Here is the second entry in this series.
Let’s get this out of the way: Albert Einstein was the pre-eminent genius physicist of the twentieth century, a man famous and exalted—and deservedly so—for his contributions to science.[1] But yes, he did come down on the wrong side of certain controversies of his time. The question below refers not to some minor or incomprehensible detail in theories of relativity, quantum mechanics, or the photoelectric effect. No, we’re talking about a major theory, some big honking construction that today is widely accepted and part of science curricula in schools everywhere.
Question 3: Which chapter of your science textbook did Albert Einstein get wrong?
Here’s a hint: the topic has nothing to do with theoretical physics.
The answer is….plate tectonics. This theory explains that Earth’s lithosphere is divided into large slabs that slide with extreme slowness above the plastic-like rocks of the mantle. The slabs gradually slam into each other at some borders, forming mountain ranges; separate at other borders, forming rift valleys; and grind past one another at places like the San Andreas Fault, causing earthquakes. It’s a helluva theory. But it did not come easy.[2]
https://www.youtube.com/watch?v=uCD0fPSsdBA
In 1958, geologist Charles Hapgood published a book entitled “Earth’s Shifting Crust: A Key to Some Basic Problems of Earth Science.” The book’s basic problems are a series of perplexing discoveries and observations, such as fossilized flora and fauna beneath the ice of Antarctica. Hapgood’s overall explanation, which he calls crust displacement, incorporates a wobbly Earth axis, the centripetal force of Earth’s rotation, and the weight of polar ice caps. Pointedly, his explanations deny the existence of drifting continents or puzzle-piece slabs of Earth’s crust, ideas he harshly discredits and ridicules.
Einstein wrote the foreword for this book. I reviewed that foreword just now. To be fair, Einstein does not discuss, nor even mentions, any of the principles of the theory we now call plate tectonics. However, Einstein praises the “electrifying” ideas of Hapgood, which he summarizes in a few paragraphs. Einstein also lauds Hapgood for his boldness, his insight, and his “cautious and comprehensive presentation” of evidence.
We have many reasons to be charitable to Einstein about this foreword. Writing it was one of the last public actions of his life; he died in 1955 at the age of 76 years. Nevertheless, that action endorsed a lot of utter bunk.
What morals might this story offer? One lesson is that even the greatest among us can make mistakes. Another is that genius in one field does not necessarily translate to other pursuits, nor might genius persist throughout a lifetime. I think the key lesson, however, is that devising sweeping scientific theories is a difficult, error-prone undertaking for anyone. The reason is that the natural world extends beyond humans’ limited senses and perspectives, which means it often fails to conform to our expectations or thinking. Or to state this idea more distinctly: Nature is bonkers. Science insists otherwise, which makes science difficult.
It’s easy—and a mistake, I think—to dismiss Charles Hapgood and his ilk as either slug-headed old farts or prattling doofuses. Instead, try considering science from their mid-twentieth century perspective, before the onset of computers and undersea exploration and global positioning satellites. Within the limited infrastructure and framework of the era, plate tectonics does seem like a bonkers idea.
Have you seen continents? They’re really big, aren’t they? They’re made of rocks, too. Not chalk or talcum powder, but granite and limestone, which are very heavy. You can’t move a big, rocky continent across an ocean the way you’d shove a sofa across the living room.
Instead of accepting the bonkers idea of plate tectonics, Hapgood came up with bonkers ideas of his own, as listed in the earlier paragraph. Hapgood was not alone. Others of the era invented their own bonkers ideas, such as land bridges.
I’ve always liked land bridges. I think they’re the closest that science has come to the logicality of Noah’s Ark. The history is as follows:
Much to the annoyance of the Old-guard Geologists, their colleagues in paleontology were discovering fossilized species of horses, reptiles, ferns, and what-have-you, each with specimens found on opposite sides of the Atlantic Ocean. Fossil pairs they identified clearly represented the same species. How could these land lubbers have crossed all that seawater? The OgG’s were forced to put on their thinking caps. But without breaking much of a sweat, they announced that land bridges had once spanned the ocean. The bridges allowed for safe passage of the now-fossilized animals and plants. Later, the bridges sank.[3]
Let’s take a moment to analyze these land bridges. I picture them as somewhat wider, significantly longer versions of the causeway across Lake Pontchartrain in Louisiana, which you can observe as your airplane approaches Louis Armstrong New Orleans International Airport[4]. At a length of 24 miles, the causeway holds the world record for longest continuous span over water. Trucks and cars cross it without incident every day, but their drivers know and understand the purpose of the journey, which takes about half an hour.
Now picture Mr. and Mrs. Prehistoric Lizard at the African end of a 3,000 mile land bridge across the Atlantic. “Hey Phyllis,” says Steve Lizard, whose mate is named Phyllis, “how about a quick stroll after dinner?”
“Sure, let me get my hat,” says Phyllis, who does not wear hats.
We need both lizards to embark on the journey because they’re going to die en route, meaning their offspring will take over. If we assume that each female lizard will travel 50 miles westward before laying its last clutch of eggs, an assumption I think is quite ambitious, then the lizards will need about 60 generations to reach North America or South America. We also must assume that the land bridge provides the plants, fresh water, and other environmental support necessary for either a transient or resident lizard population, and that conditions are sufficiently stable to prevent significant lizard evolution, which the fossils show did not occur. We also must assume that the land bridge eventually sinks, which is why we can’t see it today.
I have read that an ambitious young scientist once searched the Atlantic Ocean for signs of sunken land bridges. He was unsuccessful, perhaps because the land bridges never existed.
Keep in mind that the explanation from plate tectonics is that the lizards died together in one region. Then the land itself split apart, forming the Atlantic Ocean as the process continued. To me this explanation seems the more reasonable, but I was trained a tad differently than the land-bridges crowd.
To sum up, many new discoveries forced the geologists of the mid-twentieth century to reconsider their ideas about Earth. Some faced the challenging question of: How can I abandon my comfortable perspective for some new idea that’s clearly bonkers? But I’ll wager at least a few of them were debating a slightly different question: Which of these many new bonkers ideas could possibly be correct?
Question 5: What happens to a pencil that is thrown into deep space?
Let us now return to Einstein’s proper turf.
You are an astronaut in deep space, and you gleefully toss a pencil—or a rock, or whatever small object strikes your fancy—into the dark void in front of you. What happens to the object?
If you are versed in the laws of motion as proposed by Isaac Newton, then you might proclaim that the object will continue moving forward at its original velocity. This motion will continue until the object approaches some other object, perhaps a planet or a star or a massive Klingon battle cruiser[5], any of which would apply the force of gravity and alter the object’s trajectory.
It only takes one of Newton’s laws of motion to justify this prediction. This is the first law, also called the law of inertia. An object in motion tends to stay in motion with the same speed and direction, until acted upon by a net external force.
Three cheers for Isaac Newton! His genius was to apply observations that anyone could make and synthesize laws that anyone can understand. We teach Newton’s laws of motion, albeit in simplified forms, to children in third grade.
So, um, what do Einstein and modern physics have to say about the tossed pencil? They say—and I’m really sorry about this, because it screws up a popular question in science textbooks—but they say Newton is wrong. The motion laws don’t apply, at least not indefinitely through space-time. In the universe as physicists understand it today, a tossed pencil, even without an external force, will gradually and inexorably slow to a stop. The reason is because it is traveling through an expanding universe.
If this statement bothers you, remember that the genius of Einstein was to apply observations that no one had made to synthesize laws that no one could understand.[6]
I exaggerate, but still.
You might be wondering how, if the tossed pencil comes to a stop, it could still obey the law of conservation of energy. I hear that Einstein struggled with this question too. He thought he had a solution, but then it was disproven by a German mathematician-slash-physicist named Emmy Noether. I had never heard of Emmy Noether before, and I certainly don’t recall her name in the women-in-science profiles that come up in science education. If you’re looking to report on an influential woman in science history, she’s a worthy candidate.
Turns out that the conservation of energy does not apply in an expanding universe. The energy of a pencil moving through space will simply….go away. Don’t ask me to explain more.
Earlier, I claimed that nature is bonkers. If you doubt me, read or listen to astrophysics interpreters like Neil deGrasse Tyson or Brian Cox, who will channel for you the work of Einstein, Stephen Hawking, Edwin Hubble, Roger Penrose, and the names go on. They will tell you that space and time are intertwined and form a kind of fabric that mass disrupts, that relative time decreases to zero at the event horizon of a black hole, and that the big bang occurred at all points of the existing universe simultaneously. They may also show you a photo of several distant galaxies that includes the same galaxy in two different locations, due to the bending of light around a black hole, a phenomenon called gravitational lensing.[7]
If you reach the point where you believe you have a firm understanding of the nature of the universe and how it operates, you might consider applying for a professorship at any number of universities, or as an alternative, admittance to a good sanitarium.
Joking aside, I don’t think astrophysicists are crazy. It’s the sanity of the universe I’m more worried about.
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That’s all for tonight, campers. Thank you for your interest, and please look forward to our next installment of….Confounding Questions in Science.
[1] Not much fame from the twentieth century has persisted to current times, but Albert Einstein is an exception. His name, image, style, and famous equation remain the touchstones of the stereotypical scientist. Ask your kid to draw a picture of a scientist, and they’ll likely pick up on the wild hair, at minimum. I’m not sure who managed Einstein’s public relations campaign, but they did an amazing job.
[2] Cue the song by Ringo Starr. I’m delighted that Ringo is in the Rock and Roll Hall of Fame as a solo act, along with his inclusion as a Beatle. I’m not sure why he’s there twice, but whatever the reason, it works for me.
The Hall itself is a tourist attraction on the shores of Lake Erie in Cleveland, Ohio, a short detour for anyone traveling on I-90. I recommend it along with the Cleveland Art Museum (which is free) or an evening of baseball with the Cleveland Guardians (not free.) For anyone who hasn’t been paying attention, the Guardians were originally named the Cleveland Cultural Insensitivities. The new name was announced in 2021, and ever since the transition has seemingly gone quite smoothly. Go Guards, even though I am a fan of my hometown team, the Minnesota Twins.
[3] If you know who Jon Lovitz is, hear him saying “Yeah, that’s the ticket!”
[4] Louis Armstrong was a great jazz musician, and he helped introduce jazz to a wide audience. The airport, like all of coastal Louisiana, is in danger of sinking under rising ocean waters, a potential fate that might have interested the land bridge geologists.
[5] Star Trek presented spaceships as large, massive constructions. The ships from the 1960s version of the show held a crew of a few hundred people. By the 80s, ship populations swelled into the thousands (if my Internet search is to be trusted.) The fictional characters lived in fairly roomy quarters and enjoyed dedicated spaces for their work, relaxation, and entertainment. In real life, even if we figured out interstellar space travel, could we build ships that elaborate? Remember that the Apollo spacecraft were too small for bathrooms, while the International Space Station looks like a hamster habitat. We do have seafaring ships for pleasure cruises that approach the scale of the Enterprise, which is as close to a relevant example as I can think of.
[6] The credit for the conclusion that the universe is expanding goes to Edwin Hubble, for whom the telescope is named, and not to Einstein. According to an article in Science Daily and some other sources, Einstein initially believed the universe was static. He eventually signed on to Hubble’s model, thanks to a lot of deep thinking and the persuasion of the astrophysicists of the time. But it’s a little cheeky, or hero-worshipping, to suggest that we’re living in “Einstein’s universe.” Lots of other scientists helped form the modern understanding.
[7] My wife and I indeed studied this very photo at a lecture from Professor Brian Cox, delivered at a stately theater in Boston, Massachusetts. Brian Cox was touring the country like a rock-and-roll star, albeit without an opening act and much less expensive tickets.
