Neil deGrasse Tyson, astrophysicist and director of the Hayden Planetarium, joins comedian Chuck Nice for another Cosmic Queries grab bag episode of StarTalk Radio. The conversation covers a wide range of physics topics from optics and gravitational waves to black holes and the future of life on Earth.

The discussion explores fundamental physics concepts including how light behaves in different media, the mechanics of LIGO's gravitational wave detection, and the historical persecution of scientific thinkers. Tyson references De Revolutionibus by Copernicus and its influence on Giordano Bruno's revolutionary but heretical ideas about extraterrestrial life.

Later topics shift to speculative science, including quantum entanglement applications, the futility of time capsules, and post-human evolution scenarios drawn from After Man, a book exploring how species might evolve after human extinction.

How Light Slows Down Through Different Materials

Light always travels at the speed of light between molecules, but interactions with matter create an effective slowdown through the index of refraction.

"The index of refraction, if you take the speed of light and divide by the index of refraction, that's the speed of light in that medium" - Neil, with diamond having an index of 2.4, meaning light travels at only 40% normal speed.

Anti-reflective coatings work by using "a coating that's half the wavelength of the light that you're using" so reflected light becomes out of phase and cancels itself out.

Total internal reflection occurs at a specific angle where light "never enters the next medium because this bend now takes it backwards into the medium itself."

LIGO's Brilliant Solution to Gravitational Wave Detection

The fundamental challenge is that if space stretches, measuring devices should stretch proportionally, making detection seemingly impossible.

LIGO solves this by using "two lasers at right angles to each other" so when one stretches in a particular direction, the perpendicular laser remains unaffected.

Einstein's 1916 prediction of gravitational waves and invention of laser principles led to detection exactly 100 years later: "Einstein was gangster" - Chuck.

Giordano Bruno's Fatal Vision of Cosmic Life

After reading Copernicus' De Revolutionibus, Bruno reasoned that if Earth orbits the sun like other planets, then stars might be suns with their own planets and life.

The Catholic Church executed Bruno in 1600, burning him "upside down naked in the Campo di Fioro" with "a stake into his mouth to shut his ass up."

Bruno's last words were "your God is too small," challenging the geocentric view that Earth was the sole object of divine creation.

Tyson argues that a universe created solely for Earth would be inefficient: "I don't need to do all this" - referring to trillions of galaxies if only Earth mattered.

The Futility of Time Capsules and Communication with the Future

"There's nothing less interesting to a subsequent generation than an earlier generation's time capsule" - Neil, citing forgotten capsules like one he found buried near the Unisphere.

Technology becomes obsolete so quickly that items like Metro cards and iPods, once cutting-edge, are now "non-existent" and "nobody wants them."

Chuck suggests putting transcripts of Trump speeches in a time capsule so future generations can read "the words of the most powerful person in the world."

Post-Human Earth: When Rodents Rule the World

After Man explores speculative evolution after human extinction, particularly how rodents might evolve without human predation limiting their size.

"What's limiting the size of rats? The size of the hole they will run into so that you don't harm them" - Neil, suggesting rats could grow to human size without this constraint.

Humans are uniquely fragile with only one species (Homo sapiens) remaining, while rodents represent "one of the most successful branches in the tree of life."

The environmental message isn't "save Earth" but "save your ass" because "Earth's going to be fine" without humans.

Quantum Entanglement and Black Hole Information Paradoxes

Quantum entangled instruments might theoretically allow data collection from inside black holes since entangled particles should "instantaneously mirror" each other's states.

However, faster-than-light communication remains limited because "the information is already built into it" - you can't send new instructions after entanglement.

The jury is still out on fully exploiting quantum entanglement for communication, with current understanding "less favorable than you want to believe it is."