Physics Professor Ronald Mallett discussed his breakthrough research on time travel, which is based on Einstein's theories of relativity. "If we can control gravity with a device, then we can actually control time, as well, and that could lead to a machine," he said. The force of gravity is actually the bending of empty space, and the energy of light can create gravity, therefore light can potentially manipulate time, he explained.

Mallett's idea for a machine involves using a circulating light beam with a series of mirrors, that can twist empty space. According to Einstein, if you bend space, then you bend time. "If I twist space, I can twist the line of time into a loop," connecting the past to the future, he said. When a person travels back to the past, they will have altered the past, so the future may not play out in the way the way it originally did. This is known as the 'Butterfly Effect' where some little thing leads to a chain of reactions that alters the future, he detailed.

A time machine could only travel as far back as when the machine was first turned on. So for instance, if a machine was invented this year, time travelers from 2030 could only travel as far back as 2011, he continued. One of the more practical and important uses for time travel would be to send information back in time, rather than a person-- like an early warning device for earthquakes or tsunamis that could save the lives of thousands of people, Mallett noted. He also touched on the time travel work of other scientists including Kip Thorne, who looks at using wormholes to create a path to the past, and Richard Gott, who theorizes about 'cosmic strings.'

Technology Update

First hour guest, Internet privacy and technology expert Lauren Weinstein commented on a new kind of electronic tattoo, as well as other technology stories. The ultrathin patch placed on the skin could prove useful for medical monitoring of the body, but the technology also has potential for misuse, with unauthorized people being able to read the information, he noted. He also spoke about controversies around BART's wireless shutdown in order to quell a protest, and Google Plus' requirement for people to use their real names.

News segment guests: Jeff Nelken, Brad Steiger