quantum mechanics

From The Great Courses Daily, May 5, 2020: Fermilab scientist Dan Hooper writes about how Einstein’s failure in achieving a unified field theory didn’t stop the others. Physicists continue to search for a theory of everything that unites the effects of general relativity with the quantum mechanical nature of our world.

Quantum mechanics is perhaps the most misunderstood of modern physics topics, with many counterintuitive concepts like cats being both alive and dead and with claims that something doesn’t exist until a human looks at it. In this 10-minute video, Fermilab scientist Don Lincoln boils quantum mechanics down to its essence and demystifies this mystifying theory.

In recent years, scientists have found ways to study black holes, listening to the gravitational waves they unleash when they collide and even creating an image of one by combining information from radio telescopes around the world. But our knowledge of black holes remains limited. So scientists are figuring out how to make do with substitutes — analogs to black holes that may hold answers to mysteries about gravity and quantum mechanics.

The inability of scientists to create a theory of quantum gravity arises from long-standing tensions between general relativity and quantum mechanics. There have been few approaches with any success. Don Lincoln explains one of the few promising ideas, called loop quantum gravity, in this 9-minute video.

A reader asks, “If atoms are mostly empty space, then why does anything feel solid?” James Beacham, a researcher with the ATLAS Experiment Group at Ohio State University, explains in this two-minute video.