".30 Bullet Piercing an Apple" by Harold Edgerton

Harold Edgerton may have been the only electrical engineering professor from MIT ever to have his scientific work displayed at New York’s Museum of Modern Art (MOMA).  His stop-motion image of a milk drop splashing in a plate of the liquid was included in MOMA’s first photography exhibition in 1937 and is now part of its permanent collection.  Edgerton had pioneered the use of a stroboscopic flash synchronized with a high-speed camera to capture motion that was otherwise too rapid to be detected by the human eye: a .30 caliber bullet passing through an apple at 2,800 feet per second, a hummingbird’s wings in flight, a balloon bursting, an arrow flying from an archer’s bow at the moment of release.  To create these images, he used exposures as short as one third of a microsecond (one millionth of a second).  In perhaps his most audacious undertaking, Edgerton and his colleagues photographed a nuclear explosion at the instant of its detonation, using specially designed equipment that had no mechanical shutter and that enabled them to take exposures as brief as one ten-millionth of a second.  No wonder Life Magazine dubbed him “the man who stopped time.”

Although Edgerton made significant technical advances in coupling stroboscopic flashes with high-speed cameras, he was not the first to create a sensation with stop-motion photography.  A landscape photographer named Eadweard Muybridge did a series of animal locomotion studies in the 1870s using a high-speed shutter he had invented to prove that all four hooves of a galloping horse left the ground at the same time.  Until the mid-19^th century, exposure times were too slow to capture movement at all.  This explains why Matthew Brady mostly photographed the dead rather than the living in Civil War battles, because corpses didn’t move.  Early photographs of crowded city streets appeared nearly empty, because the glass-plate negatives were incapable of registering moving figures.  When faster exposure times finally allowed photographers to capture busy street scenes, Oliver Wendell Holmes was astonished by the awkward poses of pedestrians caught in mid-stride. “Is motion but a succession of rests?” he wondered. “Motion is as rigid as marble, if you only take a wink's worth of it at a time.”

Holmes had put his finger on a problem that had puzzled philosophers since at least the time of Zeno of Elea in the 5^th century BCE.  At any given moment, the world appears at a standstill, so how can anything move?  As if inspired by one of Edgerton’s photographs, Zeno argued that an arrow in flight is really motionless because in any particular instant it can only occupy a space equal to itself.  If an arrow can only occupy a space equal to itself, how does it advance to the next moment, when it also appears to hover motionless in the air?  Zeno used this and other paradoxes to show that motion was an illusion.  And yet, if you stood in the path of that arrow, you were liable to discover otherwise, which meant that something else had to give.

The problem may not be motion as such but in the idea of a moment, an infinitesimal slice of time made concrete in those photographs of bullets piercing an apple or an arrow in flight.  Photographs appear to be instantaneous, but they are not really.   A moment, by definition, has no duration, but a photograph with zero exposure time would show nothing.  Even Edgerton’s images of nuclear detonations required a ten-millionth of a second of exposure time.  That’s a ten-millionth of a second of motion as light traveled from an exploding hydrogen bomb and left an imprint on exposed film.  Edgerton’s photographs appeared to stop time in its tracks, but all he really did was slow it down enough so motion too rapid for the human eye could be seen.

Early one frigid winter’s morning I ventured out with my camera and tripod to take pictures at a colonial-era mill site not far from my home in Connecticut.  All that remained of the mill was a stone retaining wall by a waterfall at one end of a long pond.  As I picked my way along a snowy path from the parking lot, I could hear the rush of water.  But when I got to the retaining wall at the top of the falls, all I could see at first was snow and ice below.  Then in a small gap in the snow, I saw a thin carapace of blue ice and beneath it rapidly flowing water.  And so it is with time – not time as we usually think of it, an abstract measure of change that we neatly segment into past, present and future, nor those frozen slices of time that we capture in photographs, but time as we actually experience it lying below the surface of thought: free flowing, indivisible, inexorable, the onward rush of life.  As the philosopher Henri Bergson once wrote, “We do not think real time, we live it.” 

According to one estimate, some 880 billion photographs are taken every year, and that number will soon top one trillion.  I doubt people give much thought to what they are doing when they take a picture.  They are looking for a keepsake, a reminder of happy times: an evening out with friends, a church picnic, a new addition to the family, a wedding or a baptism.  It is life that they seek, but life as it has never existed in the slipstream of time, life that lasts forever.  Photographic images are taken from life like pages torn from a book.  They seem so real, so of-the-moment.  And yet those images, like the moments they appear to capture, are essentially an illusion.