Questioning the Foundations of Physics pp 151-164 | Cite as

# Is Quantum Linear Superposition an Exact Principle of Nature?

## Abstract

The principle of linear superposition is a hallmark of quantum theory. It has been confirmed experimentally for photons, electrons, neutrons, atoms, for molecules having masses up to ten thousand amu, and also in collective states such as SQUIDs and Bose-Einstein condensates. However, the principle does not seem to hold for positions of large objects! Why for instance, a table is never found to be in two places at the same time? One possible explanation for the absence of macroscopic superpositions is that quantum theory is an approximation to a stochastic nonlinear theory. This hypothesis may have its fundamental origins in gravitational physics, and is being put to test by modern ongoing experiments on matter wave interferometry.

## Keywords

Quantum Theory Interference Pattern Linear Superposition Fundamental Constant Interference Experiment## Notes

### Acknowledgments

This work is supported by a grant from the John Templeton Foundation.

## References

- 1.K. Hornberger, S. Gerlich, P. Haslinger, S. Nimmrichter, M. Arndt, Rev. Mod. Phys.
**84**, 157 (2011)CrossRefADSGoogle Scholar - 2.M. Arndt, O. Nairz, J. Vos-Andreae, C. Keller, G. Van der Zouw, A. Zeilinger, Nature
**401**, 680 (1999)CrossRefADSGoogle Scholar - 3.S.L. Adler, A. Bassi, Science
**325**, 275 (2009)CrossRefGoogle Scholar - 4.A. Bassi, G.C. Ghirardi, Phys. Rep.
**379**, 257 (2003)CrossRefADSzbMATHMathSciNetGoogle Scholar - 5.A. Bassi, K. Lochan, S. Satin, T.P. Singh, H. Ulbricht, Rev. Mod. Phys.
**85**, 471 (2013)CrossRefADSGoogle Scholar - 6.G.C. Ghirardi, A. Rimini, T. Weber, Phys. Rev. D
**34**, 470 (1986)CrossRefADSzbMATHMathSciNetGoogle Scholar - 7.G.C. Ghirardi, P. Pearle, A. Rimini, Phys. Rev. A
**42**, 78 (1990)CrossRefADSMathSciNetGoogle Scholar - 8.A. Bassi, D.G.M. Salvetti, J. Phys. A
**40**, 9859 (2007)CrossRefADSzbMATHMathSciNetGoogle Scholar - 9.S.L. Adler, J. Phys. A
**40**, 2935 (2007)CrossRefADSzbMATHMathSciNetGoogle Scholar - 10.A. Bassi, D.-A. Deckert, L. Ferialdi, Europhys. Lett.
**92**, 50006 (2010)CrossRefADSGoogle Scholar - 11.W. Feldmann, R. Tumulka, J. Phys. A: Math. Theor.
**45**, 065304 (2012)CrossRefADSMathSciNetGoogle Scholar - 12.S. Nimmrichter, K. Hornberger, P. Haslinger, M. Arndt, Phys. Rev. A
**83**, 043621 (2011)CrossRefADSGoogle Scholar - 13.O. Romero-Isart, Phys. Rev. A
**84**, 052121 (2011)CrossRefADSGoogle Scholar - 14.M. Arndt, A. Ekers, W. von Klitzing, H. Ulbricht, New J. Phys. 14 (2011)Google Scholar
- 15.J. Clauser, M. Reinsch, Appl. Phys. B: Lasers Opt.
**54**, 380 (1992)CrossRefADSGoogle Scholar - 16.K. Hornberger, S. Gerlich, H. Ulbricht, L. Hackermüller, S. Nimmrichter, I. Goldt, O. Boltalina, M. Arndt, New J. Phys.
**11**, 043032 (2009)CrossRefADSGoogle Scholar - 17.S. Gerlich, S. Eibenberger, M. Tomandl, S. Nimmrichter, K. Hornberger, P.J. Fagan, J. Tüxen, M. Mayor, M. Arndt, Nat. Commun.
**2**, 263 (2011)CrossRefADSGoogle Scholar - 18.S. Nimmrichter, P. Haslinger, K. Hornberger, M. Arndt, New J. Phys.
**13**, 075002 (2011)Google Scholar - 19.S. Bose, K. Jacobs, P. Knight, Phys. Rev. A
**56**, 4175 (1997)CrossRefADSGoogle Scholar - 20.W. Marshall, C. Simon, R. Penrose, D. Bouwmeester, Phys. Rev. Lett.
**91**, 130401 (2003)CrossRefADSMathSciNetGoogle Scholar - 21.T. Kippenberg, K. Vahala, Science
**321**, 1172 (2008)CrossRefADSGoogle Scholar - 22.M. Aspelmeyer, S. Groeblacher, K. Hammerer, N. Kiesel, J. Opt. Soc. Am. B
**27**, A189 (2010)CrossRefADSGoogle Scholar - 23.J. Chan, T. Alegre, A. Safavi-Naeini, J. Hill, A. Krause, S. Groeblacher, M. Aspelmeyer, O. Painter, Nature
**478**, 89 (2011)CrossRefADSGoogle Scholar - 24.A. O’Connell, M. Hofheinz, M. Ansmann, R. Bialczak, M. Lenander, E. Lucero, M. Neeley, D. Sank, H. Wang, M. Weides et al., Nature
**464**, 697 (2010)CrossRefADSGoogle Scholar - 25.O. Romero-Isart, A. Panzer, F. Blaser, R. Kaltenbaek, N. Kiesel, M. Aspelmeyer, J. Cirac, Phys. Rev. Lett.
**107**, 020405 (2011)CrossRefADSGoogle Scholar - 26.F. Karolyhazy, A. Frenkel, B. Lukács, in
*Quantum Concepts in Space and Time*, ed. by R. Penrose, C.J. Isham (Clarendon, Oxford, 1986)Google Scholar - 27.L. Diósi, Phys. Lett. A
**120**, 377 (1987)CrossRefADSGoogle Scholar - 28.R. Penrose, Gen. Relativ. Gravit.
**28**, 581 (1996)CrossRefADSzbMATHMathSciNetGoogle Scholar - 29.L. Diósi, Phys. Rev. A
**40**, 1165 (1989)CrossRefADSGoogle Scholar - 30.S.L. Adler,
*Quantum Theory as an Emergent Phenomenon*(Cambridge University Press, Cambridge, 2004) pp. xii \(+\) 225Google Scholar - 31.T.P. Singh, J. Phys. Conf. Ser.
**174**, 012024 (2009)CrossRefADSGoogle Scholar - 32.T. P. Singh, (2011). arXiv:1106.0911
- 33.K. Lochan, T.P. Singh, Phys. Lett. A
**375**, 3747 (2011)CrossRefADSzbMATHMathSciNetGoogle Scholar - 34.K. Lochan, S. Satin, T.P. Singh, Found. Phys.
**42**, 1556 (2012)CrossRefADSzbMATHMathSciNetGoogle Scholar - 35.O. Oreshkov, F. Costa, C. Brukner, Nat. Commun.
**3**, 1092 (2012)CrossRefADSGoogle Scholar