Curiosity Box: Kai, in this book, you travel around the world. What’s an amazing, surprising, or funny story from your journeys?
Kai Kupferschmidt: One thing that has really stuck with me was visiting Yoshikazu Tanaka in his laboratory outside Kyoto. Tanaka had worked on creating a blue rose for more than a decade, before he finally succeeded in breeding a rose that produced blue pigment. I asked him what his first thought was when he saw that flower for the first time and was expecting him to describe his joy and exhilaration.
He said: “Could be bluer.”
Incidentally, Tanaka works for Suntory, a beverage company famous for its whisky (it features heavily in “Lost in Translation”). So while I was in Kyoto I did go on a tour of the brewery including a whisky tasting. I was probably the only person on that tour who really doesn’t like whisky.
CB: What’s a place you’d really like to go back to? One you haven’t been able to visit yet?
KK: I hope I’ll have a chance to visit Crater Lake in Oregon again some day, which is famous for its blue water. When I was there the smoke from wildfires was hanging in the air and it was not very sunny. It’s a beautiful place in any weather, but I could tell how stunning it must be in sunny conditions. So I hope to see that some day.
Crater Lake, Oregon
There are also many places I still want to see. I have a whole list of “blue” places I want to visit when I have the chance. I would love to see hyacinth macaws in the wild, for instance, and there is a species of frog whose males for a brief period each year change their skin color to blue. I really want to go and see this too.
CB: One thing we love about this book is that the reader isn’t just learning about the color blue; to explain and explore it, they also learn about the physics of visible light, and x-ray crystallography, and cellular biology and a vast array of other scientific principles and processes. Which was the hardest thing to explain? The easiest?
KK: Yes, this was one of the challenges in writing this book. You can only explain things really well that you have understood really well yourself. I studied molecular biomedicine, and so explaining things like the evolution of color vision or plant pigments was much easier for me than, say, the physics of what makes lapis lazuli appear blue. But the nice thing about being a science journalist is that you can just call experts and ask them to explain these things until you understand them well enough to explain them to others.
CB: What’s something you wish you knew when you started writing the book?
KK: Sometimes it helps not to know a lot at the outset. I started this book with a lot of questions and knowing very little about what I might find in terms of answers. There are much more efficient ways to write a book I think, but it made for an exhilarating experience and I really enjoyed it.
CB: So...what’s your second favorite color? What intrigues you about it?
KK: I've never really thought about that! It’s probably green. I just find it very soothing and it is amazing to think that chlorophyll, which colors leaves green, is likely the most abundant pigment on earth.
Come to think of it, it’s also fitting for green to be my second favorite color given that many languages do not have separate words for green and blue.
CB: Do you have a favorite hue of the color blue? One that instantly grabs you?
KK: The one that most stands out to me is International Klein Blue. That’s the hue “created” by the artist Yves Klein. (It’s really the combination of synthetic ultramarine and a specific binding agent called Rhodopas M60A that does the trick.) At one point when I was writing the book I went to Paris to see some of Yves Klein’s works at the Centre Pompidou. I remember standing in front of this large, entirely blue canvas there and just having this very visceral reaction to it. The color really packs a punch in a way that I have rarely experienced. It’s almost as if the blue is so intense that it just overwhelms your senses, as if you cannot put any distance between yourself and the color.
Another blue that comes close is YInMn blue, which I got to produce myself in Mas Subramanian’s lab at Oregon State University in Corvallis.
Feeling Blue: 7 unique shades, including Klein Blue, chosen by Vsauce for their re-imagination of the famous Soma Cube puzzle in the Fall Curiosity Box
CB: What’s something that you really wanted to put in the book, but just didn’t quite fit in somehow? Something that got edited out?
KK: There is so much. The color blue is endlessly fascinating, and there is no way to include everything there is to say about it in one book. I really had to force myself to just focus on some things and the structure of the book helped with that.
One thing I would have loved to talk about but that did not fit well into the structure is the story of Paul Ehrlich and methylene blue. Ehrlich was a famous researcher (he won a Nobel prize in 1909), and he discovered that a blue dye called methylene blue was good at staining bacteria or the malaria parasite but not human cells for instance. It gave him the idea that the compound might actually work as a drug against these pathogens, and that was really the birth of chemotherapy, and has led to the modern era of antibiotics and other drugs.
CB: You originally wrote this book in German; is the English edition different in any way? How is it experiencing your book in another language?
KK: This is something I really struggled with. These days I write mostly in English (I work as a journalist for Science Magazine). But I carried the idea for this book around with me for a long time and it became very personal. So when I started writing it, I wanted to make sure I found a voice that felt like it was truly me, that sounded like me. And I just felt more comfortable doing that in my mother tongue, German.
The translator did a fantastic job, but invariably there is something about the sound that is just hard to convey in a different language. And of course there is a whole chapter in the book about language that is an absolute nightmare to translate! It is all about the meanings of “blue” and has a lot of wordplays. On the other hand, the English version is a special case, because I do speak the language, and I did go over the translation and made changes where I felt I could convey a better sense of what I meant. That is a luxury I do not have with the other translations of this book, for instance the Korean version that came out recently, or the Italian one which is coming soon.
CB: What was something that really surprised you when you were researching the book?
KK: I was really surprised how much history is associated with some of the blue compounds I researched, and how easily stories went from beauty and joy to horror and darkness. Take Prussian Blue, which alchemists discovered by accident in Berlin at the start of the 18th century. It quickly became a pigment beloved by artists. Van Gogh used it in his "Starry Night,” Hokusai in his famous print “Under the Wave Off Kanagawa.” But researchers trying to understand its chemical composition then discovered a deadly poison, prussic acid or cyanide. This became the basis for Zyklon B, the poison the Nazis used to carry out mass murder in their concentration camps. Today, Prussian Blue in yet another twist is an important medicine to treat certain types of poisoning.
CB: What’s your next project?
KK: For the last one and a half years I have been completely immersed in covering the COVID-19 pandemic for Science Magazine. I hope for all of our sakes that I can get back to writing about other things again soon but I feel that it is still too early to make any such plans.
CB: Finally, this book is still new, so it may be too soon to ask this, but: are there any updates on some of the research you mention in the book? It looks like some Spix’s Macaws were born in the wild a month or so ago. Has David Dobson managed to stabilize ringwoodite, for example? Did Suntory breed a bluer rose?
KK: I have no updates from Dobson or Suntory yet. Mas Subramanian’s YInMn blue finally hit the shelves as a color for artists this year, and he has pushed forward on developing another class of blue pigments. Since the book has come out there have also been quite a few interesting scientific developments: I recently wrote about a research paper that found a new way to produce a blue food colorant from red cabbage, for instance!
We’d like to thank Kai for sitting down and taking the time to answer our questions, and hope you enjoy Blue: In Search of the World’s Rarest Color!