Irreversible Processes in Physical Theory

Article metrics


PROF. R. C. L. BOSWORTH'S view, if I understand him properly, is that held by most physicists since the time of Boltzmann. It has become famous through Eddington's metaphor of the arrow of time. It consists of the following two theses : (1) Every non-statistical or ‘classical’ mechanical process is reversible; this, to quote Prof. Bosworth, “is ensured by the ordinary laws of motion which are invariant with respect to change from +t to −t”; (2) irreversibility enters into physics “by means of parameters which have only a statistical significance”; or in Eddington's way of putting it, the increase of entropy (or of statistical disorder) determines the “arrow of time”.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Nature, 177, 538 (1956).

  2. 2

    Nature, 179, 1297 (1957).

  3. 3

    Brit. J. Phil. Sci., 8, 151 (1957).

  4. 4

    Einstein, A., Ann. Phys., 17, 549 (1905); 19, 371 (1906).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

POPPER, K. Irreversible Processes in Physical Theory. Nature 181, 402–403 (1958) doi:10.1038/181402b0

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.