EMILY KWONG, BYLINE: Hey. This is Emily Kwong, SHORT WAVE reporter. So when our team is wrapping up an episode, we sometimes do the wave, like in a sports stadium, to celebrate another day, another episode. And we come back and do it tomorrow. That's the promise of SHORT WAVE.
But we need your financial support to keep making the show for you. There's a fundraiser going on right now across NPR podcasts. And you can truly keep this wave rolling by going to donate.npr.org/short and give to your local member station. It supports our work. Again, that's donate.npr.org/short. Thank you so much.
(SOUNDBITE OF MUSIC)
MADDIE SOFIA, HOST:
You're listening to SHORT WAVE from NPR.
KWONG: Hey everybody. Podcast reporter Emily Kwong here with a new voice to the show, Scott Neuman - NPR reporter and editor. Hi, Scott.
SCOTT NEUMAN, BYLINE: Hey there.
KWONG: So it's the 150th anniversary of the periodic table - nerds that we are, we've been celebrating on SHORT WAVE. We did an episode on helium, you may have heard.
NEUMAN: Great episode, very uplifting.
KWONG: Wow. You went there. All right. So word around the science desk is, Scott, you have a different element you want to make a case for. What do you got for us?
NEUMAN: Well, I think aluminum - or as the Brits call it, aluminium - is pretty interesting.
KWONG: OK. Sell me on this. Why is aluminum fascinating?
NEUMAN: Well, first of all, it's the most abundant metal on earth. Soda cans, aluminum foil, our smartphones are all made out of it in some way. But it might surprise you that aluminum was once incredibly rare.
KWONG: Oh, really? Why?
NEUMAN: Well, it's not really found in nature as a pure metal. It has to be extracted. And in the early 19th century, that was really difficult to do. It was so rare that aluminum was more valuable than gold.
KWONG: Ooh. So Aesop - stay with me - would have been writing about the goose that laid the aluminum egg.
NEUMAN: Sure. Sure, Emily. Yeah.
KWONG: Didn't land it. That's fine. But why aren't we saying today, you have a heart of aluminum?
NEUMAN: Well, science happened, Emily.
(SOUNDBITE OF MUSIC)
NEUMAN: Really, it's two scientists working independently on different continents came up with a solution that changed everything for our element.
KWONG: OK. So today on the show - aluminum, its journey from precious metal to beer can.
NEUMAN: And we'll tell you how the Wright brothers might not have gotten up in the air without it.
(SOUNDBITE OF MUSIC)
KWONG: OK, Scott. We're talking aluminum on today's show in honor of the 150th anniversary of the periodic table of elements. And once upon a time, aluminum was incredibly rare and valuable, right?
NEUMAN: Yeah. And an example right in our own backyard - the Washington Monument. It was the tallest building in the world when it was completed in 1884. And they wanted to cap it with something extra special.
KWONG: I'm guessing by your face that it is aluminum.
NEUMAN: It is aluminum. They also wanted something that conducted electricity as part of a lightning rod system. But there were much less expensive options for that. At the time, aluminum was about $16 to $17 a pound. In today's money, that would have been well over $400, so pretty expensive.
KWONG: Whoa. That's a lot of money for a little decoration on the top of the Washington Monument.
NEUMAN: It was. And guess what? Just a couple of years later, the price of aluminum would fall off a cliff. By 1889, the price had fallen to about $2 a pound.
KWONG: So why the big aluminum slump?
NEUMAN: Well, because an efficient and cheap method for extracting aluminum from ore was discovered. And it transformed how we use it.
KWONG: OK. Right. Right. So if aluminum has to be extracted, what does it look like in nature? Do you just stumble across it and say, oh, there it is. There's aluminum.
NEUMAN: I asked Donald Sadoway this. He's a professor of materials chemistry at MIT.
NEUMAN: And he explained that even though aluminum is easy to find, it's very reactive. So it's always bound up with something else. So every time you want to get some of it, you've got to extract it from that other stuff around it. And when aluminum attaches to things, the bond is...
DONALD SADOWAY: Very strong. And it takes enormous energy to break that bond and pull the aluminum metal out of the compound. But it also gives you something that's very strong and very light.
KWONG: Oh, OK. So aluminum's kind of clingy. No problem. But I'm guessing we need a process to break its bond with what it attaches to, right?
NEUMAN: Right. But first, a little history. Aluminum was first discovered by a British chemist, Sir Humphry Davy.
KWONG: Well, that's a fancy British name.
NEUMAN: It's a perfect British name in the early 1800s. And for decades, scientists and tinkerers tried and mostly failed to find a good method for extracting aluminum in large quantities. But then in 1886, two different men - one working in Ohio and the other in northwestern France - independently came up with the way to isolate aluminum that was both cheap and efficient. And by the way, they were both 22 years old.
KWONG: That's very young to be coming up with something so important.
NEUMAN: Right. And this guy, Charles Martin Hall, he was from the United States. And he was inspired by a lecture at Oberlin College in which his chemistry professor said that the person who discovered a practical way to produce aluminum will, quote, "bless humanity and make a fortune for himself."
KWONG: Very motivating.
NEUMAN: Yeah. It's called the profit motive, I think. And the other guy is Paul Heroult.
KWONG: That's the French person. Can I just say...
KWONG: ...This is a very multinational aluminum race...
NEUMAN: Right. Yes.
KWONG: ...That's unfolding in the 1800s.
NEUMAN: Yeah. Yeah.
KWONG: It's fascinating. OK. So you have Paul, and you have Charles, right?
NEUMAN: That's right. Both of them realized that the answer involved electricity - a lot of it. And they were in luck because they were working at a time when electricity had just become available on an industrial scale.
KWONG: Right. Got to have electricity to break aluminum's bond.
NEUMAN: Yeah. So aluminum is often found bound up in this rock called bauxite. And when the bauxite ore is dissolved into a big steel vat and this stuff called cryolite is mixed in, that elusive aluminum has a chance to break free.
NEUMAN: But you need electricity to make that happen.
KWONG: Oh, OK. Oh, is this electrolysis, like when you use electricity to make a chemical reaction happen?
NEUMAN: Right. The process these two men discovered is that when you create an electrical current within the vat with a positive side and a negative side, the aluminum ions can separate out into pure metal. And it sinks to the bottom.
KWONG: Like, it gets pulled to the bottom.
NEUMAN: Yeah. And once the metal pulls, it's poured off and voila, as Heroult might have said...
KWONG: Our French guy.
NEUMAN: ...Pure aluminum.
KWONG: Wait. So you're saying, though, that these two 22-year-old dudes discovered this process independently of each other across an ocean?
NEUMAN: Hall and Heroult actually fought over ownership of the process to smelt aluminum from bauxite.
KWONG: They fought.
KWONG: Science battle. Here we go.
NEUMAN: Well, Heroult filed for a patent about six weeks before Hall. But the American was able to prove that he actually made the discovery a few weeks before his rival thanks to the meticulous laboratory notes kept by his sister and assistant, Julia Brainerd Hall.
KWONG: See? The unspoken contributions of women to science - I'm just going to put that out there.
NEUMAN: OK. Ultimately, the two men settled their dispute and became friends.
KWONG: That's a really nice story. All right. At the end of the day, this process is what made extracting aluminum easier, right?
NEUMAN: Well, kind of. Aluminum by itself is not really that strong. But when you combine it with other elements, you make alloys. And then that becomes really useful.
ROBERT VAN DER LINDEN: It would take many, many more years to make aluminum practical.
NEUMAN: That's Robert van der Linden. He's a curator at the Smithsonian National Air and Space Museum.
VAN DER LINDEN: What made it possible was the invention of aluminum alloys, which have the strength and the lightness, not just the lightness. Pure aluminum is light, but it's not strong.
NEUMAN: But still, the development of the Hall-Heroult process, as it came to be known, was a major milestone in the industrial revolution.
KWONG: I like it. So when I pick up a beer can, you're telling me it's made of alloys, not pure aluminum?
NEUMAN: Beer cans, bicycles, cars, sandwich wrap. And alloys of aluminum played a key role in the first flight.
KWONG: Oh, the Wright brothers.
NEUMAN: Right you are. And remember Donald Sadoway, the MIT professor from earlier?
NEUMAN: He said something really interesting about all this when I was talking to him.
SADOWAY: I think this is a really good example of how the advent of a new material enables all kinds of fantastic technology. It wasn't the design. I mean, you go back to Leonardo. There's designs for flying machines. But you can't build them out of anything practical.
KWONG: Until the advent - I guess, more importantly, the availability of aluminum.
NEUMAN: Exactly. In 1903, Orville and Wilbur Wright were struggling to figure out how to design their Wright Flyer - you know, the one that went on to make history for the first flight.
KWONG: Oh, I know. It's the one on all the North Carolina license plates - except, you know the Wright brothers are originally from Ohio?
NEUMAN: I do. And did you know that North Carolina's license plates are aluminum, like everybody else's?
KWONG: Fair. But I guess you're saying the flight wouldn't have been possible without aluminum?
NEUMAN: Yeah. Well, the point is that all of this wouldn't have been possible without Charles Taylor. He was the Wrights' mechanic.
KWONG: Everyone needs a good mechanic.
NEUMAN: Right. Exactly. And he's the one that suggested using an alloy of aluminum and copper for the block of the Flyer's four-cylinder engine, which was a novel idea, to reduce the airplane's overall weight.
VAN DER LINDEN: The original Wright Flyer, the '03 Flyer, was a very marginal airplane at best.
KWONG: Oh, wow. Diss. OK.
NEUMAN: Robert van der Linden from Smithsonian again. The Wright Flyer is one of his specialties.
VAN DER LINDEN: So it needed every ounce of strength and every ounce of weight saved possible to get that thing in the air. And even then, it was overweight.
NEUMAN: But as you know, the flight was successful. Aluminum became the dominant metal in aviation. And recycling it was cheaper and less time-consuming than refining it from ore. So during World War II, Americans were encouraged to turn in their aluminum pots and pans and even aluminum foil from gum wrappers and cigarette packs to help with the war effort.
(SOUNDBITE OF ARCHIVED RECORDING)
BING CROSBY: (Singing) Collect today for the USA 'cause junk can win the war.
UNIDENTIFIED PERSON: Aluminum for defense.
KWONG: This is a very catchy tune. I would donate...
NEUMAN: Definitely an earworm. Yeah.
KWONG: ...In this time.
NEUMAN: And, I mean, NASA turned to aluminum alloys for the Apollo missions for the same reason as airplanes...
NEUMAN: ...Weight and strength, which is why the next generation Orion space capsule is being made largely out of an aluminum-lithium alloy.
KWONG: So aluminum in combination with other things is really what made high-altitude travel possible. Is that right? Am I overreaching?
NEUMAN: No. No, no. That's accurate. And that's why I asked the same question of Robert van der Linden of the Smithsonian.
VAN DER LINDEN: No aluminum? (Laughter). Well, first off, as a historian, that's a counterfactual question. So I'm not supposed to, like, answer something like that. However, those are really cool questions - what-if question. I don't see it happening because there's really no other metal or any other material out there that could do what aluminum alloys have done.
KWONG: Good old aluminum. Or should I say aluminium? Wait. What's up with that, by the way? What's the right way?
NEUMAN: Remember Davy, the element's discoverer?
KWONG: Yes. The guy with the great British name.
NEUMAN: He gets a large share of the blame for all this confusion over the U.S. and the British spellings and pronunciation of the word. He couldn't decide what to call it. First, he liked alumium, then aluminum. The Americans picked up on that spelling and pronunciation. But the British scientist argued it should be aluminium. And they stuck to their guns. That issue was a major controversy, it seems.
KWONG: (Laughter) Those stubborn Brits.
(SOUNDBITE OF MUSIC)
KWONG: All right. Scott Neuman, this has been fascinating. Thank you so much. The element America and Europe have been fighting over since the 1800s I never thought about this way until now.
NEUMAN: It was my pleasure.
(SOUNDBITE OF MUSIC)
KWONG: Today's episode was produced by Rebecca Ramirez and edited by Viet Le (ph). Shout out to Burley (ph), our fact-checking queen. And of course, many thanks to James Willetts, who did some amazing engineering on this episode. And I'm SHORT WAVE reporter Emily Kwong. Host Maddie Sofia is back tomorrow. We'll see you then for another episode of NPR's SHORT WAVE.
(SOUNDBITE OF MUSIC)
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.