Niels Bohr: Physics and the World

Herman Feshbach, Tetsuo Matsui, Alexandra Oleson

• Publisher: Routledge
• Year: 2014
• eBook ISBN: 9781317699156
• Edition: 1
• Topic: History
• Subtopic: 20th Century History
• Index: History

Containing the proceedings of the symposium held by the American Academy of Arts and Sciences to celebrate the 100th anniversary of the birth of Niels Bohr, this collection was first published in 1988.

More than any other individual, Bohr was responsible for the development of quantum mechanics and for many of its applications in the pursuit of fundamental understanding of physical reality. In addition to his unique role in the discovery and elucidation of quantum theory, Bohr led the study of the fission of nuclei and was greatly concerned with the impact of the existence of the atomic bomb in the post-World War II era.

This unique volume provides a panoramic view of modern physics, some of the philosophical issues associated with quantum theory, the impact of this momentous scientific development on the political circumstance of the Cold War Era and the qualities of a superlative scientist.

Do Black Holes Emit Black-Body Radiation?

T.D. Lee

COLUMBIA UNIVERSITY

I. EPR Phenomena and Inclusive Experiment

Outside a black hole, or in a constant accelerating frame, one deals with space-time manifolds that possess horizons. It is well-known [1,2] that observers bounded within such a manifold can detect radiation whose characteristics bear a remarkable resemblance to that from a black body. However, before discussing this subject, let me briefly mention two basic points about quantum mechanics:

1. It is well known that a pure quantum-mechanical state can carry coherent phase correlations between dynamical variables that are localized in different regions outside each other’s light cones. For example, in the decay

π^0 → γ(1) + γ(2)

(1.1)

the electric field of γ(1) is parallel to the magnetic field of γ(2), no matter how far apart these two photons are. Such correlations have to be expressed in terms of the quantum-mechanical amplitude, not the classical probability. This point was questioned by the celebrated Einstein-Podolsky-Rosen article [3]; the subsequent papers by John Bell [4] and others have completely clarified this non-classical aspect of quantum mechanics.

A quantum-mechanical state vector | S〉 is defined globally, depending on a space-like surface S which spreads to infinity. Therefore, its coherence can extend to local variables that are far away from one another, outside each others’ light cones. In the literature most of the discussions on the Einstein-Podolsky-Rosen phenomena are for microscopic systems like π⁰ or positronium. As we shall see, they are also applicable to macroscopic systems, such as the black-hole radiation.

2. Quite often in physics, even for a pure state it is difficult to measure all commuting variables in the system. For example, we may measure only the single pion distribution in a high...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Original Title Page
• Original Copyright Page
• Table of Contents
• Preface
• Overview
• Niels Bohr and the Development of Physics
• On the Origins of the Copenhagen Interpretation
• Niels Bohr and Atomic Physics Today
• Condensed Matter Physics: Does Quantum Mechanics Matter?
• Nuclear Physics: Comments and Reflections
• The New Ether
• Recent Developments in Cosmology
• Black Holes and the Foundations of Quantum Mechanics
• Do Black Holes Emit Black-Body Radiation?
• Quaternionic Quantum Field Theory
• Light and Life: Niels Bohr's Legacy to Contemporary Biology
• Bertlmann’s Socks and the Nature of Reality
• Fifty Years Later: When Gedanken Experiments Become Real Experiments
• Physical and Philosophical Issues in the Bohr-Einstein Debate
• The Soviet Reaction to Bohr’s Quantum Mechanics
• Niels Bohr and the First Principles of Arms Control
• American Attitudes on Security: Comments
• Science, Technology, and the Arms Race: European Perspectives
• Index