God not only plays dice, He also sometimes throws the dice where they cannot be seen.
In this particular post we will be discussing one of my favorite universal phenomena, black holes. They are the most powerful force in the cosmos, able to wreak havoc and destruction on an incomprehensible scale. Yet they also seem to be a major key to the formation of galaxies and a big reason why any of us are even here to talk about it. We’ll discuss this, what we think black holes are and what they may do, and end with a scenario involving a black hole near Earth. This is not a scientific text. I’m just a pop-science junkie and I am fascinated by the mysteries of the universe. So let’s begin at the beginning.
In the late 18th century cosmology was still very much in its infancy. We had a pretty good picture of the solar system and how it operated, but the distant stars still eluded us. There were many theories for how the universe was constructed and mos tall of them came back to a steady state model. This theory proposed that the universe was always here just as it is. It is infinite, eternal, and unchanging. This included theories about the spontaneous creation of matter to fill this infinite, eternal space. And if you were a physicist alive at the time, it would make perfect sense to you. The technology was limited so the theories had to be as well. The “discovery” of black holes came about during an experiment to test the effects of gravity by John Mitchell. Mitchell, a geologist by trade, dabbled in various arenas of science. And by dabbled I mean made revolutionary discoveries that would have made Einstein tip his hat.
During his various tests he attempted to measure the effects of gravity on light. Again the science was limited by the technology but in 1783 he wrote a letter to the Royal Society in London detailing what he called, “dark stars”. Bodies containing an absurd amount of density that “trap” everything near it, including light. he lamented that he didn’t have the tools necessary to further study this possible phenomena but he hoped his efforts would help future generations discover the truth. A true scientist in every sense of the word. But his work didn’t get many looks. It didn’t fit well with the steady state model that dominated science and it would be more than a century before that model changed. Light was seen as a wave. A wave without mass. So very few people could be convinced that gravity could so strongly effect something with no mass. So Mitchell’s study sat unnoticed until a patent official from Zurich changed everything.
In the early 20th century the steady state model was coming to an end. The technology was beginning to catch up to the science and people were viewing the universe in a different way. Followed closely together was Albert Einstein’s theory of relatively in 1915, and Edwin Hubble’s 1925 paper detailing stars beyond our own galaxy. Yes, at this time we still assumed our galaxy was it. Nothing beyond it but empty space. Hubble proved otherwise with a telescope large than any that had come before it. But the big discovery relevant to our issue was Einsteins ‘s theory. It changed the concept of space, time, and gravity. Now they were all linked. Einstein’s theory proposed that sufficient mass curves spacetime significantly, and nearby objects fall in toward it. Given the speed of the object, it will either crash into the mass or “fall” into an orbit around it.
It also became apparent that light had a dual property as both a wave and particles. This reopened discussion on “dark stars”. If a dense mass curved space enough, and light was a series of particles following a definite path in space, the mass could indeed “trap light”. All paths the light would travel are now bent back in toward the object and light cannot escape from it. But the objects being discussed now were no longer dark stars. If gravity could have such an effect, what would be its limit? How far could it collapse an object? Karl Schwarzschild was at the forefront of this study. His work, also released in 1915, proved that a star of sufficient mass would collapse in on itself to a point that it literally falls in on itself. Many were skeptical. They felt some device was in place preventing such a catastrophic ripping of spacetime. And indeed there was. But only for certain stars who did not have enough mass to fully collapse. They would reach a point then settle into what we call a neutron star.
But now it was almost accepted that black hoes were a possibility. It was still very much theory though. Mostly because it was insanely difficult to actually find and catalog a black hole. Well, the absurdity of it all was a turn off to many as well. A “hole” in space? Where does it go? What happens to the material sucked into it? Gravity was and is one of the big mysteries of the cosmos. Gravity is weak. It can be overcome with a tiny magnet. But it is constant. It wins in the end through sheer attrition. It takes a great amount of energy to escape the Earth’s gravitational pull. It extends all the way out past the moon but lessens as you move further away. With a black hole we are talking about an object with a mass thousands or even millions of times greater than the Earth. There was also the argument about whether black holes were actual physical objects or not. A small group of physicists believed strongly that they were but most of the community had already brushed them off as unfounded speculation on Einstein’s equations.
For decades researchers on black holes was relegated to the basement of physics, like a zoologist looking for Bigfoot. But important people still took interest. In 1939, a team of physicists led by Robert Oppenheimer, the father of the atomic bomb, determined that black holes were indeed a possibility. If a star of sufficient mass began to collapse, no known force was available to stop it. In the late 50’s the black hole picture began to morph into what we know today. Schwarzschild’s model was studied relentlessly and a new term, event horizon, was invented for the “flat surface” framing his models. The event horizon is the point of no return. Once you cross into it there is no going back. A black hole’s gravitational pull actually isn’t that strong outside the event horizon. But once across it the pull is tremendous and nothing, not even light, can escape. And this is also where physics starts getting real weird. Imagine for a moment you are in a space shuttle orbiting a black hole. You’re watching a fellow astronaut move toward the event horizon. He’s moving, and moving, and moving, then all of a sudden he stops. Frozen motionless in time.
But the other astronaut is still moving. To them time is still moving along just as it should. This is gravitational time dilation. As you move closer to massive objects, time slows down. As Einstein’s theory shows, space and time are one. So a significant warping of space will result in a like warping of time. The astronaut in the ship will also see his comrade redshifting as he or she approached the event horizon and the visible light reflected from them becomes less and less. Eventually it will become so dim you can no longer see them even though they are there. Then our astronaut friend becomes one with the black hole. But what exactly does that mean? This would be the next big battle in black hole research. Where does everything go and does it just disappear? And do things actually “escape” them?
In the mid 20th century talk began about what a black hole is exactly. It is all still just theory after all. Even though research on them is taken more seriously, there is still a school of physicists who insist they don’t even exist. And even if they did it would be under exotic conditions they had yet to find in the universe. But, the “known universe” was only a few decades old at this time so no one should have been so absolute about something they just discovered. What boosted interest in black holes was the confirmation of the existence of neutron stars when scientists observed a pulsar in 1967. The same theories that led to neutron stars also led to black holes. More great young minds began taking black hole research more seriously and the field increased significantly. It was also around this time that the term ‘black hole’ actually began to be used.
Over the next few decades equations were produced to define and describe the structure of black holes and the concept of the singularity. A singularity is a point where things merge and become one. It was theorized that every black hole contained a singularity at its center. Singularities were, and in some places still are, the most controversial part of black hole physics. Number one, physics was incapable of describing it. In a singularity the laws of physics we understand do not exist. Up is left, right is purple, and the trees sleep with the moonlight. Gravity becomes infinite. Infinite is a tricky word that many mathematicians and physicists dislike. It’s not a real number. You get into the concept of “imaginary numbers” and other voodoo tricks we use to try to grasp what we can’t grasp. Just take a moment to think about infinity. Think about infinite gravity. An endless pressure forever increasing.
Still, theories were produced that proved to be mathematically sound. But science needs observation and it’s currently impossible to observe a singularity. The next big point of contention is what happens to matter drawn into that singularity. Early theories suggested that the information of an object, it’s essential quantum make-up, was lost or destroyed inside the black hole. This caused an uproar in the scientific community. One of the basic tenets of physics is that this cannot happen. You’ve probably heard it simplified in the phrase “matter/energy cannot be created or destroyed”. Matter just becomes energy and vice versa. The conservation theory. All energy in a system is constant. You just can’t up and remove it from the universe. A major supporter of this theory was Stephen Hawking, probably the most famous scientist since Einstein. He believed the information crossing the event horizon was lost to the universe forever and that every black hole was essentially the same regardless of what information it consumed.
With the dawn of quantum mechanics, many of Hawking’s previous theories began to crumble. In quantum mechanics all information stays the same at the quantum level no matter what happens. It’s make up now determines its makeup in the future. But Hawking was suggesting that the radiation patterns in every black hole would be the same and so different quantum makeups would conform into the same type. Quantum mechanics proved this was pretty much impossible. Even inside a black hole. Not only was information not lost, stuff actually “escapes” black holes in the form of radiation and various cosmic rays. Black holes emit jets of gas and energy away from them as they feed, stretching light years into space. Some longer than entire galaxies. In 2004 Hawking was forced to admit he had made an error and gladly accepted the new findings.
By the mid 70’s observational data was beginning to leak in on black holes. Black holes can’t actually be observed. Thus the name. However you can study the area around it to see signs of its existence. Most notably it’s effect on the gravitational fields of nearby objects. Scientists began observing gravitational abnormalities in various areas of space and cold only come to one conclusion. An object of incredible density was nearby. But they couldn’t see it. Still it was the most reasonable conclusion. Nothing they had discovered could even come close to producing the effects seen. This research led to another shocking discovery in the last decade or so. It seems that almost every galaxy in the universe, especially ones like our own, contains a supermassive black hole at its center. Supermassive black holes are just that. Black holes of an inconceivable size. It is accepted fact that stellar(normal) black holes are created from collapsing stars. But the star that forms a supermassive black hole would have to be so colossal that it seems impossible to think it could even pull its self together let alone sustain the processes necessary to form a black hole. They could have possibly formed when a proto-galaxy collapsed in on itself.
A possibly more believable theory is that they began as stellar black holes long ago and absorbed enough matter over time to reach this titanic size. Or that they were created during the turbulent moments following the Big Bang. No matter the reason they seem to be tied to galaxies in some ways. And just how remains unclear. For the longest time we felt the size of a supermassive black hole and it’s galaxy were tied together. That theory went out the window in December of this year. Scientists discovered two black holes of colossal size. One black hole ten million solar masses in size and the other almost double that. A solar mass is the size of our sun. It’s 20 million times larger than our sun. And they are far too big to be in the galaxies they are in. Or so we had thought. And how do they get there? Scientists believe the galaxy forms around the black hole. As the black hole feeds, the energy it emits pushes the bulk of the galaxy back out of its reach and gives it room to grow. Another discovery was made earlier in March and for the first time scientists caught a black hole feeding.
But we’re still no closer to figuring out exactly what they are. Again, we love observations, and gamma bursts on a satellite just don’t give us enough to paint a clear picture. And everything about the singularity contained within is pure conjecture. As OI said before, many people are not comfortable with the word infinite. So many physicists feel there is a limit to what can be packed into a black hole. So when it reaches its limit does it just “throw up” the excess? But, of course, some physicists think there is no theoretical limit. Because some people think black holes are more than just a collection of densely packed matter. Some theorists believe black holes are actually gateways to other dimensions.
There is science behind this though. Real science. A few decades ago talk of other dimensions was best left to science fiction writers. Now it’s one of the most popular subjects in labs and classrooms around the world. ‘Cause who ever said there were only 3 dimensions? Einstein’s equations produced a lot of things he never thought they would. That any scientist ever thought they would. One of the most interesting and compelling is the possibility of other dimensions.
As I stated before, gravity is a weird thing we are still very much trying to figure out. It’s distribution across the universe seems, uneven. One of the biggest discoveries of the 20th century was Hubble’s discovery of the expanding universe. What we found out decades later is not only is it expanding, the expansion is speeding up. An incredibly surprising revelation considering that, given the amount of observable matter in the universe, it should be physically impossible for it to still be gaining speed. It’s like something we can’t see is accelerating the expansion of the universe. One possibility thrown out early on was “dark energy/matter”. Another clever trick to explain what we don’t understand. According to physicists about 90% of the matter that make sup the universe is missing or can’t be seen. Hence the term, dark matter. A way to explain the expansion and why stars at the edges of galaxies move as fast as those further in. Another thing that just shouldn’t happen.
But some physicists are contesting the notion of dark matter. They believe the extra gravity is coming from other dimensions. Some believe there is a whole universe right next to ours, and it exerts its gravity on us and we on them. Maybe the reason gravity isn’t as strong as other universal forces is because some of it is lost to these other dimensions. And black holes are just gravity wells connecting two universes. But how messed up is it if every black hole contains a universe? Including ours. And gravity just flows freely between them all. Connects us to them. Plans are already underway to test these theories. I look forward to the results.
The following is highly theoretical and extremely implausible. But, not impossible.
It is morning(eastern time), February 12, 2012. All around the globe people are beginning and ending their days. Not knowing this will be the last one ever on Earth. At 10:00 a.m. EST, a huge deviation in the orbit of the moon is detected. Almost as if something is pulling it off course, closer to the Earth. Confident it’s a calibration era, machines are reset and the test is run again. The results are the same only now the orbit is further degraded. Hours later reports come in all around the globe of huge seismic activity. As though every plate on earth were going off simultaneously. And some creepy data suggesting that mountains are shrinking. Falling back into the earth.
Then the sinkholes begin. Enormous chunks of earth, some the size of a state, begin falling away. Officials are at a loss to explain what is going on. Then 7 hours after the initial reading on the moon, the news come in. And it is grim. Experiments at the large hadron collider have produced an until now unknown side effect. A black hole. It has sunk to the center of the Earth and is now eating it away piece by piece. In less than 24 hours there will be very little left of the planet that is once our home. The black hole’s modest size has only increased its hunger and it devours the earth at a rate far greater than some of its larger brethren.
Panic and chaos erupts across the globe as everyone realizes this is it. Some find peace with what is happening while most lose their fucking minds. Coastal areas are destroyed as the steadily approaching moon wreaks havoc on the oceans. Oceans that soon fall away to be eaten by the beast at the center of our globe. As the earth begins to fracture and distort the core ceases to produce a magnetic field. Remaining plant and animal life slowly begin to suffocate as the Earth’s atmosphere is pulled away. 15 hours after the initial discovery there is nothign left living on Earth. And the planet is barley recognizable. Looking almost like a dented tin can it continues to fall in on itself toward the awaiting black hole. Any human who may have fallen toward the black hole Earth on would have experienced something freaky. If they go in feet first that is where they will first feel it. And it won’t be all at once. The black hole will exert a constant even pull that stretches the very molecular fiber of your body as you are unraveled like an old sweater. A spaghetti string slurped up by the black hole. Not a bad way to go. Painful? Oh I’d have to think it’s unbearable. But its gotta look pretty cool.
20 hours in and the Earth is gone. Replaced by the cosmic entity that devoured it. But it’s not over. Soon the moon reaches the event horizon and joins us in the singularity. All becomes one at the center of the black hole. No trace that the Earth ever existed. That humanity was ever here. And then it turns to look at Mars.
So I hope you enjoyed this highly unscientific discussion of a strange scientific phenomena. And don’t worry, the odds of the LHC producing a sustainable black hole are so tiny they aren’t even worth considering. And if one got anywhere near us, cosmically speaking, we’d know well ahead of time. Which would just wind up being torture since there isn’t anything we can do about it. But, maybe in the thousand years it takes to get here, we can figure out how to get the fuck outta here.