in making it possible for us to do things

that would've seemed like magic tricks not too long ago-

space travel, flight!

For most of history, that seemed absolutely impossible.

Birds can do it.

We're stuck here on the ground, looking up.

Think of how many gods and mythical figures

were given the power of flight.

We wanted it so bad, and now we've managed to do it.

The oldest living person in the world was alive

when the Wright brothers flew the first flight at Kitty Hawk

and now we have a helicopter on Mars.

The more we understand ourselves and our Universe,

the more magnificent it is.

I'm Sasha Sagan,

and I'm the author of a book

called "For Small Creatures Such as We."

I was brought up with a very scientific worldview.

My dad was the astronomer Carl Sagan,

and he and my mom, writer-producer Ann Druyan,

fell in love working on the Voyager Record,

which is a golden phonograph

that is a compilation of the sounds of life on Earth.

Greetings and human languages, and one whale language.

- 'Hello from the planet Earth.'

- Music from around the world.

Sounds of a heartbeat.

Brainwaves of a young woman in love

who happened to be my mom.

These two records are on the Voyager Spacecraft,

and they have a shelf life of a billion years.

Right now, the Voyager Spacecrafts

are the furthest objects from Earth

ever touched by human beings.

And then my parents wrote essays and books,

and the television series "Cosmos,"

about the awe and wonder that we can find in the Universe.

Things that we really do understand

that we've managed to discover

can be presented with enthusiasm and wonder and awe

that makes people feel welcome in reveling

in how astonishing things are in the natural world,

as revealed by science.

- 'In the last few millennia

we have made the most astonishing and unexpected discoveries

about the cosmos and our place within it.'

- One of the things I learned

from my parents is this idea of tolerating ambiguity.

Sometimes when we make up an answer,

it's just a placeholder because we're so bad

at sitting with an empty question mark.

But I think we can all improve

on sitting with the discomfort of not knowing.

Tolerating ambiguity, waiting until you have evidence,

knowing that sometimes the evidence will change,

is central to any scientific advancement.

My dad, one of the things he was most curious about

in his life was:

Are we alone in the universe?

Is there anybody else out there?

- 'Everyone wants to know how unique the human species are.

How is it possible that in a galaxy of 400 billion stars

that we are the only inhabited planet?

Is that possible?'

- He was so eager to understand.

He wanted to find out what was really going on.

But the discomfort we sit with,

even with the very small questions,

reveals how we feel about the unanswered great mysteries

in our lives.

It's so hard to not know.

Even the future tortures us

with our inability to predict it.

And we have struggled for eons with this problem.

It's a source of so much stress,

but science is the only, only tool

that has given us any real shot.

I think about "A Connecticut Yankee in King Arthur's Court":

an eclipse was terrifying all over the world.

The Sun goes away all of a sudden.

What could be more petrifying?

And now we know when they're coming, and we know it's safe.

It won't hurt us.

Little by little,

we're getting some of the tools

that we've always longed for through science.

Not that long ago, for our species,

so much in life, even the most mundane, ordinary things

would've seemed like a magic trick.

And I think that's true for so much of science,

and so much of the reality of our Universe.

And the more we understand ourselves and our planet,

the more magnificent it is.

My dad felt an enormous, joyful wonder

about the Universe from his earliest childhood.

If he had been born a few hundred years earlier,

it would've been a lot harder for him to get the answers

that he so deeply craved

about our place in the Universe.

A quote that you'll often hear of his is:

"I don't want to believe, I want to know."

And I think that really sums up a lot of his philosophy.

He really instilled in me this idea

that reality, nature, is more astonishing

and more breathtaking than the stories

that we create for ourselves.