INTRODUCTION
MONSTERS
A black hole has come for Central City. Chaos erupts. People scramble for cover because, there, in the clear blue sky, is a churning black sphere. Whipping around the black void is a fiery red-orange disk filled with what’s left of stars and other cosmic crumbs.
And worse? The black hole’s powerful gravity is more than Central City can withstand. Street lamps hurl toward the black void. Skyscrapers fracture and give way. Like an epic super-vacuum cleaner, the black hole is ripping everything apart brick by brick—doom is certain. That’s unless comic book superhero the Flash, aka Barry, can save Central City and the planet by flying into that ominous point of no return. Can Barry overcome the most powerful force known to exist?
POP CULTURE ALERT! Emmy award–winning TV series The Flash premiered in 2014, telling the story of scientist Barry Allen, who is struck by lightning and gains super speed, becoming the fastest man alive. Like any superhero going about his own business, trouble quickly follows, and Barry (the Flash) must use his power for good! This popular TV show, inspired by the comic book series of the same name, is seven seasons strong and still going (as of this writing). Comic Creator: DC Comics; Run: 1940 through 2016. Tagline: “Lightning fast action, mystery, and adventure.”
Too bad Barry can’t ask the crew of the Starship Enterprise for advice. They know what it’s like to stare down a black hole. In the 2009 movie Star Trek, they find out the hard way what happens when you fly too close to a black hole. Even at warp speed, there is no escape. Cracks spread across the ceiling of the ship. The black hole appears in flashes and it is breathtaking in size and semi-invisibility. The famous spaceship is helpless against the forces of gravity. The black hole is like a magnet with supernatural control. If they don’t come up with a plan, the Enterprise and her crew will be lost to the black depths forever.
These plot twists have all the right stuff: clever fiction, actual science—all tossed together for an outrageous adventure. And let’s face it, there is no other cosmic character that commands such credible and certain destruction as a black hole! Powerful. Deadly. Unseen. Nothing in space captures our imaginations like black holes. Nothing.
Black holes are a reliable “go-to” when it comes to drumming up drama, ratcheting up tension, summoning suspense, and hinting at locked secrets of the universe and those inside ourselves. After all, black holes gobble up anything that gets too close. That much we know. But beyond the basics, black holes represent the limits of human knowledge itself!
Yes, black holes can be the perfect partner in our efforts to explain what we long to discover. Are black holes portals to another universe? A secret door to an intergalactic highway? Do they stalk galaxies, swallowing stars and planets? Are they capable of scarfing down entire solar systems in one fiery gulp? And what happens if a person is sucked up by a black hole? Will they become a long string of human spaghetti? Are black holes star shredders? Terrifying and fascinating. And that’s exactly what makes them so cool!
BOOKSHELF: The Care and Feeding of a Pet Black Hole by Michelle Cuevas. The fact that we know so little about black holes makes them the perfect world-building buddy to invent details, powers, and behaviors, like a habit of following kids home from NASA. That’s what happens to fictional character Stella Rodriguez. When she visits NASA and a black hole follows her home, she makes a lot of discoveries. She can explain the anatomy of a black hole and she observes how it eats everything in sight. But the one thing it doesn’t seem capable of consuming? Her broken heart. This middle-grade book is less of an intense high stakes sci-fi adventure and more of a love letter to black holes and surviving grief.
It’s easy to think you know what black holes actually look like. Our imaginations are that good. Plus, artists have used every tool they have, from pens and paint to sophisticated computer graphics, to create jaw-dropping images. Like magicians, they made real what we could only imagine. They offered space fans an educated guess, often based on the best science. But even though these images were smart guesses, fancy guesses, visually stunning guesses, they were still—just guesses. These realistic images of a dark force, illuminated only by a bright ribbon of star leftovers slung around this deadly nothingness, well … they are so realistic, so awe-inspiring, it’s no wonder they make for mind-blowing TV and movie scenes, magazine and book illustrations.
But the truth is that no one had seen a black hole. No one. No human being, no telescope, no space bound probe had ever seen a black hole. Ever.
A scientist named Sheperd Doeleman was determined to change that.
It was an impossible goal. One that promised heart-crushing failure.
The technology they needed did not exist—unless they invented it.
And he couldn’t do it alone. He would need a team of scientists to help. But, just like it often happens in comic books, when heroes try to do something impossible, the world was in trouble. Wars were breaking out. Countries were closing their borders. Instead of banding together to solve problems, people were looking at each other with suspicion and distrust.
The quest required nothing less than quick thinking, innovation, perseverance, teamwork, and united dedication to an epic goal: explore and expand the very limits of human knowledge by taking a picture of something that had never been seen before—a black hole.
CHAPTER 1
WAIT, WHAT IS A BLACK HOLE IRL?
Black holes are what happens after particularly large stars die. Star death is fairly dramatic—especially when it comes to massive stars, the biggest stars of all. When it’s their time to die, massive stars go out in a blaze of glory.
Huge, bright, and superheavy, they must be more than eight times the mass of the Sun to be officially labeled “massive.” These stars spend their lives growing. Expanding and expanding, fueled by constant nuclear fusions at their core. Gravity pulls the mass of a star to its center. But there is another force pushing the star outward from the center. That’s the heat and pressure from the nuclear fuel at the core. These two forces keep a star in check. One pushing out. One pulling in.
That is, until it runs out of fuel.
Then, that multimillion-year-long growth spurt comes to an end and the star collapses in on itself. Imagine those outer edges of the star slamming into the core in less than a second. The impact sets off an enormous explosion. Shock waves rush out into the cosmos. In fact, the explosion is so powerful and large, it has its own name: supernova.
The supernova remnant Cassiopeia is the glowing debris field left behind after a massive star exploded. (Credit: NASA)
LINGO ALERT! Gravitational Collapse. Ugh, let me go! The star’s gas is superheated and this creates pressure. And that pressure wants to expand and escape. But ugh, gravity! Gravity just can’t let it go. Gravity keeps the star pulled together. And gravitational collapse happens when something contracts or pulls in on itself toward its own center of gravity because its own gravity becomes stronger than other forces. In the case of a dying star, gravitational force becomes stronger than the force of pressure from the hot core, because it’s run out of fuel. That leads to the star’s gravitational collapse.
The post-supernova leftovers collapse once again, shrinking down, down, down into a single point. This teeny tiny point is even smaller than a single atom! It is infinitely small (as in never-ending in its smallness) and it has infinite mass. So, it’s pretty heavy. And like any heavy, massive thing, it has powerful gravity. The more mass, the more gravity. Endless amount of mass? Well, that puts its gravity in a whole new category!
ALTERNATIVE MASSIVE STAR AFTERLIVES: Post-supernova, massive star remains can regroup and become a neutron star (superdense and small, neutron stars are full of busy neutrons), or the bits and pieces and dust clouds of former greatness can drift off into outer space.
To get even an inkling of what this is like … imagine taking an Egyptian pyramid that weighs nearly six million tons. Now, imagine shrinking it and squishing it until that pyramid is small enough to fit into the palm of your hand—only it still weighs six million tons! But what if that superheavy pocket-size pyramid gobbled up anything that traveled too close to it? And that six million tons of mass keeps growing, becoming heavier and heavier?
That’s similar to what happens when a massive star collapses in on itself. Those super squished star leftovers compact down into a single point. That single point is called the singularity.
And the singularity is what scientists believe lies inside black holes.
Just like stars come in different sizes, so do black holes. Stellar mass black holes are on the smaller side; intermediate black holes make up the middle. And supermassive black holes are the biggest of all. After all, they have at least one MILLION times more mass than our Sun. How these ginormous monsters are born is still a bit of a mystery. Some scientists think they are formed when black holes merge (which sounds friendly and mature, but probably is super violent and awe-inspiring as far as space dramas go).
And even though it’s just a teeny tiny point, all of that matter, that mass, has an unbelievably powerful gravitational pull. It is so intense that if anything gets too close, it can’t escape. Not even light. The black hole can even bend space itself.
TRAMPOLINE TIME!
It’s easy to think of space as an endless black nothingness, with stars artfully placed here and there. But as super smart physicist Albert Einstein explained, space is more like fabric. He called this fabric space-time, based on the idea that space and time are connected like different threads that are woven together to create a single fabric. Think about it this way. Right now, you are reading this book … at a particular time and at a particular location in space. Those two things are connected. He also realized that space-time controls how everything moves in the universe. If there is a bend in space-time, that bend actually changes the way objects move. And what creates changes in space-time? Objects with mass such as you, me, Earth, other planets, and especially black holes.
ALBERT EINSTEIN lived from 1879 to 1955. He was one of the most important scientists of the 20th century. This Nobel Prize–winning physicist is famous for E=mc2. This equation explains the relationship between mass and energy. His theory of general relativity (and more) is still being used and tested today!
Albert Einstein, 1879–1955. (Photo by Orren Jack Turner, via Library of Congress)
Finding this difficult to wrap your head around? Einstein gave us a great example to help us visualize his idea. Imagine the space-time fabric is like the surface of a trampoline. When you roll a bowling ball onto that black rubbery surface, what happens? The trampoline sags. Now imagine you roll golf balls across the trampoline. What will happen to their paths? They will roll toward the bowling ball in a spiral along the curved, sagging surface of the trampoline. The same is true of how things move around a black hole. A black hole’s bend in space-time changes the trajectory and orbit of nearby objects. The scientific word for this is the geodetic effect.
LINGO ALERT! Theoretical physicists use physics to explain our world and make predictions about our world. These predictions become theories and those theories are then tested.
EUREKA! A DAYDREAM THAT CHANGES THE WORLD
In the early 1900s, everyone accepted Isaac Newton’s idea that a mysterious force known as gravity kept planets in place. But when Einstein began thinking about how mass moves through space and time, he realized this idea had its limits.
Einstein conducted a series of thought experiments about it—focused daydreams where he used his imagination to think through different problems and scenarios. These thought experiments allowed Einstein to test ideas in his mind’s eye, like a virtual laboratory.
Even while working as a clerk in a Swiss patent office, Einstein spent every available minute thinking about the universe and trying to unlock its mysteries. One day he spotted a window washer high on a ladder, scrubbing away. Einstein wondered what they would each experience if the man fell? From Einstein’s point of view, the man would appear to be falling fast, straight to the ground. But to the window cleaner, what would he experience? Would it seem to him like time had slowed down? Yes! Also, the man would experience weightlessness, because the ground wasn’t pushing up against him. This idea gave birth to his theory of special relativity. But his journey to better understand gravity and our cosmos was not over.
Soon, Einstein realized that space-time itself can bend and curve. And if that’s true, well then objects must travel along the curved path. He realized that light wasn’t merely a wave, but made up of small packets called photons. And that a beam of light, or stream of photons, would also bend as it travels the curve.
During an eclipse of the Sun in 1919, when the Moon blocked almost all of the Sun’s light from Earth, it turned day into night. This darkness allowed astronomers to see a star shining right next to the Sun. But astronomers already knew about this star. And actually, it was located behind the Sun. It really shouldn’t have been visible at all. EXCEPT if you apply Einstein’s theory about space-time and light traveling this curve, then we can understand that the star had not moved. Rather, its light was traveling around the Sun’s distortion of space-time to reach Earth!
So, Isaac Newton was right. Earth’s gravity does affect the Moon, but Einstein figured out how: Earth’s mass bends space-time, giving the Moon a path to move around the Earth. Then he wrote down his theory in a set of field equations—math problems that would describe the physical field of space-time.
American physicist John Wheeler would later summarize it like this: “Space-time tells matter how to move. Matter tells space-time how to curve.”
But coming up with the equations didn’t necessarily mean solving them! Other scientists picked up the torch.
PUTTING EINSTEIN TO THE TEST! Mercury has a wonky, wobbly orbital path. Before Einstein’s theories and field equations came along, all scientists had was Newton’s theory on universal gravity. And Newton’s math failed to predict the path Mercury took around the Sun (which seemed to be constantly changing). Could Einstein’s theory do the trick? The answer is yes. Einstein’s theory correctly predicted Mercury’s orbital path.
In 1916, physicist Karl Schwarzschild examined Einstein’s theory of general relativity while thinking about the universe. Looking at the math, Schwarzschild realized the theory of general relativity predicted the existence of a region of space from which nothing could escape. Describing it as a hole in the very fabric of space-time, he believed this hole was shaped like a sphere and that once anything got too close or passed a point of no return, it could not escape.
Thought of another way, it’s as if you go into the school bathroom, flush the toilet, and it opens up a dark bottomless pit—one that is capable of swallowing you and everything in the school, town, country, and planet, followed by the universe (sorry if this has been your fear all along) with a single flush.
BRAIN BENDER! Schwarzschild also realized that everything we understand about physics disappears into the black hole because not even information can make its way out.
Copyright © 2021 by Anna Crowley Redding
