The 500-Year-Long Science Experiment
In the year 2514, some future scientist will arrive at the University of Edinburgh (assuming the university still exists), open a wooden box (assuming the box has not been lost), and break apart a set of glass vials, in order to grow the 500-year-old dried bacteria inside. This all assumes the entire experiment has not been forgotten, the instructions have not been garbled, and science—or some version of it—still exists in 2514.
By then, the scientists who dreamed up this 500-year experiment, Rolf Möller, a microbiologist at the German Aerospace Center, and his U.K. and American collaborators, will be long dead. They’ll never know the answers to the questions that intrigued them back in 2014, about the longevity of bacteria. Möller’s collaborator at the University of Edinburgh, Charles Cockell, once forgot about a dried petri dish of Chroococcidiopsis for ten years, only to find the cells were still viable. Scientists have revived bacteria from 118-year-old cans of meat and, more controversially, from amber and salt crystals millions of years old.
All this suggests, says Möller, that “life on our planet is not limited by human standards.” Understanding what that means requires work that goes well beyond the human lifespan.
Physically, the 500-year experiment consists of 800 simple glass vials containing either Chroococcidiopsis or another bacterium, Bacillus subtilis. The glass vials have been hermetically sealed with a flame. Half are shielded with lead, to protect them from the radiation of radon or cosmic rays, which can cause DNA damage. (A duplicate set of the vials sits in the Natural History Museum in London for backup.) Every other year for the first 24 years, and then every quarter century for the next 475, scientists are supposed to come test the dried bacteria for viability and DNA damage. The first set of data from the experiment was published last month.
Opening vials, adding water, and counting colonies that grow from rehydrated bacteria is easy. The hard part is ensuring someone will continue doing this on schedule well into the future. The team left a USB stick with instructions, which Möller realizes is far from adequate given how quickly digital technology becomes obsolete. They also left a hard copy on paper. “But think about 500-year-old paper,” he says, how it would yellow and crumble. “Should we carve it in stone? Do we have to carve it in a metal plate?” But what if someone who cannot read the writing comes along and decides to take the metal plate as a cool, shiny relic, as tomb raiders once did when looting ancient tombs?
No strategy is likely to be completely foolproof 500 years later. So the team asks that researchers at each 25-year time point copy the instructions so that they remain linguistically and technologically up to date.
Möller and his colleagues are among the most ambitious scientists to plan a long-term experiment, but there have been others. In 1927, a physicist named Thomas Parnell poured tar pitch into a funnel and waited for the highly viscous substance to slowly drip down. When Parnell died, custodianship of the pitch drop experiment passed along a chain of physicists, who dutifully recorded each drop. The last one fell in April 2014, and the experiment can last as long as there is more pitch in the funnel.
Plant biology has several long-term studies, too. At a fertilizer magnate’s country estate in England, scientist been studying how different fertilizers affect the particular crops grown in the same fields year after year since 1843. In Illinois, agricultural scientists have been carried out a corn breeding study since 1896. And at Michigan State University, a botanist in 1879 buried 20 glass bottles of 50 seeds to be dug up at regular intervals and tested for viability. The location of the bottles are kept secret to prevent tampering. The last bottle will be dug up in 2020.
Michigan State University also houses an E. coli experiment that could run for centuries. Since February 1988, the lab of microbiologist Richard Lenski has been watching how E. coli acquire mutations and evolve over the generations. They’re currently on generation 70,500. Because E. coli replicates so quickly, it’s like watching evolution on hyperspeed.