TED Radio Hour - Making sense of the sun

Episode Date: November 20, 2024

The sun rises and sets every day of our lives, but it still holds many mysteries. This hour, TED speakers share the latest in probing, replicating, and harnessing the power of our massive star. Guests include astrophysicist Nour Rawafi, fusion physicist Tammy Ma, renewable energy strategist Rebecca Collyer and science journalist David Baron. TED Radio Hour+ subscribers now get access to bonus episodes, with more ideas from TED speakers and a behind the scenes look with our producers. A Plus subscription also lets you listen to regular episodes (like this one!) without sponsors. Sign-up at: plus.npr.org/tedCorrection: a previous version of this story referred to Nour Rawafi as a NASA scientist, when in fact he is a scientist at the Johns Hopkins Applied Physics Laboratory (APL) and NASA. The international team working on NASA's Parker Solar Probe mission are comprised of scientists from APL, NASA, and several other organizations.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

This is the TED Radio Hour. Each week, groundbreaking TED Talks. Our job now is to dream big. Delivered at TED conferences. To bring about the future we want to see. Around the world. To understand who we are. From those talks, we bring you speakers and ideas that will surprise you.

You just don't know what you're going to find. Challenge you. We truly have to ask ourselves, like, why is it noteworthy? And even change you. I literally feel like I'm a different person. Yes. Do you feel that way? Ideas worth spreading.

From TED and NPR. I'm Manoosh Zamoroti. Today on the show, an exploration of one of the most powerful forces in our lives, the sun, starting on September 1st, 1859. That day, a British astronomer named Richard Carrington was looking at the sun and sketching sunspots, the dark patches on the solar surface. He was watching through his telescope and drawing them by hand. This is astrophysicist, Nora Rwaffe.

And all of a sudden he saw something new. It was a bright light that lasted for nearly five minutes. And he just was mesmerized of this new thing that he never seen before. Carrington had no idea what it was. until the next day when strange things started happening. Electric currents zipped through telegraph wires, setting telegraph stations on fire. Communications the world over were knocked out. Meanwhile, bright colored lights, aurora, lit up the sky.

People were seeing aurori in daytime around the whole globe. The New York Times described them as streamers, rapidly changing hue from red to orange, orange to yellow, yellow to white, back to brilliant red. In the Rocky Mountains, the sky was so bright at midnight that confused gold miners woke up and started making breakfast. Carrington connected the dots and hypothesized that the bright light he'd seen was a solar flare, a storm on the sun, so powerful that the radiation it released reached the earth, disrupting the magnetic fields that surround our planet. But there were a lot of skepticism.

It took really decades afterwards to realize, yeah, actually we are connected to the sun. Carrington was eventually proven right. This incident is now referred to as the Carrington event, and it is the strongest geomagnetic storm ever recorded. Meaning, if it were to happen today... In some places, people will be out of power, for months, maybe for even years.

And the economic losses will be in the trillions of dollars. Nowadays, we depend a lot on satellites, communication satellites or GPS, satellites over there in space. So these geomagnetic storms can impact technology in space. And one prime example of this is the loss of Space X of nearly 40 satellites in 2023 or 24. That's actually what's the result of a geomagnetic storm. It just knocks them out.

Exactly. Absolutely. So solar storms can spell disaster. But the good news is that now, scientists like Nora Rwaffe at the Johns Hopkins Applied Physics Laboratory and NASA are constantly monitoring sunstorms. We know what the sun does at any moment. When there is an explosion, a flare or corner mass ejection, we see it. We know what direction they are going, how powerful they are, how fast they are, and we can even predict what would be the impact here on the Earth environment. But, Noor and his team also have a spacecraft that is orbiting the sun

and is due to fly closer to it than ever before, collecting data so that we can better understand why these storms happen and solve other solar mysteries. Without the sun, there will be no life on Earth, there will be no solar system, there will be no Earth. So in a way, we are the sons of the sun. It's our star. We owe our existence to the sun. But also our daily life depends on it.

The sun is at the center of our solar system. It rises and sets on every day of our lives. We worship it. Absolutely have to have it. But there is so much we don't know about this massive star that we depend on. So today on the show, making sense. of the sun. What powers it and how we can replicate and harness that power? So back to Tunisian astrophysicist Nora Rwaffe and his team of international scientists.

Their spacecraft, the Parker Solar Probe, has been orbiting the sun for the past six years, completing a full revolution around it every three months. And on Christmas Eve, 2024, it is due to touch the sun. Since the dawn of the space age, NASA has wanted to fly a spacecraft as close as possible to the sun. Here's Nora Rwaffe on the TED stage. But getting very close to a star is extremely risky and really hard. How would we protect a probe from just melting? How could it adjust for any problem on its own when you cannot communicate with it?

Until recently, we simply didn't possess the technology. In 2018, that all changed with the launch of Pakistan. probe. Arcad Solar Corp is the first spacecraft to ever fly through the solar corona. It has revolutionized our understanding of the sun. So the probe is roughly the size of a small car and making sure it wouldn't go up in flames as it approached the sun was an engineering feat. The only thing standing between the probe and the incineration is an ingenious 11.5 centimeter thick, 2.3 meter wide carbon foam shield. On Christmas, Christmas Eve, 24, the shield's sun-facing side will endure about 1,000 degrees Celsius.

The shield reflects light, absorbs heat, and is cooled by a network of water-filled pipes. All this system will be operating on December 24, 2024, when Parker Solar Probe achieves humanity's closest ever approach to a star. This will be a monumental and audacious achievement. In 69, we landed humans in the moon. And 24, we're going to embrace the star. It's being described as an attempt to touch the sun. Is that accurate? Well, we are flying within the solar corona.

So the solar corona is part of the sun. Uh-huh, uh-huh. So we are flying through it. We are touching the atmosphere of the sun. And what information will be coming back to you? Barker Solar Probe have a whole suite of instruments. around it. We have an imager, a white light imager that will image the solar wind and all that solar activity that happens as it propagates from the sun all the way out. We have also instruments

that measure magnetic fields, temperatures, densities, fluctuations, velocities, energetic particles that are flying almost at the speed of light. How does it send back all of this data to you? That is a challenge for us. because the geometry doesn't allow us to talk to the spacecraft all the time. So we need the spacecraft to be in certain areas of space when the antenna can point to Earth. That way we can communicate. And basically we sent information to the spacecraft.

The spacecraft can send us data and information as well. The sun holds over 99.8% of the solar system total mass. It's sheer size is mind-boggling, requiring. more than 1.3 million Earths to feel its volume. All of that mass is in the form of plasma, a glowing soup of electrically charged particles. At the solar core, gravity is exceedingly high, producing temperatures in excess of 15 million degrees Celsius.

The solar surface is plenty hot, 6,000 degrees, hot enough to melt anything we know. But in the corona, we're talking millions of degrees Celsius. How can it be over 300 times hotter, despite being the sun's outermost layer. Physicists have suggested since the 50s that all of that heat must generate a constant flow of particles. This is the solar wind.

It speeds away at up to 3 million kilometers per hour. At that speed, you can get from the earth to the moon in under 20 minutes. Behind all this is the sun's magnetism. As solar magnetic fields twist, bent, and tangled, they store enormous amounts of energy. And when they snap, huge explosions like flares and coronal mass ejections release this energy

and turn it into heat and accelerating the plasma. It takes only a handful of these strong events to fulfill our current energy needs for some 200,000 years. That is the whole span of modern human's existence. The sun does that in minutes to a few hours. The same explosions propel particles to nearly the speed of light and turn them into formidable hazard to spacecrafts and to humans in space.

Our power grid convicts were victim, like in March 1989 in the northeast of the U.S. Canada, when a succession of solar storms caused an intense geomagnetic storm. So we need to learn how the sun does all this and more. What is the prediction in terms of solar flares and storms in the next day? decade or so. Well, we are at the solar maximum now, and that's actually one of the big mysteries is predicting how strong the solar cycle will be. That's one of the big things that now we are

trying to understand, but it's not really easy at all. So we need some new missions to help us understand what is going on in the interior of the sun itself and observe the sun for a long time from different viewpoints to come to terms how the magnetic fields form in the solar interior and how they rise to the surface and how what is the source of their cyclic nature. And if you think of it, Parker's solar probe is flying through origin of space that we never visited before. And whatever measurement we make there might actually carry with it a potential discovery for us. You have a look of absolute delight on your face as you're describing this.

Did you think you would learn these things in your lifetime? Sometimes it's still kind of, it's like a dream, but you are living it. And the fascinating thing about Park Solar Probe is also that the pace of the mission is so fast, so rough. Every three months, we have a flyby around the sun, and we have a new. you load of data. We are like spoiled kids in a way. Whenever we get a new load of data, we jump on it. We are so curious what is in you in it. The data we are getting from it is so loaded with knowledge, with new things that we need to investigate. That is going to take us decades from now to look into it. And in a way, Barka Solar Prop will serve generations to come, many generations to come.

And for me, Parker Solar Probe is a mission for the ages. That was astrophysicist Noor Rwaffe. He is a senior scientist at the Johns Hopkins Applied Physics Laboratory and the project scientist for NASA's Parker Solar Probe. You can learn more about the Parker Solar Probe mission at science.nasa.gov slash sun. And you can see Noor's full talk at TED.com. On the show today, the sun. I'm Manoosh Zamoroti, and you're listening to The TED Radio Hour from NPR.

We'll be right back. It's the TED Radio Hour from NPR. I'm Manoosh Zamoroti. And on today's show, The Sun. In Central California, there is a government research facility, a massive campus with a particular building, a building like no other. It's 10 stories tall, the size of full. three football fields stacked side by side. And in there is the largest, most energetic laser in the world.

A laser that criss-crosses from one side of the building to the other, being amplified and then split, amplified and split again and again and again until there are 192 lasers, all firing at once. To create for just a fraction of a fraction of a little. second, a burst of energy, a blip of burning plasma, a star. So fusion is the reaction that powers the sun. This is Tammy Ma. She is the scientist leading the fusion project at the Lawrence Livermore Laboratory.

Fusion is one of the most fundamental reactions of the universe that makes. makes life possible here on Earth and is responsible for almost everything in the world around us. In space, stars make fusion look easy. Their gigantic mass creates such immense gravitational forces that hydrogen is squeezed together, fused together, into the heavier element of helium. And through that process, generating a ton of energy, a ton of heat. And so you can think of the sun and the stars as these giant balls of plasma that are constantly fusing. There is no way to create that kind of gravity here on Earth. But Tammy and her colleagues do have a way of bringing those elements together.

That super powerful laser. And if we can recreate fusion here on Earth in a controlled way, If we can make it work, it is the holy grail of energy. Fusion means unlocking a different kind of nuclear power. On the TED stage, Tammy Ma recently explained the big benefits of fusion power. For one thing, it creates a tremendous amount of energy. How tremendous? Well, one single pound of fusion fuel has the same amount of energy as 5,000

barrels of oil or three and a half million pounds of coal. And speaking of fuel, the field that we need for fusion is also very abundant. Fusion needs hydrogen isotopes called deuterium, which is found naturally in seawater and another one called tritium. We actually have enough fusion fuel on Earth to last us 30 billion years of human consumption at today's levels. Fusion also promises. to be clean, because when hydrogen and helium are fused together, they don't release carbon. Carbon is nowhere in that equation. And fusion is considered pretty safe. In order to start a fusion reaction, we first have to put energy into the system to make the atoms fuse. To stop a fusion reaction, the power going in just needs to be turned off. And while fusion creates some waste,

It's not the kind of waste that will last for tens or hundreds of thousands of years. Instead, the low-level nuclear waste of fusion can decay away in just decades. Now, to be fair, there are some downsides to fusion, too. Fusion is incredibly complex and incredibly difficult. The development of fusion has been and will be expensive. But the potential benefits of fusion are so bright, that it is worth it. I mean, there is a joke.

I'm sure everybody always says this to you, Tammy, but the joke is like, Fusion is just around the corner. It is the new source of energy in the next five years, the next decade. It's kind of like the sign at the bar that says, free beer tomorrow.

That's a good analogy. So we call Fusion one of the grand scientific and technological challenges of humankind. We've been trying to recreate fusion on Earth since we understood what fusion was. So British scientists actually figured out the fusion reaction and patented it in the early 1940s. But you have to build tools that are strong enough that can help you to contain that plasma. And you have to keep it going

long enough that you could generate a lot more energy out than you put in in order for fusion to be commercially viable. Fusion experiments big and small are happening all around the world. One major milestone many are working towards fusion ignition. So the definition of ignition is more energy out of the fusion reaction than the laser energy that it took to actually get the reaction going. That is the goal of Tammy's lab, which cost 3.5 billion, and took 12 years to build.

Let's go back to that ginormous laser. It's called the National Ignition Facility, or NIF. We're going to split that beam into 192 weights and then directed towards the fusion chamber. Half the laser beams go up and half come down, and they're going to concentrate their light on a tiny cylinder that sits right in the middle, about the size of a pencil eraser.

The lasers go into that cylinder and create a bath of x-rays that then envelop the little fuel pellet that sits right in the middle. We're going to reach temperatures of over 180 million degrees Fahrenheit, hotter than the center of the sun, and pressures that would feel like 100 billion Earth atmospheres pressing down on you. And then we start a little spark right in the center, creating a miniature star and with it a huge burst of energy.

And if we do it right, we can actually get a whole lot more energy out than the energy that went in to start all of us. So NIF is the most energetic, the largest laser system in the world. Explain what that actually means, like how much energy it uses. So every time we fire those lasers, it is a thousand times the power of the entire U.S. electrical grid. Whoa. I know that sounds crazy. Yes, it does.

You know, every time we fire the lasers, it's not like your lights flicker at home, right? You don't know we take a shot. So what we're doing is we're taking a huge amount of energy, but we're compressing it down into just nanoseconds, fractions of the blink of a human eye. And so that's why we're able to actually draw our energy off of the Alameda County electrical grid. It's about $21 in electricity for shot. So not crazy, crazy.

And then that energy all gets concentrated on that fusion fuel to try to recreate a miniature star in the laboratory. I mean, it sounds like the most incredibly powerful high-tech oven on our planet. But like an oven, can you turn on a light and see what's happening inside? How do you know it's working? That is a great question. What we're able to do is with our diagnostic instruments, try to pull out all the information that we can. We're able to capture particles that can tell us by how fast they were moving, what temperature the plasma was. We have some of the fastest x-ray cameras in the world, capable of 50 billion

frames per second so that we can... 50 billion? 50 billion frames per second, yeah. So we can piece those together and create a movie of how that plasma is actually forming. And from that, infer how good the experiment. was. Our team at Lawrence Livermore National Lab are the stewards of work that started in 1960 because of national security. We need to understand fusion to understand how to ensure that our U.S. nuclear arsenal stays safe and effective. And that is what has provided the steady funding to pursue this very difficult physics challenge over decades. And in that time, we've improved our physics understanding and computational simulation models.

We've designed new diagnostic instruments capable of taking better, clearer, faster pictures of the experiment. We've continuously pushed up the laser energy and found ways to build better targets. And guess what? In December of 2022, we finally did it. Our team at Lawrence, Livermore National Lab demonstrated fusion ignition. For the very first time in human history,

we generated a controlled thermonuclear fusion reaction in the laboratory that generated more energy out than went in with the lasers to start in. And now, now we've actually been able to repeat ignition four more times in just the last 15 months, with our most successful experiment, giving us over twice as much energy out as we put in with the lasers. Getting ignition was the core goal of the NIF, your laser. It was a key milestone for fusion science. But what was that moment like for you personally? Funny enough, Manus, I have actually slept through a lot of those experiments.

We run the machine 24 hours a day, seven days a week. But I did get the call the next morning. morning when I was at the airport and my boss actually calls me and whispers into the phone and says, Tammy, I think we got ignition. And I paused for a second because this is something that we've been working on for, like I said, decades. And I just burst into tears. I was so excited. Oh, you did? Yeah, and I started jumping up and down at the gate. And so I was just absolutely thrilled and tears were rolling down my face because it's something that you and a team of people

have dedicated your life to and to be able to be there for that breakthrough was just enormous. So are we done? Well, not quite. In order to move towards that fusion energy future, we'll have to figure out how to harness this energy in a working fusion power plant.

And to be clear, there's still a long scientific, and engineering road ahead. Just to build on our successes at NIF, we'll have to build more efficient lasers, mass-manufactured targets, and figure out robotics for automated operations and more. The depth and breadth of this challenge

will require sustained investment from government and private industry and all of us working together. We're all racing to make this reality, but there's still a lot more work to be done. What do you say to critics who, you know, maybe they say the same thing about landing on the moon? Why are we pouring billions and billions of dollars into projects that may or may not work when we could be using that money right now to solve problems with technologies, take solar, for example, that we do know that they work? How do you respond to people who feel that way about fusion?

I respond that it is the human story, and it is what makes us human to continue exploring and continue pushing the boundaries. Because there's all kinds of benefits as you do that that you don't even know about. For example, extreme ultraviolet lithography, EUV lithography, which is the technology that allows us to print, smaller and smaller computer chips with greater and greater capability, that technology was actually a spin-out from laser fusion research. And it was nothing that we intended to do, but there's all kinds of benefits to doing forefront science and technology development. And fusion is one of them. And for me, even being able to help a little bit, being able to push the boundaries and do science and generate conditions like we have at the center of the sun, right, here on Earth.

Experiments that have never been done before is just so exciting and so motivating. And if I can contribute a little bit to pushing the field forward, I'm happy. That was Tammy Ma. She leads the inertial fusion energy initiative at the Lawrence Livermore National Laboratory. You can watch her full talk at ted.npr.org. On the show today, the sun, including how humans can collect all the energy that naturally emanates from it. As humanity, we've always harnessed the power of the sun. You know, people putting out their clothes to die, people drying fruit and vegetables, people orientating their houses towards the sun.

This is the story of our survival. This is Rebecca Collier. She is the executive director of Renew 2030, a global coalition working to rapidly scale renewable energy, especially solar energy. In the turn of the last century, in the 1900s, people started to really think about how to do that from a technology and an electronics perspective. And so the solar panel was born. And at the beginning, it was really inefficient and really expensive to build. but by improving the technology bit by bit by bit, the cost of a solar panel has come down to now these days being cheaper,

not just than coal, but also than natural gas power. And that means that solar, both distributed solar, that you can put on your backyard, or large-scale solar that might cover a football field, it's really now cost-competitive and scalable. Finally, some good news about dealing with climate change. The world is on track to install 29% more solar technology in 2024 than the previous year. More than half of the energy added to the U.S. electrical grid comes from solar now.

Those rates are even higher overseas. But Rebecca's organization wants countries to make this transition even faster. We want solar alongside wind to make up the backbone of the electricity system by 2030. And that feels like a hurt. I mean, it's interesting. It's popular in my neighborhood to put solar panels on your roof, but I haven't done it yet because it's still something you have to go seek out. It's still putting in a fair amount of money before you see returns. So as easy as it is, and as much as I see it in my life, it still feels like we haven't quite gotten to the moment where it takes over. Is that, that's just my personal experience. But tell me if that's a indicative of what you're saying? I really think it depends where you are. So I want to turn this back and ask you loads of questions. Like, you know, what would it take? You know, do you want more leaflets through the door? Do you want neighbors knocking on the door and saying, oh, let's do it together?

Do you want a tax rebate from the government? Or is it that you actually, when you do a renovation, you want your contractor to include it in a package and not even to have a think about it? Those are some of the things that we've seen work in other places. You're right, it's not everywhere, but we saw a huge uptake in Europe after the Russian invasion of Ukraine, partly because people were so concerned around their energy bills. In America, you've got some amazing credits in the Inflation Reduction Act. And in China, it's panel after panel after panel being rolled out across homes and schools and hospitals. So I think in some markets, we've reached a tipping point.

But in others, it's still just getting off the ground. In a minute, what a solar success story looks like. We hear about one of the biggest solar plants on the planet in Morocco. On the show today, making sense of the sun. I'm Manus Shumeroody, and you're listening to the TED Radio Hour from NPR. Stay with us. It's the TED Radio Hour from NPR. I'm Manoosh Zamoroti.

On the show today, making sense of the sun. And we were just talking to Rebecca Collier, who leads Renew 2030, an organization with partners all over the world working to accelerate the growth of solar power. Rebecca says solar technology is not a one-size-fits-all solution. There are small-scale distributed solar installations, the kind you might find on a house or hospital rooftop. But in other parts of the world, enormous solar installations are being built in vast sunny deserts,

which could eventually power entire nations. That is the hope for Morocco. Home to the largest solar energy plant in the world. Nur, which means light in Arabic, is so vast it can be seen from space. The Nur-War-Zat solar plant is located southeast of, Marrakesh, on the edge of the Saharan desert. The landscape out here, it's almost like it's from another world. It feels like we could be on Mars.

Morocco has always had to import its energy, so this new approach has gotten a lot of media attention. In Morocco, we don't have petrol, we don't have gas, to be independent. We have chosen to use the clean energy because of the climate change challenge. A few years ago, Rebecca went to see the plant for herself. It's a magical experience. We were driving over, like, low, bumpy hills, and at first you couldn't see the plant in the distance.

And you turn a corner and then suddenly, even though you're still quite a few miles away, you can see the sparkle of the panels shining in the sun in the distance. And you can see this huge tower in the center of football field after football field of solar panels. It's almost like the stem of a flower with all the solar petals around it, all facing in towards a central stem. And then the sun bounces off the panels

and the majority of them are mounted on the ground so that they can reflect the sun's beams directly into a central tower. Much as you would do if you're catching light off a mirror and trying to make it shine on the wall, but every single panel pointing in one direction, and that turns a traditional electricity generating turbine. And where is the energy going from there? Well, the real benefit of renewables is where it stays in country for local use in boosting

the economy and boosting local industries that have an aspiration to also use greener, cleaner alternatives. And that's actually what's happening in Morocco. It's helping to boost Moroccan industry and then the, additional electricity when it's produced can be sold for a premium, much as countries have exported oil and coal and gas in the past. Morocco has the potential to become a solar energy exporter. So solar could be a source of income for a country that's never been part of the energy market.

This could be a real economic boost for them. Well, I mean, that's certainly the thesis of many of us in this space is that we see new solar states emerging, ones with their ability to produce not just solar electricity for domestic consumption, they can produce electricity for export. And that can be a new source of revenue and change the sort of energy and geopolitical landscape for a more secure and reliable one.

I mean, like the amount of land that we're talking about is just extraordinary. But that's what's, needed. Well, I mean, I don't want the listener to come away with the impression that we're putting concentrated solar plants everywhere. That's is a technology that is really, really suited to areas with the best potential around the world. So large, flat, desert-like spaces. These can produce the best solar thermal potential. But a solar rooftop on a school in a city, or solar on your household is also helping to offset emissions as well.

So it's a combination of both the little and the large. I mean, that's so interesting. We were just talking to Tammy Ma, who heads up the Fusion Project at Lawrence Livermore. And, you know, for her, it's the tech. That's the barrier to entry. But that is not the case with solar. The technology is there. The sun is shining.

It sounds like you're saying a marketing. issue? Well, let's first of all just say up front, most people really don't object to solar. Plenty of times, it's just that they haven't thought about it. They have been told that it's unreliable and needs lots of repair so they don't feel confident in the aftercare or the follow-up that might come with installing solar. So if you've got that sweet spot where there's some initial curiosity and the barrier isn't something insurmountable, then indeed it's, I mean, I didn't want to say it's a marketing problem, but it's a familiarity and confidence problem. And often what's needed more than anything else is knowing that a community similar to yours

has done a project that's similar to yours. Because we hear that a lot from critics, like, well, what about the days when the wind doesn't blow or the sun doesn't shine? Renewables are two dependent on nature, which we can't control? Well, that's one of the brilliant patterns of nature, is that often our demand for electricity is at the sunniest peaks. We've now got wind that can complement nature. It's often the windiest hours are when the sun isn't shining. We've also got multiple ways to store the sun when the sun actually stops shining.

It's batteries and grid technology that can store wind and solar. or transport them from where they're produced to where they're needed. And so that's one of those enduring myths about renewable energy, but it's not borne out by the science at all. I mean, it's very tempting, Rebecca, to be like, oh, few, there's a good climate story. Something is working. We can do this. And if we just, you know, figure out this last few steps to go solar, all will be well.

Can we say that or is that way too optimistic? Well, you know, I think if we had time, you'd be absolutely right. You know, we have incredible engineers and incredible communities. And we will find our way, I think, slowly and surely to that type of genuinely more equitable, low-cost energy future. The trouble is that time isn't on our side. So the reason why we created Renew 2030 was so that we didn't lose sight of the urgency of ramping up solar and wind. It's not like 2050 going, you know, carbon-free. It's not like 2050, no, you're right.

And so I do think that, you know, the new technology stories are the hopeful side of the climate agenda. They really are. If I had started out 20 years ago and solar and electric vehicles were where they are, I wouldn't have been able to give you a hopeful story on climate change. And also when I started out in climate, we were on track for a decimating six-degree future of warming. And we've cut that by most expert predictions to three degrees of warming. But that is still the dangerous tipping points in our weather systems that we are facing daily now. So I don't want people to take away a black and white picture of hope or despair or all or nothing.

The technologies that have come down in cost that we've been talking about today, concentrated solar thermal, different forms of storage, distributed solar. They really are a hopeful story. But also, they aren't moving fast enough to help combat the worst effects of climate change. And they need a helping hand. And so that's where projects like mine come in. That's Rebecca Collier, Executive Director of Renew 2030. You can see her on the TED stage at TED.com. So we have talked mainly about the sun as a source of power

and inspiration for scientific achievement. But beyond the hard science, most of us might think of the sun in simpler terms. It is our steady companion who wakes us up in the morning and slips away every night. But most days pass without us really thinking about this relationship with the sun. Science journalist David Barron says sometimes it takes a solar event, like an eclipse, to remind us just how awe-inspiring our son is. Here he is on the TED stage.

I am not some mystical, spiritual sort of person. I studied physics in college. I used to be a science correspondent for NPR. In the course of working on a story for NPR, I got some advice from an astronomer that challenged my outlook and frankly changed my life. You see, the story was about an eclipse,

a partial solar eclipse that was set to cross the country in May of 1994. And the astronomer, I interviewed him, and he explained what was going to happen and how to view it, but he emphasized that as interesting as a partial solar eclipse is, a much rarer total solar eclipse is completely different. In a total eclipse, the moon completely blocks the face of the sun, creating what he described as the most awe-inspiring spectacle in all of nature.

And so the advice he gave me was this. Before you die, he said, you owe it to yourself to experience a total solar eclipse. Well, honestly, I felt a little uncomfortable hearing that from someone I didn't know very well. It felt sort of intimate, but it got my attention, and so I did some research. Now, the thing about total eclipses is, if you wait for one to come to you, you're going to be waiting a long time. Any given point on Earth experiences a total eclipse about once every,

400 years. But if you're willing to travel, you don't have to wait that long. And so I learned that a few years later, in 1998, a total eclipse was going to cross Aruba. So I talked to my husband and we thought, well, February, Aruba, sounded like a good idea anyway. So we headed south to enjoy the sun and to see what would happen when the sun briefly went away. Well, the day of the eclipse found us and many other people on the beach waiting for the show to begin. And we wore eclipse glasses with cardboard frames and really dark lenses that enabled us to look at the sun safely. And a total eclipse begins as a partial eclipse, as the moon very slowly makes its way in front

of the sun. So first it looked like the sun had a little notch in its edge. And then that notch grew larger and larger, turning the sun into a crescent. And it was all very interesting, but I wouldn't say it was spectacular. I mean, the day remained bright. If I hadn't known what was going on overhead, I wouldn't have noticed anything unusual. Well, about ten minutes before the total solar eclipse was set to begin, weird things started to happen. A cool wind kicked up.

Daylight looked odd, and shadows became very strange. They looked bizarrely sharp as if someone had... turned up the contrast knob on TV. And then I looked offshore and I noticed running lights on boats. So clearly it was getting dark. And then all of a sudden, the lights went out. Well, at that, a cheer erupted from the beach. And I took off my eclipse glasses because at this point, during the total eclipse, it was safe to look at the sun with the naked eye. And I glanced upward and I was just dumbstruck. I had lived on earth long enough to know what the sky looks like. I mean, I'd seen blue skies and gray skies and starry skies and angry skies and pink skies at sunrise.

But here was a sky I had never seen. Up above, it was a deep purple gray like twilight. but on the horizon it was orange like sunset, 360 degrees. And up above, in the twilight, bright stars and planets had come out. And they were all in a line. And there, along this line, was this wreath woven from silvery thread, and it just hung out there in space, shimmering. Now that was the sun's outer atmosphere, the solar corona. And pictures just don't do it justice.

It's not just a ring or halo around the sun. It's finely textured like it's made out of strands of silk. So there was the sun and there were the planets. And I could see how the planets revolve around the sun. It's like I had left our solar system and was standing on some, alien world looking back at creation. And for the first time in my life, I just felt viscerally connected to the universe

in all of its immensity. And I stood there in this nirvana for all of 174 seconds, less than three minutes. When all of a sudden, it was over. The sun burst out, the stars and the planets and the corona were going, gone, the world returned to normal, but I had changed. And that's how I became an umbraphile,

an eclipse chaser. And so this is how I spend my time and harder and money. Every couple of years, I head off to wherever the moon's shadow will fall to experience another couple minutes of cosmic bliss. And over time, I've become something else. An eclipse. evangelist. I see it as my job to pay forward the advice that I received all those years ago. And so let me tell you, before you die, you owe it to yourself to experience a total solar eclipse. It is the ultimate experience of awe. Now, admittedly, some folks consider my evangelizing a little out there. My obsession eccentric. I mean, why focused so much attention on something so brief?

This is a lesson I've learned, and it's one that applies to life in general. Duration of experience does not equal impact. One conversation, hell, one glance, can change everything. Cherish those moments of deep connection with other people, with the natural world, and make them a priority. Yes, I chase eclipses. You might chase something else, but it's not about the 174 seconds.

It's about how they change the years that come after. Thank you. That was science journalist David Barron. You can watch his full talk at ted.com. Thank you so much for listening to our episode as we tried to make sense of the science. Sun. It was produced by Katie Montalione, James Delahousie, Rachel Faulkner White, and Fiona Giron. It was edited by Sanaz Meshkampur and me. Our production staff at NPR also includes

Matthew Cloutier and Harsha Nihada. Our executive producer is Irene Noguchi. Our audio engineers were Robert Rodriguez, Gilly Moon, and David Greenberg. Our theme music was written by Romteen Arablewe. Our partners at TED are Chris Anderson, Roxanne Highlash, Alejandra Salazar, and Daniela Ballorezzo. I'm Manozyzumeroi, and you have been listening to the TED Radio Hour from NPR.