Could the missing energy in the universe be measured in a laboratory experiment?

Paul Warburton and colleagues at the London Centre for Nanotechnology think the answer may be yes, and have been funded by the UK Engineering and Physical Sciences Research Council (EPSRC) to investigate further.

In the late 1990’s measurements by astronomers showed that around 70% of the energy in the universe is in the form of so-called dark energy. This dark energy is not only responsible for the accelerating expansion of the universe but also was the driving force for the big bang. One possible source of this dark energy is vacuum fluctuations which arise from the finite zero-point energy of a quantum mechanical oscillator.

Vacuum fluctuations can be measured using a low-noise electronic device known as a Josephson junction. It was recently predicted by Christian Beck and Michael Mackey that if vacuum fluctuations are the source of dark energy, then the measured spectrum of vacuum fluctuations in a Josephson junction should drop off sharply at frequencies above around 2000 GHz. Paul Warburton’s group, in collaboration with Dr Zoe Barber and colleagues at the University of Cambridge, are developing new types of Josephson junctions which can measure at these high frequencies.

The project was recently highlighted in the Spanish newspaper El Pais : [external link] (in Spanish).


Figure 1: Nanoscale Josephson junctions fabricated in Paul Warburton’s laboratory at the London Centre for Nanotechnology. These tiny electronic devices might hold the key to the secrets of the origin of the universe.


Notes for editors

1. About the London Centre for Nanotechnology

The London Centre for Nanotechnology is an interdisciplinary joint enterprise between University College London and Imperial College London. In bringing together world-class infrastructure and leading nanotechnology research activities, the Centre aims to attain the critical mass to compete with the best facilities abroad. Research programmes are aligned to three key areas, namely Planet Care, Healthcare and Information Technology and bridge together biomedical, physical and engineering sciences. Website: www.london-nano.com

2. About University College London

Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. In the government's most recent Research Assessment Exercise, 59 UCL departments achieved top ratings of 5* and 5, indicating research quality of international excellence.

UCL is in the top ten world universities in the 2007 THES-QS World University Rankings, and the fourth-ranked UK university in the 2007 league table of the top 500 world universities produced by the Shanghai Jiao Tong University. UCL alumni include Marie Stopes, Jonathan Dimbleby, Lord Woolf, Alexander Graham Bell, and members of the band Coldplay. Website: www.ucl.ac.uk