WEBVTT FILE 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