About this Video

• Video Title: What Bothers Physicists About Black Holes (Interview with Brian Cox)
• Channel: Cleo Abram
• Speakers: Cleo Abram, Brian Cox
• Duration: 01:13:44

Introduction

This video features an extended interview between Cleo Abram and physicist Brian Cox about black holes. The discussion delves into cutting-edge research, exploring the mysteries surrounding black holes, including the information paradox and the holographic principle. The conversation aims to explain complex concepts in an accessible way, highlighting the ongoing debates and unanswered questions within the field.

Key Takeaways

• Black Holes Explained: A black hole is formed when a massive star collapses beyond its Schwarzschild radius, creating a region of spacetime with such extreme gravity that not even light can escape. The singularity at the center isn't a place, but a moment in time – the end of time.
• Two Perspectives: From the perspective of an observer falling into a supermassive black hole, nothing unusual happens until they approach the singularity. However, an outside observer would see their time slow down and eventually stop at the event horizon.
• Spaghettification: For smaller black holes, tidal forces (spaghettification) become significant, stretching and squishing the falling object as it approaches the singularity. For supermassive black holes, this effect isn't felt until well inside the event horizon.
• Information Paradox and Hawking Radiation: Hawking radiation, emitted from a black hole's event horizon, initially seemed to suggest information loss. However, recent research indicates that information about what fell into the black hole is encoded in this radiation, though the mechanism remains unclear. The holographic principle and the concept of black hole complementarity offer possible explanations.
• Emergent Spacetime: Black hole research suggests that spacetime might be emergent, arising from a deeper, underlying structure of information, possibly resembling a network of quantum bits. This connects black hole physics to the development of quantum computers.

The central question that bothers physicists about black holes is the apparent paradox of information loss. The accepted laws of physics state that information is conserved, meaning it cannot be destroyed. However, Stephen Hawking's initial calculations on black hole radiation suggested that information is lost when a black hole evaporates via Hawking radiation. This contradicts the fundamental principle of information conservation. The video explores the ongoing research and different perspectives attempting to resolve this paradox, including the holographic principle and black hole complementarity.