Dr. Samantha Burns, played by guest star Karen Holness, is a physicist at Humphries University. She, and her partner, Dr. Amanda Meyers, are responsible for designing the singularity engine, a highly advanced alternative energy source.
Original Timeline
Originally slated to die during the destruction caused by asteroid Helios-685, she survived and continued to work on the singularity engine, a device known to be many orders of magnitude more efficient than any power source both manmade or existing in nature up to this point in history.
After her research was accepted for publication, she and Meyers celebrated, discussing the potential of their project winning a Nobel Peace Prize. Eleven months later, their work was granted a patent.
Twenty years from the present time, an unforeseen gamma ray burst from the singularity engine triggers a civilization ending event, wiping out 1.4 billion people in a matter of hours. Subsequent degradation of the Ozone Layer kills any survivors of the initial blast.
Traveler 7189, as host Andrew Graeme, explains to Burns how the the singularities coalesce to produce the gamma ray burst, and while crestfallen, she agrees that her research cannot continue. She assures Carly and Graeme that Meyers will understand too, once she sees the math.
Reset Timeline
Sometime after MacLaren returns to August 2001, he anonymously delivers a note reading "HELIOS" to Burns, warning her of the future disaster.