The Physical Worldornament
physical world logo

The Restless universe
Introduction to The restless Universe

1 The lawful Universe

2 The clockwork Universe

3 The irreversible Universe

4 The intangible Universe

5 The uncertain Universe

6 Closing items


Other titles in the Physical World series

Describing motion

Predicting motion

Classical physics of matter

Static fields and potentials

Dynamic fields and waves

Quantum physics: an introduction

Quantum physics of matter

Answer and comments

See Question 1.11 with its relevant text

See all the questions

Question 1.11
Briefly describe the opposition that exists between reductionism and emergence.

Reductionism is an attempt to interpret everything in terms of fundamental phenomena. For a physicist, this implies trying to explain everything in terms of fundamental particles and their interactions.

Emergence stresses the fact that certain phenomena arise only in complex systems, and have no direct counterpart in terms of fundamental phenomena. For example, an iron bar has a strength that is not directly related to the strength of iron atoms.

Most physicists believe that everything can be related, in principle, to fundamental phenomena. In principle, the strength of an iron bar can be explained in terms of the forces between atoms, which in turn can be explained in terms of quantum field theory. The hard-line reductionist might therefore dismiss the strength of the rod as being of minor importance, since it is a consequence of more fundamental ideas. Most physicists (and even more engineers) would disagree. Advocates of emergence delight in the fact that new phenomena, such as rigidity, emerge from more basic laws. Far from dismissing ideas such as rigidity they use them as valid concepts in their own right.

See Question 1.11 with its relevant text

See all the questions


Advanced Search
and search tips

Relevant Links

A note on powers of ten and significant figures

Some highlights of physics

Featured Physicists

Suggestions for further reading

» Questions, answers and comments



S207 The Physical World