A type V civilization is able to harness all the power available from the observable universe. It might not be possible for us to detect the existence of such a civilization because we are in the universe from which they are drawing energy. We could only perceive their energy usage as laws of physics. Their power usage is projected at 2 x 1049 watts.7 These would be the Gallifreyans of Doctor Who.
A type VI civilization is able to harness all the power available from multiple universes. This type of civilization would have learned how to alter the laws of physics that apply to different universes. As a bonus, type VI can pack up and move when their universe dies. The death of a universe is the subject of chapter 21. Just for now understand this: it happens.
The power projection for a type VI civilization trends toward infinity. In fiction, I like writing about type VI civilizations when I can. In my short story “Chronology,” published in M-Brane SF, I had a few lost citizens from a type VI civilization interact with us type 0 types. Mayhem ensued.
A type VII civilization is able to create a universe and then harness the power of each universe they create. These civilizations must remain outside the universes they create. This amounts to deity status. This might appear in fiction as mythology.
In the bonus materials for this chapter, I offer an alternative classification of civilizations. Instead of power usage, it considers size. As always in physics, size matters.
ARE THERE QUANTUM ENERGY SOURCES?
Yes, and they are based on two quantum phenomena that are exploited a lot in science fiction: virtual particles and zero-point energy. And guess what? They both owe their existence to our old friend from chapter 2, the Heisenberg uncertainty principle.
Let's make quantum mechanics weirder by bringing energy into our discussion. Because it is a function of wavelengths (the cause of all things fuzzy), its measurement has uncertainties. Like momentum and position, these uncertainties can't be reduced to zero simultaneously. These uncertainties give rise to virtual particles and zero-point energy, both of which have been used liberally in science fiction techno speak for energy.
Virtual particles are little somethings that are allowed to arise from nothing…as long as they promise to return back to nothing after a duration too quick to be observed.8 These virtual particles permeate all of space, doing some very helpful things such as regulating particle decay and mediating the exchange of forces between particles.9
For example, when two negatively charged electrons repulse each other, they are exchanging virtual photons. These virtual particles are little messages saying, “Hey, you! Back off!” Because these virtual photons exist only for a short time, they can't travel very far, unlike lower-energy photons (let there be light).
This explains why the electric force is stronger at short distances. In fact, all the basic forces described in the first interlude diminish with distance for this reason. The caveat is that, although gravity also diminishes with distance, physicists have yet to reconcile this force with quantum mechanics.
Space is not as empty as you might think. Nature abhors a vacuum, so space seethes with virtual particles winking in and out of existence. Thanks to pesky particles popping up throughout the universe, action occurs at every point in space and time. Everything, everywhere, oscillates. Virtual particles are the quantum white noise of the cosmos. The energy from all that Jell-O-like quivering is called zero-point energy, which, by the way, is always nonzero.10
IS THERE EVIDENCE OF VIRTUAL PARTICLES?
The best-known experimental evidence of zero-point energy is called the Casimir effect. In 1948, Dutch physicist Hendrik Casimir predicted that a dense metal plate in a vacuum (the unlikeliest place to find energy) would be bombarded on both sides by virtual particles.11 If you put two such plates very, very close, there won't be enough space between them for larger virtual particles to pop into existence.
Because the vacuum pressure is now less between the plates than on their outer surfaces, they experience a net force pushing them together. The effect was successfully tested in 1997 by Steve K. Lamoreaux of the Los Alamos National Laboratory.12
Another name for zero-point energy you might hear about in either science magazines or in science fiction is vacuum energy.
VIRTUAL PARTICLES AND ZERO-POINT ENERGY IN SCIENCE FICTION
Virtual particles are everywhere, and if they could be harnessed, imagine how advantageous that would be for colonization, war, and all the other ways we like to utilize cool things we discover.
Just as a caveat, remember that zero-point energy is already the lowest possible energy of a system. You have to be a savvy science fiction creator to come up with a plausible way of collecting it without using up more energy than you get out. According to physicists, extracting this energy is unlikely. Not so for the creative fiction writer!
A decrease in zero-point energy is known as negative energy. If a civilization could control this energy, a reduction in zero-point energy in front of a spacecraft would reduce resistance (negative energy would pull) and rapidly accelerate a spacecraft to near the speed of light. If this is a full type III civilization then perhaps with the aid of tachyon particles, the ship's acceleration might exceed the speed of light (temporarily exiting conventional space to do so).
Tachyons are hypothetical particles believed to have never traveled slower than the speed of light. The speed limit rule only applies to mass that started out slower than the speed of light. What is often forgotten is that in special relativity, the rule is symmetrical: anything traveling faster than the speed of light cannot travel slower than the speed of light.
PARTING COMMENTS
A lot of the time, science fiction provides unlimited energy for whatever civilization it describes. We know better. Fuel for energy is a limited resource, even when mining thermal energy from a black hole. Even capturing unlimited zero-point energy consumes limited resources.
The Kardashev scale is a ranking system of societies based on power usage. Do they rely solely on planetary resources? Do they use solar power? Do they mine black holes? How about batteries powered by virtual particles? Zero-point energy? No matter what, the Kardashev system has a ranking for them.
CHAPTER 6 BONUS MATERIALS
BONUS 1: AN INWARD LOOK: AN ALTERNATIVE CLASSIFICATION OF CIVILIZATIONS
Instead of energy usage, the Barrow scale classifies technological civilizations by their ability for inward manipulation, the control of smaller and smaller entities.13 A lot of our -ologies, like biotechnology, nanotechnology, and even information technology, come from our ability to manipulate at small scales. Barrow believed there is more to explore in small scales than large ones. Plus there is no speed of light limit. The Barrow scale lays out the following:14
A type I-minus is capable of manipulating objects larger than the scale of themselves by mining, building structures, and joining and breaking solids.
A type II-minus is capable of manipulating genes and altering the development of living things, transplanting or replacing parts of themselves, and reading and engineering their genetic code.
A type III-minus is capable of manipulating molecules and molecular bonds to create new materials.
A type IV-minus is capable of manipulating individual atoms, creating nanotechnologies on the atomic scale, and creating complex forms of artificial life.
Our civilization is transitioning between Type III minus and Type IV minus.
A type V-minus is capable of manipulating the atomic nucleus and engineering the nucleons.
A type VI-minus is capable of manipulating the most elementary particles of matter (quarks and leptons) to create organized complexity among populations of elementary particles.
A type Omega-minus is capable of manipulating the basic structure of space and time.
BONUS 2: COMPARING ENERGY SOURCES
In comparing various fuel sources, the energy returned on energy invested (EROEI) ratio is sometimes used. It shows how much energy is released relative to the
amount of energy needed to get at the resource.
Resources with the highest EROEI are hydroelectric, coal, and oil. Although coal and oil originally held very high EROEI, the value is declining—it costs more and more to find and dig up these fossil fuels. The EROEI for finding oil went from 1,200 in 1919 to 5 in 2007.15 This means we get five times more energy from fuel than the energy expended to find it. That is still a lot, but it is declining.
The problem with the EROEI metric is that it does not explicitly account for environmental costs. These costs necessarily increase as the difficulty of acquiring fossil fuels increases. Because of falling EROEI, alternatives such as wind, natural gas, solar, and nuclear are being considered more and more.
The sun provides clean energy, but how do we exploit it? We currently use photovoltaic panels made of silicon, but solar panel efficiency is nothing to write home about. The record in 2014 was 46 percent efficiency.16 The typical solar panel is about 20 percent efficient.17
Besides panels, the sun's energy can be captured by letting plants do the work for us. Biofuels such as ethanol (from corn) is made from seeds. With this method, however, the hazard is that farmers will plant seeds for fuel instead of food. This can be especially problematic in developing countries.
It's a pity that nobody has found an exploding black hole. If they had, I would have won a Nobel Prize.
—Stephen Hawking
Brace yourself. Parts of this chapter will give you flashbacks to all the general relativity goodness you read about in chapter 1. Einstein's equations of general relativity demonstrate the positive relationship between mass and gravity. The more massive an object, the more spacetime dips around it. The bigger the dip, the greater the gravitational field. A black hole is the mother of all dips.
Black holes come in different sizes—they can be as small as an atom with the mass of a mountain, or enormous with the mass of over one million suns (called a supermassive black hole).1 It is believed that every large galaxy contains one of these supermassive black holes at its center. As discussed in chapter 1, the supermassive one at the center of our galaxy, the Milky Way, is called Sagittarius A*. The size of central black holes might play a role in how galaxies form.
HOW DO BLACK HOLES ARISE?
No definitive answer for this exists, but we do have one strong possibility based on a star's lifecycle. The power of a star comes from the nuclear reaction taking place in its core. The reaction causes outward pressure that is balanced by the weight of gravity from the star's mass. The nuclear power pushes out while gravity pushes in.
As the star gets older, it changes its process from combining hydrogen into helium to fusing helium into carbon. Then it changes carbon into oxygen, and then oxygen into silicon, and finally silicon into iron—a cosmic dead end. Iron is a stable element, so the energy output from fusion is no longer possible. Without fusion producing outward pressure to challenge gravity, the outer layers of hydrogen, helium, carbon, and silicon that were previously created burn around the iron core.
At this point, the size of the star plays a big role in its destiny. Stars below what is called the Chandrasekhar limit, roughly 1.4 times the mass of our sun, will collapse into a white dwarf.2 Their cores stopped fusing at carbon because they don't have enough mass to generate the gravitational pressure necessary to overcome the electromagnetic repulsion between protons. This is why there is no fusion of carbon into the heavier elements.
With bigger stars, those above the Chandrasekhar limit, the iron core continues to build up as these successive layers burn through their remaining fuel and then crash down on the core. The core is compressed further until it completely loses the battle with gravity and collapses, causing a colossal explosion. Materials, including the heavier elements beyond iron, are blasted outward. This is called going supernova.
If the original star had a lot of mass, say ten times that of our sun, then more fireworks arise after the supernova explosion. The core compresses further, ramming atoms against each other and transforming protons into neutrons until—voila!—we have a neutron star.
If the star was over twenty-five times the size of our sun, then the neutrons can't prevent the gravitational pressure from collapsing the star further. The star will occupy a smaller and smaller portion of space while maintaining its mass until it becomes an infinitely small, dense point known as a gravitational singularity—the heart of a black hole.
This is where the known laws of physics break down. A gravitational singularity presses so deeply into the fabric of spacetime that it creates a gravity well steep enough that the escape velocity is greater than the speed of light. No escaping light means it goes dark.
Fig. 7.1. Illustration of a singularity. (Modified from image by iStock Photo/Yurkoman.)
Named for Karl Schwarzschild, who solved Einstein's general relativity equation for a star's gravitational field, the Schwarzschild radius defines the radius of a given mass at the point at which no force could stop it from continuing its collapse to a singularity. When an object is compressed smaller than its Schwarzschild radius, it becomes a black hole.
The estimated Schwarzschild radius of the earth is nine millimeters. If the earth could be compressed down to that size, it would collapse into a black hole.3 Our sun would have to be compressed to a radius of three kilometers before it turned dark and holey. Don't worry, this won't happen to either the earth or the sun. Probably.
WHY DOES ESCAPE VELOCITY MATTER?
Escape velocity is an important concept if you plan to launch a rocket from Earth or anything else with significant mass. If you throw a ball up into the air with all your strength, even if you have an arm strength of NFL quarterback Aaron Rodgers, it will slow, stop, and fall back to Earth. Gravity works against your best efforts. To escape Earth's orbit, you need to heave the ball at escape velocity, the minimum velocity needed to escape a massive body.
It shouldn't come as a surprise that the more gravity (mass) a planet has, the greater the escape velocity becomes. You would need to toss that ball at about eleven kilometers per second (km/sec) or twenty-five thousand miles per hour (mph) to escape Earth. Now, if you are on Jupiter, you would need to hurl the ball at 59.5 km/sec (133,018 mph).4 The escape velocity of the sun is 618 km/sec (1,381,601 mph). The good news is that if you plan to chuck a rock off the moon, you need to accelerate it to a scant 2.4 km/sec (5,369 mph).
The escape velocity of a black hole is where things get interesting, at least for a cosmologist. Maybe not so much for the engineer and pilot aboard a starship, however. The escape velocity is greater than the speed of light (300,000 km/sec).5 If your starship flew somewhat near a black hole then its path will begin to curve toward it. A good pilot can probably avoid it.
If you pass too close then no pilot can prevent your ship from falling in. The critical distance between escaping and falling in is called the event horizon. Think of an event horizon as a fence with a big Keep Away sign hammered into it. Personally, I would do what it says.
HOW DO BLACK HOLES RELATE TO SPAGHETTI?
If you do decide to ignore the warning and trespass on the event horizon, I hope you like pasta. This is not an adventure I would recommend. However, if you insist, the first thing you do is put on the latest spacesuit and disembark from your starship. There is no reason to endanger the rest of the crew.
In space, you orientate yourself toward the black hole feetfirst so that you can watch your approach to the event horizon. According to general relativity, as you enter, you feel a strong gravitational pull on your feet. This pull will get stronger and stronger relative to the amount of gravity pulling down on your head. You begin to stretch. This continues until you are stretched into something resembling a skinny noodle, referred to us humans as spaghetti. Scientists call this effect spaghettification, and I bet it isn't fun.
If you prefer to consider this thought experiment from a quantum point of view, then you will simply burn up when you hit the event horizon. An event horizon that follows quantum
rules will be highly energetic. I bet you still wouldn't have fun.
DO BLACK HOLES LAST FOREVER?
No, black holes do not last forever. They emit small amounts of radiation and evaporate away. In 1974, Stephen Hawking showed that black holes evaporate via Hawking radiation.6 He discovered something with his name. What were the odds of that?
Anyway, Hawking radiation arises when pairs of negative and positive virtual particles pop into existence near an event horizon. Normally they would annihilate each other, but because of their proximity to the black hole, they are unable to complete their marriage contract and are forced to part ways. One of them gets caught in the event horizon while the other escapes into space.
The particle that falls into the black hole has negative energy, thereby reducing the mass of the black hole, thus creating evaporation. Recall that, according to general relativity, mass and energy are equivalent. When the black hole sucks down a negative energy particle, it is sucking in negative mass. And as with most things in physics, size matters. The smaller the black hole, the quicker it loses mass. As it shrinks, its temperature will rise until it explodes. Or it might simply fade away, depending on your theory of choice.
On a technical note, the above is just a mental visualization of math. As the potential energy evaporates from the black hole (positive energy) it must be offset by the shrinking potential energy stored in the black hole to conserve the overall amount of energy in the universe. This subtraction is why it is called negative energy. It is a math thing.
An evaporating black hole could be a good thing. It is shedding energy back into the universe, so in principle it could be harnessed as an energy source. Of course, a much higher-level civilization, probably a type III, would be required to mine all the thermal (hot) energy. How could that happen, you'd like to know?
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