100 years of the quantum

  title={100 years of the quantum},
  author={Max Tegmark and J. Wheeler},
  journal={Scientific American},
As quantum theory celebrates its 100th birthday, spectacular successes are mixed with outstanding puzzles and promises of new technologies. This article reviews both the successes of quantum theory and the ongoing debate about its consequences for issues ranging from quantum computation to consciousness, parallel universes and the nature of physical reality. We argue that modern experiments and the discovery of decoherence have have shifted prevailing quantum interpretations away from wave… Expand
The coming of a classical world
Quantum theory’s unusual predictions stem from its basic formalism which involves concepts like the wavefunction or probabilityamplitudes instead of probabilities. Many serious doubts have beenExpand
On Unitary Evolution and Collapse in Quantum Mechanics
In the framework of an interference setup in which only two outcomes are possible (such as in the case of a Mach–Zehnder interferometer), we discuss in a simple and pedagogical way the differenceExpand
How Can the No-Collapse and the Collapse Interpretations of Quantum-Mechanics Give the Same Description?
It is shown that no-collapse and collapse interpretations of quantum mechanics give equal object states (which predict everything that is observable) if one bases the relevant relations on the VonExpand
A Realist Analysis of Six Controversial Quantum Issues
This essay provides a philosophically realistic analysis of six phenomena central to the authors' current confusion: quantization, field-particle duality, superposition, entanglement, nonlocality, and measurement, which concurs with the scientific paradigm as it has been known since Copernicus. Expand
The Philosophy behind Quantum Gravity
This paper investigates some of the philosophical and conceptual issues raised by the search for a quan- tum theory of gravity. It is critically discussed whether such a theory is necessary in theExpand
Global and local aspects of causality in quantum mechanics
Quantum mechanics forces us to reconsider certain aspects of classical causal- ity. The 'central mystery' of quantum mechanics manifests in di erent ways, depending on the interpretation. ThisExpand
Quantum computation and hidden variables
Many physicists limit oneself to an instrumentalist description of quantum phenomena and ignore the problems of foundation and interpretation of quantum mechanics. This instrumentalist approachExpand
Wave packet spreading: Temperature and squeezing effects with applications to quantum measurement and decoherence
A localized free particle is represented by a wave packet and its motion is discussed in most quantum mechanics textbooks. Implicit in these discussions is the assumption of zero temperature. WeExpand
Quantum Mechanics and Multi-World Interpretation—A Dialogue between a Cat and Everett
This article starts with the famous experiment Schrodinger’s Cat and tells us two well-known answers to quantum mechanics in the history, that is the Copenhagen Interpretation and the Multi-World Interpretation. Expand
Decoherence, einselection, and the quantum origins of the classical
as quantum engineering. In the past two decades it has become increasingly clear that many (perhaps all) of the symptoms of classicality can be induced in quantum systems by their environments. ThusExpand