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)
