How accurately do your artworks model the physical processes that inspire them?

I walk a fuzzy line between creating artworks that are suggestive of phenomena in nature and avoiding the whole trap of modelling. One example is a sculpture I’m building for the new Chabot Observatory [in California], called Black Hole. The effect is suggestive of how, when black holes form, they clear out areas of space as they suck in all the gas and other material around them. A lot of people see this piece and say: “Oh, this is a model of a black hole.” But you can’t really model these things. They’re on such huge scales, and they involve such alien materials. So I intend these sculptures more as conversation pieces: things that evoke thoughts and questions.

Your work is often referred to as the “art of chaos”. Do you agree with that label?

I prefer the term “turbulence”. Turbulence is something nature does-it’s a whole way of flowing that frequently recurs in nature. What draws me to turbulence is that, in many cases, it’s beautiful. That beauty is an often subtle balance between order and disorder. You have a very complicated pattern, yet there’s something your mind and eyes pick up on. People are fascinated with the weather, and I think part of the reason is that it’s out of our control. There’s an underlying order, but it’s a complex order that doesn’t lend itself to control or accurate prediction. When I build a sculpture, a big part of the process is getting the thing so it’s in that balance between order and beauty and unpredictability.

Do your sculptures fall more into the category of science or art?

They’re definitely not scientific experiments, because they’re often much more uncontrolled and complicated. In scientific experiments you strive to simplify all the extraneous forces, whereas I sometimes deliberately introduce such forces to make something more interesting. On the other hand, they’re not really artworks in the traditional sense. Most sculptures are a celebration of the skill of the artist. You look at any art magazine, and the table of contents is all names. You look in a science magazine, and the table of contents is all phenomena. In the art world, it’s all about the artist’s cleverness or their mastery of certain media. In the things that I make, even though I’ve created the physical structure, it’s really not me that’s doing the sculpting. It’s something other than me, something beyond me, something larger than me.

Who has had the biggest influence on your work? An artist or scientist?

It was Frank Oppenheimer, the Manhattan Project physicist who went on to found San Francisco’s Exploratorium, a hands-on science museum where for 15 years I was artist-in-residence. I had Frank’s ear for hours each day. It was wonderful-I finally had someone I could ask all these questions that had been puzzling me for years.

Like: “What’s actually flowing through a wire when you turn on the light?” Frank loved questions like that. He would take me through every electricity exhibit in the museum, explaining each one until he was sure I had it right. Then he’d end this long explanation with: “Basically, we don’t know what goes through a wire.”

It was an awakening. It made me realise that what we do know is based on very small windows. Not many things in nature lend themselves to mathematical analysis. The whole idea of the limits of what’s knowable have been woven through everything I’ve done.

So your sculptures are not experiments-yet they do ask scientific questions?

Yes, but a difference between what scientists do and what I do is that their questions are much more specific. They’re looking for an answer they can quantify or reproduce. Whereas I’m setting up a system that allows the natural phenomenon or process to sculpt itself, in a way. So it’s like asking a question. What happens if I combine air and sand? Fog and air? Water and air? What will result? But I’m not asking for a numerical answer, I’m asking for a visual answer.

Slice of Wind is a sculpture of yours mounted outside the Engineering School at the University of Colorado at Boulder. How did you put that together?

It’s a 10-foot-square panel covered with very thin stainless steel discs, loosely mounted on pins so that they can pivot in all directions. All these pins are mounted on a flexible PVC backing plate, which can be shaken by a bar mounted on a spring. When the piece is working normally, it reveals all the patterns and textures of the wind. Even on that small scale, there’s incredible detail: patterns of turbulence, waves and vortices. And it’s on a scale that hasn’t been explored extensively in scientific research. There’s been a lot of interest over the years in small-scale turbulent flows around objects like aeroplane wings and cars. There’s also been a lot of interest in large weather systems, much of it from satellite imagery. But this middle ground-the scale of wind in architecture, the scale of the wind in which we live our lives-hasn’t been visualised that much. I see this piece as a window into that scale.

What purpose does shaking the bar serve?

You can use it to resonate the backing plate, and when you do, you create very complicated resonance patterns that overpower the wind. As soon as you stop, the wind takes over again. I see the piece as a metaphor for something the engineering students will be facing their whole careers. They’ll be designing artificial systems that lend themselves to geometry and analysis, yet will also have to interact with the wind, earthquakes and natural systems that are much more complicated.

(Kahn asks me to lie on the floor of his studio. I look upward, into the bottom of a suspended plastic dish over a metre across. Within the bowl, water swirls in a hypnotic and tumultuous vortex.)

This is called Wind Over Lake. I built it for the Alameda County office building in Oakland, California. It’s a big clear bowl, shaped like a wok, in which there are five gallons of water. A propeller, above, circulates the air, drawing it up from the centre and distributing it to the sides and back down. The sculpture is set into the ceiling, like a skylight. So you essentially get the underwater view of a water spout, something few people have seen and lived to tell about it. The piece is completely sealed-there’s just water and air in there. So these two systems become coupled together, just like the atmosphere and the ocean. They start influencing each other. The wind ripples the water, and the waves affect the air, which in turn intensifies the waves. It’s continually changing.

And you built three similar exhibits for the lobby of the National Oceanographic and Atmospheric Administration?

That’s right. All three deal with boundary layers-clouds and air, land and air, ocean and air. These are the places where interesting things happen, where complicated phenomena occur. All the models of global warming, El Niño and climatic patterns depend on a knowledge of what’s happening at those interfaces-and a lot of it is very poorly understood. I went to NOAA, visited a lot of the scientists and saw what they did. Most of them are sitting in front of computers all day, trying to come up with mathematical descriptions of what nature is doing. It struck me that it wouldn’t be a bad thing to have these people walk by something real every day.

Tornado is your most popular sculpture. How does it work?

It’s basically a rotating airflow, with a central updraft. In air vortices, the updraft is many times stronger than the rotation. The combination of gentle rotation and strong updraft produces what the scientists who model tornadoes call the “swirl ratio”. When you get it within a certain numerical balance, you get an excellent vortex.

How do you make the tornado visible?

There’s a fine stream of fog introduced through a series of holes in the base of the structure. It’s created with an ultrasonic humidifier that vibrates two million times a second. That incredibly rapid vibration breaks water up into tiny droplets. But it doesn’t impart any heat to them, so it’s different from steam, which has a mind of its own. This is a cool fog that is easily sculpted by the air. The fog is drawn up into the vortex and makes the vortex visible.

Real tornadoes do their own thing, and we can’t influence them. Why did you make your tornadoes interactive?

I think it’s important for people to learn that some natural systems can be influenced and they will recover, whereas other systems, when you perturb them, are irreparably changed. One example is the Tornado. If you gently run your hand through it, it will curve around and recover. But if you jump through it, or wave your hands rapidly inside it, you completely disrupt the airflow, and it disappears. Sometimes it takes many minutes before the vortex can reorganise itself. I view that as an interesting metaphor for many natural systems that humans interact with. Like the oceans. You can perturb the oceans in certain ways and they will naturally recover. But there are some ways you can perturb them where it will take a very long time for them to recover-or they may be changed forever.

If money were no object, what would you build?

Part of my philosophy is that in our culture, with its increased interest in computers and television and media-with the bombardment of mediated experiences-people have fewer and fewer opportunities to nurture their ability to observe and look closely. So my underlying goal is to create objects or places designed to encourage and nurture observation. One of the pieces I’m building for Chabot is called Cloud Observatory. It has reclining chairs, large cylinder-shaped tubes that will frame a portion of the sky, and polarising filters. The idea is to create a place that says: “It’s OK to sit here and look at the clouds.” I’d like to create places like that, places that frame a natural phenomenon in a way that focuses people’s attention and awareness.

“Was that great or what?” The cynic’s answer would have been: “What?” A total
eclipse of the Sun had come and gone and, as the weather forecasters had warned,
the seaside resort of Torquay was covered in cloud. We couldn’t see any of the
spectacular solar phenomena: the bands, Baily’s beads, diamond ring and
corona.

But I couldn’t be cynical. The black sky to the west, which had been
darkening ominously for twenty minutes as if a storm were brewing, suddenly
swept over us.

For a minute, before the sudden second dawn, the distant Brixham peninsula
and the yacht-scattered sea glittered with camera flashes.

The English are famous for being excited by small pleasures, especially by
the seaside: a walk along the front, a sandcastle, eating fish and chips. But
the eclipse really was great. Even better than a nice cup of tea.

The English Channel

Months of anticipation and planning were over. And the thick cloud wasn’t
going to ruin the trip.

Our vantage point was the dive boat Wey Chieftain II, 16 kilometres south of
Portland, Dorset. On board was an unusual assortment of people: teenagers from
Tower Hamlets in inner London, artists and even blind people—a total
eclipse assaults all the senses.

With a few minutes to go to totality, the sea became eerily calm and the
temperature dropped so sharply that we all shivered despite our coats. Seagulls
settled down in the water, unsure what was happening. Someone on deck turned on
a miniature television, and we crowded round to see pictures of the black disc
of Moon surrounded by the Sun’s pearly corona, taken by an aircraft high above
the clouds.

In a moment, it was night, and thousands of lights twinkled all along the
shoreline. A lighthouse beam stabbed out from the Dorset coast.

Then, as abruptly as it started, totality was over. The sea came alive with
light. “It was the greatest experience of my life,” announced one of the
teenagers. “It was like a dream,” said another.

On the way back to Portland, we stopped the boat. Half a dozen people, still
drunk on the experience, jumped overboard and swam about whooping in the chilly
waters.

Alderney, Channel Islands

Along with about 250 professional astronomers, taking a break from Britain’s
National Astronomy Meeting, I’d taken the 6 am boat from Guernsey and made my
way to Alderney’s Fort Albert.

It was a strange but appealing marriage of scientific day trip and village
fĂŞte, as experts discussing solar prominences filed past marquees and
children preparing to dance the hokey cokey.

With just a few minutes to go, the Sun peeped out, reduced to a crescent of
light. Then the clouds shrouded it once more.

Darkness, and flashes of lights from the yachts in the harbour, told us that
totality had arrived. More than a minute passed. Then, abruptly, the clouds
parted, revealing a ghostly corona. We erupted.

As totality ended, fĂŞte intervened once more: a contingent of the
Alderney Blowers brass band, dressed up as sunflowers, struck up their “eclipse
fanfare”. They may have blown the moment away, but it couldn’t really detract
from our cloud-choreographed drama.

Munich, Germany

Maybe I’m difficult to please, or maybe Bavaria’s capital just isn’t the
place to get inspired by a wonder of nature. I saw no crazed birds or bats. And
I’m afraid I wasn’t really moved.

The temperature plummeted. The shadow cone bore down on us. It went dark, of
course. And unlike millions of hopeful eclipse chasers farther west, I had a
clear sky for the totality.

One of the people who shared my Munich rooftop was British banker John
Walker. Eventually, he got off his mobile phone and proclaimed that the eclipse
was such an awesome sight he might even try to see another one.

Would I do the same? Probably not.

But if you’re ever in Munich you should really check out the terrific little
skeleton wearing a lacy frock, artfully reclining in a glass-sided tomb in St
Peter’s church.

I hate to say it, but a skeleton in a dress eclipsed the eclipse for me.

Lake Balaton, Hungary

By the time we reached our lakeside destination, conditions were perfect.
About 200 people, mostly locals or German tourists, sat in our small field.

With glasses of beer in hand, we watched with mounting excitement. One of our
group discovered an entertaining alternative to the pinhole projector: by
crossing our parted fingers, we were able to project multiple crescent-shaped
images on each other’s backs.

The hills across the lake darkened. Pinheads of light became sharper, and
hundreds of flashlights dotted the northern shore. The sky went pink and the few
remaining clouds turned dark grey. Then, slowly, the heavens took on a green,
crepuscular hue.

Rippling shadow bands danced across our field, and the whooping started as we
were graced with a perfect view.

Our two minutes passed all too quickly. As the diamond ring dazzled, a
solitary bat flapped down the hillside.

Then, as we walked back from the field along a tree-lined road, the returning
light gave us a final treat: hundreds of crescent Suns on the asphalt, projected
through the leaves overhead.

Bucharest, Romania

It was a perfect day with cloudless skies—until the crowds started
thronging the streets at around 1 pm. We were standing in the Bulevardul Unirii,
Ceausescu’s attempt to match the Champs Elysées, which leads up to the
former dictator’s colossal administrative centre, now the Palace of Parliament.
Officials gathered on its roof, as the crowds below tested their solar
viewers.

The disappearing Sun was visible for a few minutes at a time, but patchy
clouds smothered the focus of our attention at the crucial moment.

Suddenly, darkness fell. A huge cheer went up, although all we could see of
the Sun’s corona was a faint ring fuzzed by clouds. After two minutes, daylight
returned to more cheers and whistles. As the Sun gradually re-emerged, a
sideshow stole its limelight: someone was dangling on a rope from the top of the
high-rise Intercontinental Hotel, flinging leaflets down to the street. But
police lured him back into the building before the crowd below could fathom what
the protest was about.

Esfahan, Iran

Nine centuries ago, the Persian philosopher and poet Omar Khayyam built one
of the earliest observatories in Esfahan. Although the observatory was destroyed
when the Mongols invaded, Khayyam’s passion for astronomy lives on. Lying just 2
kilometres from the centre line of totality, the city rose to the occasion.

The Emam Khomeini Square, alive with fountains and lined by craft shops, was
jammed with thousands of locals. The Iranian media had warned of the potential
dangers, so no one was without a shadow box or solar viewer. The atmosphere was
like an Iranian Woodstock, complete with T-shirts and overpriced soft
drinks.

As totality approached I took up my station before the cream dome of the
women’s mosque, famous for changing colour as the Sun shifts through the sky.
During the last five minutes of the crescent Sun, the dome ran through a full
day’s display, glowing honey, amber and peach. Venus burnt near the zenith, and
the lights crowning the minarets flickered on. The mane-like corona twisted from
the Sun, while bright red prominences danced around its edges.

There was a sudden, timeless silence. Then, from every direction, came an
expression of delight, reverence and awe: “Ma’sha’Allah!” “What wonders God has
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