Book review: Astrophysics for People in a Hurry

#books #space #universe

I normally don't review books, but this book is special, at least for me. The book Astrophysics for people in a Hurry by Neil deGrasse Tyson published in 2017 by W. W. Norton & Company. I know I am late in the book review game for this book. I've always wanted to read this book, but I never gave much priority to it and kept extending the read. But finally, I've read it and finished it within two days because I was too excited to know more about the universe, I guess.
I didn't just read this book, but I also made notes and listed some of the significant or key takeaways from this book. I am going to list them for you so that it gives a little sense to you about what this book revolves around. So here are some of the key takeaways from the book.

Chapter 1 describes how the universe was created after the big bang from the seconds and years of perspectives. Tyson describes how the universe came into play due to the right amount of energy that was applied at the right amount of masses, electrons, protons, hardros (meaning thick). This ultimately led to the existence of the sun in the milky way galaxy as he puts it this way:
"After nine billion years of such enrichment, in an undistinguished part of the universe (the outskirts of the Virgo supercluster) in an undistinguished galaxy (the Milky Way) in an undistinguished region (the Orion Arm), an undistinguished star (the Sun) was born".
Tyson further stated some events that happened million years ago on the earth, eg., the meteorite that wiped out the existence of dinosaurs and that asteroid hit is now Yucatan Peninsula.

Chapter 2, Page 44: "For ordinary household gravity, Newton's law works just fine. ... For Black holes and the large-scale structure of the universe, we need general relativity"

This statement clarifies my long-overdue curiosity of knowing when to consider Newton and Einstein's gravity laws. Tyson also stated that if the low mass and structure apply to the Einstein gravity laws then it converts into Newton gravitational laws, which is convenient, I guess.

In Chapter 3, Tyson mentioned the A. Penzias and R. W. Wilson
"A measurement of Excess Antenna Temperature at 4080 Mc/s"
experiment and journal. They were trying to establish an AT&T communication channel by eliminating all the interferences from the antenna, but they couldn't remove this one interference which they later discovered was because of the pigeon poop. As they cleared it out, the interference was decreased. They were getting this interference from all the directions they point in the sky. This experiment of excess temperature in antenna helped physicists for their study in Cosmic Microwave Background (CMB).

Chapter 3, Page 56: "Because light takes time to reach us from distant places in the universe, if we lookout in the deep space we actually see eons back in time"

This is simply because the reflection or the light from light year away object hasn't reached us yet. This reminds me of a very famous meme. It goes like this, if an alien looks at the earth from 65 million years ago, they will see the dinosaurs but not us.
The photons were trapped in the opaque universe until 380,000 years after the big bang, they were released and were allowed to travel throughout the universe. Interesting.
Our galaxy "Milky Way" is named due to its spilled milk appearance

Chapter 4, Page 72: "In either case, where there is mass there is gravity. And where there is gravity there is a curved space, according to Einstein's general theory of relativity. And where there is curved it can mimic the curvature of an ordinary glass lens and alter the pathways of light that pass through".

It's fascinating to think about the gravitational lens. There would be tons of gravitational lenses in our universe which are altering the emitting light from the galaxies. Some galaxies might seems closer, but in reality, they wouldn't be as closed to us.

Chapter 5, Page 86: "At odds in the universe were two competing effects: gravity wants to make stuff coagulate, but the expansion wants to dilute it. If you do the math, you rapidly deduce that the gravity from ordinary matter could not win this battle by itself. It needed the help of dark matter, without which we would be living - actually not living - in a universe with no structures: no clusters, no galaxies, no stars, no planets, no people".

Tyson described the dark matter as a frenemy, who is annoying but still needed to keep things intact. Scientists use dark matter to complete their equations to prove the existence of the universe. We don't know much about dark matter, but we do know that dark matter is there to keep things intact by exerting 6 times the gravitational force compare to the gravitational force from ordinary matter. Dark matter interacts with neither the strong or weak nuclear forces, electromagnetic force, and nor does it absorbs or emit or reflect or scatter light. Dark matter is our strange and invisible friend.
In Chapter 6, Tyson starts by describing the 2016 gravitational wave experiment. In 2016, we detected the gravitational waves that occurred due to a 1.3 billion-year-old explosion between two black holes, which proved Einstein's general theory of relativity of space and time. Tyson later described the effects of dark energy that works as an anti-gravity matter and responsible for the expansion of the universe. It's really fascinating to imagine the dark energy to be responsible for going against gravitational rules. Einstein released a cosmos constant for the universe in his career to show that the universe is statics and physicist Hubble proved that the universe is constantly expanding later. So Einstein removed that constant from his equations and told that it was his biggest mistake in the career. Later in 1998, that constant turned out to be the biggest center point for the physicist. That constant symbolizes the dark energy in the universe.

Our Milky Way galaxy was once spherical in shape, but now it's flattened.
In Chapter 7, Tyson stated that there are three elements formed during the big bang: Hydrogen, Helium, and Lithium. The rest of the elements are the results of heating and pressure over the course of billions of years. Tyson mostly described each element in the periodic table and how they are being used today. One of the things he said that stuck with me was that how hydrogen is used for making most dangerous bombs and oxygen extinguishes the fire, but when hydrogen and oxygen get together, they form water or liquid which helps to put out the fire.
In Chapter 8, Tyson described the importance of spherical objects in the universe. He said that the shape of a cosmic object can tell a lot of things about it. For example, Saturn is shaped like a hamburger, where pole to pole diameter is less than the equator diameter and due to this shape, the day at Saturn is only 10 hours and 30 min long. Another fact that Tyson stated that the earth's pole to pole diameter is less than ~29 miles than the equator diameter.

FAST or Five-hundred-meter Aperture Spherical radio Telescope is one of the largest telescopes ever built by China. So if aliens were to contact us, the Chinese will be the first to know.

Chapter 9 was all about the radio telescopes. Tyson described how a scientist named Herschel discovered the mysterious bands of waves in the light spectrum from the sunbeam. Even after the discovery of X-rays, gamma rays, and ultraviolet rays, scientists were using a regular telescope to view the visible light. Many supernovas emit invisible lights such as gamma rays and X-rays, but there it requires special telescopes such as radio telescopes to view the invisible light spectrum. One of the things I learned from this chapter is that water vapor in the upper environments kills the clean observations of cosmic objects since water absorbs microwave frequencies.
This is how Tyson describes the formation of Aurora lights:

"The sun loses material from its surface at a rate of more than a million tons per second. We call this the 'solar wind', which takes the form of high-energy charged particles. Traveling up to a thousand miles per second, these particles stream through space and are deflected by planetary magnetic fields. The particles spiral down toward the north and south magnetic poles, forcing collisions with gas molecules and leaving the atmosphere aglow with colorful aurora".

We should be grateful for having a protective layer around the earth, which protects us from space madness.

Overall, this book is a must-read for all the people who don't have time to read fat astrophysics books to know about our beautiful and mysterious universe.

I hope you enjoyed some of my key takeaways from the book. I will end this review with one of my favorite quotes from the book by Tyson.

The cosmic perspective enables us to see beyond our circumstances, allowing us to transcend the primal search for food, shelter, and a mate.

by Neil deGrasse Tyson