The Rift: Hard Science Fiction

by Brandon Q Morris

  From now on, the universe’s development progresses considerably more slowly. The remaining neutrons are rescued when, approximately two to three minutes after T-zero, deuterium and finally helium nuclei are formed. Here, the strong nuclear force protects the neutrons from destruction. The universe grows and grows all the while, continuing to further cool down.

  After approximately 17 minutes, it has become too cold to support any more nuclear fusion. At this point, all the still-available neutrons are then bound into atomic nuclei. Approximately three-fourths of the nuclei are hydrogen nuclei, the rest helium—heavier nuclei can be found only in traces.

  As it grows colder and colder, electrons also bind electromagnetically to positively charged atomic nuclei. They are constantly being thrown out of their orbits, however, by photons from the still boiling proto-soup. The universe, whose composition is dominated by photons, would look like a glowing fog to outside observers at this time.

  That doesn’t change for a relatively long time. Starting around 70,000 years after the Big Bang, the ratio of atomic mass and radiation is 1:1. According to the so-called Lambda-CDM model, the universe is now dominated by dark matter, whose nature can only be described by theories at the time of this writing. It has the result, however, that inhomogeneous areas left over from the inflation phase contract even more strongly, a prerequisite for the later formation of stars.

  Continued development progresses at a moderate pace. Stars ignite and go out again, galaxies coalesce and form huge clusters, black holes are formed. All of this is getting us a little off our topic. But this progression leads us back to a state that makes us aware of nothingness. Nothingness—in this case, the opposite of all matter—is right here amongst us. You yourself are mostly made up of it! The almost 1028 atoms that make up a human body consist of up to 99.9 percent empty space. Imagine a pea in the middle of a football field in a football stadium. That pea is the atomic nucleus. The electrons in the so-called atomic shells are ten-thousand times smaller and dancing around somewhere up in the nosebleed sections. If all the material constituents of your body could be packed together without these giant spaces, which kind of happens in neutron stars, your whole solid body would have a volume of around 70 milliliters, approximately the size of a small apple. The rest, as was said, is nothing.

  A vacuum is not empty

  But this is a different form of nothingness. Physicists call it a vacuum. Earlier, it was thought that vacuums were empty, but today it is clear that they are anything but empty. Why that is can be explained by quantum physics, which is concerned with the conditions of the world at very small scales. It’s a theory that was proven long ago. Its principles underlie the functioning of electronics and other modern technology.

  Here, quantum physics describes not only individual particles, but also systems made of many particles, electromagnetic fields—and, as scientists hope, also gravity. This shows that nothing is what it seems—and even empty space is filled with particles.

  Sometimes, the universe seems to act like a teenager. As long as we’re watching, everything remains quiet and calm—but as soon as the vacuum thinks it’s alone, it suddenly fills with particles from nowhere. And it does this even though we’ve all learned in school about the law of conservation of energy, which is supposed to prohibit this exact kind of behavior, right?

  The source of this child-like behavior is the Heisenberg Uncertainty principle, in particular, how it interconnects energy and time. The more precisely we want to measure energy, the less we know about the exact time of the measurement. This can be explained well using an analogy. You perhaps remember—at least I hope so—from school that the energy of an oscillation depends on its frequency, for example, how fast a pendulum swings. Imagine a clock pendulum moving slowly. My grandmother had such an old-fashioned pendulum clock in her living room.

  The pendulum needs perhaps two seconds for one cycle. If I watch it for a period of nine seconds, that is, a short time period, I can count four whole cycles. The error, or deviation, is equal to one-half cycle divided by four, that is, one-eighth, 12.5 percent. If I watch for a much longer time period, however, maybe 99 seconds, the error is still one-half cycle, but over a much larger base—percentage-wise only around one percent. By means of a longer observation period, I can determine the energy of the pendulum motion more exactly—but at the cost of the accuracy of the time measurement. This uncertainty principle is not due to any lack of ability of a human observer, but instead, it is a principle property of our universe.

  This also applies to a vacuum. The law of conservation of energy does prohibit the creation of something from nothing. But if this something disappears quickly enough, it was basically never there. If we measure the energy content of a certain piece of space over a long time period, we see that the vacuum is empty. But if we look at it for only a very short time period, due to the uncertainty principle, we can no longer be sure that nothing is actually there. Particles might have formed completely legally and then disappeared again. And quantum physics says that every state that can occur also does occur. In practice there is a big problem with this statement, but more on that later.

  How large can these virtual particles be, and what properties do they have to have? Initially, they are forced to adhere to other laws of conservation, for example, the law of conservation of charge. If a negatively-charged electron is born out of nothing, then it is also always paired with a positively-charged positron as its antiparticle.

  If the two meet, they annihilate each other—the result is two photons that balance out the energy deficit formed by the creation of the virtual particles in the universe. If one of the two falls into a black hole, the other becomes visible as so-called Hawking radiation that you learned about in the novel.

  How long these virtual particles can exist is determined by their energy. From this, we can also use Einstein’s famous equation E = mc2—where c is the speed of light and equals approximately 300,000 km/s—to also calculate the mass. The combination of electron and positron, for example, lasts at most 10-21 seconds, that is, one billionth of a trillionth of a second. In this time period, light covers a distance that corresponds to the size of an average atom. For a likely chance to see the creation of a proton and an antiproton, the observer needs to watch for only 10-24 seconds.

  Practical problems can scarcely be solved in this way, however, no matter what certain trends like “asking the universe” might try to tell you. Let’s assume you once again forgot to buy milk—if your partner wanted to use a virtual, one-kilogram milk carton produced by the universe from nothing, they would only have 10-52 seconds to pour milk from it before it disappeared again. The smallest unit of time, however, is the Planck time, which lasts about 5x10-44 seconds. Below that, time loses any meaning. The largest possible mass of a virtual particle is around one-hundredth of a milligram—that sounds tiny, but it still corresponds to the mass of around 10 billion viruses.

  Up to now it has not been possible to detect virtual particles directly. What should be detectable, however, are their interactions with the rest of the universe. If the vacuum of space is filled with constantly reappearing and disappearing particles, that must have some effect on its properties. Some scientists think that these so-called quantum fluctuations are the source of dark energy that is responsible for the accelerating expansion of the universe. That would be an elegant explanation that wouldn’t require any new exotic theories, if we can think of quantum physics as normal.

  However, there is a small, no, a huge problem. Based on the known Planck constants, physicist John Wheeler calculated that the universe must have an energy density of 1094 grams per cubic centimeter. A cube with an edge length of one centimeter cut from space would consequently weigh 10 billion billion billion billion billion billion billion kilograms. Practical observations, however, prove that the density of this theoretical cube is more than a little bit smaller. A cubic centimeter of steak weighs a few grams, and empty space is significantly lighte
r—on average, the value, according to the measurements of physicists, is around 120 orders of magnitude less.

  Can this calculation be rationalized away? Not with today’s possibilities of quantum physics. In the future, scientists hope to somehow be able to renormalize the calculated value of vacuum energy, in order to be able to reconcile it with reality. Renormalizing means, in plain language, that scientists want to find a physically meaningful number somewhere that can be used to make the ridiculous number match reality.

  There are also other observations, however, that support the existence of quantum fluctuations. Stephen Hawking used vacuum energy, for example, to explain the behavior of black holes. These have a so-called event horizon that extends around the object like a spherical shell. Anything that passes beyond this shell, or comes closer than its radius, is lost forever to normal space—the enormous gravitational force of the black hole lets nothing escape. Therefore, these objects must actually be enormously stable and show only one trend: growth.

  Hawking then used quantum fluctuations to postulate a kind of evaporation process for black holes. Namely, if a particle-antiparticle pair is created in the vicinity of the event horizon, it can happen that one of the pairs falls into the black hole, while the other pair barely escapes. The virtual particle becomes a real particle. The energy that is needed for this is taken from the black hole, so that with time the black hole loses mass and shrinks. According to Hawking, the smaller the black hole, the quicker this happens. The so-called Hawking radiation has not yet been able to be detected. That’s because, among other things, it is relatively weak. Primarily, however, it is greater the smaller the black hole is, and astronomers have not yet been able to observe such mini black holes.

  The fact that vacuum energy actually exists is shown by the ‘Casimir effect,’ which was confirmed experimentally for the first time in 1958. It was predicted by the Dutch physicist Hendrik Casimir in 1948. From quantum theory, it follows that, when two parallel, electrically conductive plates are placed in a vacuum, a force acts on these plates, pressing them together. The two plates must be very close together—for the effect to be measured, they must be spaced only a few nanometers apart. The force is created because only those virtual particles, whose wavelength matches the spacing of the plates, can be created in the intermediate space—the spacing must be a whole number multiple of the particle wavelength. Outside of the plates, however, this restriction doesn’t exist. Thus, the virtual particles create a pressure difference between the space separating the plates and the space outside the plates, which pushes the plates together. At a spacing of 11 nanometers, the pressure is at least 100 kilopascals.

  The Russian physicist Evgeny Lifshitz extended Casimir’s calculations in the 1950s to more general cases. He was able to show that the Casimir force did not only attract but could also repel. That depends primarily on the properties of the material. This prediction was verified experimentally in 2009. This could be used, scientists hope, to be able to make objects levitate without any friction.

  An extension of this concept is the dynamic Casimir effect. If the two plates of the classic Casimir effect are moved very, very quickly toward each other, it should be possible to generate real photons. Whether this actually works has not yet been proven. The now-discontinued NASA program ‘Breakthrough Propulsion Physics Project’ studied the dynamic Casimir effect for its suitability as a propulsion system for a spaceship. It was hoped that the recoil from the generated photons would be able to drive the ship through space.

  The effect, however, appears to be much too small. The physicist Steve Lamoreaux, who has studied the Casimir effect in detail and published articles on this topic, sweeps away any hope of it—anyone who burns gasoline obtains a better energy yield than with the Casimir effect. This might even have its practical significance in enabling chemical bonds in the first place, according to Lamoreaux.

  The claims of some esotericists to be able to obtain energy from nothing using the Casimir effect are also, by the way, nonsense. As explained before, the Casimir effect does not violate the law of conservation of energy. Such a violation would be necessary to build a perpetual motion machine.

  The false vacuum

  Another interesting term that you might encounter when dealing with nothingness is that of the false vacuum. Shortly after the Big Bang, in the epoch of inflation, the universe expanded very quickly. It might be possible that this inflation happened because the vacuum transitioned at that time from an excited state into its ground state, like a pendulum swinging back from its deflected state to the center.

  At first, that seems like a nice explanation for this puzzling inflation phase. But it would also produce a new danger. Perhaps space has temporarily stopped halfway and what we consider a vacuum is not really the ground state of empty space, but another excited state, a so-called false vacuum. The pendulum has basically stopped for a short period on its way back down. In this case, it would be possible for the universe to suddenly resume its inflation that had stopped at that time—the pendulum completes its swinging motion. The false vacuum would become a true vacuum, and the universe as we know it would cease to exist.

  Such an implosion would propagate through space at the speed of light. Perhaps it has even already happened, and it just hasn’t reached us yet. Scientists have calculated that we would receive a warning time of maybe three minutes if this emergency occurred.

  So, dear reader, finish the book first and you can eat later. Recently there was even the fear that humans could accidentally trigger this vacuum collapse, perhaps in particle accelerators. But it can be easily shown that nature has much better particle accelerators than we’ll be able to build in the foreseeable future. If the vacuum collapse was going to be triggered by something like that, it would have happened a long time ago.

  But perhaps I can allay your fears. As of the time of this writing, there is no evidence that we are living in a false vacuum.

  What role does the rift play in all this?

  As the idea for this book, the most fitting physical origin for the rift would be the 11-dimensional space of the multiverse. If you follow the ideas of string theory and quantum theory, it would be possible for there to be uncountable—but not infinite—four-dimensional universes like ours on an 11-dimensional matrix. Whatever disappeared in the rift would be erased or reappear in one of the numerous other universes.

  This basic matrix structure of the multiverse wouldn’t have to obey the physical laws that are valid in one of its universes. It would have its own laws that we don’t necessarily know yet. In this book, I claim that at least the relationship of cause and effect would have to be maintained. But nobody can say whether that’s true. It seems logical to me, but perhaps this logic only applies in our universe, and total chaos prevails everywhere else. So, dear reader, if the rift does appear in our sky someday, I would advise you to stay here in this universe. It’s the one we know best and continue to learn more about all the time.

  Tip: If you register at hard-sf.com/subscribe, you will receive timely updates of new HardSF publications. You will also receive the illustrated PDF version of this tour, which contains a number of impressive images.

  Glossary of Acronyms

  IAC—Instituto de Astrofísica de Canarias (Institute of Astrophysics of the Canary Islands)

  JPL—Jet Propulsion Laboratory

  LED—Light-Emitting Diode

  NASA—National Aeronautics and Space Administration

  OGS2—Optical Ground Station 2 (telescope)

  TCS—Telescopio Carlos Sánchez

  Metric to English Conversions

  It is assumed that by the time the events of this novel take place, the United States will have joined the rest of the world and will be using the International System of Units, the modern form of the metric system.

  Length:

  centimeter = 0.39 inches

  meter = 1.09 yards, or 3.28 feet

  kilometer = 1093.61 yards, or 0.62 miles />
  Area:

  square centimeter = 0.16 square inches

  square meter = 1.20 square yards

  square kilometer = 0.39 square miles

  Weight:

  gram = 0.04 ounces

  kilogram = 35.27 ounces, or 2.20 pounds

  Volume:

  liter = 1.06 quarts, or 0.26 gallons

  cubic meter = 35.31 cubic feet, or 1.31 cubic yards

  Temperature:

  To convert Celsius to Fahrenheit, multiply by 1.8 and then add 32

  To convert Kelvin to Celsius, subtract 273.15

  Excerpt: Proxima Rising

  January 1 of Year 1

  My name is Dimitri Marchenko. I am on board Messenger, mankind’s first interstellar spaceship. The ship moves through the vacuum of space at one fifth the speed of light, powered by an enormous amount of energy, with no engine and no need for one.

  I woke today according to plan at 0 hours 0 minutes 0 seconds. All systems of Messenger are functioning in the intended ranges. The star tracker, which orients itself based on the position of the stars nearest to us, reports the flight is going according to plan. The solar system in which I was born is located 28 trillion kilometers from our current position. The light of my home star, the sun, takes three years to cover this distance. But before the solar rays reach us, we will have covered yet another fifth of a light year.

  Currently, Messenger has a length of about ten centimeters, and it looks like an extremely thin nail. At the tip, which points toward the goal of the journey, the diameter is only a few micrometers. This lowers the risk of being hit by a dust particle from the interstellar medium, which would endanger the mission—at least right now, although this will soon change.