Review of "Astrophysics for People in a Hurry" by Neil deGrasse Tyson

Neil deGrasse Tyson

Neil deGrasse Tyson, an American astrophysicist, is the Director of the Hayden Planetarium, and the host of 'Star Talk' and 'Cosmos: A Spacetime Odyssey.' Tyson is also a very funny guy, and his sense of humor lightens the 'lessons' in Astrophysics for People in a Hurry - which contains a brief overview of cosmology.

I'll just touch on some topics in the book I found interesting.....some new, some not so much.

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Fourteen billion years ago the universe was teeny tiny, 'a trillionth the size of the period that ends this sentence.' It exploded in 'The Big Bang' and expanded at a phenomenal rate - one second after the big bang the universe was already several light years across (at least 18 trillion miles).


The Big Bang

By then, the forces we're familiar with had formed: gravity, the weak nuclear force, the strong nuclear force, and the electromagnetic force.



At the same time, a large array of particles had appeared, including photons, electrons, neutrinos, quarks, and more....all the stuff that makes up 'matter.'



For the first billion years the universe continued to expand and cool, and matter coalesced into galaxies. Scientists estimate that there are about 100 billion galaxies, each containing hundreds of billions of stars. Debris around some stars merged to form planets, and Earth formed in a 'Goldilocks' zone where oceans remain liquid.....allowing life as we know it to develop.


Matter coalesced into galaxies

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Sir Isaac Newton

After Sir Isaac Newton determined the laws of gravity, scientists discovered that physical forces are uniform throughout the universe. Tyson notes, "The power and beauty of physical laws is that they apply everywhere, whether or not you choose to believe in them."

The astrophysicist has a fun story about this: When Tyson told a waiter that his hot cocoa had no whipped cream, the server insisted it had sunk to the bottom. But whipped cream has low density, and floats. So Tyson gave the waiter two options: "Either someone forgot to add whipped cream or the universal laws of physics are different in this restaurant." LOL



Cosmic background radiation (CMB), seen in every direction we look, is the microwave radiation emitted by the cooling universe 380,000 years after the big bang. It's the remnant of something that was once enormously bright, but now requires special instruments to observe.



CMB was first seen by two American physicists that worked for Bell Telephone Laboratories. They accidentally discovered CMB while trying to develop new channels of communication for AT&T.....and later won the Nobel Prize for this achievement (so that's a nice perk!).

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Ordinary matter makes up everything we see and feel. It has gravity and interacts with light. However, this ordinary stuff makes up only 15 to 20 percent of the universe. A full 80 to 85 percent of the cosmos is made of a mysterious substance called 'dark matter', which has gravity but doesn't interact with light. Scientists have ABSOLUTELY NO IDEA what this is.



As if dark matter isn't sufficiently enigmatic, the universe also contains a large amount of 'dark energy.' This is a kind of 'negative gravity' that's pushing the universe apart - accelerating its expansion. As a result, anything not gravitationally connected to the Milky Way Galaxy (where we live) will rush away at an ever increasing speed.

So galaxies that are now visible to our telescopes will eventually disappear from view. Tyson notes, "In a trillion years, anyone alive in the Milky Way may know nothing of other galaxies, and will see nothing but a dark, endless void." :(



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William and Caroline Herschel

In 1781, British astronomer William Herschel discovered a new planet in our solar system. He wanted to name it after his King, in which case the planets would be called: Mercury, Venus, Earth, Mars, Jupiter, Saturn, and George. More traditional heads prevailed, and planet was named Uranus. :)

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To communicate with life elsewhere in the universe - who probably wouldn't understand our spoken languages (just watch the 2016 movie 'Arrival') - we would have to use the language of science. The Voyager spacecraft, launched in 1977, carries a plaque that shows humans, our solar system, our location in the Milky Way Galaxy, and the structure of hydrogen and the atom.


Voyager Plaque

It also carries a gold record album that has whale sounds, and music from Beethoven, Chuck Berry, and others. Tyson mentions that his favorite parody of this 'gift' is an old skit on Saturday Night Live, in which we receive a written reply from the aliens that asks "Send more Chuck Berry." Ha ha ha


Voyager Record

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Tyson's book has lots more interesting information about the universe - and how we study it. On the (slight) downside - since the book is based on a series of essays - it's a little repetitive. And there's a section on elements that veers off the topic of astrophysics.

I'd highly recommend this 'astrophysics light' book to non-specialists interested in the subject. (If you're a physicist, you presumably know all this already.)

In this life I've studied tons of biology and geology. In my next life I'd like to be an astrophysicist who solves the mystery of dark matter and dark energy. :)

Rating: 3.5 stars