1. Space Science Division, Naval Research Laboratory, Washington, District of Columbia 20375, USA.


2. National Research Council Research Associate, National Academy of Sciences, Washington, District of Columbia 20001, USA.


3. W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94305, USA.


4. Department of Physics,


5. Interactive Research Center of Science, Tokyo Institute of Technology, Meguro City, Tokyo 152-8551, Japan.


6. Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz,


7. UCO/Lick Observatories, Santa Cruz, California 95064, USA.


8. Department of Astronomy, Stockholm University,


9. The Oskar Klein Centre for Cosmoparticle Physics,


10. Department of Physics,


11. Department of Physics, Royal Institute of Technology (KTH), AlbaNova, SE-106 91 Stockholm, Sweden.


12. Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa, Italy.


13. Laboratoire AIM, CEA-IRFU/CNRS/Université Paris Diderot, Service d'Astrophysique, CEA Saclay, 91191 Gif-sur-Yvette, France.


14. Istituto Nazionale di Fisica Nucleare, Sezione di Trieste,


15. Dipartimento di Fisica, Università di Trieste, I-34127 Trieste, Italy.


16. Rice University, Department of Physics and Astronomy, MS-108, P. O. Box 1892, Houston, Texas 77251, USA.


17. Istituto Nazionale di Fisica Nucleare, Sezione di Padova,


18. Dipartimento di Fisica "G. Galilei", Università di Padova, I-35131 Padova, Italy.


19. CSPAR, University of Alabama in Huntsville, Huntsville, Alabama 35899, USA.


20. Max-Planck Institut für extraterrestrische Physik, 85748 Garching, Germany.


21. Istituto Nazionale di Fisica Nucleare, Sezione di Perugia,


22. Dipartimento di Fisica, Università degli Studi di Perugia, I-06123 Perugia, Italy.


23. Center for Research and Exploration in Space Science and Technology (CRESST),


24. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.


25. University of Maryland, College Park, Maryland 20742, USA.


26. Dipartimento di Fisica "M. Merlin" dell'Università e del Politecnico di Bari,


27. Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari, Italy.


28. Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, F-91128 Palaiseau, France.


29. Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA.


30. INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano, Italy.


31. University of Maryland, Baltimore County, Baltimore, Maryland 21250, USA.


32. Laboratoire de Physique Théorique et Astroparticules, Université Montpellier 2, CNRS/IN2P3, 34095 Montpellier, Cedex 5, France.


33. Department of Physics and Astronomy, Sonoma State University, Rohnert Park, California 94928-3609, USA.


34. Agenzia Spaziale Italiana (ASI) Science Data Center, I-00044 Frascati (Roma), Italy.


35. Dipartimento di Fisica, Università di Udine and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Gruppo Collegato di Udine, I-33100 Udine, Italy.


36. Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.


37. Université de Bordeaux and CNRS/IN2P3, Centre d'Études Nucléaires Bordeaux Gradignan, UMR 5797, Gradignan 33175, France.


38. Space Science Office, VP62, NASA/Marshall Space Flight Center, Huntsville, Alabama 35812, USA.


39. INAF Osservatorio Astronomico di Brera, I-23807 Merate, Italy.


40. Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.


41. Jacobs Technology, Huntsville, Alabama 35806, USA.


42. Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK.


43. Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, Pennsylvania 16802, USA.


44. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany.


45. Department of Physics, Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, Ohio 43210, USA.


46. Waseda University, 1-104 Totsukamachi, Shinjuku-ku, Tokyo, 169-8050, Japan.


47. Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198, Japan.


48. Centre d'Étude Spatiale des Rayonnements, CNRS/UPS, BP 44346, F-30128 Toulouse cedex 4, France.


49. George Mason University, Fairfax, Virginia 22030, USA.


50. University College Dublin, Belfield, Dublin 4, Ireland.


51. Istituto Nazionale di Fisica Nucleare, Sezione di Roma "Tor Vergata",


52. Dipartimento di Fisica, Università di Roma "Tor Vergata", I-00133 Roma, Italy.


53. Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, USA.


54. Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan.


55. Institut für Astro- und Teilchenphysik and Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, A-6020 Innsbruck, Austria.


56. Institut de Ciencies de l'Espai (IEEC-CSIC), Campus UAB, 08193 Barcelona, Spain.


57. Space Sciences Division, NASA Ames Research Center, Moffett Field, California 94035-1000, USA.


58. NYCB Real-Time Computing Inc., Lattingtown, New York 11560-1025, USA.


59. Department of Chemistry and Physics, Purdue University Calumet, Hammond, Indiana 46323-2094, USA.


60. Institució Catalana de Recerca i Estudis Avançats (ICREA), 08193 Barcelona, Spain.


61. Joint Center for Particle Nuclear Physics and Cosmology (J-CPNPC),


62. Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008, China.


63. School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar, Sweden.

Correspondence to: J. Granot⁴²S. Guiriec¹⁹M. Ohno⁵⁴V. Pelassa³² Correspondence and requests for materials should be addressed to J. Granot (Email: j.granot@herts.ac.uk), S. Guiriec (Email: sylvain.guiriec@nasa.gov), M. Ohno (Email: ohno@astro.isas.jaxa.jp) and V. Pelassa (Email: pelassa@lpta.in2p3.fr).

A cornerstone of Einstein's special relativity is Lorentz invariance—the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l _Planck  1.62  10^-33 cm or E _Planck = M _Planck c ²  1.22  10¹⁹ GeV), at which quantum effects are expected to strongly affect the nature of space–time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy^{1, 2, 3, 4, 5, 6, 7}. Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in -ray burst (GRB) light-curves². Here we report the detection of emission up to 31 GeV from the distant and short GRB 090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E _Planck on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l _Planck/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories^{3, 6, 7} in which the quantum nature of space–time on a very small scale linearly alters the speed of light.