Curiosity, images, and scientific exploration

When we gaze at nature's remarkable phenomena, we might feel a mix of awe, curiosity, and determination to understand what we are looking at. That is certainly a common response for MIT's Alan Lightman, a trained physicist and prolific author of books about physics, science, and our understanding of the world around us.

"One of my favorite quotes from Einstein is to the effect that the most beautiful experience we can have is the mysterious," Lightman says. "It's the fundamental emotion that is the cradle of true art and true science."

Lightman explores those concepts in his latest book, "The Miraculous from the Material," published today by Penguin Random House. In it, Lightman has penned 35 essays about scientific understanding, each following photos of spectacular natural phenomena, from spider webs to sunsets, and from galaxies to hummingbirds.

Lightman, who is a professor of the practice of the humanities at MIT, calls himself a "spiritual materialist," who finds wonder in the world while grounding his grasp of nature in scientific explanation.

"Understanding the material and scientific underpinnings of these spectacular phenomena hasn't diminished my awe and amazement one iota," Lightman writes in the book. MIT News talked to Lightman about a handful of the book's chapters, and the relationship between seeing and scientific curiosity.

Aurora borealis

In 2024, many people ventured outside for a glimpse of the aurora borealis, or northern lights, the brilliant phenomenon caused by solar storms. Auroras occur when unusually large amounts of electrons from the sun energize oxygen and nitrogen molecules in the upper atmosphere. The Earth's magnetic field creates the folding shapes.

Among much else, the aurora borealis - and aurora australis, in southern latitudes - are a testament to the way unusual things fire our curiosity.

"I think we respond emotionally as well as intellectually, with appreciation and plain old awe at nature," Lightman says. "If we go back to the earliest times when people were thinking scientifically, the emotional connection to the natural world was probably as important as the intellectual connection. The wonder and curiosity stimulated by the night sky makes us want to understand it."

He adds: "The aurora borealis is certainly very striking and makes us aware that we're part of the cosmos; we're not just living in the world of tables, and chairs, and houses. It does give us a cosmic sense of being on a planet out in the universe."

Galileo coined the term "aurora borealis," referring to the Roman goddess of the dawn and the Greek god of the north wind. People have created many suggestive accounts of the northern lights. As Lightman notes in the book, the Native American Cree regarded the lights as dead spirits in the sky; the Algonquin people saw them as a fire made by their creator; the Inuit tribes regarded the lights as spirits playing; and to the Vikings, the lights were a reflection off the armor of the Valkyries. It wasn't until the 1900s that geomagnetic sunstorms were proposed as an explanation.

"It's all a search for meaning and understanding," Lightman says. "Before we had modern science, we still wanted meaning, so we constructed these mythologies. And then as we developed science we had other tools. But the nonscientific accounts were also trying to explain this strange cosmos we find ourselves in."

Fall foliage

The aurora borealis is unearthly; fall leaves and their colors are literally a down-to-earth matter. Still, Lightman says, while the aurora borealis "is more exotic," fall foliage can also leave us gazing in wonder. In his book, he constructs a multilayered explanation of the subject, ranging from the chemical compounds in leaves to the properties of color to the mechanics of planetary motion.

First, the leaves. The fall hues come from chemical compounds in leaves called carotenoids (which produce yellow and orange colors) and anthocyanins (which create red hues). Those effects are usually hidden because of the presence of chlorophyll, which helps plants absorb sunlight and store energy, and gives off a green hue. But less sunlight in the fall means less chlorophyll at work in plants, so green leaves turn yellow, orange, or red.

To jump ahead, there are seasons because the Earth does not rotate on a vertical axis relative to the plane of its path around the sun. It tilts at about 23.5 degrees, so different parts of the planet receive differing amounts of sunlight during a yearlong revolution around the sun.

That tilt stems from cosmic collisions billions of years ago. Solar systems are formed from rotating clouds of gas and dust, with planets and moons condensing due to gravity. The Earth likely got knocked off its vertical axis when loose matter slammed into it, which has happened to most planets: In our solar system, only Mercury has almost no tilt.

Lightman muses, "I think there's a kind of poetry in understanding that beautiful fall foliage was caused in part by a cosmic accident 4 billion years ago. That's poetic and mind-blowing at the same time."

Mandarinfish

It can seem astonishing to behold the mandarinfish, a native of the Pacific Ocean that sports bright color patterns only a bit less intricate than an ikat rug.

But what appears nearly miraculous can also be highly explainable in material terms. There are evolutionary advantages from brilliant coloration, something many scientists have recognized, from Charles Darwin to the present.

"There are a number of living organisms in the book that have striking features," Lightman says. "I think scientists agree that most features of living organisms have some survival benefits, or are byproducts of features that once had survival benefits."

Unusual coloration may serve as camouflage, help attract mates, or warn off predators. In this case, the mandarinfish is toxic and its spectacular coat helps remind its main predator, the scorpionfish, that the wrong snack comes with unfortunate consequences.

"For mandarinfish it's related to the fact that it's poisonous," Lightman says. Here, the sense of wonder we may feel comes attached to a scientific mechanism: In a food chain, what is spectacular can be highly functional as well.

Paramecia

Paramecia are single-celled microorganisms that propel themselves thanks to thousands of tiny cilia, or hairs, which move back and forth like oars. People first observed paramecia after the development of the microscope in the 1600s; they may have been first seen by the Dutch scientist Antonie van Leeuwenhoek.

"I judged that some of these little creatures were about a thousand times smaller than the smallest ones I have ever yet seen upon the rind of cheese," van Leeuwenhoek wrote.

"The first microscopes in the 17th century uncovered an entire universe at a tiny scale," Lightman observes.

When we look at a picture of a paramecium, then, we are partly observing our own ingenuity. However, Lightman is most focused on paramecia as an evolutionary advance. In the book, he underscores the emerging sophistication represented by their arrival 600 million years ago, processing significant amounts of energy and applying it to motion.

"What interested me about the paramecium is not only that it was one of the first microorganisms discovered," Lightman says, "but the mechanisms of its locomotion, the little cilia that wave back and forth and can propel it at relatively great speed. That was a big landmark in evolution. It requires energy, and a mechanical system, all developed by natural selection."

He adds: "One beautiful thought that comes out of that is the commonality of all living things on the planet. We're all related, in a very profound way."

The rings of Saturn

The first time Lightman looked at the rings of Saturn, which are about 1,000 in number, he was at the Harvard-Smithsonian Center for Astrophysics, using a telescope in the late 1970s.

"I saw the rings of Saturn and I was totally blown away because they're so perfect," Lightman says. "I just couldn't believe there was that kind of construction of such a huge scale. That sense of amazement has stayed with me. They are a visually stunning natural phenomenon."

The rings are statistically stunning, too. The width of the rings is about 240,000 miles, roughly the same as the distance from the Earth to the moon. But the thickness of the rings is only about that of a football field. "That's a pretty big ratio between diameter and thickness," Lightman says. The mass of the rings is just 1/50 of 1 percent of our moon.

Most likely, the rings were formed from matter by a moon that approached Saturn - which has 146 known moons - but got ripped apart, its material scattering into the rings. Over time, gravity pulled the rings into their circular shape.

"The roundness of planets, the circularity of planetary rings, and so many other beautiful phenomena follow naturally from the laws of physics," Lightman writes in the book. "Which are themselves beautiful."

Over the years, he has been able to look many times at the rings of Saturn, always regarding it as a "natural miracle" to behold.

"Every time you see them, you are amazed by it," Lightman says.