Allison Hunt: My three minutes hasn't started yet, has it?
Chris Anderson: No, you can't start the three minutes.
Reset the three minutes, that's just not fair.
AH: Oh my God, it's harsh up here.
I mean I'm nervous enough as it is.
But I am not as nervous as I was five weeks ago.
Five weeks ago I had total hip replacement surgery.
Do you know that surgery?
Electric saw, power drill, totally disgusting unless you're David Bolinsky, in which case it's all truth and beauty.
Sure David, if it's not your hip, it's truth and beauty.
Anyway, I did have a really big epiphany around the situation, so Chris invited me to tell you about it.
But first you need to know two things about me.
Just two things.
I'm Canadian, and I'm the youngest of seven kids.
Now, in Canada, we have that great healthcare system.
That means we get our new hips for free.
And being the youngest of seven, I have never been at the front of the line for anything.
OK?
So my hip had been hurting me for years.
I finally went to the doctor, which was free.
And she referred me to an orthopedic surgeon, also free.
Finally got to see him after 10 months of waiting -- almost a year.
That is what free gets you.
I met the surgeon, and he took some free X-rays, and I got a good cgeorge@example.com.
And you know, even I could tell my hip was bad, and I actually work in marketing.
So he said, "Allison, we've got to get you on the table.
I'm going to replace your hip -- it's about an 18-month wait."
18 more months.
I'd already waited 10 months, and I had to wait 18 more months.
You know, it's such a long wait that I actually started to even think about it in terms of TEDs.
I wouldn't have my new hip for this TED.
I wouldn't have my new hip for TEDGlobal in Africa.
I would not have my new hip for TED2008.
I would still be on my bad hip.
That was so disappointing.
So, I left his office and I was walking through the hospital, and that's when I had my epiphany.
This youngest of seven had to get herself to the front of the line.
Oh yeah.
Can I tell you how un-Canadian that is?
We do not think that way.
We don't talk about it.
It's not even a consideration.
In fact, when we're traveling abroad, it's how we identify fellow Canadians.
"After you."
"Oh, no, no.
After you."
Hey, are you from Canada?
"Oh, me too!
Hi!"
"Great!
Excellent!"
So no, suddenly I wasn't averse to butting any geezer off the list.
Some 70-year-old who wanted his new hip so he could be back golfing, or gardening.
No, no.
Front of the line.
So by now I was walking the lobby, and of course, that hurt, because of my hip, and I kind of needed a sign.
And I saw a sign.
In the window of the hospital's tiny gift shop there was a sign that said, "Volunteers Needed."
Hmm.
Well, they signed me up immediately.
No reference checks.
None of the usual background stuff, no.
They were desperate for volunteers because the average age of the volunteer at the hospital gift shop was 75.
Yeah.
They needed some young blood.
So, next thing you know, I had my bright blue volunteer vest, I had my photo ID, and I was fully trained by my 89-year-old boss.
I worked alone.
Every Friday morning I was at the gift shop.
While ringing in hospital staff's Tic Tacs, I'd casually ask, "What do you do?"
Then I'd tell them, "Well, I'm getting my hip replaced -- in 18 months.
It's gonna be so great when the pain stops.
Ow!"
All the staff got to know the plucky, young volunteer.
My next surgeon's appointment was, coincidentally, right after a shift at the gift shop.
So, naturally, I had my vest and my identification.
I draped them casually over the chair in the doctor's office.
And you know, when he walked in, I could just tell that he saw them.
Moments later, I had a surgery date just weeks away, and a big fat prescription for Percocet.
Now, word on the street was that it was actually my volunteering that got me to the front of the line.
And, you know, I'm not even ashamed of that.
Two reasons.
First of all, I am going to take such good care of this new hip.
But also I intend to stick with the volunteering, which actually leads me to the biggest epiphany of them all.
Even when a Canadian cheats the system, they do it in a way that benefits society.
In medieval times, alchemists tried to achieve the seemingly impossible.
They wanted to transform lowly lead into gleaming gold.
History portrays these people as aged eccentrics, but if only they'd known that their dreams were actually achievable.
Indeed, today we can manufacture gold on Earth thanks to modern inventions that those medieval alchemists missed by a few centuries.
But to understand how this precious metal became embedded in our planet to start with, we have to gaze upwards at the stars.
Gold is extraterrestrial.
Instead of arising from the planet's rocky crust, it was actually cooked up in space and is present on Earth because of cataclysmic stellar explosions called supernovae.
Stars are mostly made up of hydrogen, the simplest and lightest element.
The enormous gravitational pressure of so much material compresses and triggers nuclear fusion in the star's core.
This process releases energy from the hydrogen, making the star shine.
Over many millions of years, fusion transforms hydrogen into heavier elements: helium, carbon, and oxygen, burning subsequent elements faster and faster to reach iron and nickel.
However, at that point nuclear fusion no longer releases enough energy, and the pressure from the core peters out.
The outer layers collapse into the center, and bouncing back from this sudden injection of energy, the star explodes forming a supernova.
The extreme pressure of a collapsing star is so high, that subatomic protons and electrons are forced together in the core, forming neutrons.
Neutrons have no repelling electric charge so they're easily captured by the iron group elements.
Multiple neutron captures enable the formation of heavier elements that a star under normal circumstances can't form, from silver to gold, past lead and on to uranium.
In extreme contrast to the million year transformation of hydrogen to helium, the creation of the heaviest elements in a supernova takes place in only seconds.
But what becomes of the gold after the explosion?
The expanding supernova shockwave propels its elemental debris through the interstellar medium, triggering a swirling dance of gas and dust that condenses into new stars and planets.
Earth's gold was likely delivered this way before being kneaded into veins by geothermal activity.
Billions of years later, we now extract this precious product by mining it, an expensive process that's compounded by gold's rarity.
In fact, all of the gold that we've mined in history could be piled into just three Olympic-size swimming pools, although this represents a lot of mass because gold is about 20 times denser than water.
So, can we produce more of this coveted commodity?
Actually, yes.
Using particle accelerators, we can mimic the complex nuclear reactions that create gold in stars.
But these machines can only construct gold atom by atom.
So it would take almost the age of the universe to produce one gram at a cost vastly exceeding the current value of gold.
So that's not a very good solution.
But if we were to reach a hypothetical point where we'd mined all of the Earth's buried gold, there are other places we could look.
The ocean holds an estimated 20 million tons of dissolved gold but at extremely miniscule concentrations making its recovery too cgeorge@example.com.
Perhaps one day, we'll see gold rushes to tap the mineral wealth of the other planets of our solar system.
And who knows?
Maybe some future supernova will occur close enough to shower us with its treasure and hopefully not eradicate all life on Earth in the process.
A little over 100 years ago, in 1915, Einstein published his theory of general relativity, which is sort of a strange name, but it's a theory that explains gravity.
It states that mass -- all matter, the planets -- attracts mass, not because of an instantaneous force, as Newton claimed, but because all matter -- all of us, all the planets -- wrinkles the flexible fabric of space-time.
Space-time is this thing in which we live and that connects us all.
It's like when we lie down on a mattress and distort its contour.
The masses move -- again, not according to Newton's laws, but because they see this space-time curvature and follow the little curves, just like when our bedmate nestles up to us because of the mattress curvature.
(Laughter) A year later, in 1916, Einstein derived from his theory that gravitational waves existed, and that these waves were produced when masses move, like, for example, when two stars revolve around one another and create folds in space-time which carry energy from the system, and the stars move toward each other.
However, he also estimated that these effects were so minute, that it would never be possible to measure them.
I'm going to tell you the story of how, with the work of hundreds of scientists working in many countries over the course of many decades, just recently, in 2015, we discovered those gravitational waves for the first time.
It's a rather long story.
It started 1.3 billion years ago.
A long, long time ago, in a galaxy far, far away -- (Laughter) two black holes were revolving around one another -- "dancing the tango," I like to say.
It started slowly, but as they emitted gravitational waves, they grew closer together, accelerating in speed, until, when they were revolving at almost the speed of light, they fused into a single black hole that had 60 times the mass of the Sun, but compressed into the space of 360 kilometers.
That's the size of the state of Louisiana, where I live.
This incredible effect produced gravitational waves that carried the news of this cosmic hug to the rest of the universe.
It took us a long time to figure out the effects of these gravitational waves, because the way we measure them is by looking for effects in distances.
We want to measure longitudes, distances.
When these gravitational waves passed by Earth, which was in 2015, they produced changes in all distances -- the distances between all of you, the distances between you and me, our heights -- every one of us stretched and shrank a tiny bit.
The prediction is that the effect is proportional to the distance.
But it's very small: even for distances much greater than my slight height, the effect is infinitesimal.
For example, the distance between the Earth and the Sun changed by one atomic diameter.
How can that be measured?
How could we measure it?
Fifty years ago, some visionary physicists at Caltech and MIT -- Kip Thorne, Ron Drever, Rai Weiss -- thought they could precisely measure distances using lasers that measured distances between mirrors kilometers apart.
It took many years, a lot of work and many scientists to develop the technology and develop the ideas.
And 20 years later, almost 30 years ago, they started to build two gravitational wave detectors, two interferometers, in the United States.
Each one is four kilometers long; one is in Livingston, Louisiana, in the middle of a beautiful forest, and the other is in Hanford, Washington, in the middle of the desert.
The interferometers have lasers that travel from the center through four kilometers in-vacuum, are reflected in mirrors and then they return.
We measure the difference in the distances between this arm and this arm.
These detectors are very, very, very sensitive; they're the most precise instruments in the world.
Why did we make two?
It's because the signals that we want to measure come from space, but the mirrors are moving all the time, so in order to distinguish the gravitational wave effects -- which are astrophysical effects and should show up on the two detectors -- we can distinguish them from the local effects, which appear separately, either on one or the other.
In September of 2015, we were finishing installing the second-generation technology in the detectors, and we still weren't at the optimal sensitivity that we wanted -- we're still not, even now, two years later -- but we wanted to gather data.
We didn't think we'd see anything, but we were getting ready to start collecting a few months' worth of data.
And then nature surprised us.
On September 14, 2015, we saw, in both detectors, a gravitational wave.
In both detectors, we saw a signal with cycles that increased in amplitude and frequency and then go back down.
And they were the same in both detectors.
They were gravitational waves.
And not only that -- in decoding this type of wave, we were able to deduce that they came from black holes fusing together to make one, more than a billion years ago.
And that was -- (Applause) that was fantastic.
At first, we couldn't believe it.
We didn't imagine this would happen until much later; it was a surprise for all of us.
It took us months to convince ourselves that it was true, because we didn't want to leave any room for error.
But it was true, and to clear up any doubt that the detectors really could measure these things, in December of that same year, we measured another gravitational wave, smaller than the first one.
The first gravitational wave produced a difference in the distance of four-thousandths of a proton over four kilometers.
Yes, the second detection was smaller, but still very convincing by our standards.
Despite the fact that these are space-time waves and not sound waves, we like to put them into loudspeakers and listen to them.
We call this "the music of the universe."
I'd like you to listen to the first two notes of that music.
(Chirping sound) (Chirping sound) The second, shorter sound was the last fraction of a second of the two black holes which, in that fraction of a second, emitted vast amounts of energy -- so much energy, it was like three Suns converting into energy, following that famous formula, E = mc2.
Remember that one?
We love this music so much we actually dance to it.
I'm going to have you listen again.
(Chirping sound) (Chirping sound) It's the music of the universe!
(Applause) People frequently ask me now: "What can gravitational waves be used for?
And now that you've discovered them, what else is there left to do?"
What can gravitational waves be used for?
When they asked Borges, "What is the purpose of poetry?"
he, in turn, answered, "What's the purpose of dawn?
What's the purpose of caresses?
What's the purpose of the smell of coffee?"
He answered, "The purpose of poetry is pleasure; it's for emotion, it's for living."
And understanding the universe, this human curiosity for knowing how everything works, is similar.
Since time immemorial, humanity -- all of us, everyone, as kids -- when we look up at the sky for the first time and see the stars, we wonder, "What are stars?"
That curiosity is what makes us human.
And that's what we do with science.
We like to say that gravitational waves now have a purpose, because we're opening up a new way to explore the universe.
Until now, we were able to see the light of the stars via electromagnetic waves.
Now we can listen to the sound of the universe, even of things that don't emit light, like gravitational waves.
(Applause) Thank you.
(Applause) But are they useful?
Can't we derive any technology from gravitational waves?
Yes, probably.
But it will probably take a lot of time.
We've developed the technology to detect them, but in terms of the waves themselves, maybe we'll discover 100 years from now that they are useful.
But it takes a lot of time to derive technology from science, and that's not why we do it.
All technology is derived from science, but we practice science for the enjoyment.
What's left to do?
A lot.
A lot; this is only the beginning.
As we make the detectors more and more sensitive -- and we have lots of work to do there -- not only are we going to see more black holes and be able to catalog how many there are, where they are and how big they are, we'll also be able to see other objects.
We'll see neutron stars fuse and turn into black holes.
We'll see a black holes being born.
We'll be able to see rotating stars in our galaxy produce sinusoidal waves.
We'll be able to see explosions of supernovas in our galaxy.
We'll be seeing a whole spectrum of new sources.
We like to say that we've added a new sense to the human body: now, in addition to seeing, we're able to hear.
This is a revolution in astronomy, like when Galileo invented the telescope.
It's like when they added sound to silent movies.
This is just the beginning.
We like to think that the road to science is very long -- very fun, but very long -- and that we, this large, international community of scientists, working from many countries, together as a team, are helping to build that road; that we're shedding light -- sometimes encountering detours -- and building, perhaps, a highway to the universe.
Thank you.
(Applause)