Starry Messenger: Cosmic Perspectives on Civilization

by Neil deGrasse Tyson

Nearly every thought, every opinion, and every outlook I formulate on world affairs has been touched—informed and enlightened—by knowledge of our place on Earth and of our place in the universe. Far from being a cold, feelingless enterprise, there is, perhaps, nothing more human than the methods, tools, and discoveries of science. They shape modern civilization. What is civilization, if not what humans have built for themselves as a means to transcend primal urges and as a landscape on which to live, work, and play.

Science distinguishes itself from all other branches of human pursuit by its power to probe and understand the behavior of nature on a level that allows us to predict with accuracy, if not control, the outcomes of events in the natural world. Scientific discovery often carries the power to broaden and deepen perspectives on all things. Science especially enhances our health, wealth, and security, which are greater today for more people on Earth than at any other time in human history.

Do whatever it takes to avoid fooling yourself into believing that something is true when it is false, or that something is false when it is true.

Objective truths apply to all people, places, and things, as well as all animals, vegetables, and minerals. Some of these truths apply across all of space and time. They are true even when you don’t believe in them.

Objective truths exist independent of that five-sense perception of reality. With proper tools, they can be verified by anybody, at any time, and at any place.

Hardly any of us have ever grown tired of waterfalls or the full Moon ascending over a mountainous or urban horizon. We persistently fall speechless at the singular spectacle that is a total solar eclipse. Who can turn away from the crescent Moon and Venus, together, suspended in the twilight skies? Islam couldn’t. That juxtaposition of a “star” with the crescent Moon remains a sacred symbol of the faith. Vincent van Gogh couldn’t turn away either. On June 21, 1889,3 he captured it from the pre-dawn skies in Saint-Rémy, France, creating what is perhaps his best-known painting, The Starry Night. And we never seem to get enough landscape panoramas from planetary rovers or cosmic imagery delivered courtesy of the Hubble Space Telescope and other portals to the cosmos. The truths of nature are rampant with beauty and wonder, out to the largest of measures of space and time.

In the White House of the 1990s, Bill Clinton kept on his Oval Office coffee table, between the two facing couches, a sample Moon rock brought back to Earth from a quarter-million miles away by Apollo astronauts. He told me that any time an argument was about to break out between geopolitical adversaries or recalcitrant members of Congress, he would point to the rock and remind people it came from the Moon.8 This gesture often recalibrated the conversation, serving as a reminder that cosmic perspectives can force you to take pause and reflect on the meaning of life, and on the value of peace that sustains it.

You’ve probably heard of pi—a number between 3 and 4 that harbors infinite decimal places, although often truncated to 3.14. Here’s pi with enough digits to see all ten numerals 0 through 9: 3.14159265358979323846264338327950 … You get pi simply by dividing the circumference of a circle by its diameter. That same ratio prevails no matter the size of the circle. The very existence of pi is a profound truth of Euclidean geometry, celebrated each year by all card-carrying geeks of the world on March 14—a date that can be written as 3.14. Math can be beautiful.

And even though an asteroid took out Earth’s big-toothed, badass dinosaurs, their absence pried open an ecological niche that allowed our tiny mammalian ancestors to evolve into something more ambitious than hors d’oeuvres for T. rex. That’s undeniably a beautiful thing—at least for the branch on the tree of life that became primates, to which we belong.

Smallpox, malaria, and the bubonic plague together have killed upwards of 1.5 billion people throughout time, worldwide. That toll far exceeds all deaths from all armed conflicts in the history of our species. Nature has killed more of us than we have of ourselves. These thoughts hardly ever (likely never) arise whenever we declare nature’s beauty.

If the gridiron of a football field were a timeline of the universe, with the Big Bang at one end and this moment at the other, then all of human recorded history would span the thickness of a blade of grass in the end zone.

Note that Venus, our nearest planetary neighbor, has no moon at all. Mars, our next-nearest neighbor, has Phobos and Deimos, two sorry excuses for moons. Both are Idaho potato–shaped and tiny enough to fit easily within the municipal boundaries of most cities. Our Moon, on the other hand, is 50 percent larger than Pluto and checks in as the fifth largest in the Solar System.

The seminal photo of planet Earth rising over the lunar landscape—you know the one—arrived in December 1968 from Apollo 8, the first mission ever to leave home for another destination. From deep space the entire Earth is laid bare. As the cosmos intends you to see it: a fragile juxtaposition of land, oceans, and clouds; isolated and adrift in the void of space, with no hint of anybody or anything coming to rescue us from ourselves. This outlook ascends a few realms higher than the overview effect and represents the true beginnings of a cosmic perspective.

Apart from serving as our first destination in space, the Moon enjoys extraordinary value across world cultures. The cycle of lunar phases informs the reckoning of time for the Chinese, Islamic, and Hebrew calendars.

One of the rewards for doing well in the moon lottery is that the Sun is four hundred times wider than the Moon, and it happens to be four hundred times farther away. This pure coincidence renders the Sun and Moon about the same size in the sky, allowing for spectacular solar eclipses. This wasn’t always the case, nor will it be so in the distant future. The Moon is spiraling away from Earth at a rate of about 1.5 inches per year. So let’s enjoy this match made in heaven while we can. Every few years, the Moon passes exactly between Earth and the Sun, precisely covering the Sun, darkening the sky, and briefly laying bare the Sun’s gorgeous outer atmosphere, called the corona. No other planet-moon combination in the Solar System can match it.

The health and wealth of the nation remains highly dependent on the economic strength of blue states, with New York, New Jersey, Connecticut, and Illinois leading the way.

A study from 2016, authored by nine wildlife scientists, modeled the predator-prey relation between cougars and white-tailed deer.28 They reported that within thirty years, a vibrant predator population dining upon unwanted deer can avoid 21,400 injuries, prevent 155 human deaths, and save $2.1 billion, all from car accidents that won’t happen. Naturally, cougars also occasionally eat people, especially small wayward children—the model predicts about thirty of them. So we have two choices: 1) Introduce hungry cats that eat thirty people in thirty years, or 2) don’t introduce hungry cats, and leave car-deer accidents unabated that injure thousands, kill hundreds, and cost billions. If the societal priority is to save lives, but the interpersonal priority is to value our emotions, then how do we balance these factors in our daily lives? Laws and legislation and national directives pivot on this. Dying in a car-deer accident, even in large numbers, can be thought of as nobody’s fault. Yet getting eaten by a large cat put there by the government is abominable. Do we admit (confess?) to ourselves that we are not cold mathematical creatures, and then celebrate our feelings, knowing they wield the power to override our rational thought? Or do we suppress all that might confound a rational decision? Could or should we allow emotions to influence legislation in response to data?

The largest known organism in the world is a single mat of mushrooms weighing 35,000 tons (nearly two-thirds the weight of the RMS Titanic). This humongous fungus lurks underground and measures miles across in the Blue Mountains of Oregon. If you’re into hard-to-pronounce, hard-to-remember italicized names for genus and species, it’s called Armillaria ostoyae. Mushrooms occupy their own kingdom of life, which split with animals in evolutionary history later than our common ancestor split from green plants. Humans and mushrooms are therefore more genetically alike than either we or mushrooms are to anything that grows in the plant kingdom.

The infamous wave-particle duality of matter disturbs many people. The term “wavicle” never caught on. Maybe it should have. The wailing takes the form: “Which is it? It’s gotta be one or the other. I must know!” The simple answer is that matter manifests as both waves and particles. Get over it. Is the infamous Schrödinger’s cat1 dead or alive in the closed box? If you open the box, you will discover the cat to be either dead or alive. Yet quantum physics tells us that if you don’t open the box, the cat is both dead and alive at the same time. Get over that one too.

In the universe, two or more seemingly contradictory facts can be simultaneously true.

The presumed binary of sex in nature is overrated and rife with exceptions, not only in ourselves but also in the rest of the animal kingdom.6

Note also that the length of our legs carries nearly all height difference between humans. When seated we are all approximately the same height, which is why driver car seats adjust forward and backward with vastly more range than they adjust up and down, if at all.

In 2020 more than one hundred monuments were removed, mostly of Confederate Civil War commanders—all in full uniform, many on horses. Statues such as these, especially those that stood silent guard over Monument Avenue in Richmond, Virginia, all remind me of slavery. We’ve come a long way since the Civil War. I’ve even been awarded an honorary doctorate from the University of Richmond. During my life, I’ve achieved what was surely unthinkable to each of these Confederate leaders—and honored for it in the cradle of the American South and birthplace of General Robert E. Lee. Yes, that’s progress, but these statues nonetheless evoke in me the country’s darkest era. I’m not debilitated by these thoughts, but they do represent a kind of socio-emotional tax I pay. Maybe all these men were kind and noble members of their community. Maybe they were pious Christians and went to church each Sunday. Maybe they helped rescue cats from trees. Could all be true. That’s not why these equestrian statues were cast in their honor. The soldiers are memorialized for defending the Southern way of life from an incursion of Northern aggressors. But there is no Southern way of life that isn’t economically and culturally conjoined with the fate of four million enslaved Africans—fully a third of the South’s population.8 To sustain the hierarchy requires an endemic belief system of racial inferiority, complete with laws that prevented the education of Negroes. A key step when you want to feel superi...

Africa is indeed the “cradle of mankind.” A few hundred thousand years ago, early humans wandered north and then west and east, populating Europe, Asia, and ultimately the Americas. Our peripatetic ancestors carried the base African genome all around the world. Those journeys took less time than you might think. Let’s do the math. If you walked 25,000 miles (Earth’s circumference) at 2 miles per hour—a leisurely pace—and you did it for eight hours per day, you would circumnavigate the globe in 4.3 years. Of course there’s no actual path or road that goes around Earth, and there’s desert and bodies of water and mountains and other stuff in the way. Nonetheless, before agriculture, generations upon generations of Africans, one after another, had plenty of time to reach every contiguous nook of Earth’s surface—driven by the search for food or by a sense of wonder about what lay beyond their horizons.

Also, consider that morals evolve across time and culture, typically by rational analysis of the effects and consequences of previously held morals, in the light of emergent knowledge, wisdom, and insight. The Bible, for example, often held up as a source of morality, is not a fertile place to find antislavery commentary, nor discussions of gender equality.

Over centuries and millennia, one thing is for sure, we’ve persistently underestimated the intelligence of our fellow animals—further evidence of our fragile ego—only to be shocked when they do something smart.

If we open the brain-to-body-weight contest to all animals, not just vertebrates, then ants win spectacularly. On average, the human brain is 2.5 percent of our body weight, yet for some ant species, their brains are closer to 15 percent of their body weight. Thinking this through, we’re forced to conclude that visiting space aliens who prioritize brains might first try to chat with the ants, then the birds, then perhaps the whales, the elephants, the dolphins. Then the mice. And then maybe—just maybe—the humans. Embarrassing.

Beyond simple hand gestures, we don’t know how to communicate meaningfully with chimpanzees. We can’t even tell them, “Come back tomorrow afternoon. I’ve got a new shipment of bananas arriving for you.” Assessing the effort that we invest trying to get big-brained mammals to do what we say, we tend to measure their intelligence by an ability to understand us, rather than measure our intelligence by an ability to understand them. Since we can’t meaningfully communicate with any other species of life on Earth—not even those genetically closest to us—how audacious of us to think we can converse at all with intelligent alien life upon first meeting them.

For these reasons death may be more important to our state of mind than we are willing to recognize. If you were to bring a colorful bouquet flowers to a loved one, and those flowers were made of plastic, or even silk, they will surely be less appreciated than if they were real. Flowers that live forever miss the point. We seek the increasing beauty of each flower in a bouquet, as they unfurl one by one in the light of the day. We’re absorbed by their irresistible aromas. We duly accept the care and feeding they require. We embrace their senescence as the stems weaken, no longer sustaining the weight of the faded petals. Florists remain in business because the death of flowers—typically within a week of receiving them—is precisely what gives them meaning to your loved one. Compare that with forever-flowers that require no maintenance, never die, have no smell, yet remain just as beautiful a week, a month, or a year later.

Of all species that ever lived on Earth, 99.9 percent of them have gone extinct.9