About the Authors

Staffan A. Qvist

staffan.qvist@physics.uu.se

Affiliation Department of Physics and Astrophysics, Uppsala University, Uppsala, Sweden

Barry W. Brook

Affiliation Faculty of Science, Engineering & Technology, University of Tasmania, Hobart, Australia

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SQ BWB. Performed the experiments: SQ BWB. Analyzed the data: SQ BWB. Contributed reagents/materials/analysis tools: SQ BWB. Wrote the paper: SQ BWB.