Mars Nation 2 continues the story of the last representatives of Earth, who have found asylum on our neighboring planet, hoping to build a future in this alien world.
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Mars Nation 3
Does the secret of Mars lurk beneath the surface of its south pole? A lone astronaut searches for clues about the earlier inhabitants of the Red Planet. Meanwhile, Rick Summers, having assumed the office of Mars City's Administrator by deceit and manipulation, tries to unify the people on Mars with the weapons under his control. Then Summers stumbles upon so powerful an evil that even he has no means to overcome it.
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A Guided Tour of the Universe
Introducing The Universe
Allow me to introduce the universe, from the Latin ‘universus’ meaning ‘whole.’ Also known as the cosmos, space, outer space. Born 13.8 billion years ago. Today, around 92 billion light-years across—but probably infinite and topologically flat—and weighing 1053 kilograms—a 1 with 53 zeroes—but still not fully grown.
On the run: Because the universe is continuously growing, all its components appear to be moving away from us. That means that the further an object is from Earth, the faster it’s fleeing. At a distance of one megaparsec—more than three million light-years—this Hubble speed amounts to 72 kilometers per second.
Cold: The cosmic background radiation contributes to its temperature of nearly minus 270 degrees Celsius—which is not quite absolute zero (minus 273.15).
Empty: Indeed, our night sky is richly populated. But that’s deceptive, because fundamentally speaking the universe consists of empty space. If you built a huge house, say 30 kilometers cubed, you’d only need to place a single grain of sand inside it to represent a similar average density. Every cubic meter of the cosmos contains an average of 0.3 protons.
Electrically neutral: There are, it seems, exactly as many carriers of positive charges as negative ones.
Low levels of antimatter: Proof that the laws of nature for particles and antiparticles are not symmetrical.
Without a center: Our Milky Way Galaxy has a core, but the universe as a whole has no center.
Populated by 100 billion galaxies in which 130 sextillion stars and roughly the same number of planets have come together. There are more stars in the universe than there are grains of sand on all of Earth’s beaches.
Known types of matter make up 4 percent of the universe, including approximately 1.57 x 1079 protons and electrons and a billion times more photons. Add to that 23 percent dark matter, and 73 percent dark energy. Between 90 and 99 percent of the neutral atoms of the universe are hydrogen atoms.
Home to black holes, giant stars, pulsars, quasars, galaxy clusters, nebulae—but also planets with their moons and life forms such as humans.
Where did the universe come from? What were the circumstances of its birth? Which fascinating processes have played out in it since? When and how will it die?
What scientists know about all of this has changed dramatically in recent years. Allow yourself to be carried away to a world beyond all imagination—the cosmos in which you live.
The time before time
The existence of everything might not have started at Zero Hour. A biography normally begins with birth—for the universe, the widely accepted theory of the Big Bang. But sometimes it’s worth looking at the parents, or at least generally at the genealogy of the object of the biography.
And that’s not to imply a creator of the universe. In The Grand Design, Stephen Hawking demonstrated very vividly why the universe didn’t require a creator. That doesn’t stop anyone from believing in a God. But from a scientific point of view, the presence of any structure that isn’t necessary for the laws of physics, or indeed the world to function, is irrelevant. In any case, the concept of a creator is not an object of scientific research, but one of human belief.
It is nevertheless worthwhile to search for predecessors, ancestors, parents of the universe as we know it, because... the Big Bang has a small problem. Literally, it must have played out in the tiniest of spaces. The closer you come to it, the more densely the total energy of the cosmos must have been compressed in a unit of space, until everything was concentrated in one point of infinite density. This state is incompatible with the Theory of General Relativity. This is where Einstein’s work falls short. Physicists therefore view the Big Bang in combination with a theory of the macro and the micro—the universe and the quantum world.
A world made of strings
For this we have two candidates. One is string theory, according to which space is made up of tiny objects something like piano strings. These ‘strings’ are one-dimensional, and they vibrate with a particular frequency that can be assigned an energy. Physicists have now developed this idea into ‘M Theory’ along with other structures, point particles, and especially branes, which can have up to nine dimensions. To get from there to the elementary particles and laws of nature as we know them, you have to ‘wind’—as the scientists call this process—the extra dimensions in a precise way. There are various possibilities for winding the branes and strings, and depending on the one you choose, a different kind of universe arises. There are a possible 10 to the power of 100 different possible universes, an unimaginable number. And yet a large proportion of these universes consist or consisted of the basic structures, the branes, without ever arriving at the formation of elementary particles.
Of course, many of these universes could also exist simultaneously, with the inhabitants of one having no inkling of the living beings that may exist in another. However, according to the scientists who support this theory, if three-dimensional worlds came too close to one another, due to movement through an additional eleventh dimension, they could collide—resulting in the birth of our universe in the Big Bang. What happens after that depends on the subsequent behavior of the colliding branes. If these come close to one another again, a repetitive cycle could be the result.
Loops upon loops
When considering the world before the world, a competing theory, loop quantum gravity, is even more fruitful. According to that theory, the universe only appears to be continuous. Actually, everything, absolutely everything, is quantized, which means everything is divided into small granules, even gravitation. Space is no longer the container of the universe, it’s a part of it, which is itself divided into granules and takes on the form of a net made of lines and knots. The elementary particles then correspond to various types of knots. In between the lines and knots is nothing. Not empty space, but rather nothing at all. The theory of loop quantum gravity draws some seemingly strange conclusions, but it describes certain interesting phenomena better than other theories.
The significance of this theory for the Big Bang was first simulated in 2004 by German physicist Martin Bojowald. The first thing is to abandon the concept of the singularity, because the loop quantum universe has a certain minimum structure size, which it can’t go below. The closer you get to the Big Bang, the less it appears to be an insurmountable barrier. Instead, you reach the minus time with a ‘pop’—a new, different, or precursor universe, in which all directions—including that of time—are reversed. This is not a big problem for physicists, because the laws of nature are conveniently symmetrical. This ‘universe before the universe’ contracted toward the Big Bang.
This theory has revived the once-popular ‘Big Bounce’—the idea that the universe periodically contracts and expands. If the universe contracts a great deal under the influence of gravity, then the quantum loop fabric will eventually rupture space-time—and under the influence of this ‘quantum recoil,’ gravity will turn into a powerfully repulsive force that forces the universe outward again.
Rebirth from nothing
A third mechanism for a cyclically changing universe was suggested in 2011 by English mathematician Roger Penrose. He dedicates himself to the phenomenon of time in his book Cycles of Time. A popular co
ncept of the end of the universe is that at some point all matter turns into energy, into photons moving eternally at the speed of light, for which time therefore stands still—an astronaut flying at the speed of light would not age either. Space would then lose its meaning, because its expansion isn’t measurable when there’s no time. Who could disprove that a billion light-years aren’t just a few centimeters?
It might sound strange, but that’s exactly how the universe looked shortly after the Big Bang. The universe consisted of pure energy for which there was no concept of time. However, only a mathematician would dare to combine such seemingly distant states into one. If its expansion in space is not defined, then the universe that has just perished into eternal energy could also provide the seed of a new Big Bang.
Nothing but theories?
Can any of these theories be proved? So far this has all basically been plausible fiction. But scientists have ideas about how they might trace the legacy of the precursor universe. Because not everything has to perish in the ‘Big Crunch.’ In 2017, Bernard Carr and Alan Coley demonstrated that a specific type of black hole could survive the unfavorable conditions of the Big Bang. Unfortunately, the search for such ancient objects is made difficult by the fact that low-mass black holes could also have arisen during the Big Bang. Their existence was deduced by Stephen Hawking in the 1970s.
These ‘primordial’ black holes have been just as hard to locate as their even older cousins from the precursor universe—the less mass such an object has, the harder it is to find. Even in the Penrose universe there could be remnants of the precursor universe. Its mass wouldn’t necessarily have been completely annihilated. It would have been sufficient for the amount of energy simply to have vastly exceeded it.
The Big Bang
The defining moments of the universe began in darkness. So far scientists haven’t had the theoretical means to probe back to the beginning of the universe—and yet they have some very concrete ideas about it.
Zero Hour
Scientists still don’t know with any certainty what happened at the beginning, about 13.8 billion years ago. The total matter of the universe—today 1053 kilograms—was at this moment located at a single point, a singularity, in which the laws of nature did not yet have any influence. So you have to imagine a kind of infinitely dense primordial soup, consisting of particles that are no longer known today. A force, the primordial force, determined the movement of these particles. The temperature of the primordial soup, if you can even use the term ‘temperature,’ must have been about 1032 degrees. There were neither electrons nor photons, nor was there any light. If there had been an ‘outside,’ an observer wouldn’t even have been able to see what was currently playing out.
This ultra-hot something was under immense pressure, and the cosmos expanded. The length of time this took is calculated based on the known laws of nature. It’s equivalent to Planck time, that is, the time light takes to cover a Planck length. That’s 10-43 or 0.000,000,000,000,000,000,000,000,000,000,000,000,000,000,1 seconds. In any case, at this point in time, ‘time’ didn’t yet exist. The English language is insufficient to accurately convey this paradox.
Physics begins
It’s not until 10-43 seconds after the Big Bang that we can even begin to use physics to try to understand the universe. The tiny drop of matter was still under unbelievable pressure. But it had cooled a little because it had expanded. Then gravity was separated off from the primordial force, counteracting the expansion of the universe by exerting an attractive force.
But gravity was much weaker than the pressure of the Big Bang, so the universe continued to expand at a rapid pace. Because this expansion reduced the average energy of the primordial soup, it contained fewer and fewer of those exotic particles that existed at the beginning. After 10-38 seconds had passed, the powerful nuclear force and the electroweak force were also separated from the primordial force.
The universe—a soccer ball
Next followed the so-called inflation phase, in which the universe expanded by a factor between 1030 and 1050. This means that if it had been the size of a proton, it expanded to the size of a soccer ball. This inflation, which scientists place between 10-38 and 10-35 seconds after the Big Bang, needed so-called inflatons to provide a reasonable explanation—that is, one fitting into the cosmological world view. These particles, which never reappeared again, were not pulled toward each other by gravity, but instead they repelled each other.
This is seen as the only way the universe could have grown so much in such a short time. The reason this explanation is not considered absurd is the fact that it provides an explanation for other phenomena in the cosmos today, such as the homogeneity of the universe and its low curvature.
The first particles
10-35 seconds after the Big Bang, the density of the universe was now high enough for the first particles known to us today to come into being. For example, electrons and positrons, quarks—which later combined to become protons and neutrons—and antiquarks, neutrinos, precursors to photons, and gluons, which were responsible for the strong nuclear force.
Particles and antiparticles existed in equal numbers. When they met, they mutually annihilated each other. There was a constant coming and going. The new particles behaved normally under the influence of gravity. They attracted one another, which caused the expansion of the universe to decelerate somewhat. A quark-gluon plasma prevailed at this time, and this can be simulated today by computers.
All forces already exist
Scientists are still not in agreement, but if the laws of nature were ever subject to supersymmetry, then they were broken. The theory of supersymmetry assumes that for every known particle, there was a superpartner that differed by half a spin. Supersymmetry elegantly combines particles and force carrier particles, which mediate the known interactions.
These superpartners would have to have been so heavy that they could only have existed at the initial stage of the universe. Today we can only observe ordinary particles, so this supersymmetry no longer exists. It’s assumed that, at the moment supersymmetry was dismantled, the particles received their mass from the still hypothetical Higgs boson.
About 10-10 seconds after the Big Bang, the last two forces that are known today came into existence, the weak nuclear force—which plays a significant role in nuclear fusion—and the electromagnetic force. A little later, the universe cooled down to just two trillion degrees so that quarks could no longer exist alone, and protons and neutrons, or antiprotons and antineutrons, joined together. The gluons served as the glue.
Matter and antimatter still existed in equal amounts. But this state didn’t persist for long. Particles and antiparticles were incinerated into photons, and the universe, which was now 10 trillion kilometers—about a light-year—across and a trillion degrees, emptied rapidly. We owe the fact that we even exist to a small amount of excess matter. At that point, from one billion particle-antiparticle pairs there emerged one excess particle that was not destroyed. There are only guesses as to where this asymmetry came from. Obviously, the laws of nature are not symmetrical in every respect.
The next wave of annihilation
A fifth of a second after the Big Bang, the universe was 500 trillion kilometers across, roughly 50 light-years. Its interior had cooled to 20 billion degrees. Now neutrons and electrons took center stage. The naturally unstable neutrons were shattered by the weak nuclear force into an electron, a proton, and a neutrino. Electrons and positrons annihilated each other, and there was again an excess of matter.
About one second after the Big Bang, considering the now vast cosmic distances, the weak nuclear force was no longer strong enough to provide a nuclear force between neutrinos and ordinary matter. The neutrinos released at that time have been racing through the universe ever since, with almost no interactions, as a measurable, constant neutrino background.
From then on the development of the universe proceeded much more slowly. The remaining neutrons wer
e preserved when, about two to three minutes after T-zero, deuterium and then helium atoms formed. The strong nuclear force now protected the neutrons from being destroyed. Meanwhile the universe grew and grew, continually cooling as it did so.
After about 17 minutes it was too cold for further nuclear fusion to take place. At this point all remaining neutrons were bound to atomic nuclei. Approximately three-quarters of the nuclei were hydrogen nuclei, the rest were helium—heavy nuclei existed only in trace amounts.
As it became colder, electrons bonded electromagnetically to positively-charged atomic nuclei. But they were constantly thrown off course by the photons of the still-hot primordial soup. At this point, the universe, composed predominantly of light particles, would have looked to an observer like a glowing nebula.
This didn’t change for a relatively long time. From about 70,000 years after the Big Bang, the ratio of atomic mass to radiation was 1:1. According to the Lambda-Cold Dark Matter model, the universe was now dominated by dark matter, the nature of which can only be theorized about today. As a result, non-homogeneous regions left over after the inflation phase contracted even more, a prerequisite for the later formation of stars.
The clear universe
Around 380,000 years after the Big Bang, the foundation for one of the first pieces of evidence humans have for our theory of the origin of the universe emerged—cosmic background radiation.
At a temperature of just over 2,700 degrees, the protons no longer had enough energy to smash electrons out of their orbits around atomic nuclei. So the light was no longer diffuse—the universe suddenly became apparent, and the era of the neutral atom began. Today, every cubic centimeter of the cosmic vacuum contains about 400 light particles of cosmic background radiation. In the context of the history of the cosmos, scientists call this event ‘recombination.’
The Death of the Universe: Hard Science Fiction (Big Rip Book 1) Page 26
