WEBVTT 00:00:01.600 --> 00:00:02.834 Supported by 00:00:02.834 --> 00:00:04.350 Supported by Protocol Labs 00:00:04.350 --> 00:00:05.419 Supported by Protocol Labs Follow your curiosity. 00:00:05.419 --> 00:00:09.187 Supported By Protocol Labs Follow your curiosity. Lead humanity forward. 00:00:09.187 --> 00:00:09.437 Protocol Labs Follow your curiosity. Lead humanity forward. 00:00:09.437 --> 00:00:09.687 Follow your curiosity. Lead humanity forward. 00:00:16.820 --> 00:00:19.129 "In all the universe, 00:00:19.129 --> 00:00:24.540 "In all the universe, there stands only one known tree of life." 00:00:31.421 --> 00:00:34.443 "Does it stand alone? 00:00:34.443 --> 00:00:40.311 "Does it stand alone? Or is it part of a vast cosmic wilderness?" 00:00:46.038 --> 00:00:52.537 "Imagine a museum containing every type of life in the universe." 00:00:58.362 --> 00:01:00.757 "What strange things would such a museum hold?" 00:01:16.257 --> 00:01:18.667 "What is possible under the laws of nature?" 00:01:39.767 --> 00:01:40.906 LIFE 00:01:40.906 --> 00:01:45.610 LIFE BEYOND 00:01:49.016 --> 00:01:49.885 CHAPTER II 00:01:49.885 --> 00:01:55.406 CHAPTER II The Museum Of Alien Life 00:02:02.805 --> 00:02:03.657 To have any hope- 00:02:03.657 --> 00:02:05.506 of finding alien life, 00:02:05.537 --> 00:02:07.408 we have to know what to look for. 00:02:12.060 --> 00:02:13.945 But where do we begin? 00:02:15.303 --> 00:02:16.446 How do we narrow down... 00:02:16.568 --> 00:02:18.068 a seemingly infinite set- 00:02:18.068 --> 00:02:20.175 of possibilities... 00:02:27.310 --> 00:02:29.968 There's one thing we know for sure... 00:02:30.683 --> 00:02:32.045 nature will have to play- 00:02:32.075 --> 00:02:33.375 by her own rules. 00:02:36.791 --> 00:02:38.166 No matter how strange 00:02:38.196 --> 00:02:39.806 alien life might be, 00:02:40.386 --> 00:02:41.180 is going to be limited- 00:02:41.220 --> 00:02:42.596 by the same physical... 00:02:42.606 --> 00:02:44.756 and chemical laws that we are.... 00:02:46.952 --> 00:02:47.014 6 00:02:47.014 --> 00:02:47.077 6 C 00:02:47.077 --> 00:02:47.139 6 CO 00:02:47.139 --> 00:02:47.202 6 CO² 00:02:47.202 --> 00:02:47.264 6 CO² + 00:02:47.264 --> 00:02:47.327 6 CO² + 6 00:02:47.327 --> 00:02:47.389 6 CO² + 6 H 00:02:47.389 --> 00:02:47.452 6 CO² + 6 H² 00:02:47.452 --> 00:02:47.514 6 CO² + 6 H²O 00:02:47.514 --> 00:02:47.577 6 CO² + 6 H²O + 00:02:47.577 --> 00:02:47.639 6 CO² + 6 H²O + L 00:02:47.639 --> 00:02:47.702 6 CO² + 6 H²O + Li 00:02:47.702 --> 00:02:47.764 6 CO² + 6 H²O + Lig 00:02:47.764 --> 00:02:47.827 6 CO² + 6 H²O + Ligh 00:02:47.827 --> 00:02:47.889 6 CO² + 6 H²O + Light 00:02:47.889 --> 00:02:47.952 6 CO² + 6 H²O + Light → 00:02:47.952 --> 00:02:48.014 6 CO² + 6 H²O + Light → C 00:02:48.014 --> 00:02:48.077 6 CO² + 6 H²O + Light → C⁶ 00:02:48.077 --> 00:02:48.139 6 CO² + 6 H²O + Light → C⁶H 00:02:48.139 --> 00:02:48.202 6 CO² + 6 H²O + Light → C⁶H¹ 00:02:48.202 --> 00:02:48.264 6 CO² + 6 H²O + Light → C⁶H¹² 00:02:48.264 --> 00:02:48.326 6 CO² + 6 H²O + Light → C⁶H¹²O 00:02:48.326 --> 00:02:48.389 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ 00:02:48.389 --> 00:02:48.451 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 00:02:48.451 --> 00:02:48.514 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 00:02:48.514 --> 00:02:48.576 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O 00:02:48.576 --> 00:02:51.613 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O² 00:02:51.613 --> 00:02:52.312 On top of this, 6 CO² + 6 H²O + Light → C⁶H¹²O⁶ + 6 O² 00:02:52.312 --> 00:02:52.733 On top of this, 00:02:53.244 --> 00:02:53.694 each alien environment will further limit- 00:02:53.694 --> 00:02:55.239 each alien environment will further limit- -Hydrogen- 00:02:55.239 --> 00:02:55.672 each alien environment will further limit- -Oxygen- 00:02:55.672 --> 00:02:57.374 what kinds of life forms can evolve there. -Oxygen- 00:02:57.374 --> 00:02:59.376 what kinds of life forms can evolve there. -Nitrogen- 00:03:06.992 --> 00:03:09.189 Despite these natural boundaries, 00:03:09.243 --> 00:03:12.206 the possibilities are staggering to imagine. 00:03:14.235 --> 00:03:15.640 Trillions of planets, 00:03:15.778 --> 00:03:17.878 each a unique cauldron of chemicals, 00:03:17.924 --> 00:03:23.076 undergoing their own complex evolution. 00:03:28.300 --> 00:03:33.548 To guide our thinking, this museum of alien life will be divided into two exhibits: 00:03:35.768 --> 00:03:40.185 Life as we know it: home to beings with bio-chemistries like ours. 00:03:41.964 --> 00:03:47.921 And life as we don't know it: home to beings that challenge our concept of life itself. 00:03:54.132 --> 00:03:56.629 Before we venture too far into the unknown, 00:03:57.103 --> 00:03:58.587 we have to ask ourselves: 00:04:00.136 --> 00:04:03.005 what if alien life is more like ours than we think? 00:04:10.820 --> 00:04:12.729 EXHIBIT I 00:04:12.729 --> 00:04:15.017 EXHIBIT I LIFE AS WE KNOW IT 00:04:15.017 --> 00:04:15.435 EXHIBIT I LIFE AS WE KNOW IT CARBON & WATER BASED 00:04:15.435 --> 00:04:20.798 If there's one feature that unites us with these other specimes in this museum, it's carbon. 00:04:25.007 --> 00:04:29.380 Carbon is ubiquitous, it's one of the most common elements in the universe, 00:04:29.745 --> 00:04:32.751 and is very good at forming large stable molecules. 00:04:37.293 --> 00:04:41.502 Carbon has the rare ability to form four way bounds with other elements 00:04:41.807 --> 00:04:44.708 and to bind to itself in long, stable chains; 00:04:46.424 --> 00:04:49.624 enabling the formation of huge complex molecules. 00:04:56.197 --> 00:04:59.093 This versatility makes carbon the center piece 00:04:59.093 --> 00:05:01.130 in the moleculary machinery of life. 00:05:03.520 --> 00:05:07.742 And the same carbon compounds that we use have been found far from Earth, 00:05:08.736 --> 00:05:10.087 clinging to meteorites 00:05:12.359 --> 00:05:15.623 and floating in far off clouds of cosmic dust. 00:05:18.670 --> 00:05:23.518 The building blocks of life drifting like snow through the universe. 00:05:30.162 --> 00:05:34.920 And if alien life has selected other carbon compounds for the biochemistry, 00:05:35.783 --> 00:05:37.413 they will have plenty to choose from. 00:05:42.088 --> 00:05:47.570 Scientists recently identified over a million possible alternatives to DNA: 00:05:48.588 --> 00:05:49.862 all carbon based. 00:05:57.948 --> 00:06:00.795 If we ever discover other carbon based life forms, 00:06:01.650 --> 00:06:03.973 we will be fundamentally related. 00:06:07.928 --> 00:06:09.840 They will be our cosmic brother. 00:06:13.296 --> 00:06:15.137 But would they look anything like us? 00:06:19.975 --> 00:06:21.742 If they hail from Earth like planets, 00:06:22.857 --> 00:06:24.471 we could share even more in common, 00:06:25.065 --> 00:06:26.417 than just our biochemistry. 00:06:29.826 --> 00:06:33.104 What would life be like in another planets, if its evolved? 00:06:33.566 --> 00:06:36.246 Would it be like, the world today here on Earth? 00:06:37.477 --> 00:06:38.736 Or would be completely different? 00:06:40.504 --> 00:06:42.121 There are those, who argue that 00:06:42.456 --> 00:06:44.470 from the argument of convergent evolution, 00:06:44.803 --> 00:06:50.206 if conditions on other planets are similar to here, then we will see very similar life forms; 00:06:54.726 --> 00:06:58.236 animal and plant-like organisms, that look very familiar. 00:07:12.238 --> 00:07:16.618 On Earth, certain features like eyesight, echo-location and flight 00:07:16.628 --> 00:07:20.812 have evolved multiple times, independently, in different species. 00:07:23.648 --> 00:07:28.978 This process of convergent evolution could extend to alien planets like Earth, 00:07:29.222 --> 00:07:32.242 where creatures share similar environmental pressures. 00:07:35.632 --> 00:07:40.372 It's no guarantee, but there could be certain universalities of life; 00:07:44.337 --> 00:07:48.337 the greatest hits of evolution on repeat across the Universe. 00:07:58.040 --> 00:08:02.040 Each feature would be a tune to its local environment. 00:08:02.798 --> 00:08:06.798 Dimly lit planets would produce huge eyes to suck in extra light, like nocturnal mammals.