Science
by Neil deGrasse Tyson
What is the universe made of?
Neil deGrasse Tyson wrote this for readers who want the big picture of the cosmos without a course in physics. In short chapters he covers where everything came from, and the large parts of it that scientists still can't explain.
Hear a sample · read by Laura
Tyson starts nearly 14 billion years ago, when everything we can now see was squeezed into a tiny, extremely hot space. As it expanded and cooled, particles formed, then atoms, then stars and galaxies. The big bang made mostly hydrogen and helium. Heavier elements came later, from stars.
Newton realised the gravity that drops an apple also holds the Moon in orbit. Tyson's point is that the same physics works everywhere we look. Split the light from a distant star and you find the same elements we have on Earth.
Galaxies spin and cluster as if they held far more mass than we can see. That unseen mass is called dark matter. Separately, the universe's expansion is speeding up, driven by what's called dark energy. Tyson is frank that nobody yet knows what either one is.
Tyson's closing chapters step back to see us at cosmic scale. We're tiny in space and recent in time. But the carbon, oxygen and iron in our bodies were made inside stars that died before the Sun formed, so we're built from the universe as well as living in it.
The start
Everything began about 14 billion years ago, packed into a space smaller than a dot.
Same rules
The laws of physics work the same everywhere, from Earth to the farthest galaxy.
Dark matter
Most matter is dark matter. We can measure its pull but still can't see it.
Dark energy
A force called dark energy is making the universe grow faster and faster.
Star stuff
The atoms in your body were made inside stars that exploded long ago.
A story from the book
In the 1960s, Arno Penzias and Robert Wilson at Bell Labs couldn't get rid of a faint hiss in their antenna. It came from every direction in the sky. It was the leftover glow of the early universe, and it won them a Nobel Prize.
One thing to try
Find iron on the nutrition label of a cereal box this week. Every atom of that iron was made in stars that died before the Sun existed. Tell whoever's at the table. Tyson thinks that kind of cosmic perspective makes everyday worries look smaller.
Knotd has the key ideas from 250+ non-fiction books, each in a few minutes, in plain words. Astrophysics for People in a Hurry comes with a Name That Idea round to make it stick.
Get the whole book on KnotdOpen in the appWhat is the universe made of? Neil deGrasse Tyson wrote this for readers who want the big picture of the cosmos without a course in physics. In short chapters he covers where everything came from, and the large parts of it that scientists still can't explain.
The first moments; The same laws everywhere; Most of it is dark; Forged in stars.
Find iron on the nutrition label of a cereal box this week. Every atom of that iron was made in stars that died before the Sun existed. Tell whoever's at the table. Tyson thinks that kind of cosmic perspective makes everyday worries look smaller.
Yes. Knotd has the key ideas from Astrophysics for People in a Hurry in a few minutes, in plain words, plus a Name That Idea round to test them. It's one of 250+ non-fiction books in the app.
