StarTalk Podcast: Cosmic Queries – Until the End of Time, with Neil deGrasse Tyson & Brian Greene

Time's Nature

The nature of time is a profound mystery, as Brian Greene and Neil deGrasse Tyson explore whether time is a tangible entity or merely an abstract concept. They discuss the possibility that time, like space, might be composed of fundamental elements, potentially linked by quantum entanglement 1. This idea suggests that the fabric of spacetime could be woven together by these quantum threads, challenging our traditional understanding of time as merely a backdrop for events.

It's conceivable that the threads of quantum entanglement are the stitches in the fabric of spacetime itself.

--- Brian Greene

The conversation also touches on the hypothetical scenario of observing time beyond the Big Bang's horizon, where time might behave differently, though current mathematics suggests it remains consistent 2.

   

Entropy's Role

The relationship between time and entropy is pivotal in understanding the universe's progression. Neil deGrasse Tyson and Brian Greene discuss how entropy's increase is often seen as an arrow of time, suggesting that reversing entropy might alter time's flow 3. However, even if entropy were reversed, time would likely continue in its current direction, though physical processes might appear to reverse.

If we somehow did have power over entropy of the entire universe, do you think that would have any consequences at all?

--- Neil deGrasse Tyson

They also explore the potential dangers of cosmic thought, where the inability to dissipate heat in the far future could impede cognitive processes, highlighting the intricate connection between thermodynamics and consciousness 4.

   

Beyond Horizons

The concept of temporal horizons raises questions about the continuity of time beyond observable limits. Neil deGrasse Tyson and Brian Greene discuss whether time extends beyond the cosmic horizon, suggesting that while it might appear consistent, the unknown could hold surprises 2. They also ponder the universe's end, considering whether space is infinite or curved, allowing for endless travel without a definitive boundary 5.

We look out to the edge of the observable universe, and we see light that has been traveling for 13.8 billion years.

--- Neil deGrasse Tyson

This exploration of temporal and spatial boundaries challenges our understanding of the universe's structure and our place within it.