Translator: Amanda Zhu Reviewer: Peter van de Ven
Thank you very much.
I'm glad you don't have the cicadas this time around.
It was a very memorable experience.
Now the theme of TEDx Nashville is having an impact,
making a difference.
By the end of my talk,
I want to explain how each of you individually can make a difference
in deciding how humanity would answer one of the most profound questions
we may someday face.
If we get a message from an extraterrestrial civilization,
what would we say?
By the end of the day,
I want each of you to be knowing how you can participate.
I work for an organization called the SETI Institute -
Search For Extraterrestrial Intelligence.
We use telescopes like this one, our telescope in Northern California,
where we look for signals from distant stars.
We're looking for something that stands out in the cosmic static
and something that's distinctly artificial.
It takes a lot of computing power,
but if we do detect a signal,
one of the big questions that humankind is going to face is,
Should we send a reply back? and if so, What should we say?
Now, there have been a few symbolic transmissions sent out -
by symbolic, I mean they've been one-off sort of efforts,
not a sustained ongoing transmission project.
We're listening at the SETI Institute right now, not transmitting.
Here's an example from the world's largest radio telescope, in Puerto Rico,
a fifth of a mile in diameter.
This message we’ve sent,
which is written in the language of math and science.
Starting at the top,
they’re the numbers from 1 in 10 in a binary code, using ones and zeroes,
then a description of some basic chemical principles,
and once we've described some basic chemistry,
we can talk about how we're composed of chemistry.
So we talk about our own biochemical makeup,
what our DNA looks like -
both the spiral of the DNA and also the chemical composition of it -
and we also talk about what humans look like -
that might be a little bit hard for an extraterrestrial to recognize -
a schematic of our solar system,
and underneath that,
a picture of the telescope that the message is being sent from.
Well, we've also sent messages on spacecraft -
NASA launched the Pioneer spacecraft -
that included this image of a man and a woman,
that's the part that we most readily understand.
And it's also -
It's sort of a galactic postcard
that says both when and where this message was sent from.
So if you look at that kind of spidery set of lines emanating,
that's actually where we're at in our galaxy
in reference to a bunch of pulsars that pulse at a very specific frequency.
And so we're telling anyone who receives it
both where and when this message was sent from.
Now of course, as I said,
the part that might be a little bit hard for an extraterrestrial to understand
is the part on the right.
And sometimes the messages we sent have more meaning than we had intended.
So one of the common responses to this message is,
“Wait a second.
Why is the guy doing the greeting
and the woman is standing demurely by his side?”
Actually, in a follow-up, the Voyager recording,
the rules were shifted,
and the man was standing more demurely beside.
But what we need to be aware of, if we're really going to get serious
about communicating with extraterrestrials,
is they may have radically different ways of viewing the world.
And even here on earth,
we can view the same object that we're all familiar with
and depict it in very different ways.
So, if you're Maori,
you'll look at this and say, "Well, here's a human being,"
but for those who aren't initiated
into the conventions of Maori ceremonial carving,
it looks like just this nice geometrical object.
And you need some sort of a tutorial on how to make sense of it -
what part corresponds to what body part.
Or if you look at a depiction of the human being
among the Abelam of Papua, New Guinea,
their depiction will have arms and legs,
and those little circles represent eyes and stars
because, as everyone knows, in Abelam mythology,
the stars are the eyes of the ancestors looking down on us.
So it's important, as we think about how to communicate with extraterrestrials,
to realize that we may need to do some significant teaching
just to make ourselves understood.
Here are a couple of images from a Voyager recording,
another spacecraft NASA launched,
that included about a hundred pictures on one side,
and next to some of the photographs, there was another image,
in this case, a silhouette created by the artist Jon Lomberg,
that helps show extraterrestrials how to read our pictures.
So an object of the same size at the front of an image
may appear larger on the image than an object of the same size,
in this case, an antelope, that's in the distance.
Now, another way to communicate with extraterrestrials
and to say something that goes beyond basic math and science,
which a lot of messages have been about in the past,
is to talk about music.
Now we've already heard how important music is
in moving us, in conveying our humanity,
I'd like to argue that, actually, there are elements of our music
that may well be universal or at least recognizable.
And part of the beauty of music is that, at least at its basic components,
it's something that we could communicate to scientists on other worlds.
But why do we suppose extraterrestrials are going to be scientists?
Well, if they can create a telescope,
if they are interested in making contact, if they know astronomy,
then they probably know some basic math and science.
So if we can build on that,
like music has some of the same essential elements
of rhythm and frequency and amplitude and duration
that can be described by physicists.
So “Close Encounters of the Third Kind” - those five tones that we’re used to -
was one common Hollywood depiction.
We don't count on the extraterrestrials actually being able to get here;
we think that it's pretty cost prohibitive to actually travel between the stars,
very cheap, though, to send messages.
But the idea of communicating with extraterrestrials through music
isn't new.
Everyone has heard of Cyrano de Bergerac.
We think of him as this guy with the big nose.
What you don't probably know is he was a novelist,
and he wrote a fantastic story about a voyage to the moon.
And of course, in the 18th century, if you're going to voyage to the moon,
what you'd do is take a chariot and strap it onto a bunch of geese
because in the winter, they went to the moon -
everyone knew that.
And when he got there,
he communicated with these beings in a musical language,
in a musical language.
It was probably actually the fact
that the Jesuit missionaries had learned about Chinese,
a tonal language,
so they were picking up on some of that.
But the idea of using music is not a new idea.
And it's an idea that was incorporated into the Voyager recording
that I mentioned before.
So this is a spacecraft that surveyed our solar system,
and when it was done,
passed out into interstellar space.
And it bore upon it images on one side,
a little over 100 images,
and the final two images were a picture of a string quartet,
one of the instruments, and the score for part of that concerto.
And then on the flip side, that starts with music,
we see the playing of the same music,
so there's a link between the way we represent music
and what it actually sounds like.
Now, this was a NASA project,
so there was an emphasis on American and the Western classical tradition -
so there was a lot of Bach and Beethoven.
We had "Johnny be good" -
Chuck Berry got on it.
The Beatles were offered a slot
with "Sergeant Pepper's Lonely Hearts Club Band,"
but they refused for copyright reasons.
(Laughter)
I mean,
what were they thinking?
I mean, this is a great opportunity.
By the time this spacecraft is hurtling between the stars
millions of years from now,
copyright restriction will not apply.
I mean the good news is, in this cosmos there are second chances.
Many years later, NASA had a transmission of another Beatle song;
it was appropriately across the universe.
So we do have some Beatles in space,
I’m glad to report.
Now common to much of the Western classical tradition
is music based on a 12-tone scale.
And a 12-tone scale -
It might seem arbitrary;
well, if an alien even has music, what kind of scale would they use?
Why divide an octave up into 12 pieces?
It's actually a very nice way to create a scale
because if you divide an octave into 12 pieces,
then you have the intervals arranged in such a way
that you can have polyphonic music,
you can have music
that is multiple notes at the same time,
that will be scalable:
you can shift from one key to another key.
So the piano keyboard we're familiar with has 12 notes,
but there are other kinds of music too,
for example, the five-tone scale, pentatonic music,
which we see in a number of Asian musics.
We also see a 31-tone scale,
which is something that Christian Huygens had suggested
as another way of dividing up the octave.
Now the interesting thing about a 31-tone scale:
Can you imagine what that keyboard would look like?
Or what the hands of that alien would have to look like?
Now, the great thing about music is that,
in addition to giving a sense of an introduction
to our emotional experience,
it also would give an extraterrestrial
something about our sense of how we're constructed.
So the fact that we can slice an octave up into 5 or 12 or 31 pieces
says something about our ability to make auditory discriminations.
And similarly,
by looking at the way we pattern our music
and define what sounds like good melody or good harmony,
that reflects something about the cognitive structuring,
that tells an extraterrestrial indirectly something about our brains.
In fact, the Dutch logician Alexander [inaudible] has suggested
that we should send some music, in his example, Indonesian gamelan music,
and from that music
the extraterrestrials would be able to see how we logically order the world.
So that's how we might begin to express something musical,
but there are a lot of other art forms as well on earth -
it's not just restricted to music.
How would we, for example, convey something about the beauty
of one of the Western architecture's greatest monuments,
the Parthenon,
which we have a replica here in Nashville.
Well, I would argue we could start doing that,
start explaining why we view it as beautiful,
by something as simple as counting.
And it's tied into a special way of counting called the Fibonacci series,
where we start with the number one -
and in the Fibonacci series, you take a number
and add it to the next number -
and so you take one and add it to itself,
and 1 + 1 = 2, and 1 + 2 = 3,
and 2 + 3 = 5.
And what you find is
if you draw a spiral between those squares,
you end up with a shape
that's tied into objects within our natural universe -
spiral of a nautilus shell, spiral of spiral galaxies -
it's tied into proportions that we view as beautiful.
So you can look at the facade of the Parthenon,
the front of the Parthenon,
and see some of those same proportions tied into the Fibonacci series
that would give an extraterrestrial a sense of what we view as beautiful.
And we might encode it,
we might send it in something as simple as a series of pulses.
In this case, we're showing the Fibonacci series
both in the pulses and in the spaces in between.
So these are some of the ideas
that the folks who have been directly involved
in the search for extra- terrestrial intelligence
have been thinking about.
But what we want to do now at the SETI Institute
is expand the discussion,
and so we've started a new project called "Earth speaks,"
that asks the question
"If we got a signal from another civilization,
what would you want to say?"
And I want to encourage all of you to go online,
contribute your messages.
And let me give you just a sampling
of some of the messages we've gotten
from, now, over 70 countries around the world.
Some of them have a basic mathematical content like we've discussed.
This resolution’s a little bit bad,
but it's prime numbers: 2, 3, 5, 7, 11, 13,
numbers divisible only by themselves and one,
something that we would think
that mathematicians on other worlds might know as well.
This one from the Czech Republic
shows some of our ways of counting and depicting different numbering systems,
so again, sort of mathematical sort of message.
Others are more pictorial.
So this one from Mexico shows a human eye
and underneath it -
you also have the option of putting a tag or a label on your message -
this one says,
"Astronomy was started by discovering the stars with our eyes."
So we're making contact with alien astronomers.
Maybe they know -
Maybe they have eyes as well.
Or we might have images.
Some of the other images that are submitted
are actual depictions of astronomical and other objects.
This message from France shows a common theme,
which was to try to show
that we're not always so parochial in the way we think about the world
and we try to put ourselves in a broader galactic context.
So here's a snapshot from this person's home city in France
and then where that city is located on the map of our earth
and where that's located in the broader cosmos.
And here's another one
showing something about our technologies and our environments,
and at the bottom of this image,
you see a progression of hominid evolution.
And I think there's this implicit message, often, in this classical image
that humankind is at the pinnacle of evolution,
which of course a biologist would disagree with.
The thing I love about the next message
is it shows which species is really in charge on earth.
And this one says, "Make sure not to hurt the cats."
(Laughter)
Now, of course my great fear in the search for extraterrestrials
is extraterrestrials will be like intelligent cats,
and that they know we're here, but they don't care.
(Laughter) (Applause)
And then the question is -
You have one of those too, right? Yeah, my wife and I have two.
What do you do when they disagree? Who do you obey? Right?
The challenge is,
How then do you communicate with someone?
How do you make it sufficiently intriguing?
What do you appeal to?
So part of the value of this project is that we get so many new perspectives
and maybe that one of those perspectives is like the interstellar yarn
that will make our intelligent alien make contact and reply to us.
Some of the other messages:
A common one was, "Please help. Help save our planet.
Some of our species are destroying it. The rest of us can't stop them."
We see it visually with global warming.
There are also a number of messages
that talk about our ambivalence about making contact:
"Some of us are hoping to know you.
Others are afraid of you. The rest don't believe in you."
"As much as some of us would like to meet you,
most of us will be too afraid to handle your very existence.
Be prepared."
And you know, if we just look at the words that are used
and how often they're used in these messages
compared to English in general,
the word “but” is used 150 times more often.
Why?
It’s a sentence like this:
"I'd love to make contact, but my neighbor would be afraid."
(Laughter)
And the last one I love
because it conveys something about our quintessential human characteristic
of a sense of humor:
"Hello! Please come pick me up.
I'm a librarian, artist, and I prepare great Earth dishes."
(Laughter)
So these are just a sampling of the messages.
Come to the website. Check them out.
We continue the search.
You know, as we are speaking right now,
the telescopes - there are big winds in Northern California,
so we are shut down right now.
In a few hours, we will resume,
and when we do,
tonight could be the night we discover an extraterrestrial.
And so, if we do, that's when we need your help
because it shouldn't be just a handful of scientists
who decide what to say to another civilization;
it should be folks from around the world.
And so, if you want to make a difference, come to our website,
let us know what you would want to say to an extraterrestrial.
I'll be looking forward to your message.
Thank you very much.
(Applause)