or reason; give the devil his due; good riddance; send someone packing; dead as a doornail; a laughing stock; the devil incarnate; for goodness’ sake; neither a borrower nor a lender be; to thine own self be true; the be-all and end-all; by the book; the winter of our discontent; the lady doth protest too much; the play’s the thing; the sound and the fury; brave new world; and tongue-tied.

It’s worth noting that experts have found that the number of new words Shakespeare invented is impossible to determine accurately, in part because some words that turn up in his works for the first time may have been in common use before he incorporated them. In fact, at least a few words that were thought to be his inventions have recently been found in other, more obscure sources predating Shakespeare. But there’s not much question that he did create a spectacular number of new words and  phrases, most of which have remained part of common parlance ever since.

11. Adult humans can’t breathe and swallow at the same time, but newborns can. How is that possible?

Remarkably, human babies are born with their larynx, or voicebox, all the way up in the back of the mouth, not in the position it’s located in adults (about halfway up the neck). This makes breastfeeding safer for the baby because the milk flows around the sides of the raised larynx and into the stomach. The flow of air into the lungs can continue during the swallowing operation. In adults, the larynx is lower in the throat, so our esophagus instinctively closes when we swallow to prevent food or liquid from going into the lungs by mistake. Babies don’t need to do that, which undoubtedly prevents a lot of (potentially deadly) inhaling of milk.

Interestingly, having the larynx up in this position is part of the reason babies don’t talk sooner than they do; having the larynx in this position severely restricts a person’s ability to utter different vowel sounds, making the English language impossible to render coherently.

Over time, as a baby transitions from liquid to solid food during the first months of life, the larynx gradually descends down into the throat. Because it’s connected to the tongue via ligaments, this process also elongates the tongue from the back, making it ideal for enunciating words and allowing the infant to begin learning to speak.

12. How did Einstein get to be so smart?

Most people just think of Albert Einstein as a great genius who came up with the Theory of Relativity and his famous equation, E=MC squared. But if you dig a bit deeper, a lot of interesting details about his path to world renown start to emerge. He made a lot of serious mistakes and had some help with his theories that are seldom acknowledged. For example:

—  Coming up with a brilliant new way to look at the universe is one thing, but proving that it’s not just an interesting idea is a very different challenge. (Remember what Thomas Edison said: Genius is 1% inspiration and 99% perspiration!) Einstein realized that his Theory of Relativity had to be explained and proven mathematically to be accepted, but he didn’t know enough mathematics to accomplish this. So, he spent a year learning an entire branch of mathematics he hadn’t previously understood (a branch of geometry dealing with curved surfaces) in order to be able to explain and prove his theory. Even after this, the first draft of his Theory of Relativity, published in 1913, contained a number of errors in the equations that took him two years to correct. (Interestingly, he didn’t win the Nobel Prize for his Theory of Relativity because it was so complex and so revolutionary the Nobel committee thought it might end up being disproven!)

—  Einstein’s first wife, Mileva Maric Einstein, was a brilliant physicist and mathematician in her own right who worked closely with Einstein to develop his theories during their 16 years of marriage. They both studied at the Polytechnic Institute in Zurich, and by the end of their classes they had almost equal grades, except in applied physics, where she got the highest grade, 5, while he received a 1. The fact that they co-created his early work is acknowledged in numerous letters between them and in correspondence with close friends, in which Einstein himself describes the papers eventually published with just his name on them as being created by the two of them. (Apparently, she was fine with this at the time, possibly worried that the papers would be rejected simply because they were co-authored by a woman.)

After they completed the article containing the basis of special relativity, Einstein went to bed for two weeks. Mileva spent those two weeks checking the math over and over again. At one public gathering of young intellectuals, Einstein said, “I need my wife. She solves for me all my mathematical problems.”

Unfortunately, Mileva’s health declined, and Einstein fell into a relationship with his first cousin. He eventually got Mileva to agree to divorce him by promising her the money that came with winning the Nobel prize.

—  The measurement that would confirm the Theory of General Relativity—measuring the apparent position of stars near the sun during a total solar eclipse, when it would be possible to prove that the sun’s gravity was bending their light—couldn’t be done right away because World War I began just before the next total eclipse. That turned out to be fortunate for Einstein, because his predictions were slightly off! But by the time the war ended and scientists were able to make the measurement during the next solar eclipse, he had corrected his errors. As a result, his theory was confirmed.

One final note, proving that even a great genius can be fooled: In his later years, Einstein had a four-year-long affair with a woman we now know was a Russian spy!

13. Why do we have Trade Winds on the oceans?

The Trade Winds—winds that blow steadily and reliably in one direction over large sections of the Atlantic and Pacific oceans—have had a huge impact on human history. These winds made it possible for ships to sail across the great bodies of water separating the continents, allowing trade and encouraging the spread of cultures and ideas (for good or bad!). But why do those winds exist?

The Trade Winds exist because of two basic principles of physics: The tendency of warm air to rise and cooler air to sink, which ends up causing wind; and the shift in the path of a moving object that’s caused by the spinning of the planet. (This gets a little complicated, so bear with me.)

When air is heated and rises, it sucks in cooler air below to replace the air that has risen. So, when when air near the equator heats up and rises into the upper atmosphere, it sucks in cooler air at ground level. As a result, there’s a tendency for winds at ground level to move from the poles toward the equator, to replace that rising air. Winds higher up in the atmosphere tend to do the opposite, blowing from the equator toward the poles to replace the cooler air that’s sinking and moving toward the equator. This sets up an air circulation cycle, creating what we experience as wind. If our planet wasn’t spinning, we would generally have winds blowing toward the equator at ground level, and blowing toward the poles high up in the atmosphere.

The actual movement of the winds on our planet isn’t that simple, of course. That’s primarily because of what happens when an object is spinning: The path of something on that spinning object that started out moving in a straight line ends up being bent. This is referred to as the Coriolis Effect. So the wind that starts out moving straight toward the equator ends up being redirected to one side by the Earth’s spinning.

The result is that the cooler air at ground level that starts out moving from the poles toward the equator is gradually redirected until it’s actually blowing east at the middle latitudes (halfway between the equator and the poles). Those winds are known as the Easterlies, or Trade Winds—the winds that help sailing ships cross the oceans. Meanwhile, the warmer winds higher up that start out moving from the equator straight toward the poles end up being gradually redirected until they’re blowing west at the upper levels of the atmosphere.

So the Trade Winds are the cold air/warm air conveyor belt, bent by the spinning of the Earth!

14. Why do the hands of a clock run clockwise, not counterclockwise?

Surprisingly, the reason is pretty straightforward. Modern clocks were invented in the northern hemisphere, where the shadow on a sundial—used for centuries to tell the time—moves in the same direction as our clock hands do. (If clocks had been invented in the southern hemisphere, they’d probably run in the opposite direction, the way the shadow on sundials do down there!)

15.  What’s really going on in the Bermuda Triangle?

The area of ocean roughly bounded by Miami, Puerto Rico and Bermuda is well-known in popular culture as an area in which ships and planes have disappeared under mysterious circumstances. The idea that this is a special area was first put forward by author Vincent Gaddis in 1964, when he coined the phrase “the Bermuda Triangle” in an article. A bestseller published in 1974 by Charles Berlitz cemented the idea that something unusual was going on.

It’s true that there have been many reports of unusual disappearances of ships and planes in this area over the years, although the frequency of these events is fairly low. (Organizations that decide which areas of the ocean are dangerous for shipping or travel have noted that the danger, statistically speaking, is no greater than in many other areas of the globe.)

So if this part of the ocean isn’t more dangerous to sail in or fly over—statistically speaking—what’s the fuss about? It’s the unusual nature of those ship and plane disappearances that’s drawn attention to the area. Planes have disappeared without a trace after sending an all’s well signal; ships have done the same. In 1945 five Navy bombers became disoriented and disappeared; the rescue team sent out to find them the next day disappeared as well. Likewise, a number of very large cargo ships have disappeared without a trace—and without sending an SOS, suggesting that whatever happened, it happened suddenly and without warning. This has invited all kinds of wild speculation about what happened to those ships and planes.

It’s been pointed out that there may not be a single explanation. For example, fluctuations in the Earth’s magnetic field could explain the five bombers that became lost. And it’s conceivable that huge “rogue waves” could capsize a ship without warning. But one of the most interesting possibilities to explain the ships’ disappearances is the possibility of an eruption of methane bubbles from the ocean floor. This has been shown to happen in this location (as well as a few other places around the globe, which also have reported ships disappearing).

Some oceanographers have poo-pooed this explanation, saying that the turbulence of a bubble eruption wouldn’t be sufficient to sink a boat. However, it’s not the turbulence that would cause a ship to sink. A huge number of bubbles rising through water changes the specific gravity—or buoyancy—of the water. That’s the physical property that allows ships to float. If a huge mass of bubbles happens to rise to the surface directly under a floating object, that object can sink without warning. Given that the gas in question is methane, which is explosive, it’s also conceivable that a plane flying low over the ocean when a bunch of methane suddenly appears could have serious engine trouble.

All of this is hypothetical, of course, because no individual who was present at these disappearances survived to say exactly what happened. But it seems quite possible that an eruption of methane from the ocean floor—possibly combined with fluctuations in the Earth’s magnetic field and rogue waves—might explain most of the disappearances.

Fortunately, as noted earlier, these disappearances—though remarkable—have been very infrequent. So whatever happened in any given case, it seems reasonable to simply ponder the circumstances that might have caused it, rather than to worry about it happening to us!

16. Why is going to the top of a mountain on a clear night not always the best way to see the stars?

When my wife and I finally got to visit Hawaii many years ago, one of the things I was anxious to do was visit the Keck observatory at the summit of Mauna Kea on the Big Island. I’ve been privileged to see the starry sky under almost ideal conditions at ground level on two occasions, and the experience was spiritual. So I figured it would be even better if I were at a location specifically selected for its ideal star-viewing conditions.

The Keck observatory is almost 14,000 feet above sea level, above most clouds and water vapor in the atmosphere, with generally good weather. There’s almost no light pollution. These conditions make it one of the best places on Earth to see the stars, which is why the Keck telescopes were built there.

However, when we looked into taking a tour up to the observatory, and I explained my reason for wanting to go, the tour expert shook his head. “You don’t want to go up there to get a good view of the stars,” he said. “The air is so thin at that altitude that your brain doesn’t work as well, and your vision is hindered. You literally can’t see the stars as well because your eyes don’t work right.”

In fact, the astronomers using the observatory don’t work at the observatory itself. Instead, the data and visuals captured by the telescope are sent down the mountain to a research center about halfway up the mountain, where the astronomers can look at the data and analyze it with their brains fully functional!

17. What made product design suddenly become important in the 20th Century?

Before the early 20th Century, people mostly cared about whether something worked—not how it looked or whether it was user-friendly. But by the middle of the 20th Century, that had completely changed. Design and user-friendliness had become hugely important. What changed?

The change can be largely attributed to one man—Raymond Lowey. Lowey was a Frenchman, born in Paris in 1893. After fighting in World War I, he emigrated to New York in 1919. He had high expectations for what he would find, based on America’s reputation as “the golden land of opportunity,” but he was dismally disappointed by the dirty, even ugly, city he found. He was already a successful designer with engineering experience, so he took it upon himself to change the way things looked and worked in his new country.

As he transformed products from ugly to sleek and made them easier to use, sales skyrocketed, and one major company after another began hiring him to redesign their products. His redesign of the refrigerator, in particular, cemented his reputation. His designs changed trains from black locomotives to sleek aluminum showpieces. (He also redesigned the interiors of the trains and the train stations.) He made automobiles look elegant. He redesigned farm tractors to look beautiful. He redesigned company logos; buses; vending machines; even the classic Coca Cola bottle. In 1962 he was invited to redesign Airforce One for President Kennedy after commenting how ugly the original design was. Eventually he was hired by NASA to help design the Skylab space station, where he helped make sure the inside environment was psychologically sustaining and pleasant for the occupants. Perhaps most memorably, it was his idea to include a portal through which the astronauts could look at the earth below!

By the middle of the 20th Century he was credited with the way almost everything looked. In fact, Time Magazine featured him on its cover in October 1949 as The Man Who Shaped America.

18. How can you tell what someone is thinking by watching their eyes?

Actually, you can’t usually tell what someone is thinking by watching their eyes (although in certain circumstances you might be able to guess). What you CAN usually tell from watching a person’s eyes is HOW they’re thinking—or to put it differently, which internal sense they’re using in their imagination. It turns out that our eye movements change depending on whether we’re imagining an image, a sound or a feeling. In addition, our eye movements reflect whether the internal experience is something we’re remembering, or something we’re constructing in our imagination because we’ve never actually experienced it. (Authors Richard Bandler and John Grinder explain how this works in detail in their classic book Frogs Into Princes, which is all about a type of psychological counseling called Neuro Linguistic Programming, or NLP.)

There’s a basic formula that applies here, which you can easily confirm by paying close attention when you’re talking to someone. I’ll describe this from  your perspective watching the other person: if they’re remembering an image (what does your car look like?), they’ll look up and to your right. If they’re constructing an image (what would you look like with orange hair?), they’ll look up and to your left. (An important exception is that people remembering an image will sometimes simply “go inside” and leave their eyes staring straight ahead blankly…They may still be looking at you, but you can tell “their mind is elsewhere.”)

When most people are recalling an audio memory (How does your phone sound when it rings?), their eyes will go directly to your right. (A few people will look down and to your right.) When they’re constructing an audio experience they haven’t heard before (How would your voice sound if you were standing in an echo chamber?) their eyes will look over to your left. (However, some people will look down and to your right for any audio thinking.) Finally, if you ask the other person to remember a kinesthetic feeling (How does your hand feel when you pet a cat?), most people will look down and to your left. (To see a classic chart showing all of this, visit the link below:       )

It’s important to note that a minority of people will have this reversed, left to right. It’s possible that this reversal applies when someone is left-handed, but this may not be universally true. However, the vast majority people will follow the rules described above; and even if someone reverses left and right, they will be consistent. It’s wired in.

A related note: If you watch people carefully when they’re trying to answer a question, you may notice that their eyes sometimes shift around. That’s because when we’re thinking about the answer to a question we often switch from one internal sense to another. If you ask someone to construct an imaginary image, for example, the person may look up and to your right trying to recall something similar; then look up and to your left as they change the image to match the new image you’re asking them to imagine; and then look down and to your left as the image causes them to have a feeling about what they’re seeing.

It’s interesting that very few people are aware of this, although we’ve all watched other people do this our entire lives. In any case, knowing about this can make a big difference in how effectively you communicate with other people. (Check out Frogs Into Princes for more about that!)