The podcast episodes provided discuss the concept of wormholes, which are hypothetical tunnels through spacetime that could potentially enable faster-than-light travel and even time travel.

The episodes explore the scientific theories and evidence surrounding wormholes, as well as the challenges and uncertainties associated with their potential creation and traversal. Several episodes, such as Traveling Through Space and Time, with Janna Levin, Just Another Really Good Episode with Brian Greene, and Cosmic Queries - Science Epiphany, delve into the physics and implications of wormholes, including their connection to quantum entanglement and the appearance they might have.

Another episode, EP: 239 Wormholes with Ashton Forbes, specifically examines the possibility that Malaysia Airlines Flight 370 may have encountered a wormhole, leading to its mysterious disappearance.