1 00:00:01,600 --> 00:00:02,834 Sᴜᴘᴘᴏʀᴛᴇᴅ ʙʏ 2 00:00:02,834 --> 00:00:04,350 Sᴜᴘᴘᴏʀᴛᴇᴅ ʙʏ Protocol Labs 3 00:00:04,350 --> 00:00:05,419 Sᴜᴘᴘᴏʀᴛᴇᴅ ʙʏ Protocol Labs Follow your curiosity. 4 00:00:05,419 --> 00:00:09,187 Sᴜᴘᴘᴏʀᴛᴇᴅ ʙʏ Protocol Labs Follow your curiosity. Lead humanity forward. 5 00:00:09,187 --> 00:00:09,437 Protocol Labs Follow your curiosity. Lead humanity forward. 6 00:00:09,437 --> 00:00:09,687 Follow your curiosity. Lead humanity forward. 7 00:00:16,820 --> 00:00:19,129 "In all the universe, 8 00:00:19,129 --> 00:00:24,540 "In all the universe, there stands only one known tree of life." 9 00:00:31,421 --> 00:00:34,443 "Does it stand alone? 10 00:00:34,443 --> 00:00:40,311 "Does it stand alone? Or is it part of a vast cosmic wilderness?" 11 00:00:46,038 --> 00:00:52,517 "Imagine a museum containing every type of life in the universe." 12 00:00:58,362 --> 00:01:00,757 "What strange things would such a museum hold?" 13 00:01:16,257 --> 00:01:18,667 "What is possible under the laws of nature?" 14 00:01:39,767 --> 00:01:40,906 LIFE 15 00:01:40,906 --> 00:01:45,610 LIFE BEYOND 16 00:01:49,016 --> 00:01:49,885 CHAPTER II 17 00:01:49,885 --> 00:01:55,406 CHAPTER II The Museum Of Alien Life 18 00:02:02,805 --> 00:02:03,657 To have any hope- 19 00:02:03,657 --> 00:02:05,506 of finding alien life, 20 00:02:05,537 --> 00:02:07,408 we have to know what to look for. 21 00:02:12,060 --> 00:02:13,945 But where do we begin? 22 00:02:15,303 --> 00:02:16,446 How do we narrow down... 23 00:02:16,568 --> 00:02:18,068 a seemingly infinite set- 24 00:02:18,068 --> 00:02:20,175 of possibilities... 25 00:02:27,310 --> 00:02:29,968 There's one thing we know for sure... 26 00:02:30,683 --> 00:02:32,045 nature will have to play- 27 00:02:32,075 --> 00:02:33,375 by her own rules. 28 00:02:36,791 --> 00:02:38,166 No matter how strange- 29 00:02:38,196 --> 00:02:39,806 alien life might be, 30 00:02:40,386 --> 00:02:41,180 is going to be limited- 31 00:02:41,220 --> 00:02:42,596 by the same physical... 32 00:02:42,606 --> 00:02:44,756 and chemical laws that we are.... 33 00:02:46,952 --> 00:02:47,014 6 34 00:02:47,014 --> 00:02:47,077 6 C 35 00:02:47,077 --> 00:02:47,139 6 CO 36 00:02:47,139 --> 00:02:47,202 6 CO₂ 37 00:02:47,202 --> 00:02:47,264 6 CO₂ + 38 00:02:47,264 --> 00:02:47,327 6 CO₂ + 6 39 00:02:47,327 --> 00:02:47,389 6 CO₂ + 6 H 40 00:02:47,389 --> 00:02:47,452 6 CO₂ + 6 H₂ 41 00:02:47,452 --> 00:02:47,514 6 CO₂ + 6 H₂O 42 00:02:47,514 --> 00:02:47,577 6 CO₂ + 6 H₂O + 43 00:02:47,577 --> 00:02:47,639 6 CO₂ + 6 H₂O + L 44 00:02:47,639 --> 00:02:47,702 6 CO₂ + 6 H₂O + Li 45 00:02:47,702 --> 00:02:47,764 6 CO₂ + 6 H₂O + Lig 46 00:02:47,764 --> 00:02:47,827 6 CO₂ + 6 H₂O + Ligh 47 00:02:47,827 --> 00:02:47,889 6 CO₂ + 6 H₂O + Light 48 00:02:47,889 --> 00:02:47,952 6 CO₂ + 6 H₂O + Light → 49 00:02:47,952 --> 00:02:48,014 6 CO₂ + 6 H₂O + Light → C 50 00:02:48,014 --> 00:02:48,077 6 CO₂ + 6 H₂O + Light → C₆ 51 00:02:48,077 --> 00:02:48,139 6 CO₂ + 6 H₂O + Light → C₆H 52 00:02:48,139 --> 00:02:48,202 6 CO₂ + 6 H₂O + Light → C₆H₁ 53 00:02:48,202 --> 00:02:48,264 6 CO₂ + 6 H₂O + Light → C₆H₁₂ 54 00:02:48,264 --> 00:02:48,326 6 CO₂ + 6 H₂O + Light → C₆H₁₂O 55 00:02:48,326 --> 00:02:48,389 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ 56 00:02:48,389 --> 00:02:48,451 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 57 00:02:48,451 --> 00:02:48,514 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 58 00:02:48,514 --> 00:02:48,576 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O 59 00:02:48,576 --> 00:02:51,613 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O₂ 60 00:02:51,613 --> 00:02:52,312 On top of this, 6 CO₂ + 6 H₂O + Light → C₆H₁₂O₆ + 6 O₂ 61 00:02:52,312 --> 00:02:52,733 On top of this, 62 00:02:53,183 --> 00:02:53,694 each alien environment will further limit- 63 00:02:53,694 --> 00:02:53,756 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ each alien environment will further limit- 64 00:02:53,756 --> 00:02:53,819 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆ each alien environment will further limit- 65 00:02:53,819 --> 00:02:53,881 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H each alien environment will further limit- 66 00:02:53,881 --> 00:02:53,944 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁ each alien environment will further limit- 67 00:02:53,944 --> 00:02:54,006 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂ each alien environment will further limit- 68 00:02:54,006 --> 00:02:54,069 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O each alien environment will further limit- 69 00:02:54,069 --> 00:02:54,131 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ each alien environment will further limit- 70 00:02:54,131 --> 00:02:54,194 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → each alien environment will further limit- 71 00:02:54,194 --> 00:02:54,256 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2 each alien environment will further limit- 72 00:02:54,256 --> 00:02:54,319 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C each alien environment will further limit- 73 00:02:54,319 --> 00:02:54,381 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂ each alien environment will further limit- 74 00:02:54,381 --> 00:02:54,444 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H each alien environment will further limit- 75 00:02:54,444 --> 00:02:54,506 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅ each alien environment will further limit- 76 00:02:54,506 --> 00:02:54,569 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅O each alien environment will further limit- 77 00:02:54,569 --> 00:02:54,631 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH each alien environment will further limit- 78 00:02:54,631 --> 00:02:54,694 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH + each alien environment will further limit- 79 00:02:54,694 --> 00:02:54,756 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2 each alien environment will further limit- 80 00:02:54,756 --> 00:02:54,819 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2C each alien environment will further limit- 81 00:02:54,819 --> 00:02:54,881 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO each alien environment will further limit- 82 00:02:54,881 --> 00:02:54,944 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + each alien environment will further limit- 83 00:02:54,944 --> 00:02:55,006 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + E each alien environment will further limit- 84 00:02:55,006 --> 00:02:55,069 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + En each alien environment will further limit- 85 00:02:55,069 --> 00:02:55,131 ⁴⁵⁸ ʜʏᴅʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Ene each alien environment will further limit- 86 00:02:55,131 --> 00:02:55,194 ⁴⁵⁸ ᴏxʏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Ener each alien environment will further limit- 87 00:02:55,194 --> 00:02:55,256 ⁴⁵⁸ ᴏxʏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energ each alien environment will further limit- 88 00:02:55,256 --> 00:02:55,319 ⁴⁵⁸ ᴏxʏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energy each alien environment will further limit- 89 00:02:55,319 --> 00:02:55,632 ⁴⁵⁸ ᴏxʏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energy each alien environment will further limit- 90 00:02:55,632 --> 00:02:57,311 ⁴⁵⁸ ᴏxʏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energy what kinds of life forms can evolve there. 91 00:02:57,311 --> 00:02:57,436 ⁴⁵⁸ ɴɪʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energy what kinds of life forms can evolve there. 92 00:02:57,436 --> 00:02:59,376 ⁴⁰⁵⁰ ɴɪʀᴏɢᴇɴ | C₆H₁₂O₆ → 2C₂H₅OH +2CO₂ + Energy what kinds of life forms can evolve there. 93 00:03:06,992 --> 00:03:09,189 Despite these natural boundaries, 94 00:03:09,243 --> 00:03:12,206 the possibilities are staggering to imagine. 95 00:03:14,235 --> 00:03:15,640 Trillions of planets, 96 00:03:15,778 --> 00:03:17,878 each a unique cauldron of chemicals, 97 00:03:17,924 --> 00:03:23,036 undergoing their own complex evolution. 98 00:03:28,150 --> 00:03:29,360 To guide our thinking, 99 00:03:29,598 --> 00:03:31,316 this museum of alien life- 100 00:03:31,316 --> 00:03:34,396 will be divided into two exhibits... 101 00:03:35,668 --> 00:03:36,041 Life as we know it, 102 00:03:36,041 --> 00:03:37,194 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ Life as we know it, 103 00:03:37,194 --> 00:03:38,215 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ home to beings- 104 00:03:38,215 --> 00:03:40,940 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ with bio-chemistries like ours. 105 00:03:41,569 --> 00:03:41,694 EXHIBIT II LIFE AS WE DON'T KNOW IT ᴱˣᵒᵗᶦᶜ ᴮᶦᵒᶜʰᵉᵐᶦˢᵗʳᶦᵉˢ 106 00:03:41,694 --> 00:03:43,588 EXHIBIT II LIFE AS WE DON'T KNOW IT ᴱˣᵒᵗᶦᶜ ᴮᶦᵒᶜʰᵉᵐᶦˢᵗʳᶦᵉˢ And life as we don't know it, 107 00:03:43,588 --> 00:03:44,068 EXHIBIT II LIFE AS WE DON'T KNOW IT ᴱˣᵒᵗᶦᶜ ᴮᶦᵒᶜʰᵉᵐᶦˢᵗʳᶦᵉˢ 108 00:03:44,068 --> 00:03:45,038 EXHIBIT II LIFE AS WE DON'T KNOW IT ᴱˣᵒᵗᶦᶜ ᴮᶦᵒᶜʰᵉᵐᶦˢᵗʳᶦᵉˢ home to beings- 109 00:03:45,038 --> 00:03:47,818 EXHIBIT II LIFE AS WE DON'T KNOW IT ᴱˣᵒᵗᶦᶜ ᴮᶦᵒᶜʰᵉᵐᶦˢᵗʳᶦᵉˢ that challenge our concept of life itself. 110 00:03:54,022 --> 00:03:54,986 Before we venture- 111 00:03:55,042 --> 00:03:56,889 too far into the unknown, 112 00:03:57,103 --> 00:03:59,177 we have to ask ourselves... 113 00:03:59,956 --> 00:04:01,059 what if alien life- 114 00:04:01,183 --> 00:04:02,253 is more like us... 115 00:04:02,253 --> 00:04:03,939 than we think? 116 00:04:10,759 --> 00:04:12,728 EXHIBIT I 117 00:04:12,728 --> 00:04:14,746 EXHIBIT I Life As We Know It 118 00:04:14,746 --> 00:04:15,174 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ 119 00:04:15,174 --> 00:04:16,307 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ If there's one feature- 120 00:04:16,307 --> 00:04:17,327 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ that unites us... 121 00:04:17,327 --> 00:04:19,510 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ with these other specimes in this museum, 122 00:04:19,510 --> 00:04:19,922 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ 123 00:04:19,922 --> 00:04:21,245 EXHIBIT I Life As We Know It ᶜᵃʳᵇᵒⁿ ᵃⁿᵈ ʷᵃᵗᵉʳ ᵇᵃˢᵉᵈ it's carbon... 124 00:04:21,775 --> 00:04:22,025 Carbon 125 00:04:22,025 --> 00:04:22,087 Carbon ⁴ 126 00:04:22,087 --> 00:04:22,150 S Carbon ⁴ᵗʰ 127 00:04:22,150 --> 00:04:22,212 ᴀ Sᴜ Carbon ⁴ᵗʰ ᵐ 128 00:04:22,212 --> 00:04:22,275 C ᴀᴛ Sᴜʙ Carbon ⁴ᵗʰ ᵐᵒ 129 00:04:22,275 --> 00:04:22,337 R | C 0 ᴀᴛᴏ Sᴜʙʟ Carbon ⁴ᵗʰ ᵐᵒˢ 130 00:04:22,337 --> 00:04:22,400 R + | C 00 ᴀᴛᴏᴍ Sᴜʙʟɪ Carbon ⁴ᵗʰ ᵐᵒˢᵗ 131 00:04:22,400 --> 00:04:22,462 R + 7: | C 006 ᴀᴛᴏᴍɪ Sᴜʙʟɪᴍ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃ 132 00:04:22,462 --> 00:04:22,525 R + 7: 9 | C 006 ᴀᴛᴏᴍɪᴄ Sᴜʙʟɪᴍᴀ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇ 133 00:04:22,525 --> 00:04:22,587 R + 7: 9: | C 006 ᴀᴛᴏᴍɪᴄ ᴡ Sᴜʙʟɪᴍᴀᴛ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘ 134 00:04:22,587 --> 00:04:22,650 R + 7: 9: 5 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇ Sᴜʙʟɪᴍᴀᴛɪ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿ 135 00:04:22,650 --> 00:04:22,712 R + 7: 9: 56 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪ Sᴜʙʟɪᴍᴀᴛɪᴏ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈ 136 00:04:22,712 --> 00:04:22,775 R + 7: 9: 56: | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜ Sᴜʙʟɪᴍᴀᴛɪᴏɴ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃ 137 00:04:22,775 --> 00:04:22,837 R + 7: 9: 56:2 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿ 138 00:04:22,837 --> 00:04:22,900 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ 139 00:04:22,900 --> 00:04:22,962 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉ 140 00:04:22,962 --> 00:04:23,025 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡ 141 00:04:23,025 --> 00:04:23,087 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂. Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉ 142 00:04:23,087 --> 00:04:23,150 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐ 143 00:04:23,150 --> 00:04:23,212 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉ 144 00:04:23,212 --> 00:04:23,275 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿ 145 00:04:23,275 --> 00:04:23,337 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 146 00:04:23,337 --> 00:04:23,400 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 147 00:04:23,400 --> 00:04:24,545 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 148 00:04:24,545 --> 00:04:24,670 R + 7: 9: 56:25 | Period 2 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 149 00:04:24,670 --> 00:04:26,147 R + 7: 9: 56:25 | Period 2 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ Carbon is ubiquitous, 150 00:04:26,147 --> 00:04:26,287 R + 7: 9: 56:25 | Period 2 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 151 00:04:26,287 --> 00:04:26,655 R + 7: 9: 56:25 | Period 2 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ it's one o' tho most- 152 00:04:26,655 --> 00:04:27,514 R + 7: 9: 56:25 | P-block ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ it's one o' tho most- 153 00:04:27,514 --> 00:04:28,790 R + 7: 9: 56:25 | P-block ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ common elements in the universe, 154 00:04:28,790 --> 00:04:29,357 R + 7: 9: 56:25 | Group 14 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ common elements in the universe, 155 00:04:29,357 --> 00:04:29,515 R + 7: 9: 56:25 | Group 14 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 156 00:04:29,515 --> 00:04:30,529 R + 7: 9: 56:25 | Group 14 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ and is very good at forming- 157 00:04:30,529 --> 00:04:30,883 R + 7: 9: 56:25 | [He] 2s² 2p² ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ and is very good at forming- 158 00:04:30,883 --> 00:04:32,351 R + 7: 9: 56:25 | [He] 2s² 2p² ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ large stable molecules. 159 00:04:32,351 --> 00:04:32,822 R + 7: 9: 56:25 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ large stable molecules. 160 00:04:32,822 --> 00:04:33,545 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ large stable molecules. 161 00:04:33,545 --> 00:04:34,574 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 162 00:04:34,574 --> 00:04:36,829 R + 7: 9: 56:25 | Period 2 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 163 00:04:36,829 --> 00:04:37,079 R + 7: 9: 56:25 | P-block ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 164 00:04:37,079 --> 00:04:38,638 R + 7: 9: 56:25 | P-block ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ Carbon has the rare ability- 165 00:04:38,638 --> 00:04:38,888 R + 7: 9: 56:25 | P-block ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ to form four way bounds- 166 00:04:38,888 --> 00:04:40,354 R + 7: 9: 56:25 | Group 14 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ to form four way bounds- 167 00:04:40,354 --> 00:04:40,651 R + 7: 9: 56:25 | Group 14 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ with other elements... 168 00:04:40,651 --> 00:04:41,533 R + 7: 9: 56:25 | [HE] 2s² 2p² ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ with other elements... 169 00:04:41,533 --> 00:04:41,753 R + 7: 9: 56:25 | [HE] 2s² 2p² ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ 170 00:04:41,753 --> 00:04:42,433 R + 7: 9: 56:25 | [HE] 2s² 2p² ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ and to bind to itself- 171 00:04:42,433 --> 00:04:42,914 R + 7: 9: 56:25 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ and to bind to itself- 172 00:04:42,914 --> 00:04:42,977 R + 7: 9: 56:25 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ in long stable chains; 173 00:04:42,977 --> 00:04:44,556 R + 7: 9: 56:25 | C 006 ᴀᴛᴏᴍɪᴄ ᴡᴇɪɢʜᴛ: ₁₂.₀₁₁ Sᴜʙʟɪᴍᴀᴛɪᴏɴ ᴘᴏɪɴᴛ: ³⁹¹⁵ ᴷ Carbon ⁴ᵗʰ ᵐᵒˢᵗ ᵃᵇᵘⁿᵈᵃⁿᵗ ᵉˡᵉᵐᵉⁿᵗ in long stable chains... 174 00:04:46,164 --> 00:04:47,475 enabling the formation... 175 00:04:47,525 --> 00:04:51,146 of huge complex molecules. 176 00:04:56,197 --> 00:04:59,093 This versatility makes carbon the center piece 177 00:04:59,093 --> 00:05:01,130 in the moleculary machinery of life. 178 00:05:03,520 --> 00:05:07,742 And the same carbon compounds that we use have been found far from Earth, 179 00:05:08,736 --> 00:05:10,087 clinging to meteorites 180 00:05:12,359 --> 00:05:15,623 and floating in far off clouds of cosmic dust. 181 00:05:18,670 --> 00:05:23,518 The building blocks of life drifting like snow through the universe. 182 00:05:30,162 --> 00:05:34,920 And if alien life has selected other carbon compounds for the biochemistry, 183 00:05:35,783 --> 00:05:37,413 they will have plenty to choose from. 184 00:05:42,088 --> 00:05:47,570 Scientists recently identified over a million possible alternatives to DNA: 185 00:05:48,588 --> 00:05:49,862 all carbon based. 186 00:05:57,948 --> 00:06:00,795 If we ever discover other carbon based life forms, 187 00:06:01,650 --> 00:06:03,973 we will be fundamentally related. 188 00:06:07,928 --> 00:06:09,840 They will be our cosmic brother. 189 00:06:13,296 --> 00:06:15,137 But would they look anything like us? 190 00:06:19,975 --> 00:06:21,742 If they hail from Earth like planets, 191 00:06:22,857 --> 00:06:24,471 we could share even more in common, 192 00:06:25,065 --> 00:06:26,417 than just our biochemistry. 193 00:06:29,826 --> 00:06:33,104 What would life be like in another planets, if its evolved? 194 00:06:33,566 --> 00:06:36,246 Would it be like, the world today here on Earth? 195 00:06:37,477 --> 00:06:38,736 Or would be completely different? 196 00:06:38,819 --> 00:06:42,121 There are those, who argue that 197 00:06:42,456 --> 00:06:44,470 from the argument of convergent evolution, 198 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; 199 00:06:54,726 --> 00:06:58,236 animal and plant-like organisms, that look very familiar. 200 00:07:12,238 --> 00:07:16,618 On Earth, certain features like eyesight, echo-location and flight 201 00:07:16,628 --> 00:07:20,812 have evolved multiple times, independently, in different species. 202 00:07:23,648 --> 00:07:28,978 This process of convergent evolution could extend to alien planets like Earth, 203 00:07:29,222 --> 00:07:32,242 where creatures share similar environmental pressures. 204 00:07:35,632 --> 00:07:40,372 It's no guarantee, but there could be certain universalities of life; 205 00:07:44,337 --> 00:07:48,337 the greatest hits of evolution on repeat across the Universe. 206 00:07:58,040 --> 00:08:02,040 Each feature would be a tune to its local environment. 207 00:08:02,798 --> 00:08:09,491 Dimly lit planets would produce huge eyes to suck in extra light, like nocturnal mammals. 208 00:08:14,190 --> 00:08:19,231 Some people have gone so far as to say that human type organism, humanoids, 209 00:08:19,231 --> 00:08:20,809 will occur on other planets. 210 00:08:26,136 --> 00:08:29,706 The existence of other human-like organisms seems unlikely, 211 00:08:30,155 --> 00:08:33,602 given the long convoluted chain of events that produced us. 212 00:08:35,296 --> 00:08:36,400 But we can't rule it out. 213 00:08:40,817 --> 00:08:44,838 If just one in every 100 trillion Earth-like planets produced 214 00:08:44,838 --> 00:08:49,551 a human-like form, the could still be thousands of creatures like us out there. 215 00:09:02,605 --> 00:09:07,335 But in reality, we are more likely to find something lower on the food chain. 216 00:09:10,171 --> 00:09:13,423 Convergent evolution is also rampant in plant life 217 00:09:14,037 --> 00:09:19,312 and C4 photosynthesis has arisen independently over 40 times. 218 00:09:21,799 --> 00:09:25,178 Would alien plants look like ours or something else entirely? 219 00:09:36,926 --> 00:09:40,857 On Earth, plants appear green because they absorb the other wavelenghts 220 00:09:40,997 --> 00:09:42,537 in the Sun's light spectrum. 221 00:09:45,739 --> 00:09:47,778 But stars come in many colors 222 00:09:52,629 --> 00:09:56,984 and alien plants would evolve different pigments to adapt to their sun's unique spectrum. 223 00:10:04,431 --> 00:10:07,530 Plants feeding off hotter stars could appear redder, 224 00:10:08,284 --> 00:10:11,161 by absorbing their energy rich bluer light. 225 00:10:19,761 --> 00:10:24,219 Around dim Red Dwarfs stars, vegetation could appear black, 226 00:10:25,072 --> 00:10:28,155 adapted to absorb all visible wavelengths of light. 227 00:10:45,058 --> 00:10:47,572 Earth itself may have once appeared purple, 228 00:10:48,101 --> 00:10:52,004 due a pigment called retinal, that was an early precursor to chlorophyll. 229 00:10:55,019 --> 00:10:57,779 Some think that retinal's molecular simplicity 230 00:10:58,189 --> 00:11:00,547 could make it a more universal pigment. 231 00:11:04,070 --> 00:11:09,146 If so, we may find that purple, is life's favorite color. 232 00:11:19,820 --> 00:11:23,713 But the color of alien vegetation is more than just a curiosity, 233 00:11:25,696 --> 00:11:29,155 it's chemical information that could be seen from light years away. 234 00:11:34,504 --> 00:11:38,528 Earth plants leave a signature bump in the light reflected off our planet. 235 00:11:40,306 --> 00:11:43,434 Finding a similar signal from another world could point the way 236 00:11:43,647 --> 00:11:45,116 to alien vegetation. 237 00:11:50,376 --> 00:11:53,866 Perhaps this will be our first glimpse at alien life; 238 00:11:54,965 --> 00:11:58,375 a vibrant hue, cast by a distinct world. 239 00:12:12,005 --> 00:12:20,055 But the biggest influence on life won't be it's host star; it will be it's home planet. 240 00:12:20,715 --> 00:12:23,415 What happens, when you change the day - length of a planet? 241 00:12:23,495 --> 00:12:25,465 What happens when you change the tilt of a planet? 242 00:12:25,545 --> 00:12:27,626 What happens when you change the shape of the orbit? 243 00:12:27,965 --> 00:12:30,637 What happens when you change the gravity of a planet? 244 00:12:34,498 --> 00:12:38,938 Planets with long, elliptical orbits would see drastic seasons. 245 00:12:41,298 --> 00:12:44,823 There could be worlds that appear dead for thousands of years, 246 00:12:45,528 --> 00:12:47,496 then suddenly spring to life. 247 00:13:02,583 --> 00:13:07,073 Most of the rocky planets discovered so far have been massive "Super Earths". 248 00:13:09,243 --> 00:13:12,433 GJ 357 DSuper Earth Distance : ~ 31 Light Years Mass : ~ 7× Earth Temperature : ~ -53°C 249 00:13:12,570 --> 00:13:15,097 How would life evolve on these worlds? 250 00:13:18,580 --> 00:13:21,656 In the seas, gravity may not matter much at all. 251 00:13:29,590 --> 00:13:32,120 A high - gravity planet isn't high - gravity all over. 252 00:13:33,680 --> 00:13:37,660 If you're in the sea, that's where all life starts, there's very nearly no gravity, 253 00:13:37,660 --> 00:13:40,225 cause you're much the density as the stuff around you. 254 00:13:43,450 --> 00:13:47,270 It's when the animals come out on land, that they feel the gravity. 255 00:13:51,628 --> 00:13:53,628 High G - forces [vaguely, gravitational forces] would necessitate 256 00:13:53,628 --> 00:13:57,458 large bones and muscle mass in complex life on land. 257 00:13:59,748 --> 00:14:03,178 They would also demand a more robust circulatory system. 258 00:14:04,958 --> 00:14:10,578 And plant life could be stunted by the energy cost of carrying nutrients under stronger gravity. 259 00:14:17,318 --> 00:14:21,446 Low - gravity planets would more easily lose their atmospheres to space; 260 00:14:21,838 --> 00:14:25,158 and lack a magnetic field to protect from cosmic rays. 261 00:14:35,821 --> 00:14:39,091 But smaller worlds could be home to secret oases; 262 00:14:46,251 --> 00:14:49,451 huge cave systems that provide hide-outs for life. 263 00:15:02,751 --> 00:15:11,242 With steadier temperatures and protection from cosmic rays, life could thrive underground on planets with deadly surfaces. 264 00:15:26,732 --> 00:15:33,093 The smallest possible habitable planets are estimated at 2.5% Earth's mass. 265 00:15:35,042 --> 00:15:37,735 If surface life does evolve on these worlds, 266 00:15:38,822 --> 00:15:40,766 it could be a sight to behold. 267 00:15:44,584 --> 00:15:47,064 Plant life could grow to towering heights, 268 00:15:47,484 --> 00:15:50,594 able to carry nutrients higher, at lesser gravity. 269 00:15:59,194 --> 00:16:02,611 And without the need for bulky skeletons and muscle mass, 270 00:16:02,904 --> 00:16:06,031 animals could have body types, that boggle the mind. 271 00:16:22,292 --> 00:16:28,347 Despite our eager imagination, large complex lifeforms are probably a cosmic rarity. 272 00:16:31,631 --> 00:16:34,920 Here on Earth, it took three billion years for evolution 273 00:16:34,920 --> 00:16:37,234 to produce complex plant and animal life. 274 00:16:39,723 --> 00:16:42,584 Simple organisms are hardier, more adaptable 275 00:16:42,986 --> 00:16:44,041 and more widespread. 276 00:16:48,383 --> 00:16:51,390 The largest collection in the museum of alien life 277 00:16:51,390 --> 00:16:54,309 would likely be the Hall of Microbes. 278 00:17:10,306 --> 00:17:14,674 Yet finding even the tiniest alien microbe would be a profound discovery. 279 00:17:30,735 --> 00:17:33,619 And bite-sized life could leave a big footprint. 280 00:17:35,892 --> 00:17:39,997 Like stromatolites on Earth, layers of microbes could build up into huge 281 00:17:39,997 --> 00:17:41,170 rock mounds over time. 282 00:17:41,642 --> 00:17:43,876 Leaving behind eery structures. 283 00:17:48,780 --> 00:17:51,202 And in big enough numbers some alien 284 00:17:51,202 --> 00:17:54,004 bacteria could leave a distinct biosignature, 285 00:17:55,964 --> 00:17:58,622 by exhaling gases that wouldn't coexist naturally: 286 00:17:59,453 --> 00:18:01,124 like oxygen and methane. 287 00:18:07,406 --> 00:18:08,996 There's ways to make oxygen without life. 288 00:18:08,996 --> 00:18:10,579 There's ways to make methane without life. 289 00:18:11,067 --> 00:18:12,582 But to have them in the atmosphere together? 290 00:18:13,212 --> 00:18:16,501 Is almost impossible unless you've got biology making those gases at the surface. 291 00:18:17,883 --> 00:18:20,828 And it would have a imprint on the planet's spectrum of colors. 292 00:18:22,945 --> 00:18:26,267 Next generation space telescopes could find a signal like this, 293 00:18:28,574 --> 00:18:30,531 on a world not far from home. 294 00:18:32,274 --> 00:18:36,578 The closest Sun-like star with an Earth-like exoplanet in the 295 00:18:36,578 --> 00:18:40,206 habitable zone is probably only 20 light years away 296 00:18:40,489 --> 00:18:42,409 and can be seen with a naked eye. 297 00:18:46,298 --> 00:18:52,373 But there may be an even easier target to aim for than tiny Earth-like planets. 298 00:18:54,805 --> 00:19:02,008 The Brown Dwarfs: too small to be stars, to big to be planets. 299 00:19:06,389 --> 00:19:09,928 Most Brown Dwarfs are too hot to support life as we know it. 300 00:19:11,136 --> 00:19:12,604 But some are just cold enough. 301 00:19:13,978 --> 00:19:14,558 WISE 0855-0714 302 00:19:14,758 --> 00:19:15,008 WISE 0855-0714 Sub-Brown Dwarf 303 00:19:15,008 --> 00:19:15,258 WISE 0855-0714 Sub-Brown Dwarf Distance: 7 Light Years 304 00:19:15,268 --> 00:19:15,518 WISE 0855-0714 Sub-Brown Dwarf Distance: 7 Light Years Mass: 3.10x Jupiter 305 00:19:15,518 --> 00:19:22,724 WISE 0855-0714 Sub-Brown Dwarf Distance: 7 Light Years Mass: 3.10x Jupiter Temperature: -50 - -13ºC 306 00:19:24,457 --> 00:19:28,640 All the prime elements for life have been detected inside their atmospheres. 307 00:19:31,588 --> 00:19:35,755 And within these clouds, some layers would provide ideal temperatures 308 00:19:35,755 --> 00:19:37,456 and pressures for habitability. 309 00:19:46,176 --> 00:19:48,938 There could be photosynthetic plankton in these skies, 310 00:19:50,092 --> 00:19:52,500 kept aloft by churning upwinds. 311 00:19:57,603 --> 00:20:01,186 And with enough force, these upwinds could even support larger, 312 00:20:01,186 --> 00:20:02,722 more complex life. 313 00:20:06,101 --> 00:20:06,754 Predadors. 314 00:20:15,348 --> 00:20:19,238 There are over 25 billion Brown Dwarfs in our galaxy alone, 315 00:20:19,238 --> 00:20:24,396 and their sizes will make them easier targets for study. 316 00:20:27,046 --> 00:20:35,235 The first specimen we discover from the museum of life may not be from a planet at all. 317 00:20:44,142 --> 00:20:46,054 This raises a crucial question: 318 00:20:47,920 --> 00:20:50,253 what if we've been looking in all the wrong places? 319 00:20:52,618 --> 00:20:54,896 What if nature has other ideas? 320 00:20:58,925 --> 00:21:01,213 EXHIBIT II 321 00:21:01,213 --> 00:21:03,494 EXHIBIT II LIFE AS WE DON'T KNOW IT 322 00:21:03,494 --> 00:21:08,057 EXHIBIT II LIFE AS WE DON'T KNOW IT EXOTIC BIOCHEMISTRIES 323 00:21:21,172 --> 00:21:25,627 Most of the Universe is too cold or too hot for liquid water and the 324 00:21:25,627 --> 00:21:28,161 biochemistry that supports life as we know it. 325 00:21:31,514 --> 00:21:33,544 But in case our biases are misleading, 326 00:21:34,680 --> 00:21:36,307 we have to cast a wide net. 327 00:21:38,908 --> 00:21:41,431 To search for life outside the habitable zone, 328 00:21:42,271 --> 00:21:44,881 in places that seem wildly hostile to us. 329 00:21:49,586 --> 00:21:53,085 Exotic environments will demand exotic biochemistries. 330 00:21:53,646 --> 00:21:56,533 And while no element can match carbon's versatility, 331 00:21:57,125 --> 00:21:58,918 one contender is a front runner. 332 00:22:07,707 --> 00:22:10,713 At first glance, silicon seem similar to carbon. 333 00:22:13,025 --> 00:22:16,850 It forms the same four-way bonds and is also abundant in the Universe. 334 00:22:19,462 --> 00:22:23,215 But a closer look reveals that these two elements are false twins. 335 00:22:27,388 --> 00:22:32,397 Silicon bonds are weaker and less prone to forming large complex molecules. 336 00:22:36,420 --> 00:22:39,961 Despite this, they can withstand a wider range of temperatures, 337 00:22:41,050 --> 00:22:43,670 opening up intriguing possibilities. 338 00:22:47,381 --> 00:22:50,405 Life based on the silicon atom instead of carbon, 339 00:22:50,698 --> 00:22:53,262 would be more resistant to the extreme cold. 340 00:22:54,722 --> 00:22:57,982 Providing a whole new range of weird forms. 341 00:23:01,491 --> 00:23:02,755 But silicon has a problem: 342 00:23:04,616 --> 00:23:08,125 in the presence of oxygen, it binds into solid rock. 343 00:23:10,373 --> 00:23:13,339 To avoid turning to stone, silicon beings 344 00:23:13,339 --> 00:23:15,970 might be confined to oxygen free environments. 345 00:23:16,598 --> 00:23:18,717 Like Saturn's frigid moon, Titan. 346 00:23:18,717 --> 00:23:23,048 TITAN Saturnian Moon Distance: 1,2 Million KM Mass: .023X Earth Temperature: -129ºC 347 00:23:23,048 --> 00:23:27,089 Its vast lakes of liquid methane and ethane could be an ideal medium 348 00:23:27,089 --> 00:23:28,755 for silicon-based life, 349 00:23:29,204 --> 00:23:31,472 or other radical biochemistries. 350 00:23:37,433 --> 00:23:39,913 Without ample sunlight, beings on worlds 351 00:23:39,913 --> 00:23:42,961 like Titan, would likely be chemosynthetic. 352 00:23:43,337 --> 00:23:46,043 Deriving their energy by breaking down rocks. 353 00:24:01,536 --> 00:24:03,770 Such life forms could have ultra slow 354 00:24:03,770 --> 00:24:07,906 metabolisms and life cycles measured in millions of years. 355 00:24:16,015 --> 00:24:21,377 And frozen worlds aren't the only possible harbor for exotic life. 356 00:24:22,566 --> 00:24:23,026 CoRoT-7B 357 00:24:23,026 --> 00:24:23,376 CoRoT-7B Super Earth 358 00:24:23,376 --> 00:24:23,626 CoRoT-7B Super Earth Distance: ~520 Light Years 359 00:24:23,636 --> 00:24:23,886 CoRoT-7B Super Earth Distance: ~520 Light Years Mass: -8x Earth 360 00:24:23,886 --> 00:24:25,961 CoRoT-7B Super Earth Distance: ~520 Light Years Mass: -8x Earth Temperature: 1026-1526ºC 361 00:24:25,961 --> 00:24:30,279 In high temperatures, typically rigid silicon oxygen bonds become more 362 00:24:30,279 --> 00:24:31,780 flexible and reactive. 363 00:24:33,003 --> 00:24:34,831 Triggering more dynamic chemistry. 364 00:24:40,080 --> 00:24:42,846 This has led to a truly bizarre proposal: 365 00:24:43,704 --> 00:24:48,609 silicon-based life forms that live inside molten silicate rock. 366 00:25:01,093 --> 00:25:03,424 In theory, these forms could even exist 367 00:25:03,424 --> 00:25:06,104 deep beneath the Earth inside magma chambers 368 00:25:06,306 --> 00:25:08,460 as part of a shadow biosphere. 369 00:25:12,472 --> 00:25:16,505 If so, then the aliens are right under our noses. 370 00:25:20,799 --> 00:25:23,017 Other shadow biospheres have been proposed: 371 00:25:23,570 --> 00:25:27,036 forms of life living alongside us that we don't even know are here. 372 00:25:27,528 --> 00:25:30,416 Including tiny RNA-based life, small 373 00:25:30,416 --> 00:25:33,543 enough to go undetected by existing instruments. 374 00:25:46,821 --> 00:25:50,797 Clouds of dust and empty space might seem like the last place you'd expect 375 00:25:50,797 --> 00:25:52,092 to find anything living. 376 00:25:54,398 --> 00:25:57,207 But when cosmic dust makes contact with plasma, 377 00:25:57,570 --> 00:25:59,006 a type of ionized gas, 378 00:25:59,494 --> 00:26:00,717 something strange happens. 379 00:26:05,770 --> 00:26:08,338 In simulated conditions, dust particles, 380 00:26:08,341 --> 00:26:11,105 have been seen spontaneously self-organizing 381 00:26:11,105 --> 00:26:13,623 into helical structures that resemble DNA. 382 00:26:18,848 --> 00:26:22,262 These plasma crystals even begin to exhibit life-like behavior: 383 00:26:23,728 --> 00:26:28,464 replicating, evolving into more stable forms and passing on information. 384 00:26:35,715 --> 00:26:38,878 Could these crystals be considered alive? 385 00:26:41,564 --> 00:26:48,715 To some researchers, they meet all the criteria to qualify as inorganic life forms. 386 00:26:52,469 --> 00:26:57,113 So far, we have only ever seen them in computer simulations. 387 00:26:58,443 --> 00:27:04,672 But some speculate we could find them among the ice particles in the rings of Uranus. 388 00:27:12,270 --> 00:27:15,761 Plasma is the most common state of matter in the Universe. 389 00:27:17,666 --> 00:27:20,769 If complex evolving plasma crystals really exist 390 00:27:21,252 --> 00:27:22,758 and if they can be considered life, 391 00:27:23,377 --> 00:27:25,253 they could be its most common form. 392 00:27:38,505 --> 00:27:43,043 Or perhaps life is lurking in the polar opposite environment: 393 00:27:43,043 --> 00:27:46,997 inside the hearts of dead stars. 394 00:27:51,400 --> 00:27:54,319 When massive suns explode, some collapase into 395 00:27:54,319 --> 00:27:57,044 ultra dense cores called neutron stars. 396 00:27:57,044 --> 00:27:58,168 PSR B1509-58 Neutron Star Distante: 17,000 Light Years Spin Rate: ~7/second 397 00:27:58,168 --> 00:28:01,902 Hulking masses of atomic nuclei crammed together like sardines. 398 00:28:05,556 --> 00:28:07,774 Conditions on the surface are mind-boggling: 399 00:28:08,922 --> 00:28:12,210 gravity is a hundred billion times stronger than Earth's. 400 00:28:15,724 --> 00:28:19,243 But beneath their iron nuclei crust lies something strange: 401 00:28:21,474 --> 00:28:25,358 a hot dense sea of neutrons and subatomic particles. 402 00:28:34,550 --> 00:28:36,827 Stripped of their electron shells, these 403 00:28:36,827 --> 00:28:39,906 nuclei would obey entirely different laws of chemistry, 404 00:28:40,486 --> 00:28:42,714 based not on the electromagnetic force, 405 00:28:42,994 --> 00:28:44,956 but the strong nuclear force, 406 00:28:45,227 --> 00:28:46,655 which binds nuclei together. 407 00:28:49,720 --> 00:28:52,129 In theory, these particles could link-up 408 00:28:52,129 --> 00:28:55,406 to form larger macronuclei, which could then 409 00:28:55,406 --> 00:28:58,253 combine into even bigger super nuclei. 410 00:29:06,696 --> 00:29:09,665 If so, then this bewildering environment 411 00:29:09,665 --> 00:29:11,714 would mimic the basic conditions for life. 412 00:29:12,484 --> 00:29:16,745 Heavy nucleon molecules floating in a complex particle ocean. 413 00:29:22,729 --> 00:29:25,221 Some scientists have proposed the unimaginable: 414 00:29:26,532 --> 00:29:30,326 exotic life forms drifting through the strange particle sea, 415 00:29:31,143 --> 00:29:35,880 living, evolving and dying on incomprehensibly fast time scales. 416 00:29:55,942 --> 00:30:01,025 There's probably no chance of ever detecting such a strange breed of life. 417 00:30:02,572 --> 00:30:07,802 But there may be hope for finding an even more exotic form. 418 00:30:19,436 --> 00:30:22,466 Life is not something that has to evolve naturally. 419 00:30:26,286 --> 00:30:27,456 It can be designed. 420 00:30:41,566 --> 00:30:45,176 And once intelligence is introduced into the evolutionary process, 421 00:30:46,226 --> 00:30:48,206 a Pandora's Box is opened. 422 00:31:06,007 --> 00:31:12,989 Free from typical biological limitations, synthetic and machine - based life could be the most successful of all. 423 00:31:16,547 --> 00:31:20,375 It could thrive almost anywhere, including the vaccum of space, 424 00:31:20,807 --> 00:31:25,244 opening up vast frontiers unavailable to biological organisms. 425 00:31:31,777 --> 00:31:36,777 And compared to the glacial pace of natural selection, technical evolution 426 00:31:36,927 --> 00:31:41,941 allows exponentially faster growth, adaptability and resilience. 427 00:31:56,237 --> 00:32:00,377 By some estimates, autonomous, self - replicating machines could colonize 428 00:32:00,377 --> 00:32:03,923 an entire galaxy in as little as a million years. 429 00:32:18,877 --> 00:32:22,870 We can't predict how hyper - intelligent life would organise itself, 430 00:32:26,507 --> 00:32:29,893 but in theory, there could be convergent evolution at play. 431 00:32:32,247 --> 00:32:37,819 The electrical properties of Silicon might make it a universal basis for machine intelligence, 432 00:32:38,697 --> 00:32:41,689 a redemption for its biological shortcomings. 433 00:33:03,036 --> 00:33:04,776 With all its potential advantages, 434 00:33:04,776 --> 00:33:10,016 With all its potential advantages, machine life may even be a universal endpoint : 435 00:33:10,016 --> 00:33:15,393 With all its potential advantages, machine life may even be a universal endpoint : the apex of evolutionary process. 436 00:33:53,413 --> 00:33:58,123 As the universe ages, perhaps machine intelligence would come to dominate, 437 00:33:58,733 --> 00:34:03,738 and naturally occurring biological life will be viewed as a quaint starting point. 438 00:34:09,663 --> 00:34:12,156 Perhaps, we ourselves will lead this transition, 439 00:34:12,973 --> 00:34:19,695 and the great human experiment would be merely a first link in a sprawling intergalactic chain of life. 440 00:34:51,225 --> 00:35:01,959 In the end, we are still the only beings we know of in the museum of alien life. 441 00:35:07,479 --> 00:35:10,489 To truly know ourselves, we will have to know : 442 00:35:10,489 --> 00:35:13,409 To truly know ourselves, we will have to know : are we the only ones? 443 00:35:27,479 --> 00:35:32,229 Loren Eisley has said, that one does not meet oneself until 444 00:35:32,229 --> 00:35:36,531 one catches the reflection from an eye other than human.