Earth- and Space-Based Light Bucket Intensity Interferometry Arrays

Recent progress has been made in the development of low cost, portable, meter-class light bucket telescopes, as well as low cost, lightweight foam glass and spin-cast epoxy mirrors. One of many astronomical applications of light bucket telescopes is stellar intensity interferometry, pioneered by Hanbury Brown in the 1960s. Major advances in detectors, electronics, and computers now allow much fainter sources to be observed; an opportunity being explored by several intensity interferometry experiments. Intensity inteferometric arrays of three or more telescopes with much longer baselines could be used to obtain very high resolution images. Earthbased arrays with baselines of kilometers could be implemented in the near future. Space-based light bucket arrays with baselines up to 20,000-km and sensitivity down to V~20 could split bright spectroscopic binaries in nearby galaxies, thus obtaining direct distances. X-ray binaries could also be split and probed for relativistic orbital effects. The very highest nearby ‘strong gravity’ regime, that of the galactic center, could be monitored for last-time-of-light material as it enters the black hole at Sgr A*. Finally, the very granularity of space-time itself could be explored by mapping the increasing decoherence of light from cosmological sources with increasing baseline, due to the effect of the fundamental Planck scale of space-time ‘smearing’ out the fringes.