February 25, 2006: Extra Dimensions & Global Warming - Lisa Randall | Global Warming - Noam Mohr
Randall discusses her work on extra dimensions of space, explaining how the weakness of gravity relative to other forces may point to hidden dimensions beyond our perception. She describes membrane-like objects called branes in higher-dimensional space and explains how entirely different physics could govern other regions of reality. The upcoming Large Hadron Collider, she notes, may provide the first experimental evidence.
Both guests weigh in on the accelerating pace of climate change, with Randall describing Al Gore's presentation on ice core data as deeply convincing. Art presses each on the urgency of action, drawing connections between energy policy, scientific suppression, and the long-term survival of civilization.
Key Moments
Arctic ice loss and a 10-degree forecast: Mohr cites 8% Arctic ice loss per decade and a possible ten-degree century, comparing it to the five to nine degree swing of the last ice age.
Methane from livestock as overlooked driver: Mohr argues animal agriculture, not just fossil fuels, drives near-term warming, citing a University of Chicago study showing diet change beats switching to a Prius.
Ice-melt runaway tipping point: Mohr explains the albedo feedback: once enough Arctic ice melts, dark water absorbs sunlight and the warming runs away on its own.
Why gravity is so weak: Randall describes the central puzzle of her work: a tiny magnet beats Earth's entire gravitational pull, and theory wants gravity and the other forces to be comparable.
Could extra dimensions explain the unexplained: Bell asks whether other dimensions could intermix with ours and produce inexplicable phenomena; Randall says yes in principle, but doubts any have been observed.