Three-quarters of the Universe is dark energy, but nobody knows what it is. Is it an unknown form of energy that fills space, or an illusion caused by extra dimensions of space? Or is it just a flaw in Einstein’s theory of gravity? Proven techniques for investigating these questions are being refined, while new techniques are beginning to be applied to one of the most pressing problems in 21st-century physics. Part 1 discusses supernovae as standard candles.

Baryon acoustic oscillations provides a “standard ruler” for the Universe, a way to measure the details of dark energy.

Gravitational lensing, which depends on Einstein’s Theory of General Relativity, directly tests its ability to predict the growth of large-scale structure.

Warm dense matter exists in the cores of gas giant planets and the preliminary stages of nuclear fusion, among other inaccessible places. With an accelerator built at Berkeley Lab by physicists and engineers in the Heavy Ion Fusion Science Virtual National Laboratory, a collaboration of Berkeley Lab, Livermore, and Princeton, scientists will soon be able to study it in the laboratory.

BOSS, the Baryon Oscillation Spectroscopic Survey, is the most ambitious attempt yet to map the expansion history of the Universe using the technique known as baryon acoustic oscillation. BOSS achieved first light on September 14 with an upgraded spectrographic system on the 2.5-meter telescope at Apache Point Observatory.

George Smoot of the Physics Division represented Berkeley Lab at the signing of an agreement with representatives of South Korea’s University of Incheon to explore the potential for joint scientific research in energy, biology, accelerators, cosmology, and space. The agreement calls for investigation of possible collaborations in which the University of Incheon would provide facilities and Berkeley Lab would provide research programs.

Studying Einstein’s General Relativity theory and such celestial phenomena as black holes and strange attractors in a laboratory setting may soon be possible using the new breed of artificial optical materials that can bend light in unusual ways.

Finding rare and fleeting cosmic events not only requires the right kind of telescope and camera, it depends on high-performance computing that can pinpoint objects of interest among thousands of sky images while there’s still time for follow-up observations. Caltech and DOE’s NERSC join forces in just such a search, the Palomar Transient Factory.

The Nearby Supernova Factory has discovered an efficient method for standardizing the intrinsic brightness and thus the distance to the cosmic milestones known as Type Ia supernovae. The discovery underlines the crucial importance of spectroscopy in the quest to understand dark energy.

Berkeley Lab’s interest in the Planck mission to map the cosmic microwave background goes back to a proposal that evolved into the present design – and extends into the future as NERSC’s powerful computers stand by to analyze the coming flood of data.