Starry Messenger: Cosmic Perspectives on Civilization

by Neil deGrasse Tyson

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.

To deny objective truths is to be scientifically illiterate, not to be ideologically principled.

The beauty we’ve created is not even skin-deep. It washes off in the shower.

Cloud taxonomy fascinated the Scottish meteorologist Ralph Abercromby, and in 1896 he documented as many as he could around the world, creating a numerical sequence for them. You guessed it. Cumulonimbus clouds landed at number 9, unwittingly seeding the everlasting concept of being on “cloud nine” when in a blissful state.

Einstein’s equivalence of energy (E) and mass (m): E = mc2. The small c stands for the speed of light—a constant that shows up in countless places as we unravel the cosmic codes that run the universe. Among a zillion other places that it shows up, this little equation underpins how all stars in the universe have generated energy since the beginning of time.

Nature has killed more of us than we have of ourselves. These thoughts hardly ever (likely never) arise whenever we declare nature’s beauty. Maybe they should. If they did, we’d be more honest with ourselves about our place in the universe. Evidence shows that nature doesn’t actually care about our health or longevity.

After reading Joyce Kilmer’s most famous poem,12 will you ever again walk past a tree without reflecting on its silent majesty? I think that I shall never see A poem lovely as a tree. A tree whose hungry mouth is prest Against the earth’s sweet flowing breast; A tree that looks at God all day, And lifts her leafy arms to pray; A tree that may in Summer wear A nest of robins in her hair; Upon whose bosom snow has lain; Who intimately lives with rain. Poems are made by fools like me, But only God can make a tree.

In one more example, you learn that a species of unwanted algae is spreading on the surface of your favorite pond. The growth is persistent and doubles in area every day. After a month, the lake is half-covered in algae. At this rate, how much longer until algae covers the entire lake? Our primitive, linear brain calculates “one month.” But the actual answer is “one day.” Doesn’t even matter how long it took for the pond to become half-covered. If the rate of coverage doubles every day, you can be sure that when it’s half-covered, you’ve got just one day left.

I’m instead plagued by a simpler thought that, as a species, we might not possess the maturity or wisdom the future requires to assure the survival of civilization.

Full Moons get the highest tides not because of the Moon but because of the Sun. The Sun’s tides on Earth are about one-third the strength of the Moon’s tides, yet hardly anybody talks about them. During full Moon, high Sun tides add directly to high Moon tides, giving the false impression that the full Moon imparts extra gravitational influence. Furthermore, whatever false gravitational influence you ascribe to the full Moon, you must also grant to the new Moon because the Sun’s tides perfectly align there too.

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.

Consider what happens when scientists disagree. We look for one of three outcomes: either I’m right and you’re wrong, you’re right and I’m wrong, or we’re both wrong. That’s an implicit contract we carry into all arguments on the frontier of discovery. Who decides the outcome? Nobody does. Arguing more loudly or strenuously or more articulately than your opponent simply reveals how annoying and obstinate you are. The resolution almost always comes when more or better data arrive.

We are more likely to be swayed by a single person who testifies with passion than by a bar chart containing data compiled from thousands of people.

Just because your favorite number, say 27, has not come up in a while on the roulette wheel doesn’t mean 27 is “due.” Each spin has no memory of any previous spin, leaving you with the same odds on every spin. Yet every roulette table lists the results of the previous dozen or so spins, just to feed our ignorance of how probability works. Our primate brains simply can’t handle this truth.

But that works only if people are open to learning. In modern times, many of us don’t satisfy that criterion, perhaps because, according to the nineteenth-century British essayist Walter Bagehot,18 One of the greatest pains to human nature is the pain of a new idea.

When putting forth a scientific hypothesis, you should be your own greatest critic. You don’t want colleagues finding holes in your reasoning before you do. It looks bad and it reveals you didn’t do your homework. A good way to attack one’s own work is to step back and explore whether a completely opposite explanation can be constructed from the same data or from data you may have overlooked. If you succeed at dismantling your own hypothesis, it’s time to move on to another research project.