Look up for a change

The sky is inherently democratic.

It's accessible, in principle, anyway,
by anyone, everywhere,

just simply by the act of looking up.

But like so many
beautiful things around us,

it's slipping away from us,
and we haven't even noticed,

because we're honestly not really looking.

So what do we look at instead?

Well, we look at our phones,
we look at our computers,

we look at screens of all kinds.

And honestly, we rarely
even take the trouble

to look up enough to see each other,

let alone taking that next step
to looking up at the actual sky.

Now, there's a tendency to think
that the loss of our dark night skies

is the inevitable outcome
of progress, change, technology.

And you know, that's just simply not true.

Later on, I'll tell you why.

But first, I want to tell you
about my experience of the dark night sky.

I never saw a truly dark night
sky until I was 15.

I was here, in Arizona.

I was on a road trip;
I pulled over somewhere.

I have no idea where I was,
except I know what state.

And I looked up,

and the sky was just filled
with an impossible number of stars.

You see, I'm from New York City,

and in New York, you can see the moon,
you can see a couple of stars.

More often than not, they turn out
to be airplanes when they land.

(Laughter)

But there's really not much else.

As a result, most of my colleagues
who are astronomers

spent at least part of their youth
looking up at the sky in their backyard.

I never really had that experience,

and, as a result, I'm really
disappointing on camping trips.

I don't really know many constellations.

The ones I do know,
you probably know them, too.

But I'll never forget that experience

of the first time I saw
the dark night sky.

And I was just flabbergasted
at how many stars there were.

And I felt tiny.

Then I also felt like,
"Where's this been hiding this whole time?

Who's been hiding this sky from me?"

Of course, the answer is obvious
if you think about it

or if you look at the picture on the left,

where you're seeing the same neighborhood
taken during a blackout

versus on an ordinary night.

You can't see the stars
if you drown them out with light.

Take a look at our planet.

This is our planet from space.

Unlike stars, which are hot and glow
invisible light so we can see them,

our planet is, astronomically
speaking, pretty cold.

So it doesn't really glow.

When you see the planet looking
like a blue-green marble

the way it does in this picture,

you're seeing it because the sunlight
is reflecting off of it,

and that's why you can see
the oceans, the clouds, the land.

So if the sun wasn't shining on it,

we wouldn't be able
to see the earth, right?

Or would we?

This is our earth at night,

and it is one of the most
striking examples

of how we have affected
our planet on a global scale.

You can see light spidering out
across the globe everywhere.

Now, of course, there are broad expanses
of ocean that are still dark,

and in many underdeveloped areas
there's still darkness.

But you'll notice
that this is a pretty global effect.

We tend to think, when we think
of places being lit up,

of very extreme examples --
Times Square, the Vegas Strip.

But really what that picture shows you

is that it's not just
these extreme examples,

it's anywhere that uses outdoor lighting.

This tends to be a really
dramatic effect on the ground.

To understand why,

all you really have to do
is think about the shape of a lightbulb.

The lightbulb, for all practical purposes,

is more or less round.

This is great for its original intended
purpose of lighting up the indoors.

You turn it on, light goes everywhere.

An individual light bulb can light up
your whole room, more or less.

Now, that's great
if you're lighting the indoors,

but in its application
in outdoor lighting,

that traditional shape of the light bulb,

the sort of globe that spreads
light everywhere,

is actually very inefficient.

When you're outdoors,
mostly what you care about

is lighting the ground beneath you
and your immediate surroundings.

All of that light that gets scattered
outwards and upwards

doesn't actually help you
light the area around you.

What it does is scatters up into the sky

and becomes what we call
"light pollution."

Even if you don't care anything
about stargazing, this should worry you,

because it means that 60-70% of the energy
we use to light the outdoors

is wasted by blotting out the stars.

Now, like I said,
I'm a big fan of technology.

Obviously, I use technology
every day; I'm a scientist.

And there's this tendency
to say that it's progress that --

you know, I'm not suggesting
we're going to all go live by candlelight.

Indeed, technology is allowing us
to access the sky

in ways that are impossible otherwise.

One of the greatest examples of this is,
of course, the Hubble Space Telescope.

The Hubble went up into space,
it returns pictures daily,

and it allows us to see things

that we are incapable of seeing
with our naked eye,

in ways that we've never been able
to do before in all of human history.

Other examples of this
would be planetarium shows.

In the past couple of years, planetarium
shows have become more high-tech

with these great visualizations,

and even though this isn't access
directly to the sky,

it's at least access
to our knowledge about the sky.

And indeed, we can experience
the sky in a planetarium

in a way that is impossible for us to do

just sitting out and looking in the dark.

All of you have heard of the Hubble
Space Telescope and of planetariums.

But there are also ways
for technology to enable participation

in people's experience of the sky

that you may not be familiar with.

These are called
"citizen science projects."

Citizen science is when large
research projects put their data online,

teach ordinary people, like you,
to go and interact with that data

and actually contribute to the research

by making interesting or necessary
characterizations about it.

One such example of this is what
I'm showing here, called "Galaxy Zoo."

Galaxy Zoo is a project

where people get a 20-minute --
even less than that, actually -- tutorial

on how to interact
with these images of galaxies.

They learn to annotate the images,

and within a couple of minutes,
they're up and running,

and they're making really
useful categorizations

and classifications of these galaxies.

Now, it's easy to understand

why Galaxy Zoo would be an easy sell
for people to be involved with:

it involves pretty pictures;

galaxies are, generally
speaking, pretty attractive.

However, there are many other flavors
of citizen science projects

that people have delved into

that have varying levels of abstraction,

that you wouldn't necessarily think
people would jump at.

One such example of this
is the citizen science project

associated with the mission
that I'm part of,

called the Kepler Mission.

Kepler is a space telescope and it looks
for planets around other stars

by measuring the light
from those stars very precisely.

And we're looking for the dimmings

caused by stars blocking off
some of that light.

We have an associated citizen science
project called "Planet Hunters."

Planet Hunters gives you,
like Galaxy Zoo, a short tutorial,

and within a couple of minutes,
you're up and running;

you're looking at data
from the Kepler Mission

and looking for planets.

The idea behind this
is an easy sell, right?

But the actual process of planet-hunting
involves a lot of looking at graphs,

like the one I'm showing you here,
and annotating them.

I do this all day and that doesn't even
sound that interesting to me.

However, not only are people
interested in doing this,

but the citizen scientists
that work with Planet Hunters

have actually found planets in the data

that would have gone
undiscovered otherwise.

This is an author list
from the paper that they published

of the planet they discovered.

You'll see that all the people
who contributed are listed below,

and it's sort of an odd amalgam
of people's real names

and their log-in names.

You'll notice if you look carefully,
this is the first academic acknowledgment

of the importance of Irish coffee
in the discovery process.

(Laughter)

I don't want to give you the idea
that these are some out-of-work scientists

or just a bunch of nerds
that are really into this.

There are 60,000 people
who participate in these projects,

and most of them don't have
technical backgrounds.

So clearly, what this is feeding into
is people's curiosity

and their willingness to be part
of the scientific discovery process.

People want to do this.

But all of this technology

and all these digitally mediated ways
of experiencing the sky

still have something of a feel to me
like looking at an animal in a zoo.

It's a valid way
of experiencing that thing --

indeed, the lion in the cage
is still real,

the Hubble images are indeed real,

and you can get closer to a lion in a zoo
than you can in the wild.

However, it's missing something.

It's missing that savage beauty

of experiencing that very thing
in the wild for yourself,

unmediated by a screen.

The experience of looking up

and knowing that the sky you're looking at
surrounds every known living thing

in the universe

is very profound.

Think about that for a moment.

We are the only planet we know of
that has life on it.

The sky that you see is shared
by every other living thing

that we know of in existence.

One of the things
that I really like about my work

is that it allows me to step back
from my every day

and to experience the larger context,

this feeling that just as we go out
and try to find planets in the universe

that might be like ours,

it always reminds me
of how precious what we have here is.

Our night sky is like a natural resource,

it's as though it's a park
that you can visit

without ever having to travel there.

But like any natural resource,

if we don't protect it,
if we don't preserve it and treasure it,

it will slip away from us and be gone.

So if you're interested in this,

and this is something
you want to learn more about,

I encourage you in particular
to visit darksky.org

and to learn more
about the choices you can make

that can protect the dark night sky,

because it belongs to everyone,
it belongs to all of us,

and therefore, it's ours
to experience as we wish.

And it's also ours to lose.

Thank you.

(Applause)