NASA, the Department of Energy and the National Science Foundation currently fund most US research in physics and astronomy, with each agency traditionally supporting well-defined areas. But the report says that this practice could hinder the cross-disciplinary research needed to answer the eleven questions. It recommends that the three bodies work together to set up an interagency initiative on the physics of the universe to support the new scientific ventures it proposes.

Among these projects is an unmanned space mission to study the polarization of radiation left over from the big bang. Fluctuations in this ‘cosmic microwave background’ reveal the conditions in the early universe that led to the structure we see in the universe today. Previous studies of the microwave background – such as the Boomerang experiment – have been conducted from balloons high in the Earth’s atmosphere.

The report also says that a new underground laboratory should be built to conduct experiments on elementary particles including neutrinos, whose signals are swamped by more energetic particles at ground level. The properties of such particles could shed light on the nature of ‘dark matter’, a substance proposed to explain why galaxies seem to contain more matter than we can detect. A consortium of US physicists recently named the now-closed Homestake gold mine in South Dakota as a promising site for a new underground lab.

The other projects four projects recommended by the report should:

* determine the properties of ‘dark energy’, a kind of ‘repulsive gravity’ proposed to explain why the expansion of the universe is accelerating

* use space to probe the basic laws of physics, including tests of Einstein’s theories and the detection of ‘gravitational waves’

* determine the origin of the highest-energy gamma rays, neutrinos and cosmic rays

* study high-energy-density physics in devices such as accelerators to establish the laws that govern extreme astrophysical environments