Introduction
You want to understand the vast cosmos, but complex scientific jargon often blocks your path. Astrophysics overflows with technical terms that obscure the simple beauty of how reality works. Roberto Trotta solves this problem by using only the one thousand most common words in the English language to explain the universe.
An exploration of modern cosmology told using only the one thousand most common words in the English language.
The book guides you on a journey from your local cosmic neighborhood to the absolute edge of time and space. You travel outward past rocky worlds, through the expanding cosmic web, and into the mysterious domain of invisible matter.
- What are the glowing balls of fire in our sky?
- How did the universe begin from a tiny hot point?
- What invisible force holds spinning galaxies together?
- Why is the expansion of space speeding up?
1. Planets and Solar System
Our solar system consists of eight planets and minor bodies orbiting the Sun, contrasting with ancient views that placed Earth at the center of the universe.
Historically, ancient observers believed all celestial bodies revolved around Earth, while noting Crazy Stars that moved erratically. Modern science recognizes these as planets orbiting the Sun. Three additional planets were discovered using telescopes, and Pluto was reclassified as a minor planet in 2006.
Ancient people feared the planets, naming them after gods like He-Who-Talks-for-the-Gods, She-God of Love, Fight-God, Head-God, and Great-Father-God.
The Crazy Stars
You can track the motion of worlds across the night sky. The Sun sits at the center of the system, holding everything in place with its strong pull.
Home-World and Neighbors
Your Home-World sits at a safe distance from the Sun. Other worlds move along their own paths, experiencing extreme temperatures and unique year lengths.
- There are 8 planets orbiting around the Sun.
- Mercury experiences a year that is 116 days long.
- Venus reaches a distance of 38 million kilometers to Venus at its closest.
2. Cosmic Expansion and Early Universe
The universe is expanding from an initial hot point and underwent rapid inflation before cooling down.
You can observe the motion of distant star-crowds across space. Doctor Hubble used large telescopes to look at white shadows and found that their light got redder the further away they were. This red-shift reveals that space itself grows and light gets tired as it travels.
Tracing this motion backward brings you to a single hot point known as the big flash.
The Big Flash
Edwin Hubble discovered that distant nebulas are actually separate star-crowds and that their light is shifted toward the red end of the spectrum. Einstein originally resisted this idea of expansion and introduced the cosmological constant, later calling it a mistake.
The universe is measured to be 13.798 billion years ago for the age of the universe, with a 37 million years margin of error on the age of the universe. A typical galaxy contains 100 billion stars. It takes 250 million years for the solar system to orbit the milky way.
The Early Push
Immediately after the big flash, the universe expanded rapidly via cosmic inflation. Matter and antimatter particles annihilated each other, leaving a tiny excess of matter.
A party ball analogy illustrates rapid inflation, where blowing into it makes it grow drastically with every breath.
During this phase, specific events occurred on a tiny time scale:
- inflation caused a 10 to the power of 26 times size increase during inflation;
- the timing of this event happened at 10 to the power of -32 seconds after the big flash for inflation timing;
- single drops and heavier drops formed as the universe cooled over the first three minutes;
- electrons were captured by nuclei 380,000 years after the big flash when electrons were captured and the universe became transparent, allowing light to travel freely.
3. Dark Matter and Its Detection
Unseen dark matter holds galaxies together, prompting scientists to build specialized underground and space detectors.
Galaxies rotate too fast to be held together by visible matter alone, proving the existence of an invisible substance called dark matter. You can observe that visible mass is concentrated in the middle of star-crowds.
Vera Rubin observed that stars at the outer edges of star-crowds orbit just as fast as those near the center. An unseen halo of mass must provide the gravitational pull required to keep outer stars from flying away.
Doctor Zwicky and Doctor Rubin pioneered observations showing that star-crowds require extra gravitational pull from dark matter to maintain their rotational speeds. The cosmos contains 5 times more dark matter than normal matter. Today, 25 percent of the matter-energy content of the cosmos today is dark matter.
Mirror Drops
Scientists refer to this invisible substance using the author term dark matter. You will find that dark matter drops fly through a hand during a blink at a rate equal to 2 times the population of New York City.
The Big Ring
Scientists employ underground detectors, deep-ice eyes, space telescopes, and particle accelerators to search for elusive dark matter particles. Because dark matter rarely interacts with ordinary matter, experiments must be shielded from background noise.
Underground mines block cosmic rays. Lead blocks local radioactivity. Ice-filled detectors watch for high-energy neutrino flashes from the Sun, and particle colliders attempt to recreate primordial conditions.
Researchers built the Large Hadron Collider in a twenty-seven-kilometer underground ring near Geneva to collide protons and discover new particles like the Higgs boson. The machine measures 27 kilometers in circumference for the Large Hadron Collider. Researchers announced the discovery of the Higgs boson in March 2013.
4. Measuring Distances and the Dark Push
Dying Stars
Astronomers measure cosmic distances and expansion rates using standard candles such as exploding stars with uniform intrinsic brightness. Just as a lightbulb appears dimmer the farther away it is, you can use objects of known luminosity to determine distance. Type Ia supernovae serve as reliable standard candles because they explode with nearly uniform peak brightness. This allows researchers to gauge how far away star-crowds are and how fast they are receding.
Studying type Ia supernovae earned the 2011 Nobel Prize in physics and revealed that the universe's expansion is influenced by dark energy.
The Dark Push
Dying stars appear less bright than expected because a strange repulsive force known as the Dark Push is driving them away.
Astronomers discovered that far-away Dying Stars were dimmer than their distance suggested. They ruled out intervening matter drops or intrinsic differences in the stars. This left Mr. Einstein's Dark Push as the only explanation for the accelerated growth of the All-There-Is.
Mr. Einstein believed the All-There-Is was unchanging. He introduced the Dark Push to counteract the attractive pull of matter drops. Although Mr. Hubble later disproved a static universe, modern observations of Dying Stars proved that the Dark Push is real. It causes the universe to expand faster over time.
5. The Ultimate Fate and Multiverse
As the Dark Push continues to accelerate the growth of the universe, all other Star-Crowds will eventually vanish from view. The ongoing acceleration creates more empty space, generating more Dark Push and driving further expansion in an endless cycle.
Eventually, distant Star-Crowds will move too far away for their light to reach us, leaving the universe as an empty, dark silence.
The Dark Push leads to a future dark silence, while fine-tuning suggests the possibility of multiple universes.
Dark Silence
Is the All-There-Is All There Is?
The precise strength of the Dark Push resembles an improbable coin-toss outcome where four hundred coins all land on heads. If the Dark Push were even slightly different in strength, stars, planets, and life would never have formed. This extreme fine-tuning requires an explanation for why it matches our existence so perfectly.
Imagine entering a room and finding four hundred small, gray, round pieces used for buying coffee all showing heads up, which is too improbable to happen by chance alone.
To solve the puzzle of fine-tuning without invoking design, some scientists propose that there is an enormous multitude of separate rooms or universes, each with random properties. Most are dead and boring, but by chance, one of them will possess the precise conditions necessary for life.
10 Key Ideas
- Our solar system consists of eight planets and minor bodies orbiting the Sun, contrasting with ancient views that placed Earth at the center of the universe.
- The universe is expanding from an initial hot point and underwent rapid inflation before cooling down.
- Immediately after the big flash, the universe expanded rapidly via cosmic inflation.
- Unseen dark matter holds galaxies together, prompting scientists to build specialized underground and space detectors.
- Scientists refer to this invisible substance using the author term dark matter.
- Astronomers measure cosmic distances and expansion rates using standard candles such as exploding stars with uniform intrinsic brightness.
- Dying stars appear less bright than expected because a strange repulsive force known as the Dark Push is driving them away.
- The Dark Push leads to a future dark silence, while fine-tuning suggests the possibility of multiple universes.
- Eventually, distant Star-Crowds will move too far away for their light to reach us, leaving the universe as an empty, dark silence.
- To solve the puzzle of fine-tuning without invoking design, some scientists propose that there is an enormous multitude of separate rooms or universes, each with random properties.