The universe is big, but it’s peanuts compared to the eternally inflating multiverse. But just how many universes are there? What are they like? And most importantly, what can they tell us about … aliens?
One of the most startling possibilities is that our 3+1 dimensional universe may better described as resulting from a spacetime one dimension lower – like a hologram projected from a surface infinitely far away.
In this episode we dive deeper into the relationship between space and time and explore how we can geometrically map the causality of the universe and increase our understanding of how time and distance relate to one another.
We know that mass is energy… but what is energy? And where did matter and time even come from? Matt begins to dive into these intricate topics by first examining what inertial mass is, how it relates to gravitational mass, and what it all means for mass as a fundamental property.
But how does motion affect time? Let’s dive deeper into the true nature of matter and mass by exploring Einstein’s photon clock thought experiment, and the phenomenon that is time dilation.
Astronomy Cast takes a fact-based journey through the cosmos as it offers listeners weekly discussions on astronomical topics ranging from planets to cosmology. Hosted by Fraser Cain (Universe Today) and Dr. Pamela L. Gay (CosmoQuest), this show brings the questions of an avid astronomy lover direct to an astronomer. Together Fraser and Pamela explore what is known and being discovered about the universe around us.
- Ep. 579: White and Black Dwarfs
- Ep. 578: Life on Venus?!?
- Ep. 577: Mars in Opposition
- Ep. 576: Summer Stargazing Special
- Ep. 575: Observing the Moon
- Ep. 574: Trojan Asteroids
- Ep. 573: Exoplanet Atmospheres
- Ep. 572: Twists in Planet Formation
- Ep. 571: Extreme Binaries
- Ep. 570: Discovering Comets
- Ep. 569: Ethics of Commercial and Military Space, Part 1: Private Space Flight
- Ep. 568: In Situ Resource Utilization
- Ep. 567: When Satellites Need a House Call
- Ep. 566: When Comets Fall Apart
- Ep. 565: When Worlds Collide
We’ve established by now that black holes are weird. The result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.