WEBVTT 1 00:00:03.399 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:23.800 slumber under the night sky. 7 00:00:27.000 --> 00:00:30.920 Have you ever just stood outside on a perfectly clear, 8 00:00:31.079 --> 00:00:33.280 crisp night, like really far away from the city lights 9 00:00:33.280 --> 00:00:34.079 and just looked up? 10 00:00:34.159 --> 00:00:37.679 Oh? Yeah, it's almost dizzying when you really do that, right. 11 00:00:37.799 --> 00:00:40.399 You just lean your head back, you let your eyes adjust, 12 00:00:40.600 --> 00:00:44.719 and suddenly you are staring into this massive ocean of stars. 13 00:00:44.799 --> 00:00:47.079 That's a profound experience. It really makes you feel. 14 00:00:46.920 --> 00:00:49.200 Small, it really does. I mean, you're looking at our 15 00:00:49.240 --> 00:00:52.119 own Milky Way galaxy, which is home to hundreds of 16 00:00:52.119 --> 00:00:55.439 billions of stars, and that is just one galaxy among 17 00:00:55.640 --> 00:00:58.880 you know, hundreds of billions more in the observable universe. 18 00:00:58.880 --> 00:01:01.520 It's an incomprehensible scale, honestly exactly. 19 00:01:01.600 --> 00:01:03.880 And when you let the sheer scale of that wash 20 00:01:03.920 --> 00:01:08.439 over you, a very natural, almost instinctive question bubbles up. 21 00:01:08.959 --> 00:01:10.799 Where is everything big? One. 22 00:01:10.879 --> 00:01:11.920 Yeah, right, in. 23 00:01:11.920 --> 00:01:14.840 A universe so vast, with so much potential for life 24 00:01:14.959 --> 00:01:18.680 to take root, why do you hear absolute silence? Like 25 00:01:18.879 --> 00:01:21.400 why when you point the most sensitive instruments we've ever 26 00:01:21.439 --> 00:01:23.920 engineered at the cosmos, are you just met with the 27 00:01:23.959 --> 00:01:25.319 deafening quiet of the void. 28 00:01:25.840 --> 00:01:29.959 Well, it is literally the ultimate existential question in astrophysics. 29 00:01:30.000 --> 00:01:31.239 That silence is. 30 00:01:32.040 --> 00:01:33.840 It's heavy, Yeah, it really is. 31 00:01:34.159 --> 00:01:37.040 It's what physicists and astronomers have grappled with since the 32 00:01:37.159 --> 00:01:41.200 very dawn of radio astronomy, because you know, you look 33 00:01:41.200 --> 00:01:45.680 at the numbers, the sheer statistical probability of other civilizations existing, 34 00:01:45.719 --> 00:01:48.799 the Drake equation right, exactly, the Drake equation. The math 35 00:01:48.920 --> 00:01:52.879 suggests the universe should be absolutely teeming with voices. Yet 36 00:01:53.159 --> 00:01:56.439 the cosmic phone never rings, never rings, right, And this 37 00:01:56.560 --> 00:02:00.359 great silence is a phenomenon you just sort of internal wise, 38 00:02:00.439 --> 00:02:04.519 when you study the cosmos, you start to wonder, is 39 00:02:04.599 --> 00:02:08.560 humanity just a cosmic anomaly? Or you know, does intelligent 40 00:02:08.599 --> 00:02:11.400 life inevitably destroy itself before it can even speak, which 41 00:02:11.439 --> 00:02:14.479 is a terrifying thug, Oh, completely terrifying. Or maybe the 42 00:02:14.479 --> 00:02:17.599 physical distances are simply too vast for any civilization to 43 00:02:17.599 --> 00:02:20.159 bother reaching out across the dark. You start treating that 44 00:02:20.280 --> 00:02:23.639 silence as an absolute fundamental truth of the universe. 45 00:02:23.800 --> 00:02:25.599 But and this is what we're getting into today, that 46 00:02:25.800 --> 00:02:30.719 narrative of a quiet, empty cosmos might actually be completely backward. 47 00:02:30.800 --> 00:02:32.000 Yeah, it might be totally wrong. 48 00:02:32.280 --> 00:02:35.680 The universe might actually be incredibly noisy. It could be 49 00:02:35.759 --> 00:02:39.479 saturated with greetings, with data, with the very signals you 50 00:02:39.520 --> 00:02:40.479 have been desperate to. 51 00:02:40.439 --> 00:02:42.000 Find hiding in plain sight. 52 00:02:42.120 --> 00:02:46.400 Essentially exactly The catch, and it is a massive galaxy 53 00:02:46.439 --> 00:02:50.199 spanning physical catch here is that the stars themselves, the 54 00:02:50.319 --> 00:02:53.680 very suns that give life to these potential alien civilizations, 55 00:02:54.039 --> 00:02:57.599 are acting as giant, chaotic scramblers. 56 00:02:57.039 --> 00:02:59.280 Which completely changes the game, right. 57 00:02:59.400 --> 00:03:03.439 They are funnundamentally distorting these alien messages before those signals 58 00:03:03.439 --> 00:03:07.000 even reached the empty void of interstellar space. 59 00:03:07.199 --> 00:03:10.639 So the focus here is the incredibly violent physics of 60 00:03:10.639 --> 00:03:15.039 stellar weather. To really understand the great silence, you have 61 00:03:15.080 --> 00:03:18.639 to rethink the foundational assumptions of how an alien civilization 62 00:03:18.680 --> 00:03:19.960 would try to contact you. 63 00:03:19.960 --> 00:03:22.120 You have to question everything we've been doing exactly. 64 00:03:22.120 --> 00:03:24.800 You have to critically examine the biases built right into 65 00:03:24.800 --> 00:03:27.479 your own telescopes because, for the better part of a century, 66 00:03:27.879 --> 00:03:30.120 the astronomical community might have just been looking for the 67 00:03:30.280 --> 00:03:31.919 entirely wrong type of. 68 00:03:31.879 --> 00:03:34.080 Signal, which is wild to think about. 69 00:03:34.439 --> 00:03:37.520 It really is. The failure to hear them might not 70 00:03:37.599 --> 00:03:40.960 be because they aren't speaking. The failure lies and a 71 00:03:40.960 --> 00:03:45.599 fundamental misunderstanding of the altered, scrambled medium through which their 72 00:03:45.680 --> 00:03:48.319 voices are forced to travel before they ever reach Earth. 73 00:03:48.400 --> 00:03:51.240 Okay, let's unpack this a bit, because to understand why 74 00:03:51.240 --> 00:03:53.719 our search might be flawed, you really have to look 75 00:03:53.719 --> 00:03:54.759 at the historical. 76 00:03:54.479 --> 00:03:56.479 Baseline, right how we've been doing it so far. 77 00:03:56.479 --> 00:04:00.159 Exactly for the entire history of the Search for Extraterrestrial 78 00:04:00.199 --> 00:04:04.879 intelligence or SETI, scientists have optimized their massive radio telescope 79 00:04:04.960 --> 00:04:08.840 arrays to look for one very specific, highly idealized thing. 80 00:04:09.120 --> 00:04:10.800 Narrowband signals, Yes. 81 00:04:10.800 --> 00:04:15.599 Extremely narrow spikes and radio frequencies. These narrowband signals are 82 00:04:15.639 --> 00:04:20.279 basically the holy grail. The entire infrastructure is just completely 83 00:04:20.319 --> 00:04:24.480 obsessed with finding these tiny, sharp slivers of electromagnetic radiation. 84 00:04:24.759 --> 00:04:27.600 And you know that obsession is rooted in a very 85 00:04:27.639 --> 00:04:30.519 real challenge distinguishing the artificial from the natural. 86 00:04:30.560 --> 00:04:32.600 Because the universe isn't actually quiet, right. 87 00:04:32.680 --> 00:04:35.639 Oh, not at all? The universe is actually a tremendously 88 00:04:35.680 --> 00:04:39.560 loud place radiophonically. When you turn a massive dish like 89 00:04:39.600 --> 00:04:43.839 the Green Bank telescope to the sky, you don't hear silence. 90 00:04:44.560 --> 00:04:48.639 You hear a chaotic, roaring symphony of natural cosmic processes, 91 00:04:48.759 --> 00:04:51.160 like what kind of stuff. Well, you pick up the 92 00:04:51.360 --> 00:04:54.759 lingering thermal hum of the Big Bang, the cosmic microwave background. 93 00:04:55.079 --> 00:05:00.040 You hear the violent, sweeping radiation from rapidly spinning dead stars. 94 00:04:59.680 --> 00:05:01.759 Which are pulsars, okay, pul size right. 95 00:05:01.759 --> 00:05:06.160 And you hear the colossal galaxy shredding engines of distant quasars. 96 00:05:06.800 --> 00:05:11.360 All of these natural astrophysical phenomena produce radio waves, but 97 00:05:11.560 --> 00:05:15.199 the energy they produce is smeared across a huge swath 98 00:05:15.319 --> 00:05:19.160 of the radio dial. It is wide, messy, chaotic noise. 99 00:05:19.399 --> 00:05:21.839 It's kind of the equivalent of twisting the tuning knob 100 00:05:21.879 --> 00:05:24.680 on an old analog car radio and just hearing that loud, 101 00:05:24.839 --> 00:05:26.720 aggressive static across the entire band. 102 00:05:26.800 --> 00:05:29.279 That is a perfect way to describe it. Natural physics 103 00:05:29.360 --> 00:05:32.399 is inherently messy. So the bedrock assumption of the search 104 00:05:32.399 --> 00:05:34.519 strategy for the last sixty years has been that an 105 00:05:34.600 --> 00:05:39.360 advanced extraterrestrial civilization would understand this fundamental reality of astrophysics, right. 106 00:05:39.399 --> 00:05:41.120 They'd know the universe is noisy. 107 00:05:41.000 --> 00:05:43.439 Exactly if they wanted you to hear them over the 108 00:05:43.519 --> 00:05:47.240 natural roar of the universe. They wouldn't broadcast a messy 109 00:05:47.240 --> 00:05:50.000 wide signal that just blends in with the quasars. They 110 00:05:50.040 --> 00:05:55.240 would purposely broadcast a highly concentrated ultra narrow signal to 111 00:05:55.360 --> 00:05:59.079 stand out. Yes, they would pack all their transmission energy 112 00:05:59.279 --> 00:06:05.160 into one tiny, incredibly specific frequency, perhaps something mathematically universal 113 00:06:05.560 --> 00:06:10.079 like the hydrogen line frequency of fourteen hundred and twenty megahertz. 114 00:06:09.639 --> 00:06:12.920 Because nothing in nature makes that specific sound exactly. 115 00:06:13.319 --> 00:06:16.000 The logic dictates that an ultra narrow signal cannot be 116 00:06:16.040 --> 00:06:19.360 created by a collapsing star or a black hole accretion disc. 117 00:06:19.879 --> 00:06:23.399 It violates the thermodynamics of natural cosmic mission. It can 118 00:06:23.439 --> 00:06:26.000 only be created by localized, purposeful technology. 119 00:06:26.040 --> 00:06:30.199 It acts as a deliberate, undeniable techno signature, just screaming. 120 00:06:29.720 --> 00:06:31.639 Across the void, right, saying we are here. 121 00:06:31.759 --> 00:06:33.680 So imagine you're standing in the middle of a packed 122 00:06:33.680 --> 00:06:36.639 sports stadium during the final play of a championship game. 123 00:06:37.000 --> 00:06:40.399 Tens of thousands of people are screaming stomping, cheering. 124 00:06:40.160 --> 00:06:41.519 The totally deafening environment. 125 00:06:41.879 --> 00:06:45.959 Exactly, that deafening roar of the crowd is the natural 126 00:06:46.040 --> 00:06:51.360 cosmic background noise, the pulsars, the quasars, the colliding galaxies. Now, 127 00:06:51.399 --> 00:06:53.240 if you are in the stands and you want your 128 00:06:53.240 --> 00:06:54.959 friend all the way on the other side of the 129 00:06:54.959 --> 00:06:57.399 stadium to hear you, you wouldn't just. 130 00:06:57.399 --> 00:06:59.920 Yell, right. A yell is just more crowd noise. 131 00:07:00.199 --> 00:07:02.759 Exactly. A yell is messy, It just gets swallow up 132 00:07:02.759 --> 00:07:05.360 by the crowd. To be heard, you would blow a 133 00:07:05.480 --> 00:07:08.199 highly pitched, ultra sharp referee whistle. 134 00:07:08.279 --> 00:07:09.480 Oh that's a great analogy. 135 00:07:09.600 --> 00:07:14.560 Thanks. That piercing singular tone cuts through the chaotic noise 136 00:07:14.839 --> 00:07:17.439 precisely because it doesn't sound like a human voice or 137 00:07:17.480 --> 00:07:21.079 a stomping foot. That whistle is the narrow radio spike 138 00:07:21.120 --> 00:07:23.160 the arrays have been built to find in. 139 00:07:23.120 --> 00:07:26.319 The sheer extent to which the search strategy, the software algorithms, 140 00:07:26.319 --> 00:07:28.839 and the telescope hardware have been heavily biased by This 141 00:07:28.879 --> 00:07:33.600 assumption is staggering. I mean, the massive, incredibly sophisticated arrays 142 00:07:33.639 --> 00:07:37.600 operating today are at their core ultimate whistle detectors. 143 00:07:37.240 --> 00:07:39.319 Just waiting for that one sharp sound right. 144 00:07:39.720 --> 00:07:43.120 The back end computers run complex algorithms fast four E 145 00:07:43.199 --> 00:07:47.680 transforms to sift through petabytes of data, aggressively filtering out 146 00:07:47.720 --> 00:07:51.639 the roar of the stadium. They were literally mathematically trained 147 00:07:51.800 --> 00:07:56.279 to completely ignore the broad, messy noises, looking exclusively for 148 00:07:56.360 --> 00:07:57.399 that one sharp. 149 00:07:57.120 --> 00:07:59.600 Spike, which makes sense logically. 150 00:07:59.199 --> 00:08:02.199 It makes perfect lock sense based on a terrestrial understanding 151 00:08:02.240 --> 00:08:06.959 of radio engineering and signal to noise ratios. But a 152 00:08:07.160 --> 00:08:10.360 major variable was completely left out of the equation. And 153 00:08:10.399 --> 00:08:12.879 what's that the physical environment in which the whistle is 154 00:08:12.920 --> 00:08:13.759 actually being blown. 155 00:08:14.040 --> 00:08:18.040 Ah, So if the problem isn't the distance the signal 156 00:08:18.079 --> 00:08:21.600 travels across space, but the origin point itself, you really 157 00:08:21.600 --> 00:08:24.519 have to look at the immediate environment surrounding the transmitter 158 00:08:24.639 --> 00:08:27.639 exactly like what happens to that perfect piercing whistle. If 159 00:08:27.680 --> 00:08:30.560 the environment it's blown in physically bends and warps the 160 00:08:30.639 --> 00:08:32.679 sound before it even leaves the stadium. 161 00:08:32.840 --> 00:08:35.399 And this is where a groundbreaking study led by astronomer 162 00:08:35.480 --> 00:08:39.000 doctor Vishalgadjar at the Seti Institute comes in. It forces 163 00:08:39.000 --> 00:08:41.720 a direct confrontation with this exact scenario. 164 00:08:41.919 --> 00:08:43.919 This is the paradigm shift we were talking about. 165 00:08:44.120 --> 00:08:48.600 Yes, the study reveals a massive galaxy sized blind spot. 166 00:08:48.639 --> 00:08:53.279 In the traditional methodology, they identified a phenomenon called EXOIPM scattering, 167 00:08:53.639 --> 00:08:56.960 and they recognized it as a hidden gatekeeper of narrowband 168 00:08:56.960 --> 00:08:57.840 techno signatures. 169 00:08:57.879 --> 00:09:01.720 Okay, so let's break down XOIPM. XO obviously refers to 170 00:09:01.759 --> 00:09:06.159 other star systems, exoplanets, that kind of thing, and IPM 171 00:09:06.320 --> 00:09:09.840 stands for the interplanetary medium, right, But the word medium 172 00:09:10.000 --> 00:09:14.120 almost sounds too passive, like the immediate volatile environment surrounding 173 00:09:14.159 --> 00:09:15.799 a star is anything but passes. 174 00:09:15.879 --> 00:09:17.000 Oh, it's incredibly violent. 175 00:09:17.320 --> 00:09:20.159 Right. You tend to think of stars as these quiet, stable, 176 00:09:20.320 --> 00:09:23.639 glowing orbs hanging peacefully in the dark vacuum of space. 177 00:09:24.440 --> 00:09:28.240 But up close a star is a terrifyingly violent entity. 178 00:09:28.399 --> 00:09:30.840 It is basically a boiling ocean of plasma. 179 00:09:30.960 --> 00:09:31.960 Is constant chaos. 180 00:09:32.120 --> 00:09:35.519 Stars constantly blast out stellar winds, these hurricanes of highly 181 00:09:35.639 --> 00:09:39.279 energetic charged particles flying out into space, and they regularly 182 00:09:39.320 --> 00:09:43.600 suffer massive explosive events coronal mass ejections, where billions of 183 00:09:43.600 --> 00:09:46.919 tons of magnetized plasma are violently hurled outward into the 184 00:09:46.919 --> 00:09:48.279 surrounding planetary system. 185 00:09:48.600 --> 00:09:52.840 So the space immediately surrounding a star isn't empty at all. 186 00:09:53.519 --> 00:09:57.919 It is packed with a turbulent, fluctuating, electrically charged plasma. 187 00:09:58.039 --> 00:10:03.200 It's a storm exactly. Now insert your hypothetical alien civilization 188 00:10:03.320 --> 00:10:06.600 into this environment. They live on a planet orbiting an 189 00:10:06.639 --> 00:10:10.759 active star. They build a massive radio transmitter pointed at 190 00:10:10.799 --> 00:10:15.120 Earth and broadcast that perfect ultr narrow referee. 191 00:10:14.679 --> 00:10:16.519 Whistle the narrow spike right. 192 00:10:16.679 --> 00:10:19.120 The signal leaves their transmitter, but before it can even 193 00:10:19.120 --> 00:10:23.120 reach the relatively quiet vacuum of interstellar space, it first 194 00:10:23.120 --> 00:10:26.159 has to punch through its own stars turbulent plasma storm, 195 00:10:26.679 --> 00:10:29.720 and the charge particles in that plasma interact intensely with 196 00:10:29.799 --> 00:10:30.919 electromagnetic waves. 197 00:10:30.960 --> 00:10:32.679 Wait, okay, let me ask you something here. If an 198 00:10:32.720 --> 00:10:36.759 advanced civilization knows their stars blasting out all this charge plasma, 199 00:10:36.799 --> 00:10:39.799 wouldn't they just use a different communication method entirely? 200 00:10:40.080 --> 00:10:40.200 Like? 201 00:10:40.200 --> 00:10:40.279 What? 202 00:10:40.480 --> 00:10:40.559 Like? 203 00:10:40.600 --> 00:10:44.159 Why wouldn't they switch to optical SETI firing high powered 204 00:10:44.200 --> 00:10:46.559 lasers instead of radio waves if they know the radio 205 00:10:46.559 --> 00:10:48.600 waves are going to get caught in the plasma storm. 206 00:10:48.840 --> 00:10:51.519 That is a very fair question, and optical SETI is 207 00:10:51.559 --> 00:10:55.960 a valid alternative. Lasers definitely cut through plasma much more 208 00:10:56.000 --> 00:10:57.519 effectively than radio waves do. 209 00:10:57.919 --> 00:10:59.919 So why wouldn't they just do that. 210 00:11:00.159 --> 00:11:04.679 Well because optical frequencies have their own severe astrophysical gatekeepers. 211 00:11:05.120 --> 00:11:08.720 While a laser ignores plasma, it gets heavily scattered and 212 00:11:08.759 --> 00:11:10.759 absorbed by interstellar dust clouds. 213 00:11:10.799 --> 00:11:13.720 Ah Okay, the dust blocks the light exactly. 214 00:11:14.200 --> 00:11:16.480 If the alien civilization is located on the other side 215 00:11:16.480 --> 00:11:21.039 of a dense nebula, an optical laser is essentially useless. Furthermore, 216 00:11:21.240 --> 00:11:25.799 radio remains the most energy efficient way to broadcast an omnidirectional. 217 00:11:25.039 --> 00:11:27.200 Beacon like a lighthouse, right. 218 00:11:27.200 --> 00:11:29.720 If you don't know exactly where the receiver is. Sweeping 219 00:11:29.759 --> 00:11:32.759 the sky with a radio beam is vastly more economical 220 00:11:33.000 --> 00:11:35.480 than trying to pinpoint target every single star in the 221 00:11:35.480 --> 00:11:38.279 galaxy with a laser. So the assumption that they would 222 00:11:38.360 --> 00:11:41.679 use radio holds really strong, which means the signal still 223 00:11:41.679 --> 00:11:42.960 has to contend with the plasma. 224 00:11:43.080 --> 00:11:45.679 Okay, so the radio wave enters the plasma. It's kind 225 00:11:45.720 --> 00:11:49.799 of like shining a crisp concentrated green laser pointer through 226 00:11:49.879 --> 00:11:53.200 a thick, swirling bank of heavy fog, or actually like 227 00:11:53.240 --> 00:11:56.000 shining it through a heavily frosted textured glass window. 228 00:11:56.320 --> 00:11:58.320 That frosted glass analogy is perfect. 229 00:11:58.480 --> 00:12:01.799 The fog or the frosted glave is the stellar plasma. 230 00:12:02.320 --> 00:12:04.360 What comes out the other side of the glass isn't 231 00:12:04.399 --> 00:12:07.799 a sharp pinpoint dot anymore. The structure of the beam 232 00:12:07.879 --> 00:12:11.519 is completely broken. The light scatters, bouncing off all the 233 00:12:11.559 --> 00:12:16.200 dense particles. What emerges is a wide, faint, diffused glow. 234 00:12:17.080 --> 00:12:21.399 In astrophysics, we say the signal undergoes severe scattering and scintillation. 235 00:12:22.279 --> 00:12:25.639 The varying electron density in the stellar wind causes variations 236 00:12:25.679 --> 00:12:27.519 in the phase velocity of the radio. 237 00:12:27.240 --> 00:12:29.519 Wave, meaning the wave gets messed up. 238 00:12:29.639 --> 00:12:33.759 Yeah, it leads to destructive interference. The immense, tightly packed 239 00:12:33.840 --> 00:12:37.279 energy of that narrow signal gets forcibly spread out across 240 00:12:37.279 --> 00:12:40.840 a much broader range of frequencies. The sharp, towering peak 241 00:12:40.879 --> 00:12:43.799 of energy weakens, it flattens, and it smears. 242 00:12:44.200 --> 00:12:46.039 So what does that look like to the astronomers. 243 00:12:46.360 --> 00:12:48.240 Well, when you look at these signals on a spectrograph, 244 00:12:48.240 --> 00:12:50.720 which is basically a visual map of frequencies over time, 245 00:12:51.120 --> 00:12:54.840 an undisturbed narrow signal appears as a sharp, bright, continuous 246 00:12:54.879 --> 00:12:58.279 white line cutting vertically down the graph. Very obvious, very obvious. 247 00:12:58.720 --> 00:13:01.519 But after it passes through the turbulent plasma of an 248 00:13:01.600 --> 00:13:05.759 active stellar wind, that sharp white tone gets smeared out. 249 00:13:06.559 --> 00:13:10.159 It shifts into a wider, fainter, much broader shape, often 250 00:13:10.240 --> 00:13:14.480 visualized as a hazy, indistinct smear on the data plot. 251 00:13:14.720 --> 00:13:18.200 Wow. So the aliens blow the whistle perfectly, but by 252 00:13:18.200 --> 00:13:20.720 the time the electromagnetic waves actually make it out of 253 00:13:20.759 --> 00:13:24.240 their solar system's heliosphere, the whistle has been warped into 254 00:13:24.279 --> 00:13:25.919 a dull, broad roar. 255 00:13:26.159 --> 00:13:26.720 Exactly. 256 00:13:26.799 --> 00:13:29.200 The structure of the signal is stripped away, and it 257 00:13:29.360 --> 00:13:31.240 just sounds like the rest of the stadium noise. 258 00:13:31.320 --> 00:13:34.759 And that's the tragedy of it. The signal still technically exists, 259 00:13:34.840 --> 00:13:37.759 the energy was transmitted and it arrived at Earth, but 260 00:13:37.879 --> 00:13:41.799 its structural signature has been fundamentally transformed from an obvious 261 00:13:41.840 --> 00:13:46.320 techno signature into something that perfectly mimics natural, messy, cosmic 262 00:13:46.399 --> 00:13:47.200 background noise. 263 00:13:47.320 --> 00:13:48.480 The whistle becomes a roar. 264 00:13:48.559 --> 00:13:50.879 The whistle becomes a roar. And remember those back end 265 00:13:50.879 --> 00:13:54.000 computers on the telescope arrays. They are programmed to aggressively 266 00:13:54.039 --> 00:13:54.879 filter out the roar. 267 00:13:54.960 --> 00:13:55.720 They just delete it. 268 00:13:55.919 --> 00:13:58.919 They toss it out as junk data. If a signal 269 00:13:58.960 --> 00:14:02.480 gets broadened by its own star's environment, it slips completely 270 00:14:02.519 --> 00:14:06.720 below the contection thresholds. The algorithms only want the sharp lines. 271 00:14:07.039 --> 00:14:09.120 They completely ignore the hazy smears. 272 00:14:09.279 --> 00:14:11.480 That is so frustrating, It really is. 273 00:14:11.759 --> 00:14:15.639 The astronomical community has likely been systematically throwing out the 274 00:14:15.759 --> 00:14:18.799 very signals they're trying to find, all because the alien 275 00:14:18.840 --> 00:14:22.159 stars scramble them before they even reach the interstellar highway. 276 00:14:22.399 --> 00:14:25.960 Okay, but that raises a critical methodological question here. Sure, 277 00:14:26.039 --> 00:14:30.960 these are entirely theoretical alien signals interacting with theoretical alien 278 00:14:31.000 --> 00:14:34.799 stellar plasma. Since you can exactly travel to a distant 279 00:14:34.879 --> 00:14:38.200 star to run a field test, how do they actually 280 00:14:38.320 --> 00:14:41.480 prove the specific physics of this scattering? 281 00:14:41.600 --> 00:14:42.519 Right? How do you test it? 282 00:14:42.679 --> 00:14:46.440 Yeah? How do you calculate the exact mathematical relationship between 283 00:14:46.480 --> 00:14:49.879 turbulent plasma density and the smearing of a narrowband radio 284 00:14:49.919 --> 00:14:52.919 signal without an actual alien transmission to measure? 285 00:14:53.080 --> 00:14:55.960 Well, the researchers didn't just rely on abstract mathematics or 286 00:14:56.039 --> 00:15:00.120 pure computer simulations. They knew they required concrete physical proof 287 00:15:00.399 --> 00:15:03.720 of how plasma scrambles narrow signals in the real universe, 288 00:15:03.919 --> 00:15:07.080 and they realized they actually had access to a perfect 289 00:15:07.480 --> 00:15:12.320 massive localized laboratory right here, our own solar system. Oh, 290 00:15:12.360 --> 00:15:16.320 of course, you have an entire fleet of robotic spacecraft 291 00:15:16.720 --> 00:15:21.320 operating right now within our heliosphere. The Voyager probes outpassed 292 00:15:21.360 --> 00:15:26.120 the Termination shock, the New Horizon spacecraft, the Mars Reconnaissance Orbiter, 293 00:15:26.360 --> 00:15:27.759 the Parker Solar probe. 294 00:15:27.799 --> 00:15:31.759 They're essentially human made extraterrestrial transmitters exactly. 295 00:15:32.159 --> 00:15:36.840 They communicate with Earth by beaming back incredibly narrow, highly 296 00:15:36.840 --> 00:15:40.440 concentrated radio telemetry. They are blowing the exact kind of 297 00:15:40.480 --> 00:15:43.120 referee whistle set he is looking for, so that the 298 00:15:43.200 --> 00:15:47.440 deep space network antennas in California, Spain, and Australia can 299 00:15:47.480 --> 00:15:50.360 actually hear them over the background radiation of the Sun. 300 00:15:50.639 --> 00:15:53.360 That is so smart. So the researchers just repurposed our 301 00:15:53.360 --> 00:15:56.600 own deep space probes as stand ins for the alien transmitters. 302 00:15:56.639 --> 00:16:00.360 Brilliant right. By observing the narrowband radio transmissions beam back 303 00:16:00.360 --> 00:16:03.240 to Earth from our own Solar system probes, the scientists 304 00:16:03.240 --> 00:16:06.200 could monitor exactly what happened to the physical structure of 305 00:16:06.200 --> 00:16:08.879 those signals when they passed through different regions of our 306 00:16:08.879 --> 00:16:10.519 own Sun's stellar winds. 307 00:16:11.000 --> 00:16:12.759 How does that work? Geometrically? 308 00:16:13.000 --> 00:16:17.200 The technique is related to radio occultation. They could measure 309 00:16:17.200 --> 00:16:19.759 the crispness of the signal when the probe was far 310 00:16:19.799 --> 00:16:23.320 away from the Sun in relatively quiet skulace, and then 311 00:16:23.360 --> 00:16:26.279 compare it to the heavily degraded signal received when the 312 00:16:26.399 --> 00:16:29.519 orbital geometry caused the line of sight to pass dangerously 313 00:16:29.600 --> 00:16:32.519 close to the Sun's turbulent corona or like. 314 00:16:32.519 --> 00:16:34.279 Right through the path of a solar flare. 315 00:16:34.440 --> 00:16:38.279 Exactly, they gathered mountains of localized measurements literally watching the 316 00:16:38.360 --> 00:16:41.480 laser pointer hit the fog in real time. They knew 317 00:16:41.480 --> 00:16:44.679 the exact initial shape of the probe's transmission, and they 318 00:16:44.720 --> 00:16:47.200 measured the exact dissorted shape that arrived at the deep 319 00:16:47.240 --> 00:16:47.919 space network. 320 00:16:47.960 --> 00:16:49.480 Okay, so they built a baseline. 321 00:16:49.639 --> 00:16:53.519 Right. Once they established that solid, proven baseline of how 322 00:16:53.559 --> 00:16:57.279 space weather affects signals locally, they could scale the physics. 323 00:16:57.600 --> 00:17:00.440 They could take those concrete measurements and apply them thatttermatically 324 00:17:00.559 --> 00:17:03.080 to various stellar environments across the galaxy. 325 00:17:03.200 --> 00:17:04.279 That makes total sense. 326 00:17:04.680 --> 00:17:08.240 The calculations allowed them to say, if our Sun, which 327 00:17:08.279 --> 00:17:12.480 is a relatively calm G type main sequence star, scatters 328 00:17:12.519 --> 00:17:15.319 a signal by a specific metric, what is the exact 329 00:17:15.319 --> 00:17:18.160 broadening effect If the signal originated around a star with 330 00:17:18.200 --> 00:17:21.119 a stellar wind ten or one hundred times more dense. 331 00:17:21.519 --> 00:17:25.039 Here's where it gets really interesting, though. If NASA engineers 332 00:17:25.039 --> 00:17:28.680 and heliophysicists have known about this signal distorted in for decades, 333 00:17:29.119 --> 00:17:31.519 because I mean they literally have to account for solar 334 00:17:31.519 --> 00:17:35.160 plasma smearing the telemetry from Mars rovers, why did it 335 00:17:35.200 --> 00:17:37.559 take the SETI community this long to realize it would 336 00:17:37.559 --> 00:17:38.920 happened to alien signals too. 337 00:17:39.160 --> 00:17:41.200 That is the million dollar question, right. 338 00:17:41.279 --> 00:17:44.680 Surely the astronomers listening for aliens knew about the interstellar medium. 339 00:17:45.000 --> 00:17:46.799 Why is this a totally new paradigm. 340 00:17:46.960 --> 00:17:50.039 Well, the SETI community was highly aware of the interstellar medium, 341 00:17:50.440 --> 00:17:55.119 that incredibly thin, sparse dust and ionized gas that exists 342 00:17:55.160 --> 00:17:57.079 in the light years between the stars. 343 00:17:56.799 --> 00:17:58.240 The deep ocean of space. 344 00:17:58.640 --> 00:18:01.519 Right, the interstellar media does cause a minor amount of 345 00:18:01.559 --> 00:18:06.640 signal scattering. Radio astronomers build complex algorithms into their systems, 346 00:18:07.279 --> 00:18:10.960 things like dedispersion filters to account for the slow degradation 347 00:18:11.000 --> 00:18:13.759 of a signal as it travels across thousands of light 348 00:18:13.839 --> 00:18:17.519 years of the interstellar ocean. They meticulously modeled the distortion 349 00:18:17.640 --> 00:18:18.240 of the long. 350 00:18:18.119 --> 00:18:20.359 Journey, but they were so focused on the deep ocean. 351 00:18:20.400 --> 00:18:22.400 They completely forgot to look at the shoreline. 352 00:18:22.519 --> 00:18:26.400 That is exactly what happened. They completely overlooked the extreme 353 00:18:26.839 --> 00:18:30.960 catastrophic distortion happening right at the origin point. The assumption 354 00:18:31.079 --> 00:18:34.720 was just always that the signal entered the interstellar ocean perfectly. 355 00:18:34.240 --> 00:18:36.359 Intact, which is a huge oversight. 356 00:18:36.559 --> 00:18:41.119 It is, but the delay in recognizing this XOIPM gatekeeper 357 00:18:41.240 --> 00:18:44.720 is actually a classic example of the siloing of scientific. 358 00:18:44.279 --> 00:18:46.799 Disciplines, people not talking to each other exactly. 359 00:18:47.319 --> 00:18:50.720 The engineers operating the deep space network and the heliophysicists 360 00:18:50.720 --> 00:18:54.359 studying the Sun's local space weather belong to one distinct 361 00:18:54.599 --> 00:18:59.519 academic community. Their focus is entirely on maintaining probe communication 362 00:19:00.119 --> 00:19:03.079 and protecting terrestrial grids from solar flares. 363 00:19:02.960 --> 00:19:05.319 And SETI is over in a different building right. 364 00:19:05.680 --> 00:19:09.039 The radio astronomers and SETI researchers belonged to a completely 365 00:19:09.039 --> 00:19:11.960 different community, with their focus locked on the vast expanses 366 00:19:12.000 --> 00:19:16.039 of deep space. It took a massive interdisciplinary synthesis of 367 00:19:16.119 --> 00:19:20.160 local heliophysics and distant SETI targeting algorithms to create a 368 00:19:20.240 --> 00:19:24.400 unified framework. Someone finally had to step back and realize, Hey, 369 00:19:25.400 --> 00:19:27.559 the aliens have to transmit through a sun too. 370 00:19:27.880 --> 00:19:31.200 Wow. And once that interdisciplinety framework was built bridging local 371 00:19:31.200 --> 00:19:34.400 solar physics with galactic SETI searches, the numbers they ran 372 00:19:34.519 --> 00:19:37.440 on the rest of the galaxy completely broke the existing map, 373 00:19:37.559 --> 00:19:39.759 completely broke it, because when you look at the distribution 374 00:19:39.839 --> 00:19:41.960 of stars in the Milky Way, you realize our calm 375 00:19:42.319 --> 00:19:46.839 yellow Sun is actually an extreme minority, a huge minority. 376 00:19:47.200 --> 00:19:49.359 If you look at the true rulers of the Milky Way, 377 00:19:49.640 --> 00:19:52.200 you were looking at am dwarf stars, which are also 378 00:19:52.200 --> 00:19:54.759 known as red doors, and they're smaller than our Sun, 379 00:19:55.160 --> 00:19:58.240 much cooler, and they burn a dim reddish color. But 380 00:19:58.319 --> 00:20:01.400 what they lack in mass they absolutely make up for 381 00:20:01.559 --> 00:20:05.359 in sheer overwhelming numbers. Roughly seventy five percent of all 382 00:20:05.400 --> 00:20:08.319 stars in the Milky Way are M dwarfs. Seventy three 383 00:20:08.359 --> 00:20:10.200 out of every four stars you could ever point a 384 00:20:10.279 --> 00:20:15.559 radio telescope at, are these small red suns. Mathematically speaking, 385 00:20:16.079 --> 00:20:19.759 if exoplanets harboring life are out there, it is highly 386 00:20:19.799 --> 00:20:23.559 statistically probable that they are orbiting an M dwarf simply 387 00:20:23.680 --> 00:20:26.079 due to the ubiquitous nature of these stars. 388 00:20:26.480 --> 00:20:29.200 And this is where the physics of the EXOIPM scattering 389 00:20:29.319 --> 00:20:32.240 really collide with the reality of the galaxy, because if 390 00:20:32.319 --> 00:20:35.759 M dwarfs are smaller and cooler, you'd intuitively think their 391 00:20:35.799 --> 00:20:38.640 stellar weather would be quieter, right, like a smaller fire 392 00:20:38.720 --> 00:20:39.839 is less violent. 393 00:20:39.640 --> 00:20:42.200 You would think so. But M dwarfs are notoriously. 394 00:20:41.799 --> 00:20:43.680 Violent, way more violent than our Sun. 395 00:20:43.599 --> 00:20:46.839 Oh exponentially more. Their violence is a product of their 396 00:20:46.880 --> 00:20:50.599 internal structure. Because they have a lower mass, usually between 397 00:20:50.839 --> 00:20:54.160 point zero eight and point six solar masses, many M 398 00:20:54.240 --> 00:20:57.839 dwarfs lack what's called a radiative zone. They are fully convective. 399 00:20:57.960 --> 00:20:59.759 What does fully convective mean for the star? 400 00:21:00.079 --> 00:21:02.599 It means the boiling of plasma from the core all 401 00:21:02.640 --> 00:21:06.279