Death By Black Hole & Other Cosmic Quandaries

by Neil DeGrasse Tyson

  Let’s start at the bottom.

  At the end of the 1977 Disney film Black Hole, which sits on many people’s 10 worst movies list (including mine), an H. G. Wellsian spaceship loses control of its engines and plunges into a black hole. What more could special-effects artists ask for? Let’s see how well they did. Was the craft and its crew ripped apart by the ever-increasing tidal forces of gravity—something a real black hole would do to them? No. Was there any attempt to portray relativistic time dilation, as predicted by Einstein, where the universe around the doomed crew evolves rapidly over billions of years while they, themselves, age only a few ticks of their wristwatches? No. The scene did portray a swirling disk of accreted gas around the black hole. Good. Black holes do this sort of thing with gas that falls toward them. But did elongated jets of matter and energy spew forth from each side of the accretion disk? No. Did the ship travel through the black hole and get spit out into another time? another part of the universe? or in another universe altogether? No. Instead of capturing these cinematically fertile and scientifically informed ideas, the storytellers depicted the black hole’s innards as a dank cave, with fiery stalagmites and stalactites, as though we were touring Carlsbad Cavern’s hot and smoky basement.

  Some people may think of these scenes as expressions of the director’s poetic or artistic license, allowing him to invent whimsical cosmic imagery without regard to the real universe. But given how lame the scenes were, they are more likely to have been an expression of the director’s scientific ignorance. Suppose there were such a thing as “scientific license,” where a scientist, doing art, chooses to ignore certain fundamentals of artistic expression. Suppose that whenever scientists drew a woman they gave her three breasts, seven toes on each foot, and an ear in the middle of her face? In a less extreme example, suppose scientists drew people with the knee joint bending the wrong way, or with odd proportions among the body’s long bones? If this did not start a new movement in artistic expression—akin to Picasso’s flounderlike renderings of the human face—then artists would surely tell us all to go back to school immediately and take some art classes in basic anatomy.

  Was it license or ignorance that led the painter of a work in the Louvre to draw a cul-de-sac surrounded by erect trees, each with a Sun-made shadow pointing in toward the center of the circle? Hadn’t the artist ever noticed that all shadows cast by the Sun on vertical objects are parallel? Is it license or ignorance that nearly every Moon ever painted by artists is either a crescent or a full moon? Half of any month the Moon’s phase is neither crescent nor full. Did the artists paint what they saw or what they wished they had seen? When Francis Ford Coppola’s 1987 Someone to Watch Over Me was being filmed, his cinematographer called my office to ask when and where was the best occasion to film the full Moon rising over the Manhattan skyline. When I instead offered him the first quarter moon or the waxing gibbous moon, he was unimpressed. Only the full Moon would do.

  Although I rant, there’s no doubt that creative contributions from the world’s artists would be poorer in the absence of artistic license. Among other losses, there would have been no impressionism or cubism. But what distinguishes good artistic license from bad is whether the artist acquired access to all relevant information before the creativity begins. Perhaps Mark Twain said it best:

  Get your facts first, and then you can distort ’em as much as you please. (1899, Vol. 2, Chap. XXXVII)

  In the 1997 blockbuster movie Titanic, producer and director James Cameron not only invested heavily in special effects but also in re-creating the ship’s luxurious interiors. From the wall sconces to the patterns on the china and silverware, no detail of design was too small to attract the attention of Mr. Cameron, who made sure to reference the latest artifacts salvaged from missions to the sunken ship, more than two miles undersea. Furthermore, he carefully researched the history of fashion and social mores to ensure that his characters dressed and behaved in ways generally consistent with the year 1912. Aware that the ship was designed with only three of its four smoke stacks connected to engines, Cameron accurately portrays smoke coming from only three stacks. We know from accurate records of this maiden voyage from Southampton to New York City the date and time the ship sank, as well as the longitude and latitude on Earth where it sank. Cameron captures that too.

  With all this attention to detail, you think James Cameron might have paid a bit more attention to which stars and constellations were visible on that fateful night.

  He didn’t.

  In the movie, the stars above the ship bear no correspondence to any constellations in a real sky. Worse yet, while the heroine bobs and hums a tune on a slab of wood in the freezing waters of the North Atlantic, she stares straight up and we are treated to her view of this Hollywood sky—one where the stars on the right half of the scene trace the mirror image of the stars in the left half. How lazy can you get? To get it right would not have required a major realignment of the film’s budget.

  What’s odd is that nobody would have known whether Cameron captured his plate and silverware patterns accurately. Whereas for about fifty bucks you can buy any one of a dozen programs for your home computer that will display the real sky for any time of day, any day of the year, any year of the millennium, and for any spot on Earth.

  On one occasion, however, Cameron exercised artistic license commendably. After the Titanic sank, you see countless people (dead and alive) floating in the water. Of course, on this moonless night in the middle of the ocean, you would barely see the hand in front of your face. Cameron had to add illumination so that the viewer could follow the rest of the story. The lighting was soft and sensible, without obvious shadows indicating an embarrassing (and nonexistent) source of light.

  This story actually has a happy ending. As many people know, James Cameron is a modern-day explorer, who does, in fact, value the scientific enterprise. His undersea expedition to the Titanic was one of many he has launched, and he served for many years on NASA’s high-level Advisory Council. During a recent occasion in New York City, when he was honored by Wired magazine for his adventurous spirit, I was invited to dinner with the editors and Cameron himself. What better occasion to tell him of his errant ways with the Titanic sky. So after I whined for ten minutes on the subject, he replied, “The film, worldwide, has grossed over a billion dollars. Imagine how much more money it would have made had I gotten the night sky correct!”

  I have never before been so politely, yet thoroughly, silenced. I meekly returned to my appetizer, mildly embarrassed for having raised the issue. Two months later, a phone call comes to my planetarium office. It was a computer visualization expert from a post-production unit for James Cameron. He said that for their reissue of the film Titanic, in a Special Collector’s Edition, they would be restoring some scenes and he was told I may have an accurate night sky they might want to use for this edition. Sure enough, I generated the right image of the night sky for every possible direction that Kate Winslet and Leonardo DiCaprio could turn their heads while the ship sank.

  THE ONLY TIME I ever bothered to compose a letter complaining about a cosmic mistake was after I saw the 1991 romantic comedy L.A. Story, written and produced by Steve Martin. In this film, Martin uses the Moon to track time by showing its phase progressing from crescent to full. A big deal is not made of this fact. The Moon just hangs there in the sky from night to night. I applaud Martin’s effort to engage the universe in his plot line, but this Hollywood moon grew in the wrong direction. Viewed from any location north of Earth’s equator (Los Angeles qualifies), the Moon’s illuminated surface grows from right to left.

  When the Moon is a thin crescent, you can find the Sun 20 or 30 degrees to its right. As the Moon orbits Earth, the angle between it and the Sun grows, allowing more and more of its visible surface to be lit, reaching 100 percent frontal illumination at 180 degrees. (This monthly Earth-Sun-Moon configuration is known as syzygy, which reliably gives you a full Moon and, occasionally, a lunar eclipse.)


  Steve Martin’s moon grew from left to right. It grew backward. My letter to Mr. Martin was polite and respectful, written on the assumption that he would want to know the cosmic truth. Alas, I received no reply, but then again, I was only in graduate school at the time, without a weighty letterhead to grab his attention.

  Even the 1983 macho test-pilot epic The Right Stuff had plenty of the wrong stuff. In my favorite transgression, Chuck Yeager, the first to fly faster than the speed of sound, is shown ascending to 80,000 feet, setting yet another altitude and speed record. Ignoring the fact that the scene takes place in California’s Mojave Desert, where clouds of any species are rare, as Yeager darts through the air you see puffy, white, alto-cumulus clouds whizzing by. This error would surely irk meteorologists because, in Earth’s real atmosphere, these clouds would not be caught dead above 20,000 feet.

  Without those visual props, I suppose the viewer would have no visceral idea of how fast the plane was moving. So I understand the motive. But the film’s director, Philip Kaufman, was not without choices: Other kinds of clouds, such as cirrus, and the especially beautiful noctilucent clouds, do exist at very high altitudes. At some point in your life you have to learn that they exist.

  The 1997 film Contact, inspired by Carl Sagan’s 1983 novel of the same name, contains an especially embarrassing astro-gaffe. (I saw the movie and never read the book. But everyone who has read the book says, of course, that it’s better than the movie.) Contact explores what might happen when humans find intelligent life in the galaxy and then establish contact with it. The heroine astrophysicist and alien hunter is actress Jodie Foster, who recites a fundamental line that contains mathematically impossible information. Just as she establishes her love interest in ex-priest Matthew McConaughey, seated with the largest radio telescope in the world behind them, she says to him with passion: “If there are 400 billion stars in the galaxy, and just one in a million had planets, and just one in a million of those had life, and just one in a million of those had intelligent life, that still leaves millions of planets to explore.” Wrong. According to her numbers, that leaves 0.0000004 planets with intelligent life on them, which is a figure somewhat lower than “millions.” No doubt that “one in a million” sounds better on screen than “one in ten,” but you can’t fake math.

  Ms. Foster’s recitation was not a gratuitous expression of math, it was an explicit recognition of the famous Drake equation, named for Astronomer Frank Drake who first calculated the likelihood of finding intelligent life in the galaxy based on a sequence of factors, starting with the total number of stars in the galaxy. For this reason, it was one of the most important scenes in the film. Who do we blame for the flub? Not the screenwriters, even though their words were spoken verbatim. I blame Jodie. As the lead actress, she forms the last line of defense against errors that creep into the lines she delivers. So she must bear some responsibility. Not only that, last I checked, she was a graduate of Yale University. Surely they teach arithmetic there.

  During the 1970s and 1980s, the popular television soap opera As The World Turns portrayed sunrise during the opening credits and sunset during the closing credits, which, given the show’s title, was a suitable cinematic gesture. Unfortunately, their sunrise was a sunset filmed in reverse. Nobody took the time to notice that for every day of the year in the Northern Hemisphere the Sun moves at an angle up and to the right of the spot on the horizon where it rises. At the end of the day, it descends across the sky at an angle down and to the right. The soap-opera sunrise showed the Sun moving toward the left as it rose. They obviously had gotten a piece of film showing a sunset and played it in reverse for the show’s beginning. The producers were either too sleepy to wake up early and film the sunrise, or the sunrise was filmed in the Southern Hemisphere—after which the camera crew ran to the Northern Hemisphere to film sunset. Had they called their local astrophysicists, any one of us might have recommended that if they needed to save money, they could have shown the sunset in a mirror before they showed it running backward. This would have taken care of everybody’s needs.

  Of course, inexcusable astro-illiteracy extends beyond television, film, and paintings at the Louvre. The famous star-studded ceiling of New York City’s Grand Central Terminal rises high above the countless busy commuters. I would be gripeless if the original designers had no pretense of portraying an authentic sky. But this three-acre canvas contains among its several hundred stars a dozen real constellations, each traced in their classical splendor, with the Milky Way flowing by, just where you’re supposed to find it. Holding aside the sky’s greenish color, which greatly resembles that of Sears household appliances from the 1950s, the sky is backward. Yes, backward. Turns out, this was common practice during the Renaissance, back when globe makers made celestial spheres. But in those cases, you, the viewer, stood in a mythical place “outside” of the sky, looking down, with Earth imagined to occupy the globe’s center. This argument works well for spheres smaller than you, but fails miserably for 130-foot ceilings. And amid the backwardness, for reasons I have yet to divine, the stars of the constellation Orion are positioned forward, with Betelgeuse and Rigel correctly oriented.

  Astrophysics is surely not the only science trod upon by underinformed artists. Naturalists have probably logged more gripes than we have. I can hear them now: “That’s the wrong whale song for the species of whale they showed in the film.” “Those plants are not native to that region.” “Those rock formations have no relation to that terrain.” “The sounds made by those geese are from a species that flies nowhere near that location.” “They would have us believe it’s the middle of the winter yet that maple tree still has all its leaves.”

  In my next life, what I plan to do is open a school for artistic science, where creative people can be accredited in their knowledge of the natural world. Upon graduating, they would be allowed to distort nature only in informed ways that advance their artistic needs. As the credits roll by, the director, producer, set designer, cinematographer, and whoever else was accredited would proudly list their membership with SCIPAL, the Society for Credible Infusion of Poetic and Artistic License.

  SECTION 7

  SCIENCE AND GOD

  WHEN WAYS OF KNOWING COLLIDE

  FORTY

  IN THE BEGINNING

  Physics describes the behavior of matter, energy, space, and time, and the interplay among them in the universe. From what scientists have been able to determine, all biological and chemical phenomena are ruled by what those four characters in our cosmic drama do to one another. And so everything fundamental and familiar to us Earthlings begins with the laws of physics.

  In almost any area of scientific inquiry, but especially in physics, the frontier of discovery lives at the extremes of measurement. At the extremes of matter, such as the neighborhood of a black hole, you find gravity badly warping the surrounding space-time continuum. At the extremes of energy, you sustain thermonuclear fusion in the ten-million-degree cores of stars. And at every extreme imaginable, you get the outrageously hot, outrageously dense conditions that prevailed during the first few moments of the universe.

  This essay was the winner of the 2005 Science Writing Award from the American Institute of Physics.

  Daily life, we’re happy to report, is wholly devoid of extreme physics. On a normal morning, you get out of bed, wander around the house, eat something, dash out the front door. And, by day’s end, your loved ones fully expect you to look no different from the way you did when you left and to return home in one piece. But imagine arriving at the office, walking into an overheated conference room for an important 10:00 A.M. meeting, and suddenly losing all your electrons—or worse yet, having every atom of your body fly apart. Or suppose you’re sitting in your office trying to get some work done by the light of your desk lamp and somebody flicks on the overhead light, causing your body to bounce randomly from wall to wall until you’re jack-in-the-boxed out the window. Or what if you went to a sumo wrestling
match after work and saw the two spherical gentlemen collide, disappear, then spontaneously become two beams of light?

  If those scenes played out daily, then modern physics wouldn’t look so bizarre, knowledge of its foundations would flow naturally from our life experience, and our loved ones probably would never let us go to work. Back in the early minutes of the universe, though, that stuff happened all the time. To envision it, and understand it, one has no choice but to establish a new form of common sense, an altered intuition about how physical laws apply to extremes of temperature, density, and pressure.

  Enter the world of E=mc 2.

  Albert Einstein first published a version of this famous equation in 1905 in a seminal research paper titled “On the Electrodynamics of Moving Bodies.” Better known as the special theory of relativity, the concepts advanced in that paper forever changed our notions of space and time. Einstein, then just 26 years old, offered further details about his tidy equation in a separate, remarkably short paper published later the same year: “Does the Inertia of a Body Depend on Its Energy Content?” To save you the effort of digging up the original article, designing an experiment, and testing the theory, the answer is “Yes.” As Einstein wrote:

  If a body gives off the energy E in the form of radiation, its mass diminishes by E/c2…. The mass of a body is a measure of its energy-content; if the energy changes by E, the mass changes in the same sense. (1952, p. 71)

  Uncertain as to the truth of his statement, he then suggested:

  It is not impossible that with bodies whose energy-content is variable to a high degree (e.g. with radium salts) the theory may be successfully put to the test. (1952, p. 71)