1 00:00:03,000 --> 00:00:07,000 One of the most powerful supercomputers in the world 2 00:00:07,000 --> 00:00:11,000 has now been fully installed and tested 3 00:00:11,000 --> 00:00:14,000 at its remote, high altitude site 4 00:00:14,000 --> 00:00:16,000 in the Andes of northern Chile. 5 00:00:17,000 --> 00:00:21,000 This marks one of the major remaining milestones 6 00:00:21,000 --> 00:00:23,000 toward completion of ALMA, 7 00:00:23,000 --> 00:00:28,000 the Atacama Large Millimeter/submillimeter Array. 8 00:00:29,000 --> 00:00:32,000 The ALMA correlator turns ALMA's 9 00:00:32,000 --> 00:00:37,000 many antennas into one giant telescope. 10 00:00:42,000 --> 00:00:44,000 This is the ESOcast! 11 00:00:44,000 --> 00:00:48,000 Cutting-edge science and life behind the scenes 12 00:00:48,000 --> 00:00:52,000 at ESO, the European Southern Observatory. 13 00:01:01,000 --> 00:01:06,000 ALMA is the most elaborate ground-based telescope in history 14 00:01:06,000 --> 00:01:11,000 and is composed of an array of 66 dish-shaped antennas. 15 00:01:12,000 --> 00:01:15,000 Its supercomputer, or correlator, 16 00:01:15,000 --> 00:01:18,000 is a component of crucial importance. 17 00:01:19,000 --> 00:01:22,000 For ALMA to work, the faint celestial signals 18 00:01:22,000 --> 00:01:26,000 collected by each antenna must be combined 19 00:01:26,000 --> 00:01:28,000 with those from every other antenna. 20 00:01:30,000 --> 00:01:34,000 The correlator's processors will continually combine and compare 21 00:01:34,000 --> 00:01:38,000 the data from up to 64 of the antennas in the ALMA array, 22 00:01:38,000 --> 00:01:42,000 which are separated by up to 16 kilometres, 23 00:01:42,000 --> 00:01:46,000 enabling the antennas to work together 24 00:01:46,000 --> 00:01:49,000 as a single, enormous, telescope. 25 00:01:50,000 --> 00:01:53,000 The ALMA correlator has over 26 00:01:53,000 --> 00:01:59,000 134 million processors, and performs up to an unbelievable 27 00:01:59,000 --> 00:02:03,000 17 quadrillion operations per second. 28 00:02:03,000 --> 00:02:08,000 That is 17 thousand million million! 29 00:02:10,000 --> 00:02:14,000 The correlator was built specifically for this task, 30 00:02:14,000 --> 00:02:18,000 but the number of calculations per second is comparable 31 00:02:18,000 --> 00:02:21,000 to the performance of the fastest general-purpose 32 00:02:21,000 --> 00:02:24,000 supercomputers in the world. 33 00:02:25,000 --> 00:02:29,000 This unique processing challenge needed innovative design, 34 00:02:29,000 --> 00:02:33,000 both for the individual components and for the overall 35 00:02:33,000 --> 00:02:36,000 architecture of the correlator. 36 00:02:38,000 --> 00:02:41,000 The initial design of the correlator, 37 00:02:41,000 --> 00:02:44,000 as well as its construction and installation, 38 00:02:44,000 --> 00:02:48,000 was led by the US National Radio Astronomy Observatory, 39 00:02:48,000 --> 00:02:52,000 the lead North American partner in ALMA. 40 00:02:53,000 --> 00:02:57,000 The correlator project was funded by the US National Science Foundation, 41 00:02:57,000 --> 00:03:01,000 with contributions from ESO. 42 00:03:01,000 --> 00:03:05,000 As the European partner in ALMA, ESO 43 00:03:05,000 --> 00:03:08,000 also provided a key part of the correlator: 44 00:03:08,000 --> 00:03:13,000 an entirely new and versatile digital filtering system, 45 00:03:13,000 --> 00:03:15,000 conceived and built in Europe, 46 00:03:15,000 --> 00:03:20,000 was incorporated into the initial NRAO design. 47 00:03:22,000 --> 00:03:26,000 The University of Bordeaux designed and built a set 48 00:03:26,000 --> 00:03:32,000 of 550 state-of-the-art digital filter circuit boards for ESO. 49 00:03:32,000 --> 00:03:36,000 With these filters, the light that ALMA sees 50 00:03:36,000 --> 00:03:39,000 can be split up into 32 times more wavelength ranges 51 00:03:39,000 --> 00:03:42,000 than in the initial design, 52 00:03:42,000 --> 00:03:48,000 allowing astronomers to flexibly "slice and dice" the spectrum of light. 53 00:03:50,000 --> 00:03:55,000 As well as enormous technical challenges in building the correlator, 54 00:03:55,000 --> 00:04:00,000 the extreme location of the system was also a factor. 55 00:04:01,000 --> 00:04:03,000 The correlator is housed in the ALMA 56 00:04:03,000 --> 00:04:06,000 Array Operations Site Technical Building, 57 00:04:06,000 --> 00:04:10,000 the highest-altitude high-tech building in the world. 58 00:04:11,000 --> 00:04:16,000 At 5000 metres altitude, the air is thin, meaning that 59 00:04:16,000 --> 00:04:21,000 twice the normal airflow is necessary to cool the supercomputer. 60 00:04:23,000 --> 00:04:28,000 The thin air also makes it impossible to use spinning computer disk drives, 61 00:04:28,000 --> 00:04:31,000 as their read/write heads rely on 62 00:04:31,000 --> 00:04:36,000 a cushion of air to stop them crashing into their platters. 63 00:04:36,000 --> 00:04:40,000 Furthermore, the correlator had to be designed to withstand 64 00:04:40,000 --> 00:04:44,000 earthquakes, which are common in this region. 65 00:04:46,000 --> 00:04:49,000 ALMA began science observations in 2011 66 00:04:49,000 --> 00:04:52,000 with a partial array of antennas. 67 00:04:53,000 --> 00:04:56,000 A section of the correlator was already in use 68 00:04:56,000 --> 00:04:59,000 to combine the signals from these antennas, 69 00:04:59,000 --> 00:05:02,000 but now the full system is complete, 70 00:05:02,000 --> 00:05:08,000 ready for ALMA to begin observations with a larger number of antennas. 71 00:05:12,000 --> 00:05:15,000 The successful installation of the new supercomputer 72 00:05:15,000 --> 00:05:21,000 marks an important step toward the completion of ALMA in the near future. 73 00:05:23,000 --> 00:05:27,000 By using the array's unparalleled observational power, 74 00:05:27,000 --> 00:05:34,000 scientists will gain new insights into the hidden wonders of the Universe. 75 00:05:41,000 --> 00:05:45,000 ESOcast is produced by ESO, the European Southern Observatory www.eso.org 76 00:05:45,000 --> 00:05:49,000 ESO, the European Southern Observatory, is the pre-eminent intergovernmental science and technology organisation in astronomy, 77 00:05:49,000 --> 00:05:52,000 designing, constructing and operating the world’s most advanced ground-based telescopes. 78 00:05:55,000 --> 00:05:59,000 Transcription by ESO ; translation by —