1,000 Facts About the Universe & Astrophysics E-Book

Dominik Mikulaschek

• Herausgeber: tredition
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 247

Veröffentlichungsjahr: 2026

Beschreibung

How did the universe begin? What are black holes? How do stars, galaxies, space-time, and the laws of the cosmos work? This book opens up the fascinating world of astronomy, astrophysics, and cosmology in a way that is exciting, easy to understand, and highly informative at the same time. Through 1,000 astonishing facts, you will discover the greatest wonders and mysteries of the universe—from our solar system to the most distant galaxies, from planets and exoplanets to supernovae, neutron stars, black holes, dark matter, and relativity. Whether you have been fascinated by outer space for a long time or are simply looking for an extraordinary book of knowledge about the universe, this book will help you understand complex relationships with ease and guide you step by step deeper into modern astronomy. The content is clearly written, compactly explained, and structured in a way that captivates both beginners and curious advanced readers. Among other things, you will learn how stars are born and die, why black holes are among the most mysterious objects in the universe, how galaxies evolve, what space and time are all about, and which unanswered questions still occupy researchers today. The book combines scientific topics with language that remains accessible and inspires you to keep exploring. What you can expect in this book: 1,000 exciting facts about the universe, astronomy, and astrophysics Knowledge about planets, stars, galaxies, black holes, and exoplanets Clear explanations of cosmology, space-time, relativity, and dark matter An ideal book for marveling, learning, referencing, and giving as a gift Perfect for anyone who wants to learn more about the secrets of the universe This book is the ideal choice for anyone interested in astronomy books, universe books, astrophysics, cosmology, knowledge about space, black holes, stars, galaxies, and the great questions of our existence. It is suitable for teenagers and adults, for lovers of knowledge, amateur astronomers, and anyone inspired by the cosmos. A great book of knowledge about the universe—full of fascinating facts, spectacular phenomena, and astonishing insights into space, time, and the infinite vastness of the cosmos.

Leseprobe

Dominik Mikulaschek, born in 1983 in Linz, has devoted many years to the subjects of knowledge, science, and the clear communication of complex ideas. His special interest lies in the fundamental questions of our existence: the origin of the universe, the laws of nature, and the mysteries that still remain unsolved today.

For him, the focus has never been on simply collecting facts, but on developing a deeper understanding of what lies behind them. Knowledge reveals its true value only when connections become visible, when individual pieces of information form a bigger picture, and when even demanding subjects can be explained in a way that is clear, accessible, and engaging.

This book was created with exactly that purpose in mind. “1,000 Facts About the Universe & Astrophysics” guides readers into the fascinating world of astronomy, cosmology, stars, planets, black holes, spacetime, and relativity in a way that is easy to understand. It combines scientific topics with language that sparks curiosity, provides orientation, and makes the beauty of the cosmos easier to grasp.

This book is for everyone who does not only want to be amazed, but also wants to understand — and who is ready to look beyond everyday life into the infinite vastness of the universe.

Dominik Mikulaschek

1,000 Facts About the Universe & Astrophysics

Astronomy, cosmology, stars, planets, black holes, space-time & relativity | The big book of knowledge

(1,000 amazing facts)

tredition GmbH

© 2026 Dominik Mikulaschek

Printing and distribution on behalf of the author:

tredition GmbH, Heinz-Beusen-Stieg 5, 22926 Ahrensburg, Germany

This work, including all parts thereof, is protected by copyright. The author is responsible for the content. Any use without his consent is prohibited. Publication and distribution are carried out on behalf of the author, who can be reached at: Dominik Mikulaschek, Holzwurmweg 5, 4040 Linz, Austria.

Contact address in accordance with the EU Product Safety Regulation: [email protected]

Contents

Introduction

Chapter 1: Cosmic overview: sizes, times, scales

Chapter 2: The Big Bang & Early Universe: What We Know

Chapter 3: Expansion, Dark Energy & the Fate of the Cosmos32

Chapter 4: Dark Matter: Evidence, Models, Open Questions43

Chapter 5: Galaxies: Structure, Types, Collisions54

Chapter 6: The Milky Way: Structure, Centre, Neighbourhood65

Chapter 7: Stars: Birth, Life, Death76

Chapter 8: Supernovae & Neutron Stars: Extreme Physics87

Chapter 9: Black Holes: Horizons, Jets, Paradoxes98

Chapter 10: Gravity & Relativity: Understanding Space-Time

Chapter 11: Time & Time Dilation: When Seconds Tick Differently

Chapter 12: Quanta in the Cosmos: When the Small Influences the Large

Chapter 13: The Solar System: Planets, Moons, Curiosities

Chapter 14: Exoplanets: Alien Worlds & How We Find Them

Chapter 15: Atmosphere & Climate of Other Worlds164

Chapter 16: Astrobiology: Life in space – opportunities and limitations175

Chapter 17: Telescopes & observatories: how we look into space186

Chapter 18: Space travel and missions: probes, rovers, records199

Chapter 19: Cosmic radiation and particles from space

Chapter 20: Unsolved mysteries of astrophysics: what is still missing

Introduction

Imagine lying in a meadow on a clear summer night, looking up and suddenly realising that you are not just staring at a black canvas with a few twinkling dots, but directly into the abyss of infinity. At that moment, you usually feel incredibly small, almost insignificant, like a tiny speck of dust in a storm that has been raging for billions of years, but this is precisely the misconception that this book aims to correct: you are not just a passive observer of the universe, you are an integral part of it – literally made from the material that was forged eons ago in the glowing hearts of dying stars. To many, astrophysics sounds like complicated formulas, dusty lecture halls and mathematics that make you wake up at night covered in sweat, but in reality it is the most exciting detective story ever written. It's about the fundamental question of how everything could have come from absolute nothingness, why time is stretched like chewing gum near black holes, and why we can now know with certainty what is happening in galaxies so far away that their light took longer to reach us than the Earth has even existed. This book is not about feeding you isolated facts that you memorise for an exam and forget the next day, because knowledge only comes alive when you recognise the patterns behind the apparent chaos and understand how things are connected. Why do stars twinkle while planets emit a steady light? Why don't we fall off the globe, even though we are spinning through space at thousands of kilometres per hour? And what actually happens to reality when you approach the speed of light? Dominik Mikulaschek breaks down the most complex topics in modern science to their essentials: clarity, logic and the ultimate "aha" moment that will change your worldview forever. It is a guide for curious minds who not only want to know that the universe is expanding, but also want to understand what that means for our own existence and our distant future. We live in a privileged era in which we can look back almost to the Big Bang with high-performance telescopes and land probes on comets racing through absolute darkness like icy time capsules, and yet most of what is out there remains a vast, fascinating mystery – from the mysterious dark matter to the question of whether we are really the only beings who have ever tried to crack the code of the cosmos. This book provides you with 1,000 precise building blocks to assemble your own picture of the universe and offers you the freedom to change your perspective and perceive things that others carelessly pass by. Those who know more see more – and those who see more are less likely to be bored in a world where every street corner hides a physical wonder. It is an invitation to forget the daily grind for a moment and instead marvel at the true nature of reality, because the brightest minds were never those who knew the most, but those who could marvel the longest. Get ready for a journey without a seatbelt, from the smallest quanta that make up our bodies to the most massive superclusters at the edge of visibility. The world will never cease to amaze you once you open this book and begin to see the invisible threads that hold everything together. Let's dive into the greatest adventure the human mind has ever undertaken: understanding everything that is.

Chapter 1: Cosmic Overview: Sizes, Times, Scales

50 facts with real background knowledge

1. The Astronomical Unit: The Fundamental Ruler of the Solar System

The astronomical unit (AU) describes the average distance between the Earth and the Sun (approx. 150 million kilometres). This value serves as a fundamental ruler within our solar system. It helps us understand that the light from the Sun takes about eight minutes to reach us, which illustrates the speed limit in the solar system.

2. The light year: distance measured in time

A light year is not a measure of time, but a unit of measurement for distance. It corresponds to the distance that light travels in a vacuum in one year (approximately 9.46 trillion kilometres). Since the universe is so vast, measuring distances in kilometres would result in numbers that are too large to comprehend. Astronomers therefore use light years as the standard measure for distances between stars.

3. The observable universe: 13.8 billion years old and 93 billion light years

The observable universe has a diameter of approximately 93 billion light years. Although the universe is only 13.8 billion years old, the visible area is significantly larger due to the expansion of space. This boundary defines everything that we could theoretically ever see due to the speed of light.

4. The speed of light: the absolute barrier in the cosmos

The speed of light is the absolute maximum speed for information and matter. In a vacuum, light travels at almost 300,000 kilometres per second. Nothing can break through this barrier, which has profound implications for our understanding of cause and effect. Because of this limitation, when we look at the stars, we are always looking directly into the past.

5. The structure of the cosmos: Two grains of sand in a cathedral

The universe consists largely of empty space. Even within galaxies, the distances between stars are so vast that collisions are extremely rare. You can imagine it as two grains of sand floating in a huge cathedral. This enormous emptiness shapes the structure of the entire cosmos.

6. The five per cent problem: the dominance of dark matter

Matter as we know it makes up only a tiny fraction of the universe. Planets, stars and ourselves are made up of atoms that account for less than five per cent of the total energy density of the cosmos. The rest is accounted for by mysterious dark matter and dark energy. This shows us how little we know about the true nature of reality.

7. The Big Bang location: The raisin in the rising cake

The cosmos has no centre where the Big Bang took place. Expansion happens everywhere at once because space itself is growing. Every galaxy sees all the others moving away from it, which is often compared to a raisin cake rising in the oven. So there is no preferred location in the universe.

8. Cosmic background radiation: the oldest light in the universe

Cosmic background radiation is the oldest light we can measure in the universe. It was created about 380,000 years after the Big Bang, when the universe became cool enough for photons to travel unimpeded. Today, this light reaches us as weak microwave radiation from all directions of the sky. It is one of the strongest pieces of evidence for the Big Bang theory.

9. Galaxy clusters: the cosmic web of giants

Galaxy clusters are the largest structures in space bound together by gravity. They consist of hundreds or thousands of galaxies that influence each other. These clusters are connected by giant filaments that form the large-scale "cosmic web". In between are gigantic empty spaces, known as voids.

10. The dominance of the Sun: 99 per cent of the mass

The Sun contains over 99 per cent of the total mass of our solar system. All the planets, moons, asteroids and comets combined are almost negligible in weight compared to our home star. This dominance generates the gravitational force that keeps everything in stable orbits. Without this mass, there would be no orderly planetary system.

11. The parsec: the geometric unit used by astronomers

A parsec is another important unit of measurement for distances in astronomy. One parsec is equivalent to approximately 3.26 light years and is based on the geometric parallax of the Earth's orbit. Astronomers often use this unit because it can be calculated directly from observations of star positions. It is the preferred unit for specialist publications.

12. Gravity: The weakest force that governs everything

Gravity is the weakest of the four fundamental forces, but it dominates the entire cosmos. Unlike nuclear force, it acts over infinite distances and is always attractive. It causes gas clouds to condense into stars and galaxies to stay together. At the atomic level, however, it plays almost no role.

13. The cosmic age: 13.8 billion years of space-time

The universe is approximately 13.8 billion years old. This figure was determined by measuring the rate of expansion and background radiation. Before this time, neither space nor time existed in the form we know today. Knowing this age allows us to chronologically classify the development of the first stars and galaxies.

14. Time dilation: the relative clock

Time is not absolute in the universe, but depends on motion and gravity. Time passes more slowly near massive objects or at high speeds. This effect must even be taken into account for GPS satellites to function correctly.

15. Space temperature: Just above absolute zero

The temperature of space is just above absolute zero. Due to cosmic background radiation, empty space has a temperature of about 2.7 Kelvin (minus 270.45 degrees Celsius). This coldness is a direct result of the extreme expansion of the universe.

16. Interstellar medium: The cradle of stars

Interstellar space is not completely empty, but contains gas and dust (mainly hydrogen and helium). Although the density is extremely low, the mass in a galaxy adds up to enormous quantities. This material gives rise to future generations of stars.

17. Twinkling: An optical illusion of the atmosphere

Stars only twinkle because their light rays are deflected by turbulence in the Earth's atmosphere. In space, they shine as calm, sharp points of light. Planets usually twinkle less because they are not point-like but flat sources of light.

18. Andromeda light: a glimpse into the past

The light we see from the Andromeda galaxy is over two million years old. Since it is 2.5 million light years away, when we look at it, we are looking back to a time when modern humans did not yet exist on Earth. Telescopes thus function like time machines.

19. Event horizon: The one-way street in the black hole

The event horizon marks the boundary where the escape velocity reaches the speed of light. Anything that crosses this boundary can never return, not even light. It is a physical one-way street in the fabric of space-time.

20. Superclusters: Clusters of galaxy clusters

Superclusters are collections of galaxy clusters and are among the most massive structures in space. Our Milky Way is part of the Laniakea supercluster. These structures show that matter in the universe forms clumps and is not evenly distributed.

21. Redshift: The expanding universe

Cosmic redshift shows that the universe is expanding. When a galaxy moves away from us, its light waves are stretched and appear redder. The further away a galaxy is, the faster it moves away.

22. Sidereal day: The more precise clock

A sidereal day (the rotation of the Earth relative to distant stars) lasts only about 23 hours and 56 minutes. The conventional solar day is longer because the Earth travels a little further each day on its orbit around the Sun. For astronomy, the sidereal day is the more precise timekeeper.

23. Planetary orbits: Kepler's ellipses

Planetary orbits are not perfect circles, but ellipses. Johannes Kepler realised that the Sun is not at the exact centre, but at one of the foci of these ellipses. This discovery revolutionised the understanding of celestial mechanics.

24. Cosmic isolation: space expands faster than light

The space between galaxies is expanding faster than light can travel. This does not violate the theory of relativity, as space itself is expanding. In the distant future, many galaxies will disappear behind the cosmic horizon and become unreachable.

25. Vacuum energy: the energy of empty space

Vacuum energy is a form of energy inherent in empty space itself. According to quantum theory, an "empty" volume is never truly empty, but rather filled with fleeting particle pairs. This energy is associated with dark energy, which accelerates the expansion of the universe.

26. The distance ladder: the measuring stick for infinity

The distance ladder is a system for measuring distances in space. For nearby stars, parallax is used, while for distant galaxies, so-called standard candles (such as supernovae) are used. Each step of the ladder builds on the accuracy of the previous one.

27. The Milky Way: Our place on the edge

The Milky Way has a diameter of approximately 100,000 to 200,000 light years. This disc is home to 100 to 400 billion stars. Our solar system is located on the edge, 26,000 light years from the centre.

28. Stardust: The building blocks of life

Almost all the heavy elements in your body (carbon, oxygen, iron) were created inside massive stars through nuclear fusion. When these stars explode, they scatter the building blocks throughout space. We are literally made of stardust.

29. Sunlight delay: The 500-second reality

Light from the Sun takes about 500 seconds to reach Earth. If the Sun stopped shining at that moment, we would not notice it until more than eight minutes later. This delay limits our real-time communication in space.

30. Valles Marineris: The super canyon on Mars

Valles Marineris on Mars is over 4,000 kilometres long and up to seven kilometres deep. Mount Everest would fit into this canyon almost 20 times. Such geological superstructures are possible on other planets.

31. Flat geometry: The parallel axiom in the cosmos

The universe is flat. This means that two parallel rays of light remain parallel even over billions of light years. Geometry is closely related to the total mass density of the cosmos. If space were curved, light would describe large arcs.

32. Cosmic density: six atoms per cubic metre

The average density of the universe is extremely low: about six atoms per cubic metre of space. By comparison, the Earth's atmosphere contains trillions of atoms. The cosmos as a whole is almost a perfect vacuum.

33. Time travel into the future: physical time banking

Time travel into the future is physically possible and has already been proven (time dilation). Astronauts age minimally slower on the ISS. At nearly the speed of light, one could skip centuries. Returning to the past remains impossible.

34. Neutron stars: the billion-ton teaspoon

A teaspoon of matter from a neutron star would weigh billions of tonnes. These compressed stars consist almost entirely of neutrons. The entire star is compressed to the diameter of a city like Berlin – the densest objects that are not black holes.

35. Galactic orbit: 225 million years to complete one revolution

The solar system orbits the centre of the Milky Way at 220 kilometres per second. It takes us around 225 to 250 million years to complete one orbit. When we were last in this position in space, dinosaurs still roamed the Earth.

36. Gravitational constant: finely tuned gravity

The gravitational constant is one of the fundamental constants of nature and determines attraction. If this value were only slightly different, stars and planets would never have been able to form in a stable manner. Fine-tuning is a central topic in theoretical physics.

37. Hubble's law: The further away, the faster away

Hubble's law describes that the further away a galaxy is, the faster it moves away from us. The Hubble constant is a measure of the current expansion rate of the universe.

38. Dark matter: the invisible framework of galaxies

Dark matter makes up the majority of mass and holds galaxies together through its gravitational pull. Without this invisible mass, galaxies would rotate much more slowly or fly apart. It forms the invisible framework.

39. Red giant: The end of the Sun

In about five billion years, the Sun will swell into a red giant and engulf the inner planets. This happens when the hydrogen supply in the core runs out. It is a natural part of the life cycle of every star in this class.

40. Scale jump: 63,241 times magnification

One light year is equal to 63,241 astronomical units. This comparison illustrates the enormous leap between the distances in our solar system and the distances between stars.

41. Kuiper Belt: The icy archive of the solar system

The Kuiper Belt is a vast region beyond Neptune filled with icy objects and dwarf planets such as Pluto. It marks the outer boundary of the area where the large planets orbit. This region serves as an archive for the history of our cosmic home.

42. Cosmic radiation: High-energy danger from space

Cosmic rays consist of high-energy particles travelling at nearly the speed of light. The Earth's atmosphere and magnetic field protect us. In space, however, they pose a major challenge for human spaceflight.

43. Galaxy merger: The collision of the Milky Way

In about four billion years, our Milky Way will collide with the Andromeda galaxy. Hardly any stars will collide, as the distances between them are too great. The galaxies will form a new, giant elliptical galaxy.

44. The black hole: not a cosmic vacuum cleaner

A black hole is not a "vacuum cleaner" but an object with extremely strong gravity. If the Sun were to become one, the planets would continue to orbit it. Only near the event horizon is there no escape.

45. Anthropic principle: The uniqueness of our existence

The anthropic principle states that the universe must be such that it could enable intelligent life. If physical constants were slightly different, there would be no stars. It encourages reflection on the fine-tuning of nature.

46. Quarks and gluons: the smallest explains the largest

Protons and neutrons are made up of quarks held together by the strong nuclear force. Understanding the smallest building blocks helps us comprehend the beginning of the universe, when matter existed as "quark-gluon plasma".

47. Voyager 1: The most distant man-made object

Voyager 1 has reached interstellar space and is still sending data. Despite its speed, it would take tens of thousands of years to reach the nearest star. It underscores the isolation of our solar system.

48. Absolute zero: The coldest temperature

Absolute zero is minus 273.15 degrees Celsius. At this temperature, all particle motion comes to a standstill. The universe can never quite reach this point because it is constantly flooded with energy.

49. Big Bang: The mocking name

The term "Big Bang" was originally a mocking name given by an opponent of the theory (Fred Hoyle). But the name stuck. The theory itself does not describe an explosion, but a sudden expansion of space.

50. The Big Freeze: The cold end of eternity

The universe could end in a "Big Freeze", in which all stars go out and matter decays. In the end, an unimaginably large, dark and cold space would remain. This is one of several possible scenarios for the cosmic finale.

Chapter 2: The Big Bang & Early Universe: What We Know

50 facts with real background knowledge

1. The Big Bang: The creation of space and time itself

The Big Bang was not an explosion in an existing space, but the sudden creation of space and time itself. There was no "outside" and no empty container into which the universe grew. Instead, the fabric of space-time expanded simultaneously at every point. This process continues to this day and forms the foundation of modern cosmology.

2. The singularity: the infinitely dense point

In the so-called singularity, the entire universe visible today was concentrated in a single, infinitely dense point. At this point, our known laws of physics fail. Mathematically speaking, temperature and density were infinitely high. Only with quantum gravity can we hope to describe this extreme primordial state.

3. The Planck era: The birth of physics

The Planck era marks the earliest moment of the universe that we can theoretically comprehend. It lasted only about 10−43seconds, during which all four fundamental forces (gravity, electromagnetism, strong and weak nuclear forces) were still united into a single primordial force. This phase lies beyond our current measuring capabilities.

4. Cosmic inflation: The sudden expansion

Immediately after the Planck era, the universe expanded exponentially in what is known as inflation. In less than a quadrillionth of a second, the cosmos increased in size by a factor greater than the entire size of the universe today. This phase explains the astonishing uniformity of the universe.

5. Matter-antimatter asymmetry: The slight excess

In the early universe, matter and antimatter were created in almost equal amounts. Physics predicts that the two would have annihilated each other. However, there was a tiny excess of matter (about one particle in a billion) that remained after the annihilation. This tiny remnant forms everything we see today, including stars and galaxies.

6. Elementary particle soup: the era of quarks

In the first milliseconds, the universe was an extremely hot soup of fundamental particles, mainly quarks and gluons. It was too hot for these particles to combine into protons or neutrons. The density was so high that the forces were extremely short-range.

7. Neutrino background: invisible radiation

The neutrino background radiation was released about one second after the Big Bang and flows through space. It is extremely difficult to detect because neutrinos hardly interact with matter. It carries information about the temperature and density of the universe when it was only one second old.

8. Big Bang nucleosynthesis: The birth of helium

In the first three minutes, the universe cooled down so that protons and neutrons could combine to form light atomic nuclei. Hydrogen (75 per cent) and helium (25 per cent) were created, along with traces of lithium. Heavier elements were not formed until much later, inside stars.

9. The Dark Age: 380,000 years of darkness

After the formation of the first atoms, the so-called dark age prevailed. There were no stars yet, and the universe was filled with neutral hydrogen gas. It took a while for the first massive stars to form, which re-ionised the gas and illuminated the universe.

10. Formation of atoms: the light breaks through

About 380,000 years after the Big Bang, the universe cooled to about 3,000 Kelvin. Electrons were able to combine with atomic nuclei. Space became transparent, and photons were able to spread unhindered. We see this released light today as cosmic background radiation.

11. The earliest framework of matter: dark matter as glue

Dark matter was the first to form clumps due to its gravitational pull. It served as the "framework" or "seed" for the later visible galaxies. Normal matter fell into these gravitational wells, which massively accelerated the formation of structures.

12. The first generation of stars: stars without metals

The first stars (Population III) formed about 150 to 200 million years after the Big Bang. They consisted only of hydrogen and helium and were extremely massive and short-lived. Their explosions (supernovae) scattered the first heavy elements ("metals" in astronomy) throughout space.

13. The reionisation era: the end of darkness

The reionisation era began when the UV light from the first stars converted the neutral hydrogen of the dark age back into ions (plasma). This process illuminated the universe and created the conditions under which galaxies could form.

14. Cosmic Horizon: The Visible Limit of the Universe

The cosmic horizon marks the boundary beyond which light has not yet reached us due to the finite age of the universe. It is the boundary of the observable universe. It is not a physical wall, but a limitation imposed by the speed of light.

15. The Hubble volume: the radius of observation

The Hubble volume describes the part of the universe that is not moving away from us faster than the speed of light would allow. Everything beyond this boundary is theoretically unreachable and invisible, as light cannot overcome the expanding space.

16. The time-temperature relationship: heat as a clock

In the early universe, time and temperature were inextricably linked. Physics can be defined by temperature: the younger the universe was, the hotter it was. The cooling of the universe was the clock for the formation of different forms of matter and structures.

17. The homogeneity of the universe: uniformity through inflation

Inflation solved the homogeneity problem: it expanded a tiny, uniform region of space so much that it filled the entire observable universe. This explains why cosmic background radiation has almost exactly the same temperature in all directions.

18. The Higgs field: mass for the particles

Shortly after the Big Bang, the particles did not yet interact with the Higgs field. Only when the field changed its state did the fundamental particles acquire their mass. The mass of matter is thus a direct result of the existence of this field.

19. The matter dominance transition: gravity takes the lead

About 50,000 years after the Big Bang, the universe cooled down to such an extent that the density of matter exceeded the density of radiation. The gravity of matter became dominant. This transition was crucial for the later formation of structures such as galaxies and galaxy clusters.

20. The primordial fluctuations: the seeds of galaxies

Tiny quantum fluctuations from the time of inflation were blown up to cosmic proportions by the expansion. These tiny density fluctuations served as the "seeds" for the later galaxies. The entire cosmic structure we see today is a result of this quantum physics.

21. Dark energy: the late accelerator

Dark energy only took the lead in the expansion of the universe about six billion years ago and has been accelerating it ever since. It is a mysterious force that counteracts gravity and today accounts for 70 percent of the total energy density.

22. Magnetic monopole deficit: The problem of isolation

Theory predicts that extremely heavy magnetic monopoles must have formed in the early universe. Since we do not observe them, this is another problem that inflation solves. The exponential expansion diluted the monopoles so much that only extremely few remain today.

23. Baryogenesis: The birth of the building blocks of the nucleus

Baryogenesis is the process by which an excess of quarks over antiquarks arose (matter-antimatter asymmetry). This process is essential, but its exact cause is one of the greatest mysteries of particle physics. Only this excess made the existence of stars and galaxies possible.

24. The isotropy of the universe: identical conditions everywhere