1 00:00:00,030 --> 00:00:04,050 [slate] 2 00:00:04,070 --> 00:00:08,060 [slate] 3 00:00:08,080 --> 00:00:12,130 So first part of this 4 00:00:12,150 --> 00:00:16,210 discovery comes from the LIGO observatory which for the first 5 00:00:16,230 --> 00:00:20,350 time detected gravitational waves, ripples in space-time 6 00:00:20,370 --> 00:00:24,550 from two colliding neutron stars 7 00:00:24,570 --> 00:00:28,610 And if that wasn't enough just two seconds later 8 00:00:28,630 --> 00:00:32,710 with the Fermi Gamma Ray space Telescope we detected 9 00:00:32,730 --> 00:00:36,860 a short bright flash of high energy light that we call a gamma ray 10 00:00:36,880 --> 00:00:41,020 burst. This alerted the entire astronomical community 11 00:00:41,040 --> 00:00:45,080 to the fact that something very exciting was happening and over 12 00:00:45,100 --> 00:00:49,170 70 telescopes from around the world, searched for a counterpart 13 00:00:49,190 --> 00:00:53,370 in other wavelengths. They were able to identify the host galaxy and 14 00:00:53,390 --> 00:00:57,380 study the remains of this explosion in amazing details. 15 00:00:57,400 --> 00:01:01,430 [slate] 16 00:01:01,450 --> 00:01:05,560 That's exactly what I'm saying. For the first time we could actually 17 00:01:05,580 --> 00:01:09,750 weigh the amount of heavy metals that were formed in one of these 18 00:01:09,770 --> 00:01:13,810 systems. Over two hundred times the weight of the Earth. 19 00:01:13,830 --> 00:01:17,960 was formed in gold and platinum following the merger of these 20 00:01:17,980 --> 00:01:22,110 systems. They were thrown out at very high speeds and dispersed throughout 21 00:01:22,130 --> 00:01:26,180 the universe and eventually they were formed as 22 00:01:26,200 --> 00:01:30,200 stars and planets like Earth. 23 00:01:30,220 --> 00:01:34,340 [slate] So Fermi and other 24 00:01:34,360 --> 00:01:38,510 NASA satellites quite often detect what we call gamma ray bursts, very 25 00:01:38,530 --> 00:01:42,550 short high energy flashes. Gamma ray 26 00:01:42,570 --> 00:01:46,640 radiation. Several dozen times a year at least. What 27 00:01:46,660 --> 00:01:50,750 makes this really amazing is that you're actually able to see 28 00:01:50,770 --> 00:01:54,930 the source that powered this gamma ray emission 29 00:01:54,950 --> 00:01:59,030 from gravitational waves. We could link the merger of two 30 00:01:59,050 --> 00:02:03,120 neutron stars to the gamma ray burst which is something 31 00:02:03,140 --> 00:02:07,270 we hypothesized was the case for a long time 32 00:02:07,290 --> 00:02:11,440 but now we had really direct confirmation that that was happening. That's the first time 33 00:02:11,460 --> 00:02:15,460 we've been able to do that. 34 00:02:15,480 --> 00:02:19,560 [slate] Gravitational waves are often referred to 35 00:02:19,580 --> 00:02:23,680 as ripples in space-time when a very dense 36 00:02:23,700 --> 00:02:27,860 massive object accelerates, it actually causes gravitational 37 00:02:27,880 --> 00:02:31,920 energy to propagate throughout the universe, changing the distance 38 00:02:31,940 --> 00:02:36,020 between sources that are relatively close to each other. And 39 00:02:36,040 --> 00:02:40,140 with very precise detectors on the ground we can actually measure 40 00:02:40,160 --> 00:02:44,330 those changes and use them to infer the presence of these really remarkable 41 00:02:44,350 --> 00:02:45,178 collisions.