VOA标准英语2013--科学家努力拯救早期知名照片（在线收听）

Smithsonian, Argonne Team Up to Save Earliest Known Photographs 科学家努力拯救早期知名照片

CHICAGO, ILLINOIS — The introduction of the daguerreotype in the 19th century ushered in the era of modern photography. Instead of sitting long hours for an artist to paint a portrait, customers could sit for just a few minutes while their true likeness was captured in what is now known as a photograph. Research scientists at the Smithsonian Institution are teaming up with physicists at Argonne National Laboratory outside Chicago to study these earliest known photographs, which are in danger of being lost forever.

The woman in the image most likely was in her late teens or early 20s when her likeness was preserved on this copper plate with finely polished silver in the mid-19th century.

Daniel Weinberg, of the Abraham Lincoln Book Shop in Chicago, has handled many such daguerreotypes, which are popular with collectors and historians alike.

“It was the first time you could go into a studio and have your photograph taken, and you could put it up somewhere and show it off,” he said. “They’re luminous, and they’re almost three dimensional, and you almost want to step into one.”

19th century Americana

Weinberg also said daguerreotypes were one of a kind, not meant to be reproduced like current photographs. And although invented by a Frenchman - Louis Daguerre - they changed the American landscape in the mid-1800s.

“America really took off with the daguerreotype, and a vast majority of them were American,” said Weinberg.

“It spread like wildfire in the United States. There were hundreds of thousands of daguerreotypes made over a 20-year time span,” said Ed Vicenzi, research scientist at the Smithsonian Institution.

Many of the most important images now reside at the Smithsonian and the Library of Congress, including the one of a mysterious young woman that research scientist Vicenzi whimsically calls “Clara” - although her real name is unknown.

“We don’t know her name, her family, the state she’s from,” he said.

What Vicenzi does know is the image from the past is in danger of being lost in the future unless something is done to stop the breakdown of its microscopic chemical makeup.

“So daguerreotypes are actually made up of a bunch of nanoparticles on the surface that scatter the light and this is in some ways similar to the way technology devices are made today, so we’re also interested in what did 19th century photographers know about nanotechnology unwittingly,” he said.

Preserving history

Physicist Volker Rose is working with Vicenzi, at Argonne National Laboratory, by focusing the intense X-rays of Argonne’s Advanced Photon Source at fragments of the daguerreotype.

“Those objects are almost 200 years old, and they were made at a time when the concept of nanotechnology, even the word at that time, didn’t exist,” he said.

“We can focus those X-rays down to very small spot sizes. This allows us to look very deep into material, but also get a lot of information on a very small length scale,” said Rose.

“The technology that’s available at the Advanced Photon Source will allow me to study the very early stages of degradation of daguerreotype plates. They corrode over time, but we need to learn the chemical mechanisms in order to understand how we can preserve these objects for the future,” said Vicenzi.

Vicenzi hopes his efforts at Argonne will provide the answers historians, preservationists and collectors seek to guide them in saving these images of the past - so future generations can study, understand and appreciate first-hand what life was like in the 19th century.