Welcome to the Universe: An Astrophysical Tour

When you are 31 years, 7 months, 9 hours, 4 minutes, and 20 seconds old, you’ve lived your billionth second.

And the cosmos ends. Not with a bang but with a whimper.

Astronomy, because of that peculiar history, has a fascinating legacy of early contributions by women.

We are born of this universe, we live in this universe, and the universe is in us.

Intelligence and longevity do not seem to be correlated.

The future is 1/39 as long as the past.

It’s like asking what is south of the South Pole

If a particle can fall into a black hole, it can come out of a white hole.

Since four coordinates are needed, we know that we live in a four-dimensional universe

Dark matter particles should be passing through your body right now.

Dark matter is dark; that means it does not interact with photons

You can picture the universe as an enormous loaf of raisin bread rising in the oven

It is often true that groundbreaking discoveries are made from poor data at the leading edge

As a scientist, you must embrace the inconstancy of knowledge.

We simply organized the information differently—that’s all we did. And the New York Times was making a federal case out of it.

Decade by decade: estimates of Pluto’s size got smaller and smaller.

Stephen Hawking the reputation of being the smartest person alive. Most of us agree.

Your body has to come up with about 100 watts of energy to keep yourself warm

the hottest part of the day on Earth is not at noon, but sometime after noon, because the ground absorbs visible light

We are seeing these nearby stars, not as they are at the present moment, but as they were 4 years ago

People who navigate by the stars know that the altitude of Polaris you observe is equal to your latitude on Earth.

If you must know, the brightest star in the nighttime sky is Sirius, the Dog Star.

There are people, who walk around every day, asserting that we are alone in this cosmos. They simply have no concept of large numbers, no concept of the size of the cosmos.

don’t count things, but instead count the ways things can happen.

Between 1 and 10 quadrillion ants live on (and in) Earth,

The universe today is 13.8 billion years old. By 22 billion years, the Sun will have finished its main-sequence lifetime and will have become a white dwarf. The Andromeda galaxy will have crashed into the Milky Way.

Here’s the story of how Pluto lost its planetary status and was demoted to an ice ball in the outer solar system. It’s also about my role in this at the Rose Center for Earth and Space at the American Museum of Natural History.

Our star, and most stars, are made mostly of hydrogen, which is the number one element in the universe: 90% of all atomic nuclei are hydrogen, about 8% are helium, and the remaining 2% comprise all the other elements in the periodic table. All

We begin with the stars, then ascend up and away out to the galaxy, the universe, and beyond. What did Buzz Lightyear say in Toy Story? “To Infinity and Beyond!” It’s a big universe. I