The largest of these detectors — the Toroidal LHC Apparatus (ATLAS)2,3, which weighs 7,000 tonnes, and is 45 m in length and 25 m in diameter — was designed, built and operated by an international collaboration of 2,800 scientists from more than 160 institutions in 36 nations. It consists of several layers of highly sensitive particle detectors and huge superconducting magnetic coils, which allow it to measure precisely the paths and energies of particles emerging from the interaction region (pictured above). Over the next two decades, the ATLAS collaboration will search for new fundamental particles that explain the origin of mass or account for the ‘dark matter’ that makes up most of the mass in the Universe, possibly opening doors to new dimensions of space–time.
The Hubble Space Telescope (HST) has returned iconic images of the Universe for 20 years, including photographs of galaxies further than 12 billion light years away, and its data underpin more than 8,500 scientific papers. However, a new optical telescope can surpass the HST’s image resolution by a factor of 10. The Large Binocular Telescope, located high up in Arizona’s Pinaleno Mountains, is the result of a consortium between institutes in the United States, Italy and Germany4. It boasts the two largest telescope mirrors in the world, each measuring 8.4 m across, which combine light coherently to produce an image with sharpness equivalent to a single 22.8-m-diameter mirror (pictured above right). This unrivalled high-resolution imaging will allow the LBT to search for extrasolar planets that are young counterparts of the Earth, address how super-massive black holes at the centres of galaxies form, study early epochs in the expansion of the Universe, and shed light on stellar and planetary formation.
The technical challenges are enormous: a 650-tonne structure holds two 55-m2 pieces of glass in shape, with a precision better than a micrometer, within a 13-story-high rotating steel building at an altitude of 3,200 m. The LBT relies on an adaptive optics system that adjusts the shape of its mirrors up to 1,000 times per second to counteract the blurring effects of the Earth’s atmosphere and thereby avoids the need to launch a telescope into space, which would be even more complex and costly.
The US$100 million LBT saw ‘first light’ in 2005, and became the world’s largest functional light-gathering machine in 2007 (ref. 5). By 2012, it is scheduled to operate in full function, to give us pictures of the cosmos with unprecedented clarity.