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 00:00:26.879 --> 00:00:28.719 So I want you to try and imagine something with 8 00:00:28.760 --> 00:00:32.759 me for a second. Imagine standing a full kilometer way from. 9 00:00:32.679 --> 00:00:36.079 An object, right, which is I mean that's a massive distance. 10 00:00:36.159 --> 00:00:39.520 Yeah, exactly. Just picture that immense distance. You're standing at 11 00:00:39.520 --> 00:00:43.560 one end of like at a long, perfectly straight highway, okay, 12 00:00:43.719 --> 00:00:46.560 and you're looking at something that is basically ten football 13 00:00:46.560 --> 00:00:47.640 fields away, So. 14 00:00:47.840 --> 00:00:49.759 A distance that would take you what a good ten 15 00:00:49.840 --> 00:00:51.159 or fifteen minutes. 16 00:00:50.799 --> 00:00:54.200 Just to walk exactly. It's a real trek. Now, from 17 00:00:54.200 --> 00:00:57.159 that incredible vantage point, I want you to imagine being 18 00:00:57.159 --> 00:01:01.799 able to perfectly see, and I mean visually, something that 19 00:01:01.880 --> 00:01:04.519 is exactly three point five millimeters wide. 20 00:01:04.640 --> 00:01:07.560 Oh wow, I mean three point five millimeter It's roughly 21 00:01:07.599 --> 00:01:11.040 the width of maybe two stacked pennies, or like a. 22 00:01:11.000 --> 00:01:13.799 Single grain of rice, rice grain of rice an entire 23 00:01:13.840 --> 00:01:16.799 kilometer away. That is just mind bending, right, But that 24 00:01:17.000 --> 00:01:20.599 is the exact level of visual sharpness, the sheer like 25 00:01:21.120 --> 00:01:25.840 optical perfection achieved by a newly developed Japanese X ray 26 00:01:25.879 --> 00:01:27.359 space telescope. 27 00:01:26.840 --> 00:01:29.079 Which is just an incredible engineering fee. 28 00:01:29.319 --> 00:01:32.480 It really is. But here's the thing. Getting that perfect 29 00:01:32.599 --> 00:01:37.480 image required scientists to completely abandon everything we thought we 30 00:01:37.560 --> 00:01:39.799 knew about how telescopes actually work. 31 00:01:39.879 --> 00:01:40.040 Oh. 32 00:01:40.079 --> 00:01:42.200 Absolutely, they had to throw out the entire playbook. 33 00:01:42.319 --> 00:01:44.200 You really did. I mean, they had to cross breathe 34 00:01:44.200 --> 00:01:48.840 their astronomical designs with the brutal physics of a particle accelerator. 35 00:01:48.959 --> 00:01:49.280 Yeah. 36 00:01:49.319 --> 00:01:53.040 They had to build a kilometer long vacuum tube deep 37 00:01:53.159 --> 00:01:56.319 underground just to fake a single star. 38 00:01:56.359 --> 00:01:58.799 Which is wild to even think about. 39 00:01:58.959 --> 00:02:01.920 And then after all that, they eventually strapped their creation 40 00:02:02.040 --> 00:02:03.799 to a rocket in the freezing wilderness of. 41 00:02:03.799 --> 00:02:05.439 Alaska just to see if it would survive. 42 00:02:05.719 --> 00:02:09.240 Right, And the reason they went to all of these extreme, 43 00:02:09.960 --> 00:02:14.319 almost absurd lengths to literally shrink the entire future of 44 00:02:14.360 --> 00:02:17.599 space observation down to the size of a shoebox. 45 00:02:17.759 --> 00:02:19.759 A shoe box, I mean, the journey to getting that 46 00:02:19.759 --> 00:02:23.639 technology into a shoebox is fundamentally a story about battling 47 00:02:23.639 --> 00:02:26.039 two of the most unforgiving hurdles in science. 48 00:02:26.159 --> 00:02:28.080 Yeah, what's unpack that? What are we dealing with here? 49 00:02:28.120 --> 00:02:31.439 Well, first, you are dealing with an incredibly hostile physical 50 00:02:31.560 --> 00:02:33.199 environment outer space, you know. 51 00:02:33.280 --> 00:02:36.120 Right, space is not exactly friendly, far from it. 52 00:02:36.520 --> 00:02:40.479 You have the violent shaking of suborbital rocket launches, the 53 00:02:40.560 --> 00:02:43.479 hard vacuum, the extreme temperature swings. 54 00:02:43.560 --> 00:02:46.840 It's basically a torture chamber for delicate equipment exactly. 55 00:02:47.080 --> 00:02:50.560 And second, you are hunting the most elusive, difficult to 56 00:02:50.599 --> 00:02:54.919 capture targets in the known universe. X rays, Yes, X rays, 57 00:02:55.120 --> 00:02:57.919 high energy X rays do not behave like the visible 58 00:02:58.000 --> 00:03:00.280 light we are accustomed to seeing every single day. 59 00:03:00.319 --> 00:03:02.479 They're a totally different beast, they really are. 60 00:03:02.599 --> 00:03:06.080 They actively resist being caught, they resist being focused. 61 00:03:06.159 --> 00:03:08.479 They just want to blast right through everything. 62 00:03:08.560 --> 00:03:12.120 Right, and they require a complete reimagining of optical physics 63 00:03:12.120 --> 00:03:13.080 to even look at. 64 00:03:13.280 --> 00:03:16.439 But the payoff for catching them is huge, right, I mean, 65 00:03:16.479 --> 00:03:17.680 it's the keys to the Kingdom. 66 00:03:17.840 --> 00:03:18.800 Oh, without a doubt. 67 00:03:18.879 --> 00:03:21.599 We desperately want to catch these high energy photons because 68 00:03:21.919 --> 00:03:25.080 they're the only way to really understand the universe's most violent, 69 00:03:25.520 --> 00:03:27.400 extreme temperature events. 70 00:03:27.039 --> 00:03:29.439 Because we aren't trying to look at you know, quiet 71 00:03:29.560 --> 00:03:31.080 peaceful dust clouds here. 72 00:03:31.400 --> 00:03:33.240 No, we are chasing monsters. 73 00:03:33.960 --> 00:03:35.280 That's a great way to put it. I mean, if 74 00:03:35.319 --> 00:03:39.039 you want to understand the calm, relatively cold universe, you 75 00:03:39.080 --> 00:03:41.439 look at visible light or infrared, right. 76 00:03:41.319 --> 00:03:44.039 The stuff Hubble or James Web does exactly right. 77 00:03:44.360 --> 00:03:47.960 But if you want to understand the true extremes of astrophysics, 78 00:03:48.000 --> 00:03:51.039 you absolutely must look at the X ray spectrum. 79 00:03:51.319 --> 00:03:53.439 So what exactly are we looking for? Like, what makes 80 00:03:53.479 --> 00:03:54.639 these X rays so special? 81 00:03:54.840 --> 00:03:57.319 Well, there is a distinction we should establish right away 82 00:03:57.360 --> 00:04:00.960 between soft X rays and hard X rays. Okay, because 83 00:04:01.000 --> 00:04:04.879 this new Japanese telescope it's specifically hunting the hard. 84 00:04:04.680 --> 00:04:06.439 Ones, got it? So what's the difference? 85 00:04:06.680 --> 00:04:09.759 Soft X rays have lower energy levels, and they are 86 00:04:09.759 --> 00:04:13.599 emitted by things like the million degree gas sitting in 87 00:04:13.599 --> 00:04:15.000 the corona of our sun. 88 00:04:15.120 --> 00:04:16.439 Which is still incredibly hot. 89 00:04:16.519 --> 00:04:20.360 Sure yeah, but hard X rays carry significantly more energy. 90 00:04:20.519 --> 00:04:24.120 They are the direct fingerprints of cataclysmic cosmic violence. 91 00:04:24.360 --> 00:04:26.959 Cosmic violence, I love that term. What does that actually 92 00:04:27.000 --> 00:04:27.399 look like? 93 00:04:27.560 --> 00:04:30.560 We are talking about enormous bursts of hard X rays 94 00:04:30.600 --> 00:04:34.319 being violently expelled when magnetic field lines snap and reconnect 95 00:04:34.600 --> 00:04:38.040 during massive solar flares, or we're talking about the detonation 96 00:04:38.199 --> 00:04:42.279 of dying stars, you know, the supernovae that completely outshine 97 00:04:42.319 --> 00:04:44.680 their entire host galaxies. 98 00:04:44.199 --> 00:04:46.920 Just unimaginably huge explosions, right. 99 00:04:46.720 --> 00:04:50.600 And perhaps most dramatically hard X rays are essentially the 100 00:04:50.639 --> 00:04:54.959 scream of superheated matter swirling violently around the event horizons 101 00:04:54.959 --> 00:04:55.680 of black holes. 102 00:04:55.759 --> 00:04:57.319 Oh man, the stuff falling in. 103 00:04:57.639 --> 00:05:02.160 Yes, it gets accelerated to millions of degrees by intense 104 00:05:02.279 --> 00:05:05.399 friction right before it crosses that threshold and just falls 105 00:05:05.399 --> 00:05:05.959 in forever. 106 00:05:06.160 --> 00:05:09.519 So basically the most dramatic spectacular events in the cosmos 107 00:05:09.560 --> 00:05:12.079 are happening constantly right over our heads. 108 00:05:11.839 --> 00:05:13.160 All the time twenty four to seven. 109 00:05:13.480 --> 00:05:17.759 But here is the massive physical barrier to actually seeing 110 00:05:17.800 --> 00:05:22.800 any of it. Earth is atmosphere completely utterly absorbs these 111 00:05:22.959 --> 00:05:25.319 X rays before they ever reach the ground, which I 112 00:05:25.399 --> 00:05:27.720 have to point out, from a biological standpoint, is the 113 00:05:27.759 --> 00:05:31.439 only reason we are even alive to discuss it today. Unquestionably, Yeah, 114 00:05:31.560 --> 00:05:34.120 I mean we'd be cooked otherwise exactly. I always think 115 00:05:34.120 --> 00:05:37.639 of our atmosphere as this incredibly dense wrap round pair 116 00:05:37.680 --> 00:05:40.000 of heavy duty lead lined sunglasses. 117 00:05:40.199 --> 00:05:41.959 That's a really good analogy. 118 00:05:41.680 --> 00:05:44.959 Because visible light trickles through just fine, right, which is 119 00:05:45.000 --> 00:05:48.720 why our human eyes evolve to see that specific narrow 120 00:05:48.839 --> 00:05:51.399 band of the electromagnetic. 121 00:05:50.680 --> 00:05:53.079 Spectrum, right, We adapted to the light that actually makes 122 00:05:53.120 --> 00:05:54.360 it down here exactly. 123 00:05:54.839 --> 00:05:57.560 But when it comes to ionizing radiation, the kind of 124 00:05:57.600 --> 00:06:00.360 high energy X rays that violently strip electrons away from 125 00:06:00.399 --> 00:06:04.240 atoms and you know, shattered DNA molecules, the atmosphere is 126 00:06:04.279 --> 00:06:05.319 an absolute vault. 127 00:06:05.480 --> 00:06:09.720 It's a total lockdown. The nitrogen and oxygen molecules high 128 00:06:09.759 --> 00:06:13.600 above us intercept those X ray photons through a process 129 00:06:13.639 --> 00:06:18.439 called photoelectric absorption, okay, and it is absolutely essential for 130 00:06:18.560 --> 00:06:22.079 keeping the fragile biology of Earth safe from being sterilized 131 00:06:22.120 --> 00:06:23.199 by cosmic radiation. 132 00:06:23.519 --> 00:06:26.480 So great for not getting vaporized, very great, But it 133 00:06:26.560 --> 00:06:29.759 is incredibly frustrating if you are an astrophysicist trying to 134 00:06:29.800 --> 00:06:32.199 look at the blinding flashes of a solar flare. 135 00:06:32.279 --> 00:06:35.279 Oh it's maddening. And the historical context of that frustration 136 00:06:35.360 --> 00:06:37.759 is actually super fascinating when you think about the timeline 137 00:06:37.759 --> 00:06:41.600 of astronomy. Oh so well, for thousands of years, human 138 00:06:41.639 --> 00:06:44.639 beings looked up at the night sky, you know, charted 139 00:06:44.680 --> 00:06:46.839 the stars tracked the planets. 140 00:06:46.279 --> 00:06:48.000 Like the ancient Greeks the Mayans. 141 00:06:47.879 --> 00:06:50.519 Right, and they genuinely believed they were seeing the whole 142 00:06:50.759 --> 00:06:51.399 picture of. 143 00:06:51.360 --> 00:06:53.480 The universe, because that's all they could see. 144 00:06:53.279 --> 00:06:57.319 Exactly, But they were completely blind to the high energy reality. 145 00:06:57.360 --> 00:07:01.199 They were only seeing that tiny slid of the electromagnetic 146 00:07:01.240 --> 00:07:04.120 spectrum that makes it through the atmospheric sunglasses. 147 00:07:04.199 --> 00:07:08.439 So the entire X ray universe, the violent, churning, high 148 00:07:08.560 --> 00:07:12.399 energy cosmos, was entirely invisible. 149 00:07:11.879 --> 00:07:15.560 To us, completely invisible. It wasn't until the mid twentieth century, 150 00:07:16.000 --> 00:07:19.519 specifically around the late nineteen forties and early nineteen sixties. 151 00:07:19.560 --> 00:07:22.040 Wait that recently, Yeah. 152 00:07:21.519 --> 00:07:25.160 That was when scientists first put rudimentary Geiger counters onto 153 00:07:25.240 --> 00:07:28.680 captured V two rockets and sent them above the atmosphere. 154 00:07:28.720 --> 00:07:30.959 Wow. So they literally had to shoot a rocket up 155 00:07:31.000 --> 00:07:32.879 there just to realize what was happening. 156 00:07:32.720 --> 00:07:35.120 Right, And that was the exact moment we realized the 157 00:07:35.160 --> 00:07:39.879 sky wasn't just twinkling peacefully, it was glowing and pulsing 158 00:07:40.240 --> 00:07:42.399 with intense X ray radiation. 159 00:07:42.680 --> 00:07:44.560 That must have been a mind blowing discovery. 160 00:07:44.600 --> 00:07:48.800 It changed everything because to understand the fundamental laws of physics, 161 00:07:48.920 --> 00:07:52.120 gravity and magnetism, you really have to study these high 162 00:07:52.160 --> 00:07:53.240 temperature processes. 163 00:07:53.519 --> 00:07:58.079 So imagine knowing that the most spectacular fireworks show imaginable 164 00:07:58.399 --> 00:08:01.480 is happening right above your head twenty four hours a day, 165 00:08:01.879 --> 00:08:04.800 but you are permanently trapped inside a house with no windows, 166 00:08:05.199 --> 00:08:07.519 sitting behind this impenetrable curtain of air. 167 00:08:07.800 --> 00:08:11.560 That is exactly the dilemma. Ground based X ray astronomy 168 00:08:11.639 --> 00:08:16.439 is not just difficult, it is a physical impossibility. 169 00:08:15.600 --> 00:08:18.000 Because the atmosphere acts like a solid brow wall for 170 00:08:18.040 --> 00:08:19.720 those high energy photons. 171 00:08:19.319 --> 00:08:20.720 A total brick wall. 172 00:08:20.920 --> 00:08:24.439 So because observation from the surface is a complete non starter, 173 00:08:24.920 --> 00:08:27.399 you are forced to bypass the atmosphere entirely. 174 00:08:27.519 --> 00:08:28.639 You have to go to space. 175 00:08:28.759 --> 00:08:32.120 You have to, and historically scientists started with high altitude 176 00:08:32.120 --> 00:08:35.360 weather balloons trying to get just above the thickest part 177 00:08:35.360 --> 00:08:35.759 of the air. 178 00:08:35.919 --> 00:08:37.000 Yeah, that was step one. 179 00:08:37.080 --> 00:08:40.399 When they moved to suborbital sounding rockets and eventually the 180 00:08:40.399 --> 00:08:42.799 massive permanent satellites we have up there today. 181 00:08:42.879 --> 00:08:46.360 But here's the catch. Just getting your instrument above the 182 00:08:46.440 --> 00:08:48.919 atmosphere is only solving half the problem. 183 00:08:49.080 --> 00:08:49.360 Right. 184 00:08:49.440 --> 00:08:53.279 The real nightmare, the true engineering paradox that basically melted 185 00:08:53.279 --> 00:08:56.039 my brain when I first understood it, is trying to 186 00:08:56.120 --> 00:08:59.600 actually catch and focus a hard X ray once you're 187 00:08:59.639 --> 00:09:01.039 up there in the vacuum of space. 188 00:09:01.320 --> 00:09:03.799 Because the moment you try to build a telescope for 189 00:09:03.960 --> 00:09:08.000 X rays, you have to completely discard the everyday intuitive 190 00:09:08.080 --> 00:09:12.200 understanding of how mirrors work. You really do, because think 191 00:09:12.200 --> 00:09:15.039 about it. When you picture a telescope, you picture a 192 00:09:15.240 --> 00:09:20.159 large curved piece of glass coated in a highly reflective metal. 193 00:09:20.000 --> 00:09:21.679 Right, like a big satellite dish for light. 194 00:09:21.840 --> 00:09:24.759 Yeah, like a massive, precisely engineered version of the mirror 195 00:09:24.759 --> 00:09:28.919 in your bathroom. Exactly, light hits the curve surface, bounces off, 196 00:09:29.559 --> 00:09:32.720 and focuses perfectly onto a single point where an eyepiece 197 00:09:32.840 --> 00:09:34.200 or a digital sensor sits. 198 00:09:34.360 --> 00:09:35.559 That's standard optics. 199 00:09:35.639 --> 00:09:37.759 You point a regular curve mirror at a distant star 200 00:09:37.919 --> 00:09:39.159 and boom, you have an image. 201 00:09:39.159 --> 00:09:41.480 But you absolutely cannot do that with X rays, And 202 00:09:41.559 --> 00:09:44.720 the underlying physics of why you can't is crucial to 203 00:09:44.840 --> 00:09:47.000 understanding this Japanese team's breakthrough. 204 00:09:47.279 --> 00:09:49.440 So break that down for us. Why doesn't a normal 205 00:09:49.480 --> 00:09:50.960 mirror work for an X ray? 206 00:09:51.159 --> 00:09:54.639 Well, normal mirrors rely on visible light photons, which have 207 00:09:54.840 --> 00:09:59.279 relatively long wavelengths and low energy. When visible light hits 208 00:09:59.320 --> 00:10:03.159 the atomic sit structure of silver or aluminum coating. It 209 00:10:03.240 --> 00:10:06.200 interacts with the electron clouds of those atoms and just 210 00:10:06.279 --> 00:10:07.120 bounces right back. 211 00:10:07.159 --> 00:10:08.279 It reflects right. 212 00:10:08.759 --> 00:10:12.720 But X rays, especially hard X rays, carry an immense 213 00:10:12.759 --> 00:10:16.120 amount of energy. Their wavelengths are incredibly. 214 00:10:15.559 --> 00:10:17.000 Short, so they don't bounce. 215 00:10:17.279 --> 00:10:21.200 No, if you point a normal dish shaped mirror directly 216 00:10:21.200 --> 00:10:23.919 at a black hole emitting hard X rays, the photon 217 00:10:23.960 --> 00:10:26.440 doesn't bounce, It punches straight through the mirror. 218 00:10:26.559 --> 00:10:29.120 It just glasts right through the glass, straight. 219 00:10:28.879 --> 00:10:32.600 Through, or it gets completely absorbed by the atomic structure 220 00:10:32.639 --> 00:10:36.720 of the mirror itself. Wow, it's the fundamental defining property 221 00:10:36.720 --> 00:10:39.039 of high energy photons. They penetrate matter. 222 00:10:39.320 --> 00:10:41.639 I mean, that's exactly why we use them for medical imaging, 223 00:10:41.720 --> 00:10:44.399 right to look at broken bones inside the human body. 224 00:10:44.519 --> 00:10:48.279 Exactly. They pass right through the soft tissue because the 225 00:10:48.320 --> 00:10:51.159 carbon and water molecules in our flesh don't have the 226 00:10:51.200 --> 00:10:52.679 density to stop them. 227 00:10:52.879 --> 00:10:55.279 The bones are dense enough to cast a shadow, but 228 00:10:55.360 --> 00:10:56.759 the flesh isn't right. 229 00:10:56.840 --> 00:11:00.600 So, in an astronomical context, if you build hi traditional 230 00:11:01.000 --> 00:11:05.240 dish shaped parabolic mirror and flight above the atmosphere, the 231 00:11:05.360 --> 00:11:08.200 high energy X rays from a solar flare will just 232 00:11:08.320 --> 00:11:11.120 blast straight into the dish and vanish into the metal. 233 00:11:11.200 --> 00:11:11.759 You get nothing. 234 00:11:11.840 --> 00:11:16.879 You get zero reflection, zero focus, and therefore absolutely no data. 235 00:11:16.960 --> 00:11:18.519 So how do you fix it? How do you make 236 00:11:18.559 --> 00:11:22.120 something that just wants to punch through a wall actually 237 00:11:22.159 --> 00:11:22.799 bounce off it. 238 00:11:22.799 --> 00:11:24.120 It's a geometry problem. 239 00:11:24.200 --> 00:11:27.000 And the analogy that really clarifies this geometry for me 240 00:11:27.639 --> 00:11:28.600 is the skipping stone. 241 00:11:28.639 --> 00:11:30.279 Oh that's a perfect analogy, right. 242 00:11:30.279 --> 00:11:33.559 Think about standing at the edge of a completely still 243 00:11:33.600 --> 00:11:36.159 pond with a rock in your hand. If you stand 244 00:11:36.279 --> 00:11:39.360 right over the water and throw the rock straight down, 245 00:11:39.799 --> 00:11:41.559 which is the equivalent of an X ray hitting a 246 00:11:41.600 --> 00:11:43.279 normal mirror face on, what happens. 247 00:11:43.320 --> 00:11:46.039 The rock just breaks the surface tension instantly and sinks 248 00:11:46.080 --> 00:11:47.120 right to the bottom exactly. 249 00:11:47.200 --> 00:11:49.720 It sinks. But if you want that rock to bounce, 250 00:11:49.720 --> 00:11:51.919 if you want to skip the stone across the surface 251 00:11:51.960 --> 00:11:54.480 of the pond, you have to change your geometry. 252 00:11:54.519 --> 00:11:55.440 You have to get down low. 253 00:11:55.600 --> 00:11:57.759 You have to get down low to the water and 254 00:11:57.960 --> 00:12:02.360 throw the rock at an incredibly shape, almost perfectly horizontal angle. 255 00:12:02.440 --> 00:12:05.360 You have to make it graze the surface, yes, graze it. 256 00:12:05.600 --> 00:12:09.039 And the physics concept governing this in optics is literally 257 00:12:09.080 --> 00:12:10.600 called grazing incidents. 258 00:12:10.720 --> 00:12:13.559 Grazing incidents. Okay, so how does that work with X rays? 259 00:12:13.960 --> 00:12:17.000 Well, the refractive index of all materials for X rays 260 00:12:17.039 --> 00:12:18.240 is actually slightly. 261 00:12:17.960 --> 00:12:20.080 Less than one, which means what exactly? 262 00:12:20.200 --> 00:12:23.039 It means that, unlike visible light, which bends when it 263 00:12:23.159 --> 00:12:27.840 enters glass, X rays exhibit a phenomenon called total external reflection. 264 00:12:28.440 --> 00:12:31.399 But only, and this is a huge only under extremely 265 00:12:31.399 --> 00:12:32.519 specific conditions. 266 00:12:32.639 --> 00:12:35.279 Let me guess the skipping stone conditions exactly. 267 00:12:35.799 --> 00:12:38.679 The only physical way to make a hard X ray 268 00:12:38.759 --> 00:12:41.799 reflect off a surface without being absorbed is if it 269 00:12:41.840 --> 00:12:45.000 strikes that surface at a microscopic grazing angle. 270 00:12:45.200 --> 00:12:46.720 How microscopic are we talking? 271 00:12:46.799 --> 00:12:48.919 We are talking about an angle of incidents that is 272 00:12:48.960 --> 00:12:50.679 often less than a single. 273 00:12:50.440 --> 00:12:52.200 Degree, less than one degree. 274 00:12:52.360 --> 00:12:55.679 Yes, it has to skim the metallic surface, exactly like 275 00:12:55.759 --> 00:12:57.360 your skipping stone skimming the water. 276 00:12:57.600 --> 00:13:00.799 Wait, okay, hold on. If the the X rays are 277 00:13:00.799 --> 00:13:04.159 only skipping off the very edges of this surface at 278 00:13:04.159 --> 00:13:07.399 a one degree angle, doesn't that mean the actual like 279 00:13:08.000 --> 00:13:11.080 catching area of the telescope is almost non existent? 280 00:13:11.240 --> 00:13:13.200 Yes, you hit the nail on the head. 281 00:13:13.000 --> 00:13:15.240 Because if you point a flat cylinder at the sky, 282 00:13:16.200 --> 00:13:19.919 the frontal area intercepting the light is just the razor 283 00:13:19.960 --> 00:13:23.080 thin rim of the cylinder, right, aren't you basically throwing 284 00:13:23.080 --> 00:13:25.559 away ninety nine percent of the photons you just flew 285 00:13:25.559 --> 00:13:26.720 all the way to space to catch. 286 00:13:26.840 --> 00:13:29.639 You absolutely are, and you are hitting on the exact 287 00:13:29.879 --> 00:13:32.879 critical flaw of grazing incidence optics. 288 00:13:32.960 --> 00:13:34.799 It seems so inefficient it is. 289 00:13:35.200 --> 00:13:38.759 The effective collecting area is abysmally small compared to a 290 00:13:38.799 --> 00:13:42.039 standard telescope because you can only catch the photons that 291 00:13:42.159 --> 00:13:44.399 hit the extreme inner edge of the mirror at that 292 00:13:44.519 --> 00:13:47.240 sub one degree angle. The vast majority of the X 293 00:13:47.320 --> 00:13:49.399 rays just passed straight down the empty middle of the 294 00:13:49.399 --> 00:13:51.120 tube without touching anything. 295 00:13:50.799 --> 00:13:53.240 So they just fly straight through the hole, yeah, or. 296 00:13:53.120 --> 00:13:55.279 They hit the outside of the tube and are totally lost. 297 00:13:55.720 --> 00:13:59.399 This is exactly why doctor Ikuyuki Mitsuishi, the project leader 298 00:13:59.440 --> 00:14:02.879 from the Graduate School of Science at Nagoya University, described 299 00:14:02.960 --> 00:14:06.679 their mirror specifically as a very precise. 300 00:14:06.279 --> 00:14:09.200 Funnel, A funnel that makes so much sense, not a dish, 301 00:14:09.279 --> 00:14:12.960 not a bowl, A hollow cylinder that narrows exactly. The 302 00:14:13.080 --> 00:14:15.919 X rays enter the open top of the barrel, skip 303 00:14:15.960 --> 00:14:19.360 off these smoothly sloped inside walls at that tiny grazing 304 00:14:19.360 --> 00:14:23.000 angle and get funneled down into a concentrated point where 305 00:14:23.000 --> 00:14:25.080 a digital detector sits at the bottom. 306 00:14:25.159 --> 00:14:28.399 But and this is a massive butt. The requirement of 307 00:14:28.440 --> 00:14:33.799 that incredibly shallow angle creates an engineering and manufacturing nightmare 308 00:14:34.080 --> 00:14:35.960 that basically borders on the impossible. 309 00:14:36.000 --> 00:14:38.639 Because the tolerances have to be so tight, beyond tight. 310 00:14:38.919 --> 00:14:41.559 Because the reflection angle is so shallow, the margin for 311 00:14:41.600 --> 00:14:44.799 physical error on the surface of that funnel is effectively. 312 00:14:44.399 --> 00:14:46.639 Zero, zero margin for error. 313 00:14:46.759 --> 00:14:49.279 We are not talking about millimeter precision here. We are 314 00:14:49.320 --> 00:14:51.360 not even talking about micrometer precision. 315 00:14:51.440 --> 00:14:52.639 And what are we talking about. 316 00:14:52.840 --> 00:14:55.919 We are operating in the realm of nanometer level precision. 317 00:14:56.000 --> 00:14:56.440 Nanometer. 318 00:14:56.639 --> 00:15:00.679 Yes, Doctor Mitsuishi emphasized that if any part of the 319 00:15:00.720 --> 00:15:04.759 interior of this funnel is even slightly misaligned, or if 320 00:15:04.759 --> 00:15:07.639 the surface texture is slightly rough at a microscopic level, 321 00:15:08.000 --> 00:15:11.320 the X ray photons will not bounce toward the focal point. 322 00:15:11.519 --> 00:15:12.799 They'll just scatter everywhere. 323 00:15:12.879 --> 00:15:16.080 They will scatter wildly, They will miss the tiny digital 324 00:15:16.120 --> 00:15:19.559 detector completely, and the million dollar image you just went 325 00:15:19.639 --> 00:15:23.159 to space to capture becomes nothing more than a useless 326 00:15:23.320 --> 00:15:25.120 blurry smudge of static. 327 00:15:25.480 --> 00:15:28.799 Just to establish what nanimeter precision actually looks, like, for 328 00:15:28.879 --> 00:15:32.600 you guys listening, a nanometer is one billionth of a meter, right. 329 00:15:32.480 --> 00:15:34.519 It's almost unimaginably small. 330 00:15:34.759 --> 00:15:38.279 A standard human hair is roughly eighty thousand to one 331 00:15:38.320 --> 00:15:39.759 hundred thousand nanimeters thick. 332 00:15:39.879 --> 00:15:40.279 Wow. 333 00:15:40.399 --> 00:15:43.000 Yeah, So we are talking about shaping and polishing the 334 00:15:43.000 --> 00:15:46.440 interior wall of a metallic barrel to a degree of 335 00:15:46.600 --> 00:15:50.120 absolute smoothness that is tens of thousands of times smaller 336 00:15:50.120 --> 00:15:51.320 than the width of a single hair. 337 00:15:51.639 --> 00:15:54.840 And achieving that kind of surface smoothness and a sterile, pristine, 338 00:15:54.879 --> 00:15:58.960 temperature controlled vibration isolated optical laboratory on Earth is a 339 00:15:59.000 --> 00:16:00.840 monumental undertaking on its own, right. 340 00:16:00.919 --> 00:16:02.559 Just doing it on a desk is hard enough. 341 00:16:02.840 --> 00:16:06.600 But this is where the aerospace variable completely ruins your day. 342 00:16:06.679 --> 00:16:09.279 Oh no, because this is not a lab experiment meant 343 00:16:09.320 --> 00:16:11.840 to sit nicely on a heavy granite table. This is 344 00:16:11.840 --> 00:16:12.919 a space telescope. 345 00:16:13.000 --> 00:16:17.799 Right. So you spend months, maybe years, building this flawless 346 00:16:18.000 --> 00:16:22.120 nanometer precise optical masterpiece, and then what is the very 347 00:16:22.159 --> 00:16:22.799 next step. 348 00:16:23.000 --> 00:16:24.159 You put it on a rocket. 349 00:16:24.399 --> 00:16:26.639 You strap it to the top of a giant metal 350 00:16:26.720 --> 00:16:30.919 tube filled with highly explosive rocket fuel, and you basically 351 00:16:30.960 --> 00:16:32.200 detonate it exactly. 352 00:16:32.279 --> 00:16:35.399 The agonizing reality of aerospace engineering is that you must 353 00:16:35.440 --> 00:16:40.600 subject incredibly delicate instruments to pure, unadulterated physical. 354 00:16:40.200 --> 00:16:42.120 Brutality, so counterintuitive. 355 00:16:42.279 --> 00:16:45.399 During a rocket launch, the payload inside the faring experiences 356 00:16:45.440 --> 00:16:47.879 a gauntlet of destructive forces. 357 00:16:47.440 --> 00:16:50.120 Like what is the telescope actually going through? 358 00:16:50.320 --> 00:16:53.600 First, there are the immense g forces of acceleration physically 359 00:16:53.639 --> 00:16:56.360 crushing down on the structure as it blasts. 360 00:16:55.919 --> 00:16:57.720 Off the path right just the raw speed. 361 00:16:57.919 --> 00:17:01.440 Then you have massive thermal expansion contraction as the rocket 362 00:17:01.519 --> 00:17:04.720 moves from the ambient temperature of launchpad, pushing through the 363 00:17:04.799 --> 00:17:08.200 friction of the atmosphere and into the freezing vacuum of space. 364 00:17:08.640 --> 00:17:11.240 So the metal is heating up and shrinking down rapidly. 365 00:17:11.440 --> 00:17:15.319 Yes, but the most destructive force for optics, believe it 366 00:17:15.440 --> 00:17:17.400 or not, is acoustic sound. 367 00:17:18.160 --> 00:17:20.400 Sound destroys telescopes, oh absolutely. 368 00:17:20.960 --> 00:17:24.079 The acoustic shockwaves generated by the rocket engines are so 369 00:17:24.440 --> 00:17:28.160 phenomenally loud, often exceeding one hundred forty to one hundred 370 00:17:28.160 --> 00:17:29.160 and fifty decibels. 371 00:17:29.240 --> 00:17:31.000 That's like standing inside a jet engine. 372 00:17:31.079 --> 00:17:35.240 It is. The sound waves alone can literally shatter rigid materials. 373 00:17:35.480 --> 00:17:38.079 The physical vibrations are just bone rattling. 374 00:17:38.200 --> 00:17:42.200 It's the aerospace equivalent of taking a finely tuned, meticulously 375 00:17:42.240 --> 00:17:45.640 balanced Swiss watch, throwing it into an industrial pain shaker, 376 00:17:45.920 --> 00:17:48.359 turning it on high for ten minutes, and expecting it 377 00:17:48.400 --> 00:17:49.880 to keep perfect time when you take it out. 378 00:17:49.960 --> 00:17:52.359 That is exactly what it is. And after all of 379 00:17:52.400 --> 00:17:55.640 that chaotic violence, when the firing finally opens in the 380 00:17:55.640 --> 00:17:58.720 dead silence of space, that nanometer precision has to be 381 00:17:58.799 --> 00:18:00.400 completely utterly inact. 382 00:18:00.519 --> 00:18:02.759 If a single piece of the internal mirror assembly is 383 00:18:02.799 --> 00:18:05.440 shifted by what the width of a bacteria. 384 00:18:05.000 --> 00:18:06.000 The optics are ruined. 385 00:18:06.279 --> 00:18:08.759 The optics are ruined, and the mission just fails. 386 00:18:08.559 --> 00:18:12.480 Complete failure, which brings the engineers to a very harsh realization, 387 00:18:12.759 --> 00:18:16.480 which was the astronomers at Nogoya University understood that traditional 388 00:18:16.480 --> 00:18:22.240 telescope manufacturing techniques were simply not going to survive this environment, right. 389 00:18:22.160 --> 00:18:24.559 Because how do you traditionally make these things. 390 00:18:24.920 --> 00:18:28.160 Historically, if you wanted to build a grazing incidence X 391 00:18:28.279 --> 00:18:32.559 ray telescope, you would grind curved pieces of glass or metal, 392 00:18:32.759 --> 00:18:35.640 and then you would physically bolt those different curve segments 393 00:18:35.680 --> 00:18:36.960 together to form the funnel. 394 00:18:37.079 --> 00:18:39.039 Oh, I see, you build it in pieces. 395 00:18:38.839 --> 00:18:43.480 Right, But a multipart mirror inherently has joints. It has seams. 396 00:18:43.599 --> 00:18:47.680 It relies on brackets, epoxy and microscopic screws. 397 00:18:47.480 --> 00:18:50.279 And under the extreme acoustic stress and vibration of a 398 00:18:50.359 --> 00:18:52.880 rocket ascent, seams are fatal fatal. 399 00:18:53.200 --> 00:18:55.799 Where there is a joint, there is the potential for movement. 400 00:18:56.000 --> 00:18:59.039 A seam is basically a structural vulnerability waiting to. 401 00:18:58.960 --> 00:19:03.599