RACHEL MARTIN, HOST:
There are numbers all around us - in every word we speak or write, in the passage of time. Pretty much everything in our world has a numeric foundation. But most of us don't see those numbers. It's different for Daniel Tammet. He's a savant with synesthesia. It's a condition that allows him to see beyond numbers. He experiences them in ways that may surprise you.
DANIEL TAMMET: When I was a child, I used numbers as a way to understand other children. If someone said that they were feeling sad today, I would imagine myself in a cold, dark hole and that hole was like the number six.
MARTIN: Tammet drew attention around the world about a decade ago when he set a world record reciting the measurement of pi.
MARTIN: It took him five hours to call out 22,514 numeric digits with no mistakes.
TAMMET: ...three, two, three, eight...
MARTIN: Daniel Tammet writes about that experience in a collection of essays called "Thinking in Numbers." He joined us from Paris, where he lives, and I began by asking him to explain exactly what it is he sees when he's thinking in numbers.
TAMMET: Every number has its own color, so the number one is like a shining light from a lantern. The number two is more like a flowing, darker, purple color. Three is green, and after 10 the individual digits contribute their own color, so I am seeing a blend of those primary colors. And when I recited the number pi, I would see the colors as a landscape full of textures and emotions, and I would blend together into a kind of story or poem that I could recite to those who were listening to me.
MARTIN: You write in the essay in this book about a moment during your recitation of pi when you faltered. What happened at that point? Can you describe what was going through your mind to get you back on track to conjure up that next digit?
TAMMET: At that moment in the recitation, I was over 16,000 digits into my recitation. All of a sudden, those colors disappeared and the emotion of fear overcame me. I had spent all of my childhood feeling somehow separate from my family, my classmates, and pi was my way of sharing the beauty and the calm that I experienced in this other world, the world of numbers. I worried whether I was capable, whether or not my autism would hold me back. And eventually, the landscape started to flow again. The poem came back to me and I continued the recitation to the end.
MARTIN: In one of your essays, you talk about the number 5,040. This was a number that Plato said was the absolute ideal number for a city - 5,040 land-owning families. What struck you about that idea?
TAMMET: Plato was a great thinker but he was also fascinated by numbers. And if we could only find a perfect number that we could construct an entire society upon this number. And for him, this number was 5,040. It's a highly divisible number. You can take any number of the first digits, two and three and four and five and so on and 5,040 divides evenly into them. It also divides into 12, and so in Plato's imagination, the perfect society would divide into 12. Everything would be divided evenly. There would be no war, there would be no discord.
And of course this idea is extremely attractive, typically, to our ears today, ears that hear too often news of war and famine and misery. And, at the same time, I think we're all of us wise enough to realize Plato was perhaps a little bit naive, as well. These ideas are beautiful ideas but there is always that mystery that remains at the end, that there are things that we cannot calculate. And that's something that in the end doesn't disturb me but almost reassures me to know that numbers can take us so far but there is always an element of humanity which escapes numbers as well.
MARTIN: Interesting that you talk about being OK with that; as someone who has relied on numbers in such an emotional way throughout your life, to state that numbers can't solve anything is a little bit surprising. Have you run up against that in life?
TAMMET: There's a chapter in the book about my mother and the relationship that I have with her is intensely loving, of course, but complex. When I was a child on the autistic spectrum there were many things that my mother did or said that I didn't understand. And I constructed something like a model, what mathematicians would call a predictive model, of her behavior. And of course it was impossible. There was always a way in which my mum got around even the most sophisticated calculation, and so I came to realize that there are always going to be aspects of reality that go beyond our calculations.
MARTIN: Daniel Tammet. His new book is called "Thinking In Numbers." He joined us from Paris. Daniel, it's been such a pleasure talking with you. Thank you so much.
TAMMET: Thank you as well.
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MARTIN: And you're listening to WEEKEND EDITION from NPR News.
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