The Stoner Episode with Janna Levin & Neil deGrasse Tyson – Cosmic Queries

Expansion Mechanics

Janna Levin and Neil deGrasse Tyson explore the mechanics of the universe's expansion, emphasizing that space itself is expanding, carrying galaxies along with it. Janna explains that our perception of the universe is based on interactions rather than geometry, suggesting that everything we understand is through the way particles interact over space and time 1. Neil adds that this expansion is akin to surfing, where we move with space rather than through it, driven by forces like dark energy 2.

We are moving with the expansion of the space. We are not moving with respect to our local area.

--- Janna Levin

This perspective challenges the notion of the universe expanding into something else, as the universe itself is the entirety of space 2.

   

Gravitational Waves

The discussion shifts to gravitational waves and their role in the universe's expansion. Janna Levin describes how gravitational waves, though powerful, have a subtle effect on objects, causing them to experience squeezing and stretching rather than being carried away 3. She notes that while gravity is typically attractive, dark energy introduces a repulsive force, accelerating the universe's expansion. Neil questions whether dark energy can be considered a form of negative gravity, highlighting the complexity of these cosmic forces.

The collision of the two black holes was the most powerful event human beings have detected since the detection of the big bang.

--- Janna Levin

This exploration underscores the intricate dynamics of gravitational forces and their impact on cosmic structures.