A Final Thought: Science and Sweet Corn
By Mitch Allen
As an English major, I sometimes regret not learning more about science, so I read a lot about the sciences and listen to science-themed podcasts.
Here are a few things I learned about the nature of the universe in 2020 that surprised me:
Plants Don’t Grow Out of the Ground
A plant’s structure is mostly carbon, but where does the carbon come from? It actually comes from the air. Through photosynthesis, plants absorb the carbon dioxide in the air to acquire the carbon they need to create stems, leaves, limbs, bark, flowers, seeds, etc. They also break down the carbon into glucose (sugar) to create apples, oranges, peas and beans. So when you’re enjoying an ear of Ohio sweet corn this summer, rejoice in the knowledge that it did not come from the ground; it literally arrived out of thin air.
Gravity Is Not a Force
We’ve all heard of the “force of gravity,” how massive objects attract each other. But gravity, it turns out, is not a force. One hundred years ago, Einstein showed how gravity is instead the curvature of spacetime, that is, the three dimensions of space combined with the fourth dimension of time.
One way to think of curved spacetime is to compare it to the curvature of the Earth. If you and a friend each stand on the equator 1,000 miles apart and walk due north, you will slowly get closer to each other until you finally shake hands at the North Pole. No “force” brought you together. Instead, it was the curvature of the Earth. Similarly, massive objects (like stars and planets) curve spacetime, so anything moving through space and time will have a downward trajectory toward the object.
So, then, in the absence of a gravitational force, how does an apple fall from a tree without some form of acceleration? Shouldn’t it just hang there in the air? Well, even if something isn’t moving through space, it is still moving through time (getting older), and anything that moves forward in time will have a downward acceleration.
Yeah, tell me about it.
We Are All Neanderthal
Modern humans came out of Africa and migrated to Europe and Asia where they encountered—and bred with—Neanderthals. As a result, the genetic makeup of humans today averages 2.1% Neanderthal. This explains the recent growth of hair on my back.
The International Space Station Is Just
250 Miles High
That’s right, the International Space Station (ISS) is not far out in space. It is barely above the surface of the Earth. On a standard one-foot diameter globe, it would be orbiting less than a half inch above the surface, where gravity is still quite strong. So if gravity is present, why are the astronauts floating around inside the space station? The answer is: They are falling.
If, Heaven, forbid, the cable breaks on your elevator, you and the elevator would fall at the same rate, giving you a feeling of weightlessness. The same thing happens when you crest a hill on a roller coaster. Similarly, the ISS is “falling” around the earth at 15,500 miles per hour, encircling the globe every 93 minutes. It is in orbit because the speed of the spacecraft and the Earth’s gravity are in balance. Gravity prevents the ISS from flying off into space while the speed of the space station prevents it from tumbling to the Earth. It is locked in orbit. The astronauts onboard are weightless not from a lack of gravity, but because of gravity. They are literally in a constant state of freefall.
We Use 100% of Our Brain
There is a popular myth that we use only 10% of our brain. This is nonsense. It isn’t true. We use 100% of our brain. The 10% idea was developed to ponder the extent of our mental capabilities and how each of us may unleash our hidden potential.
The Sun is a Star
Yes, everyone knows the sun is a star, but we rarely think of it that way. Perhaps the world would be a better place if we referred to the sun as “our star,” acknowledging the miraculousness and fragility of our place in the universe. At its 27-million-degree core, our star is engaged in nuclear fusion, the ramming together of hydrogen atoms to form helium. During the process, some of the mass is converted to energy (thank you, E = mc2) and that energy finds its way to the Earth, allowing—among other things—the growth of sweet corn.
By referring to the sun as the astonishing star that it is, we could lie on the beach in the starshine and apply starscreen to avoid a starburn. Of course, our star is not a benign disc in the sky. At some point in the not-so-distant future, it will unleash a giant solar flare that will fry many of our GPS satellites, causing our great-grandchildren to get lost in their self-driving cars on the way to Szalay’s Sweet Corn Farm because they have no map in the glove compartment.