Chemistry professor clarifies process that allows humans to see in low light

UConn chemistry professor Bob Birge explains a new discovery that he and several Canadian colleagues made about the process that allows humans to see in low light by reciting Robert Frost's poem, "The Road Not Taken."

In the poem, a traveler comes upon two roads and chooses to take one path to his destination over the other.

It ends with the verses: "Two roads diverged in a wood, and I/I took the one less traveled by ..."

In findings published in the journal Science last month, Birge says he and his colleagues have discovered that lasers can manipulate the efficiency of photochemistry in a protein called "bacteriorhodopsin."

The discovery has implications not only for this protein, which is a proton pump in an ancient material called "archaea-bacterium," but for all proteins that interact with the human eye that absorb light.

The most important retinal protein is rhodopsin, which is responsible for vision in humans and other animals with image-resolving eyes.

The study provides further evidence that evolution has created a coherent process to convert light energy into chemical energy in these proteins.

It also provides the first evidence that by using laser light, the efficiency of these processes can be increased or decreased by 20 percent.

"Most everything in life is incoherent," says Birge.

"When we explore options in our lives, we make choices and go down those paths and accept the consequences. In a given day, we make many choices, and because those choices are available each day, each person experiences life differently. To Frost, that was what made life interesting, and in his poem he encouraged people to explore paths not normally taken."

But the availability of many options is not always efficient, Birge says.

"Sometimes people choose options that set them back and complicate, or thwart, the achievement of goals. Nature has to limit choices to make processes efficient.