1 00:00:00,020 --> 00:00:04,040 [slate] 2 00:00:04,060 --> 00:00:08,060 [slate] 3 00:00:08,080 --> 00:00:12,130 [slate] We saw what happens when two 4 00:00:12,150 --> 00:00:16,230 neutron stars collide. Neutron stars are the smallest, most dense stars 5 00:00:16,250 --> 00:00:20,350 that we know of. The two stars spiraled in together 6 00:00:20,370 --> 00:00:24,530 In closer and closer and closer until they collide in a huge explosion 7 00:00:24,550 --> 00:00:28,590 That explosion drives jets that move out into the 8 00:00:28,610 --> 00:00:32,680 material between the stars. And afterwards there's a huge nuclear explosion 9 00:00:32,700 --> 00:00:36,810 that produced heavy elements, gold, platinum 10 00:00:36,830 --> 00:00:40,830 and uranium. [slate] 11 00:00:40,850 --> 00:00:44,900 [slate] 12 00:00:44,920 --> 00:00:48,970 The gold in your ring was produced in an explosion like this but many, many millions 13 00:00:48,990 --> 00:00:53,080 years ago. So the explosion drove the material out 14 00:00:53,100 --> 00:00:57,220 into the medium between the stars where later it coalesced to form 15 00:00:57,240 --> 00:01:01,250 the sun and our planets. [slate] 16 00:01:01,270 --> 00:01:05,420 [slate] 17 00:01:05,440 --> 00:01:09,620 This explosion was special 18 00:01:09,640 --> 00:01:13,690 because in addition to seeing the gamma rays, the highest energy form of light 19 00:01:13,710 --> 00:01:17,780 we also saw gravitational waves. We could see directly the 20 00:01:17,800 --> 00:01:21,910 imprint of these two stars spiraling closer and closer together as they 21 00:01:21,930 --> 00:01:25,940 caused ripples in space-time. 22 00:01:25,960 --> 00:01:30,150 [slate] 23 00:01:30,170 --> 00:01:34,340 Gravitational waves are ripples in space-time. Space-time is incredibly 24 00:01:34,360 --> 00:01:38,420 dense. So to cause ripples you have to have some sort of 25 00:01:38,440 --> 00:01:42,530 object that has enormous gravity like a black hole or a neutron star. 26 00:01:42,550 --> 00:01:46,690 And when these objects are rapidly accelerating 27 00:01:46,710 --> 00:01:50,760 they bend space-time and create these ripples that then travel through the universe 28 00:01:50,780 --> 00:01:54,770 to our detectors on Earth. 29 00:01:54,790 --> 00:01:58,800 [slate] 30 00:01:58,820 --> 00:02:02,990 We detected this early in the morning 31 00:02:03,010 --> 00:02:07,050 and immediately emails are flying backwards and forwards. People 32 00:02:07,070 --> 00:02:11,160 realized that we'd kind of hit the jackpot with finally 33 00:02:11,180 --> 00:02:15,310 seeing gravitational waves and normal light from the same event for the first time. 34 00:02:15,330 --> 00:02:16,850 It was like the best day ever