Picosecond discharges and stick–slip friction at a moving meniscus of mercury on glass

Article metrics


At a meeting of the French Academy in 1700, Bernoulli demonstrated that swirling mercury in an evacuated flask generates light1,2. He emphasized that this ‘barometer light’ “has not been explained since its discovery about 30 years ago” by Picard3. Here we revisit this phenomenon and find that the repetitive emission of light from mercury moving over glass is accompanied by the collective picosecond transfer of large numbers of electrons. When brought into contact with mercury, the glass acquires a net charge. This charge separation provides a force which, in our experiment in a rotating flask, drags mercury against gravity in the direction of the motion of the glass. Eventually the edge of the mercury slips relative to the glass, accompanied by a picosecond electrical discharge and a flash of light. This repetitive build-up and discharge of static electricity thus gives rise to stick–slip motion. The statistics of the intervals between events and their respective magnitudes are history-dependent and are not yet understood.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Photograph of the “barometer light”, which is the orange line of light generated at the intersection of the mercury meniscus and the wall of the rotating glass cylinder.
Figure 2: Correlation between stick–slip friction and picosecond electrical discharges at a glass–mercury interface.
Figure 3: Plot of discharge events in terms of the time to the next event and its strength.


  1. 1

    Bernoulli, J. I. Sur le phosphore du baromètre. Histoire Acad. Roy. Paris 5–8 (1700); 1–8 (1701).

  2. 2

    Harvey, E. N. A History of Luminescence (Am. Philosophical Soc., Philadelphia, (1957)).

  3. 3

    Picard, J. Sur la lumière du baromètre. Mem. Acad. Roy. Sci. 2, 202–203 (1676).

  4. 4

    Krim, J. Friction at the atomic scale. Sci. Am. 275, 48–51, 54–56 (1996).

  5. 5

    Harper, W. R. Contact and Frictional Electrification (Clarendon, Oxford, (1967)).

  6. 6

    Bowden, F. P. & Tabor, D. The Friction and Lubrication of Solids (Clarendon, Oxford, (1986)).

  7. 7

    Bhushan, B., Israelachvili, J. N. & Landman, U. Nanotribology: friction, wear and lubrication at the atomic scale. Nature 374, 607–616 (1995).

  8. 8

    Rabinowicz, E. Friction and Wear of Materials (Wiley, New York, (1965)); Polishing. Sci. Am. 218, 91–99 (1968).

  9. 9

    Kemball, C. The adsorption of vapours on mercury. IV. Surface potentials and chemisorption. Proc. R. Soc. Lond. A 201, 377–391 (1950).

  10. 10

    Hays, D. A. in Conference Series No. 48 265–272 (Conf. Ser. No. 48, Inst. Phys., (1979)).

  11. 11

    Dybwad, G. L. & Mandeville, C. E. Generation of light by the relative motion of contiguous surfaces of mercury and glass. Phys. Rev. 161, 527–532 (1967).

  12. 12

    Rayleigh, Lor Experiments upon surface-films. Phil. Mag. 33, 363–373 (1892).

  13. 13

    Handbook of Chemistry and Physics 2989 (Chemical Rubber, Cleveland, (1954)).

  14. 14

    Bernoulli, J. I. Nouvelle maniere de rendre les baromètres lumineux. Mem. Acad. Roy. Paris 178–190 (1700).

  15. 15

    Barber, B. P. & Putterman, S. J. Observation of synchronous picosecond sonoluminescence. Nature 352, 318–320 (1991).

  16. 16

    Hiller, R. A., Putterman, S. J. & Barber, B. P. Spectrum of synchronous picosecond sonoluminescence. Phys. Rev. Lett. 69, 1182–1184 (1992).

  17. 17

    Barber, B. P. et al. Defining the unknowns of sonoluminescence. Phys. Rep. 281, 65–143 (1997).

  18. 18

    Meek, J. M. & Craggs, J. D. (eds) Electrical Breakdown of Gases (Wiley, New York, (1978)).

  19. 19

    Carlson, J. M., Langer, J. S. & Shaw, B. E. Dynamics of earthquake faults. Rev. Mod. Phys. 66, 657–670 (1994).

  20. 20

    Demirel, A. L. & Granick, S. Friction fluctuations and friction memory in stick-slip motion. Phys. Rev. Lett. 77, 4330–4333 (1996).

  21. 21

    Burridge, R. & Knopoff, L. Model and theoretical seismicity. Bull. Seismol. Soc. Am. 57, 341–371 (1967).

  22. 22

    Rees, J. A. Electrical Breakdown of Gases (Macmillan, New York, (1973)).

  23. 23

    Penning, F. M. Electrical Discharges in Gases (Cleaver Hume, London, (1957)).

  24. 24

    Loeb, L. B. Fundamental Processes of Electrical Breakdown in Gases (Wiley, New York, (1939)).

  25. 25

    Moore, A. D. Electrostatics (Doubleday, New York, (1968)).

  26. 26

    Terris, B. D., Stern, J. E., Rugar, D. & Mamin, H.J. Contact electrification using force microscopy. Phys. Rev. Lett. 63, 2669–2672 (1989).

  27. 27

    Lowell, J. Tunnelling between metals and insulators and its role in contact electrification. J. Phys. D 12, 1541–1554 (1979).

  28. 28

    Kwetkus, B. A., Sattler, K. & Siegmann, H.-C. Gas breakdown in contact electrification. J. Phys. D 25, 139–146 (1992).

  29. 29

    Raizer, Y. P. Gas Discharge Physics (Springer, Berlin, (1991)).

Download references


We thank L. Knopoff, T. Erber, J. Raffelski, G. Morales, S. Cowley, R. Löfstedt and P.H.Roberts for discussions, and E. Adams and C. Hiller for archival assistance. This work was supported by the US NSF and the US Department of Energy.

Author information

Correspondence to S. J. Putterman.

Rights and permissions

Reprints and Permissions

About this article

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.