WEBVTT 00:00:00.000 --> 00:00:02.640 Welcome to the deep dive. We got a ton of awesome 00:00:02.640 --> 00:00:05.500 questions inspired by that mind blowing mysteries 00:00:05.500 --> 00:00:07.780 of the atom article. And what was that deep dive 00:00:07.780 --> 00:00:10.759 into unpack the coolest stuff without, you know, 00:00:10.859 --> 00:00:13.300 getting too lost in the weeds. Right on. I mean, 00:00:13.359 --> 00:00:16.140 the number of questions just shows how much we 00:00:16.140 --> 00:00:18.800 all want to understand these tiny building blocks 00:00:18.800 --> 00:00:21.399 that make up, well, everything from like why 00:00:21.399 --> 00:00:23.640 electrons don't just crash into the nucleus to 00:00:23.640 --> 00:00:26.059 the whole is the universe just a giant atom thing? 00:00:26.059 --> 00:00:28.120 It's going to be a wild ride for sure. OK, let's 00:00:28.120 --> 00:00:30.199 just jump right in. The first one that really 00:00:30.199 --> 00:00:32.759 caught my eye was, where do electrons even get 00:00:32.759 --> 00:00:35.320 the energy to keep whizzing around an atom's 00:00:35.320 --> 00:00:38.060 nucleus? We all kind of picture this mini -solar 00:00:38.060 --> 00:00:40.399 system, but that has some problems, doesn't it? 00:00:40.619 --> 00:00:43.479 It does. That simple picture of electrons orbiting 00:00:43.479 --> 00:00:46.679 the nucleus like planets around a sun, it doesn't 00:00:46.679 --> 00:00:49.000 really hold up when you look closer. For one, 00:00:49.179 --> 00:00:51.219 if an electron was zipping around like that, 00:00:51.479 --> 00:00:53.820 constantly changing direction, it should be radiating 00:00:53.820 --> 00:00:56.320 energy. like all the time. And if it's losing 00:00:56.320 --> 00:00:58.679 energy, it quickly spiral right into the nucleus, 00:00:58.719 --> 00:01:01.100 right? But atoms, well, they're clearly much 00:01:01.100 --> 00:01:03.380 more stable than that. Plus, atoms don't emit 00:01:03.380 --> 00:01:05.599 a continuous spectrum of light like that model 00:01:05.599 --> 00:01:08.879 would suggest. They emit light at very specific 00:01:08.879 --> 00:01:11.060 frequencies, more like a barcode than a rainbow. 00:01:11.739 --> 00:01:14.219 So that whole planetary model, while easy to 00:01:14.219 --> 00:01:16.459 imagine, it just doesn't match what we actually 00:01:16.459 --> 00:01:18.719 observe. So the article you sent mentions Niels 00:01:18.719 --> 00:01:21.849 Bohr and his like... revolutionary ideas. What 00:01:21.849 --> 00:01:25.370 did he do to kind of fix this whole mess? Bohr, 00:01:25.549 --> 00:01:28.510 back in 1913, came up with this radical idea. 00:01:29.010 --> 00:01:30.769 He said, hey, electrons can't just be anywhere 00:01:30.769 --> 00:01:33.189 around the nucleus. They're restricted to specific 00:01:33.189 --> 00:01:36.010 orbits at set distances, like quantized orbits. 00:01:36.469 --> 00:01:40.069 Imagine it like a staircase. Electrons can be 00:01:40.069 --> 00:01:41.930 on the steps, but not in between. And he said 00:01:41.930 --> 00:01:44.329 there's a minimum distance, a point closer to 00:01:44.329 --> 00:01:46.969 the nucleus that an electron simply cannot get 00:01:46.969 --> 00:01:48.819 to. And this wasn't just guess, it was based 00:01:48.819 --> 00:01:51.659 on Max Planck's earlier work on the quantization 00:01:51.659 --> 00:01:54.260 of energy. Right, Planck's idea that energy isn't 00:01:54.260 --> 00:01:57.019 a continuous flow, it comes in these like discrete 00:01:57.019 --> 00:01:59.359 packets, little chunks of energy, right? I remember 00:01:59.359 --> 00:02:02.299 that from the article. Exactly. Planck had shown 00:02:02.299 --> 00:02:05.219 that objects absorb or emit radiation in these 00:02:05.219 --> 00:02:07.760 packets called quanta, and the energy of each 00:02:07.760 --> 00:02:09.939 quantum is directly tied to the frequency of 00:02:09.939 --> 00:02:12.699 the radiation. It's all related by a constant, 00:02:13.000 --> 00:02:15.080 Planck's constant, which is super important in 00:02:15.080 --> 00:02:17.919 all of this. Moore took that crazy idea and said, 00:02:17.939 --> 00:02:20.419 hey, maybe it applies to electrons orbiting the 00:02:20.419 --> 00:02:23.210 nucleus too. So he postulated that the angular 00:02:23.210 --> 00:02:26.110 momentum of an electron in an allowed orbit has 00:02:26.110 --> 00:02:28.680 to be a multiple of Planck's constant. divided 00:02:28.680 --> 00:02:32.139 by 2 pi. Basically, there are only specific allowed 00:02:32.139 --> 00:02:34.919 zones where an electron can hang out around the 00:02:34.919 --> 00:02:37.419 nucleus. So it's not just the distance, but those 00:02:37.419 --> 00:02:39.539 distances are tied to specific energy levels 00:02:39.539 --> 00:02:42.379 set by this, like quantum rule. The article also 00:02:42.379 --> 00:02:44.180 mentions a deeper explanation, something about 00:02:44.180 --> 00:02:46.500 quantum mechanics and the wave particle duality 00:02:46.500 --> 00:02:49.120 of electrons. That sounds pretty intense. It 00:02:49.120 --> 00:02:51.300 is, and it gives a much fuller picture of what's 00:02:51.300 --> 00:02:54.400 happening. Quantum mechanics revealed this crazy 00:02:54.400 --> 00:02:57.500 idea that everything, including electrons, acts 00:02:57.500 --> 00:03:00.319 like both a particle and a wave. So instead of 00:03:00.319 --> 00:03:02.719 a tiny electron zipping around, think of it as 00:03:02.719 --> 00:03:04.840 a wave that's kind of spread out around the nucleus. 00:03:05.460 --> 00:03:07.199 And just like a guitar string, which can only 00:03:07.199 --> 00:03:09.199 vibrate at certain frequencies to make standing 00:03:09.199 --> 00:03:12.780 waves and musical notes, the electron wave around 00:03:12.780 --> 00:03:16.020 a nucleus has to fit the space in a stable way. 00:03:16.300 --> 00:03:18.840 The allowed orbits, as the article probably mentioned, 00:03:19.400 --> 00:03:21.800 correspond to these stable standing wave patterns 00:03:21.800 --> 00:03:24.569 of the electron. That first orbit, the closest 00:03:24.569 --> 00:03:26.810 one, that's basically the fundamental standing 00:03:26.810 --> 00:03:29.069 wave that can fit around the nucleus without 00:03:29.069 --> 00:03:31.469 canceling itself out. Okay, that wave thing is 00:03:31.469 --> 00:03:33.409 really helpful to visualize. So it's not just 00:03:33.409 --> 00:03:35.810 specific energy levels, it's the electron itself 00:03:35.810 --> 00:03:37.550 being a wave that's confined in these stable 00:03:37.550 --> 00:03:39.949 patterns. The article also mentions a totally 00:03:39.949 --> 00:03:41.930 different angle, something about energy balance 00:03:41.930 --> 00:03:44.009 in the atom. How does that fit in? It's another 00:03:44.009 --> 00:03:46.150 way to look at it, focusing on the forces at 00:03:46.150 --> 00:03:48.620 play within the atom. You've got the electron, 00:03:49.199 --> 00:03:51.159 negatively charged, being pulled towards the 00:03:51.159 --> 00:03:53.719 positively charged nucleus by the electromagnetic 00:03:53.719 --> 00:03:57.039 force. But the electron is also moving, so it 00:03:57.039 --> 00:03:59.479 has kinetic energy, and that tends to keep it 00:03:59.479 --> 00:04:02.819 moving away. In a stable atom, these two forces 00:04:02.819 --> 00:04:05.439 are balanced. What's interesting is that the 00:04:05.439 --> 00:04:08.080 electron's total energy, if you add up its kinetic 00:04:08.080 --> 00:04:10.740 and potential energy, is actually negative. That 00:04:10.740 --> 00:04:12.340 negative energy means it's bound to the nucleus 00:04:12.340 --> 00:04:15.039 you'd need to add energy to rip it away. Right. 00:04:15.039 --> 00:04:17.339 So it's like the electron is trapped by the nucleus. 00:04:17.420 --> 00:04:19.560 So even without the wave stuff, it can't just 00:04:19.560 --> 00:04:21.920 crash into the center because of this balance 00:04:21.920 --> 00:04:24.519 of forces. The article mentioned something about 00:04:24.519 --> 00:04:26.600 quantum mechanics keeping it perpetually stuck 00:04:26.600 --> 00:04:29.180 in orbit, even in this model. What's that all 00:04:29.180 --> 00:04:32.240 about? Even in this energy picture, quantum mechanics 00:04:32.240 --> 00:04:35.240 is still crucial. It says the electron can't 00:04:35.240 --> 00:04:37.699 just lose energy gradually, like a ball slowing 00:04:37.699 --> 00:04:40.720 down. It can only exist at those specific energy 00:04:40.720 --> 00:04:43.000 levels we talked about, those quantized levels. 00:04:43.540 --> 00:04:46.149 So As the electron is pulled toward the nucleus, 00:04:46.649 --> 00:04:48.970 it hits that lowest energy level, the ground 00:04:48.970 --> 00:04:51.870 state. And it can't go any lower without breaking 00:04:51.870 --> 00:04:54.069 the rules of quantum mechanics. It's like there's 00:04:54.069 --> 00:04:56.810 no basement below the ground floor. To get closer 00:04:56.810 --> 00:04:58.889 to the nucleus, it would need even less energy, 00:04:59.209 --> 00:05:01.990 which is simply not allowed. Wow, that's deep. 00:05:02.350 --> 00:05:04.050 OK, let's switch gears for a sec. Another question 00:05:04.050 --> 00:05:06.089 was about the very beginning, like how did the 00:05:06.089 --> 00:05:08.550 first atom even form in the early universe? I 00:05:08.550 --> 00:05:10.410 think the article mentioned some crazy numbers 00:05:10.410 --> 00:05:12.350 about how many atoms there are out there. It 00:05:12.350 --> 00:05:14.649 did. The observable universe, just the part we 00:05:14.649 --> 00:05:17.730 can see, has something like 10 quadrillion vigintillion 00:05:17.730 --> 00:05:20.050 atoms. That's the one with 78 zeros after it. 00:05:20.589 --> 00:05:23.110 And every single one of those tiny atoms made 00:05:23.110 --> 00:05:25.509 even tinier electrons, protons, and neutrons 00:05:25.509 --> 00:05:27.689 all came from the Big Bang, the big explosion 00:05:27.689 --> 00:05:30.089 that started it all. But getting from that to 00:05:30.089 --> 00:05:32.970 the first atom, well, it was a long, complicated 00:05:32.970 --> 00:05:35.540 process. Right. And the article mentions that 00:05:35.540 --> 00:05:37.800 we can't even quite picture the very, very beginning, 00:05:37.879 --> 00:05:40.300 something about t equals zero and the Planck 00:05:40.300 --> 00:05:43.959 time. What's the problem there? Our current understanding 00:05:43.959 --> 00:05:46.379 of the universe, like our best model, it works 00:05:46.379 --> 00:05:48.819 really well up to a tiny fraction of a second 00:05:48.819 --> 00:05:51.800 after the Big Bang. But if we try to go all the 00:05:51.800 --> 00:05:54.399 way back to t zero, we hit a wall. It's called 00:05:54.399 --> 00:05:57.100 a singularity, a point of infinite density and 00:05:57.100 --> 00:05:59.220 temperature, and our physics just breaks down 00:05:59.220 --> 00:06:01.639 there. We can only go back as far as one plank 00:06:01.639 --> 00:06:04.139 time, which is about 10 to the power of negative 00:06:04.139 --> 00:06:07.720 43 seconds after the Big Bang. Before that, the 00:06:07.720 --> 00:06:10.579 universe was so extreme we need new physics to 00:06:10.579 --> 00:06:12.540 understand it, something that combines gravity 00:06:12.540 --> 00:06:14.540 and quantum mechanics, which we don't have yet. 00:06:14.600 --> 00:06:16.819 So before that tiny fraction of a second, it's 00:06:16.819 --> 00:06:19.819 basically a mystery, a big unknown. But the article 00:06:19.819 --> 00:06:22.199 talks about the Planck epoch itself and this 00:06:22.199 --> 00:06:24.379 idea that all the forces in the universe were 00:06:24.379 --> 00:06:27.459 unified during that time. Right. During that 00:06:27.459 --> 00:06:30.019 super short Planck epoch, from the very beginning 00:06:30.019 --> 00:06:33.079 up to about 10 to the negative 43 seconds, it's 00:06:33.079 --> 00:06:35.959 thought that all four fundamental forces, gravity, 00:06:36.379 --> 00:06:39.079 electromagnetism, the weak force and the strong 00:06:39.079 --> 00:06:41.860 force, were all combined into one super force. 00:06:42.139 --> 00:06:45.519 The universe was so hot and dense, these forces 00:06:45.519 --> 00:06:48.839 were all essentially the same. Then comes inflation, 00:06:49.500 --> 00:06:52.300 this period of crazy fast expansion, like faster 00:06:52.300 --> 00:06:54.839 than light even. Yeah, after the Plank epoch. 00:06:54.970 --> 00:06:58.290 From about 10 to the negative 36 to 10 to the 00:06:58.290 --> 00:07:01.209 negative 33 seconds after the Big Bang, the universe 00:07:01.209 --> 00:07:03.050 went through this insane growth spurt called 00:07:03.050 --> 00:07:05.709 cosmic inflation. And yet, during that tiny sliver 00:07:05.709 --> 00:07:07.750 of time, it expanded way faster than the speed 00:07:07.750 --> 00:07:09.750 of light. But it's important to remember, it 00:07:09.750 --> 00:07:11.790 wasn't stuff moving faster than light through 00:07:11.790 --> 00:07:14.899 space. It was space itself expanding. which is 00:07:14.899 --> 00:07:17.040 allowed by Einstein's theory of relativity. Right, 00:07:17.199 --> 00:07:18.980 that's a key distinction. Okay, so we've got 00:07:18.980 --> 00:07:21.839 inflation, and then our standard model of cosmology 00:07:21.839 --> 00:07:24.019 starts to work pretty well around 10 to the negative 00:07:24.019 --> 00:07:26.579 12 seconds. What happens between then and the 00:07:26.579 --> 00:07:28.860 formation of the first atoms? Okay, so after 00:07:28.860 --> 00:07:31.060 inflation, the universe is still hot and dense, 00:07:31.699 --> 00:07:34.560 but it's cooling down and expanding. We get to 00:07:34.560 --> 00:07:37.180 the quark epoch, around 10 to the negative 11 00:07:37.180 --> 00:07:39.829 seconds after the Big Bang. That's when the electromagnetic 00:07:39.829 --> 00:07:42.370 and weak forces become distinct, and the Higgs 00:07:42.370 --> 00:07:46.029 field pops up, giving particles mass. So the 00:07:46.029 --> 00:07:48.370 building blocks for atoms, quarks, and electrons 00:07:48.370 --> 00:07:51.230 are there, but it's way too hot for them to combine. 00:07:51.910 --> 00:07:53.350 They give it like having all the Lego pieces, 00:07:53.370 --> 00:07:54.910 but they can't snap together because they're 00:07:54.910 --> 00:07:57.310 shaking too much. So all the ingredients are 00:07:57.310 --> 00:07:58.850 there, they're just not coming together yet. 00:07:59.129 --> 00:08:01.689 What happens next as things cool down more? As 00:08:01.689 --> 00:08:03.910 the universe cools, we enter the Hadronibbock, 00:08:04.149 --> 00:08:06.189 around 10 to the negative 5 seconds after the 00:08:06.189 --> 00:08:09.509 Big Bang. The quark soup cools down enough for 00:08:09.509 --> 00:08:11.810 quarks to finally bind together, thanks to the 00:08:11.810 --> 00:08:14.529 strong force, and form hadrons, things like protons 00:08:14.529 --> 00:08:17.529 and neutrons. Now it's a trillion degrees Kelvin, 00:08:17.769 --> 00:08:19.889 still crazy hot, but at least we've got the pieces 00:08:19.889 --> 00:08:23.529 for atomic nuclei. Then, around one second after 00:08:23.529 --> 00:08:26.430 the Big Bang, we have the leptin epoch. Most 00:08:26.430 --> 00:08:28.790 matter and antimatter particles annihilate each 00:08:28.790 --> 00:08:30.410 other, leaving a little bit of regular matter 00:08:30.410 --> 00:08:33.649 behind. And that leftover matter, protons, neutrons, 00:08:33.889 --> 00:08:36.149 electrons, is what will eventually form all the 00:08:36.149 --> 00:08:38.549 atoms. But why there's more matter than antimatter? 00:08:38.889 --> 00:08:41.330 That's a whole other mystery. So now we have 00:08:41.330 --> 00:08:43.490 protons and neutrons, the building blocks of 00:08:43.490 --> 00:08:45.470 atomic nuclei. When do those actually start to 00:08:45.470 --> 00:08:47.929 form? That's Big Bang Nucleosynthesis, which 00:08:47.929 --> 00:08:50.409 happens a few minutes after the Big Bang. Protons 00:08:50.409 --> 00:08:52.909 and neutrons start fusing together, forming the 00:08:52.909 --> 00:08:55.529 nuclei of the lightest elements. Mostly hydrogen, 00:08:55.850 --> 00:08:58.629 just single protons, and helium -4, which has 00:08:58.629 --> 00:09:00.950 two protons and two neutrons. There are tiny 00:09:00.950 --> 00:09:02.850 bits of other stuff like deuterium and helium 00:09:02.850 --> 00:09:05.610 -3, but those are much rarer. But remember, at 00:09:05.610 --> 00:09:08.289 this point, it's just nuclei, no electrons attached 00:09:08.289 --> 00:09:11.490 yet. It's all still a hot, ionized plasma. Right. 00:09:11.529 --> 00:09:15.049 So the universe is this hot, opaque soup of charged 00:09:15.049 --> 00:09:17.889 particles. What changes that? That's the photon 00:09:17.889 --> 00:09:20.879 epoch. which lasts for about 380 ,000 years. 00:09:21.600 --> 00:09:23.240 The universe is like a thick fog because light 00:09:23.240 --> 00:09:25.279 can't travel very far without bumping into all 00:09:25.279 --> 00:09:28.059 these charged particles. Finally, around 3000 00:09:28.059 --> 00:09:30.419 Kelvin, the electrons are slow enough to be captured 00:09:30.419 --> 00:09:33.179 by those nuclei forming neutral atoms. That's 00:09:33.179 --> 00:09:35.179 recombination. And it's a big deal because it 00:09:35.179 --> 00:09:37.139 makes the universe transparent. That's when the 00:09:37.139 --> 00:09:39.320 universe first became transparent, right? That's 00:09:39.320 --> 00:09:41.279 when the cosmic microwave background radiation 00:09:41.279 --> 00:09:43.779 was released, that first light from the early 00:09:43.779 --> 00:09:47.169 universe that we can still see today. Wow, what 00:09:47.169 --> 00:09:49.629 a journey from that unimaginable beginning to 00:09:49.629 --> 00:09:52.210 the first atoms. Yeah, it's mind -blowing to 00:09:52.210 --> 00:09:54.070 think about the sheer scale of time and energy 00:09:54.070 --> 00:09:57.090 involved. And the whole process from the Big 00:09:57.090 --> 00:10:00.789 Bang to atoms, it highlights how complex even 00:10:00.789 --> 00:10:03.950 the simplest things really are. Alright, let's 00:10:03.950 --> 00:10:05.710 shift gears again and talk about something that 00:10:05.710 --> 00:10:08.600 seems simple but is actually... pretty weird 00:10:08.600 --> 00:10:11.679 when you think about it. Do atoms ever really 00:10:11.679 --> 00:10:13.840 touch each other? Like when I put my hand on 00:10:13.840 --> 00:10:16.200 a table, what's going on at the atomic level? 00:10:16.360 --> 00:10:18.759 That's a great question. We think of touching 00:10:18.759 --> 00:10:21.889 as straightforward, right? But at the atomic 00:10:21.889 --> 00:10:24.370 level, it's way more complicated. Atoms don't 00:10:24.370 --> 00:10:27.450 really have hard surfaces, like we imagine. They're 00:10:27.450 --> 00:10:30.110 more like fuzzy clouds of probability, constantly 00:10:30.110 --> 00:10:31.970 moving and interacting with each other. Yeah. 00:10:31.990 --> 00:10:34.269 The article talked about the nucleus being tiny 00:10:34.269 --> 00:10:37.190 and electrons existing in these probability clouds 00:10:37.190 --> 00:10:39.570 that could technically extend forever, even though 00:10:39.570 --> 00:10:41.230 they're most likely to be found close to the 00:10:41.230 --> 00:10:43.429 nucleus. So it's not like two billiard balls 00:10:43.429 --> 00:10:46.710 clinking together. Exactly. Quantum mechanics 00:10:46.710 --> 00:10:49.090 tells us we can't pinpoint exactly where an electron 00:10:49.090 --> 00:10:52.009 is. Probability of finding it in a certain region 00:10:52.009 --> 00:10:54.570 and those probability clouds don't have sharp 00:10:54.570 --> 00:10:57.710 edges They just fade out so in a quantum sense. 00:10:57.970 --> 00:11:00.450 There's not really a defined surface for an atom 00:11:00.450 --> 00:11:03.350 to touch Okay, so if atoms aren't really touching 00:11:03.350 --> 00:11:06.049 in a solid way What's happening when I push on 00:11:06.049 --> 00:11:08.889 a wall and feel that solidity what you feel is 00:11:08.889 --> 00:11:10.909 solidity is actually the electromagnetic force 00:11:10.909 --> 00:11:14.269 at work? As atoms get close, their electron clouds 00:11:14.269 --> 00:11:17.149 start to overlap. And because of the Pauli exclusion 00:11:17.149 --> 00:11:19.389 principle, which is a fundamental rule in quantum 00:11:19.389 --> 00:11:22.370 mechanics, no two electrons can be in the exact 00:11:22.370 --> 00:11:25.649 same state. So as the clouds get closer, the 00:11:25.649 --> 00:11:27.610 electrons have to shift to higher energy states 00:11:27.610 --> 00:11:30.309 to avoid being in the same state. And that takes 00:11:30.309 --> 00:11:33.029 energy, is why you feel resistance to solidity. 00:11:33.070 --> 00:11:35.289 So it's the repulsion between electron clouds 00:11:35.289 --> 00:11:37.580 that makes things feel solid. And the article 00:11:37.580 --> 00:11:39.580 also mentions van der Waals forces, which are 00:11:39.580 --> 00:11:42.200 like a weak attraction between atoms. How do 00:11:42.200 --> 00:11:44.669 those play into touching? Van der Waals forces 00:11:44.669 --> 00:11:47.110 are another example of the electromagnetic force, 00:11:47.190 --> 00:11:49.769 but it's a more subtle effect. They come from 00:11:49.769 --> 00:11:52.370 temporary fluctuations in the electron clouds, 00:11:52.649 --> 00:11:55.190 creating these tiny fleeting dipoles that attract 00:11:55.190 --> 00:11:57.590 each other. They're weaker than the forces that 00:11:57.590 --> 00:11:59.870 hold atoms together in molecules, but they're 00:11:59.870 --> 00:12:02.230 still important, like for how geckos stick to 00:12:02.230 --> 00:12:04.909 walls. So it's not really touching in the usual 00:12:04.909 --> 00:12:07.210 sense, but it is atoms getting close enough to 00:12:07.210 --> 00:12:09.509 feel each other's electromagnetic fields. What 00:12:09.509 --> 00:12:12.490 about the nuclei, the tiny centers of atoms? 00:12:12.940 --> 00:12:16.440 ever touch. Nuclei touching is very rare because 00:12:16.440 --> 00:12:18.919 they're all positively charged so they repel 00:12:18.919 --> 00:12:21.340 each other strongly but there's this quantum 00:12:21.340 --> 00:12:23.720 thing called tunneling where particles can sometimes 00:12:23.720 --> 00:12:26.000 pass through barriers even if they don't have 00:12:26.000 --> 00:12:28.679 enough energy to do so classically. This is how 00:12:28.679 --> 00:12:31.980 nuclear fusion happens where two nuclei get close 00:12:31.980 --> 00:12:34.879 enough to overcome the repulsion and fuse together 00:12:34.879 --> 00:12:37.879 releasing a lot of energy like in stars. So in 00:12:37.879 --> 00:12:39.799 a way you could say that's a form of nuclear 00:12:39.799 --> 00:12:41.480 touching but it's not something that happens 00:12:41.480 --> 00:12:44.070 easily. So, touching at the atomic level, it's 00:12:44.070 --> 00:12:46.649 not what we think. It's a dance of electromagnetic 00:12:46.649 --> 00:12:49.970 forces, quantum mechanics, and it's what gives 00:12:49.970 --> 00:12:52.870 us the world we experience. Absolutely, and understanding 00:12:52.870 --> 00:12:55.850 those forces and rules at the atomic level, it 00:12:55.850 --> 00:12:58.450 explains so much about the world around us. Okay, 00:12:58.509 --> 00:13:00.389 here's another question that seems basic but 00:13:00.389 --> 00:13:02.990 is actually pretty interesting. Are two atoms 00:13:02.990 --> 00:13:05.750 of the same element really identical? Like, is 00:13:05.750 --> 00:13:08.330 a carbon atom just a carbon atom no matter what? 00:13:08.549 --> 00:13:11.289 Not necessarily. Even if they have the same number 00:13:11.289 --> 00:13:13.549 of protons, which defines the element, there 00:13:13.549 --> 00:13:15.870 are still ways they can be different. Their electrons 00:13:15.870 --> 00:13:17.730 can be in different energy states, for example. 00:13:18.230 --> 00:13:21.330 Think of a neon sign. The light comes from electrons 00:13:21.330 --> 00:13:23.789 in excited states falling back to lower energy 00:13:23.789 --> 00:13:26.809 levels. But not all neon atoms in the sign are 00:13:26.809 --> 00:13:28.990 excited at the same time, so they're not identical 00:13:28.990 --> 00:13:31.129 in that sense. So even if they have the same 00:13:31.129 --> 00:13:33.250 number of protons and electrons, their energy 00:13:33.250 --> 00:13:35.740 states can be different. What else? Even if they 00:13:35.740 --> 00:13:37.620 have the same electron configuration, they might 00:13:37.620 --> 00:13:40.320 be moving at different speeds. Like in a solid, 00:13:40.440 --> 00:13:42.679 the atoms are kind of vibrating in place, while 00:13:42.679 --> 00:13:44.980 in a gas, they're zipping around much faster. 00:13:45.519 --> 00:13:48.139 So their motion can be different, even if they're 00:13:48.139 --> 00:13:50.759 the same element. OK, so energy states and motion 00:13:50.759 --> 00:13:53.039 can make them different. But what if they're 00:13:53.039 --> 00:13:55.960 both at rest and have the same electron configuration? 00:13:56.460 --> 00:13:59.039 Are they identical, then? The article mentioned 00:13:59.039 --> 00:14:01.340 isotopes, so maybe that's relevant. Isotopes 00:14:01.340 --> 00:14:04.120 are definitely important. Even if two atoms have 00:14:04.120 --> 00:14:06.639 the same number of protons and electrons, they 00:14:06.639 --> 00:14:08.820 can have different numbers of neutrons in the 00:14:08.820 --> 00:14:11.139 nucleus, which makes them isotopes of the same 00:14:11.139 --> 00:14:14.059 element. And while isotopes have similar chemical 00:14:14.059 --> 00:14:16.600 properties, their masses are different, and they 00:14:16.600 --> 00:14:18.779 can behave very differently in nuclear reactions. 00:14:19.179 --> 00:14:21.539 Carbon -14 dating, for example, relies on the 00:14:21.539 --> 00:14:24.559 fact that carbon -14 is radioactive while carbon 00:14:24.559 --> 00:14:27.679 -12 is stable. So same element, same electron 00:14:27.679 --> 00:14:30.120 configuration, same motion, but different isotopes 00:14:30.120 --> 00:14:33.220 still not truly identical. Anything else? Believe 00:14:33.220 --> 00:14:36.120 it or not, there's even more. Just like electrons, 00:14:36.419 --> 00:14:38.779 protons, and neutrons in the nucleus can also 00:14:38.779 --> 00:14:41.659 be in different excited states. and the nucleus 00:14:41.659 --> 00:14:43.899 itself can have different properties like spin. 00:14:44.320 --> 00:14:46.539 So even if you had two atoms with the same number 00:14:46.539 --> 00:14:48.799 of protons and neutrons and the same electron 00:14:48.799 --> 00:14:51.500 configuration, their nuclei could still be slightly 00:14:51.500 --> 00:14:53.950 different. So it's really, really hard to find 00:14:53.950 --> 00:14:56.169 two atoms that are exactly the same in every 00:14:56.169 --> 00:14:58.710 way. The article even said that proving two atoms 00:14:58.710 --> 00:15:01.149 are identical, like down to the quantum level, 00:15:01.250 --> 00:15:04.389 could win you a Nobel Prize. Yeah. Quantum mechanics 00:15:04.389 --> 00:15:06.970 says that if two atoms have all the same properties, 00:15:07.129 --> 00:15:09.769 they're indistinguishable. But in reality, there 00:15:09.769 --> 00:15:12.330 are so many possible states for an atom that 00:15:12.330 --> 00:15:15.190 it's almost impossible to find two that are perfectly 00:15:15.190 --> 00:15:17.470 identical in practice. OK, let's move on to something 00:15:17.470 --> 00:15:20.529 a bit more visual. Does an atom have a color? 00:15:20.789 --> 00:15:22.850 Like if everything is made of atoms, do those 00:15:22.850 --> 00:15:25.110 atoms themselves have colors? That's a great 00:15:25.110 --> 00:15:27.750 question. We see colors everywhere, and it's 00:15:27.750 --> 00:15:29.610 natural to think those colors might come from 00:15:29.610 --> 00:15:32.570 the atoms themselves. But color, as we see it, 00:15:32.629 --> 00:15:35.549 is actually a creation of our brains, not an 00:15:35.549 --> 00:15:38.110 inherent property of atoms. It's all about how 00:15:38.110 --> 00:15:41.049 our eyes detect and interpret different wavelengths 00:15:41.049 --> 00:15:43.909 of light. Right. Color is about how we perceive 00:15:43.909 --> 00:15:46.009 light. So to understand atomic color, we need 00:15:46.009 --> 00:15:48.730 to understand light itself, right? Exactly. Light 00:15:48.730 --> 00:15:51.190 is a form of electromagnetic radiation that travels 00:15:51.190 --> 00:15:53.629 in these tiny packets of energy called photons, 00:15:54.029 --> 00:15:56.629 which also act like waves. The electromagnetic 00:15:56.629 --> 00:15:59.309 spectrum is huge, from radio waves to gamma rays, 00:15:59.850 --> 00:16:02.049 but our eyes can only see a tiny part of it, 00:16:02.250 --> 00:16:04.519 the visible light spectrum. That's why we see 00:16:04.519 --> 00:16:06.860 colors, because different wavelengths of visible 00:16:06.860 --> 00:16:09.379 light correspond to different colors. The article 00:16:09.379 --> 00:16:11.159 even mentioned that our eyes probably evolved 00:16:11.159 --> 00:16:12.700 to see these wavelengths, because that's the 00:16:12.700 --> 00:16:14.240 part of the spectrum that travels well through 00:16:14.240 --> 00:16:16.960 water where life first began. That's fascinating. 00:16:17.240 --> 00:16:19.460 So how does light interact with atoms to create 00:16:19.460 --> 00:16:22.460 the colors we see in objects, like a blue shirt? 00:16:22.720 --> 00:16:25.019 When light hits an object, the atoms in that 00:16:25.019 --> 00:16:27.120 object can absorb some of the light's energy. 00:16:27.480 --> 00:16:29.799 That absorbed energy can bump electrons in the 00:16:29.799 --> 00:16:32.460 atoms up to higher energy levels. They can also 00:16:32.460 --> 00:16:34.409 re -emit light. either at the same wavelength 00:16:34.409 --> 00:16:37.710 or a different one. The color we see is the light 00:16:37.710 --> 00:16:40.350 that's reflected back to our eyes. So a blue 00:16:40.350 --> 00:16:42.690 shirt looks blue because it absorbs most colors 00:16:42.690 --> 00:16:45.370 except blue, which it reflects. And the way light 00:16:45.370 --> 00:16:47.529 interacts with an object also depends on the 00:16:47.529 --> 00:16:49.629 arrangement of the atoms, which is why snow and 00:16:49.629 --> 00:16:51.450 ice look different even though they're both water. 00:16:51.769 --> 00:16:54.509 So for big objects, color comes from the collective 00:16:54.509 --> 00:16:57.450 behavior of a ton of atoms interacting with light. 00:16:57.759 --> 00:17:00.379 But what about a single atom? Can it reflect 00:17:00.379 --> 00:17:03.000 light and have a color on its own? That's where 00:17:03.000 --> 00:17:05.660 it gets tricky. Atoms are much, much smaller 00:17:05.660 --> 00:17:08.539 than the wavelengths of visible light. So a single 00:17:08.539 --> 00:17:10.720 atom can't really reflect light in the way a 00:17:10.720 --> 00:17:12.779 big object does. It's like trying to reflect 00:17:12.779 --> 00:17:15.839 a huge ocean wave off a tiny grain of sand. It 00:17:15.839 --> 00:17:18.519 just doesn't work that way. OK, so no reflection. 00:17:18.859 --> 00:17:21.500 But what about other ways atoms emit light, like 00:17:21.500 --> 00:17:24.079 thermal radiation or the light from a neon sign? 00:17:24.420 --> 00:17:26.539 Can that be considered an atom's color? Well, 00:17:26.559 --> 00:17:28.720 with thermal radiation, like the glow from a 00:17:28.720 --> 00:17:31.380 hot object, the light emitted is a continuous 00:17:31.380 --> 00:17:33.880 spectrum, meaning it'd have all the colors. The 00:17:33.880 --> 00:17:35.740 overall color depends on the object's temperature, 00:17:35.940 --> 00:17:38.819 not the specific atoms. But with gas discharges, 00:17:38.960 --> 00:17:41.559 like in a neon sign, you do get specific colors. 00:17:42.099 --> 00:17:44.500 The electric current excites the atoms, and as 00:17:44.500 --> 00:17:47.079 their electrons jump between energy levels, they 00:17:47.079 --> 00:17:49.839 emit light at very specific wavelengths, which 00:17:49.839 --> 00:17:52.960 correspond to specific colors. Each element has 00:17:52.960 --> 00:17:55.420 its own unique set of these emission lines, kind 00:17:55.420 --> 00:17:57.599 of like a fingerprint. So in a way, you could 00:17:57.599 --> 00:18:00.140 say that's the atom's color, but only when it's 00:18:00.140 --> 00:18:02.819 excited by something like electricity. So while 00:18:02.819 --> 00:18:05.640 a single atom can't really reflect a color, each 00:18:05.640 --> 00:18:08.079 element does have a unique way of emitting light, 00:18:08.299 --> 00:18:11.119 a specific set of wavelengths that act like a 00:18:11.119 --> 00:18:13.140 color fingerprint. Yeah, that's a good way to 00:18:13.140 --> 00:18:15.299 put it. It's a different kind of color than what 00:18:15.299 --> 00:18:17.240 we see in everyday objects, but it's still a 00:18:17.240 --> 00:18:19.779 way that atoms interact with light and emit specific 00:18:19.779 --> 00:18:22.259 colors. Alright, let's dive into the nucleus, 00:18:22.539 --> 00:18:24.500 the heart of the atom. We know it's packed with 00:18:24.500 --> 00:18:27.220 protons, all positively charged, and those charges 00:18:27.220 --> 00:18:29.799 should repel each other, so why doesn't the nucleus 00:18:29.799 --> 00:18:32.099 just fly apart? You're right, the repulsion between 00:18:32.099 --> 00:18:35.059 those protons is strong. incredibly strong at 00:18:35.059 --> 00:18:37.700 those tiny distances. But the nucleus is held 00:18:37.700 --> 00:18:40.259 together by another force, even stronger than 00:18:40.259 --> 00:18:42.880 the electromagnetic force, the strong nuclear 00:18:42.880 --> 00:18:44.960 force. The strong nuclear force. That must be 00:18:44.960 --> 00:18:47.339 pretty intense to overcome all that repulsion. 00:18:47.440 --> 00:18:49.880 It is. At the super short distances within the 00:18:49.880 --> 00:18:52.380 nucleus, it's about 100 times stronger than the 00:18:52.380 --> 00:18:54.839 electromagnetic force. Yeah. But it's also very 00:18:54.839 --> 00:18:57.500 short range. It basically only works inside the 00:18:57.500 --> 00:18:59.769 nucleus. Understanding this force is where things 00:18:59.769 --> 00:19:01.710 get really complicated and that's where quantum 00:19:01.710 --> 00:19:04.930 chromodynamics or QCD comes in. Quantum chromodynamics, 00:19:04.950 --> 00:19:06.750 that sounds heavy. What does it tell us about 00:19:06.750 --> 00:19:09.589 the strong force? Well QCD tells us that protons 00:19:09.589 --> 00:19:11.809 and neutrons aren't actually the most fundamental 00:19:11.809 --> 00:19:14.390 particles. They're made up of even smaller particles 00:19:14.390 --> 00:19:16.549 called quarks, which are held together by other 00:19:16.549 --> 00:19:19.490 particles called gluons. And gluons carry this 00:19:19.490 --> 00:19:22.170 thing called color charge, which is kind of like 00:19:22.170 --> 00:19:24.410 electric charge but totally different. And the 00:19:24.410 --> 00:19:27.150 strong force is all about how these color charges 00:19:27.150 --> 00:19:30.230 interact through the gluons. There's also this 00:19:30.230 --> 00:19:32.650 thing called color confinement, which means that 00:19:32.650 --> 00:19:35.170 you can't have a free quark or gluon by itself. 00:19:35.450 --> 00:19:37.329 They're always bound together in groups, like 00:19:37.329 --> 00:19:39.789 the three quarks that make up a proton or neutron. 00:19:40.089 --> 00:19:42.230 So gluons are like the glue holding the quarks 00:19:42.230 --> 00:19:44.910 together inside protons and neutrons. But how 00:19:44.910 --> 00:19:46.829 does that explain the attraction between protons 00:19:46.829 --> 00:19:49.529 and neutrons in the nucleus? The force between 00:19:49.390 --> 00:19:52.009 quarks is the strongest. But there's a residual 00:19:52.009 --> 00:19:54.250 effect that acts between the protons and neutrons 00:19:54.250 --> 00:19:57.450 themselves. It's mediated by particles called 00:19:57.450 --> 00:20:00.450 mesons. And even though this residual strong 00:20:00.450 --> 00:20:02.809 force is weaker than the force between quarks, 00:20:03.269 --> 00:20:05.369 it's still stronger than the electromagnetic 00:20:05.369 --> 00:20:08.210 repulsion between protons at those very short 00:20:08.210 --> 00:20:11.009 distances. Think of it like this. The strong 00:20:11.009 --> 00:20:13.589 force is like super strong glue that works only 00:20:13.589 --> 00:20:15.930 up close, and it's strong enough to hold the 00:20:15.930 --> 00:20:18.440 nucleus together despite the electrical repulsion 00:20:18.440 --> 00:20:20.660 trying to push it apart. So it's a tug of war 00:20:20.660 --> 00:20:23.279 between these forces, and thankfully the strong 00:20:23.279 --> 00:20:26.400 force wins, otherwise atoms wouldn't exist. Exactly. 00:20:26.880 --> 00:20:28.819 And it's this delicate balance that gives us 00:20:28.819 --> 00:20:30.880 the diversity of elements we see in the universe. 00:20:31.279 --> 00:20:33.599 This next question is a big one. How big is a 00:20:33.599 --> 00:20:35.660 proton? I mean, they're the building blocks of 00:20:35.660 --> 00:20:38.039 atoms, but how small are they really? Yeah, figuring 00:20:38.039 --> 00:20:40.240 out the size of a proton is actually a lot harder 00:20:40.240 --> 00:20:42.180 than you might think. You can't just, like, put 00:20:42.180 --> 00:20:44.980 it under a microscope. Protons aren't solid balls. 00:20:45.099 --> 00:20:47.700 They're more like fuzzy clouds of quarks and 00:20:47.700 --> 00:20:50.920 gluons. And the way we measure their size is 00:20:50.920 --> 00:20:52.940 by looking at how other particles, like electrons, 00:20:53.519 --> 00:20:55.599 scatter off them. So it's like trying to figure 00:20:55.599 --> 00:20:57.359 out the shape of something by throwing things 00:20:57.359 --> 00:20:59.259 at it and seeing how they bounce off. Pretty 00:20:59.259 --> 00:21:01.660 much. For a long time, everyone agreed that a 00:21:01.660 --> 00:21:05.180 proton was about 0 .8768 fentometers across, 00:21:05.319 --> 00:21:08.140 which is incredibly tiny. A fentometer is one 00:21:08.140 --> 00:21:11.339 quadrillionth of a meter. But then, in 2010, 00:21:11.940 --> 00:21:14.519 an experiment using muons instead of electrons 00:21:14.519 --> 00:21:17.759 found a smaller value. Muons are much heavier 00:21:17.759 --> 00:21:20.079 than electrons, so they get closer to the proton 00:21:20.079 --> 00:21:22.799 and give a more precise measurement. And this 00:21:22.799 --> 00:21:25.339 discrepancy, well, it caused a big stir in the 00:21:25.339 --> 00:21:27.240 physics world. Some people thought it meant there 00:21:27.240 --> 00:21:29.740 was new physics we didn't understand. So a tiny 00:21:29.740 --> 00:21:32.220 difference in measurement created this huge mystery. 00:21:32.640 --> 00:21:35.730 It did. But then, more recent experiments, both 00:21:35.730 --> 00:21:38.390 with muons and electrons, have confirmed that 00:21:38.390 --> 00:21:41.250 smaller value. It turns out it was probably just 00:21:41.250 --> 00:21:43.269 a really, really difficult measurement to get 00:21:43.269 --> 00:21:46.250 right. So as of now, we think the proton is about 00:21:46.250 --> 00:21:50.049 0 .833 femtometers across, which is still mind 00:21:50.049 --> 00:21:53.589 -bogglingly small. But the whole saga highlights 00:21:53.589 --> 00:21:55.869 how challenging it is to measure these fundamental 00:21:55.869 --> 00:21:57.670 properties of the universe. Okay, here's another 00:21:57.670 --> 00:22:00.509 one that seems counterintuitive. If atoms are 00:22:00.509 --> 00:22:03.509 mostly empty space, how can things feel solid? 00:22:03.750 --> 00:22:05.650 I mean, if I'm mostly empty space and this table 00:22:05.650 --> 00:22:07.910 is mostly empty space, why don't I just fall 00:22:07.910 --> 00:22:09.730 right through it? It's a great question, and 00:22:09.730 --> 00:22:11.589 it gets to the heart of how we perceive the world. 00:22:12.509 --> 00:22:14.829 Imagine if we could magically scale up a table 00:22:14.829 --> 00:22:17.910 so its atoms were the size of melons. The table 00:22:17.910 --> 00:22:20.609 would be gigantic, right? But even at that scale, 00:22:20.799 --> 00:22:23.440 Most of it would still be empty space. The nuclei 00:22:23.440 --> 00:22:25.500 would be tiny specks inside those melon -sized 00:22:25.500 --> 00:22:27.559 atoms. And the electrons, while they wouldn't 00:22:27.559 --> 00:22:29.359 be orbiting like planets, they'd be more like 00:22:29.359 --> 00:22:32.140 swarms of bees buzzing around those nuclei. Too 00:22:32.140 --> 00:22:34.319 fast to see individually. OK, so even blown up, 00:22:34.500 --> 00:22:36.799 it's still mostly empty space. But why does it 00:22:36.799 --> 00:22:39.759 feel solid? It all comes back to those electrons 00:22:39.759 --> 00:22:42.839 and the Pauli exclusion principle. Those swarms 00:22:42.839 --> 00:22:46.079 of electrons are all doing their own dance, following 00:22:46.079 --> 00:22:48.779 specific patterns dictated by quantum mechanics. 00:22:49.400 --> 00:22:51.900 And the exclusion principle says that no two 00:22:51.900 --> 00:22:53.960 electrons in an atom can have the same dance 00:22:53.960 --> 00:22:57.059 moves. So when you push on the table, the electrons 00:22:57.059 --> 00:22:59.019 in your hand get close to the electrons in the 00:22:59.019 --> 00:23:01.019 table, and they can't just pass through each 00:23:01.019 --> 00:23:03.059 other because of the exclusion principle that 00:23:03.059 --> 00:23:05.359 have to change their dance moves, which requires 00:23:05.359 --> 00:23:09.230 energy. And that energy is what you feel as resistance, 00:23:09.890 --> 00:23:12.170 the solidity of the table. So it's not the empty 00:23:12.170 --> 00:23:14.609 space that matters. It's the way those electrons 00:23:14.609 --> 00:23:17.390 interact that creates the feeling of solidity. 00:23:17.630 --> 00:23:20.430 Exactly. It's the quantum rules governing those 00:23:20.430 --> 00:23:22.849 tiny particles that give rise to the macroscopic 00:23:22.849 --> 00:23:25.329 properties we experience every day. OK, next 00:23:25.329 --> 00:23:28.569 question. Why do atoms even bother forming molecules? 00:23:28.710 --> 00:23:30.289 Like, why don't they just stay as individual 00:23:30.289 --> 00:23:32.930 atoms? That's a great question. It's all about 00:23:32.930 --> 00:23:36.269 energy. as the article likely explained. Atoms, 00:23:36.470 --> 00:23:38.069 like everything else in the universe, tend to 00:23:38.069 --> 00:23:40.690 seek out the lowest energy state, the most stable 00:23:40.690 --> 00:23:43.230 configuration. Think of a ball rolling down a 00:23:43.230 --> 00:23:45.450 hill. It'll naturally settle at the bottom where 00:23:45.450 --> 00:23:47.849 its potential energy is lowest. Atoms are kind 00:23:47.849 --> 00:23:50.529 of the same way. So how does forming molecules 00:23:50.529 --> 00:23:53.190 lower their energy? We'll take the simplest molecule, 00:23:53.549 --> 00:23:57.109 hydrogen gas, H2. When two hydrogen atoms are 00:23:57.109 --> 00:23:59.789 far apart, their total energy is basically the 00:23:59.789 --> 00:24:02.180 sum of their individual energies. But as they 00:24:02.180 --> 00:24:05.099 get closer, their electron clouds start to overlap 00:24:05.099 --> 00:24:07.700 and the electrons can air act with both nuclei. 00:24:08.420 --> 00:24:10.839 This creates a new shared energy state that's 00:24:10.839 --> 00:24:12.720 lower than the energy of the two separate atoms. 00:24:13.299 --> 00:24:15.599 That's a covalent bond where the atoms share 00:24:15.599 --> 00:24:18.059 electrons to achieve a lower energy state. So 00:24:18.059 --> 00:24:20.420 it's like teamwork sharing electrons to be more 00:24:20.420 --> 00:24:23.660 stable. Exactly. And the article likely explained 00:24:23.660 --> 00:24:26.259 how the exact distance between the atoms in a 00:24:26.259 --> 00:24:28.700 molecule is determined by the balance between 00:24:28.700 --> 00:24:31.690 attractive and repulsive forces. If they're too 00:24:31.690 --> 00:24:34.529 close, the nuclei repel each other. If they're 00:24:34.529 --> 00:24:36.809 too far apart, the attraction from the shared 00:24:36.809 --> 00:24:39.970 electrons weakens. There's a sweet spot where 00:24:39.970 --> 00:24:42.450 the total energy is minimized, and that's the 00:24:42.450 --> 00:24:45.269 bond length. And what about more complex molecules, 00:24:45.470 --> 00:24:48.009 like water? For more complex molecules, things 00:24:48.009 --> 00:24:50.509 get more complicated, of course. But the basic 00:24:50.509 --> 00:24:53.349 principle is the same. Atoms bond together to 00:24:53.349 --> 00:24:56.099 achieve a lower energy state. And the specific 00:24:56.099 --> 00:24:58.539 ways they bond are governed by the same quantum 00:24:58.539 --> 00:25:00.759 mechanical rules that determine the behavior 00:25:00.759 --> 00:25:03.400 of electrons. For example, the article likely 00:25:03.400 --> 00:25:05.619 talked about how atoms try to fill their outermost 00:25:05.619 --> 00:25:07.980 electron shells, which makes them more stable, 00:25:08.079 --> 00:25:10.519 like the noble gases. And this desire to have 00:25:10.519 --> 00:25:13.279 a full outer shell is what drives much of chemistry. 00:25:13.700 --> 00:25:15.460 So it's like atoms are playing a game of electron 00:25:15.460 --> 00:25:18.140 musical chairs, trying to grab a seat in a full 00:25:18.140 --> 00:25:20.480 shell by forming bonds with each other. It's 00:25:20.480 --> 00:25:22.640 a good analogy. And the rules of the game are 00:25:22.640 --> 00:25:25.400 set by quantum mechanics. Okay, this next question 00:25:25.400 --> 00:25:29.759 is about something truly extreme. Neutron stars. 00:25:30.380 --> 00:25:33.500 Are they basically just giant atoms? That's an 00:25:33.500 --> 00:25:35.200 interesting way to think about it, and the article 00:25:35.200 --> 00:25:37.619 probably explored the similarities and differences. 00:25:38.079 --> 00:25:40.720 Neutron stars are some of the most extreme objects 00:25:40.720 --> 00:25:43.619 in the universe. They're born when massive stars 00:25:43.619 --> 00:25:46.500 die in these incredibly violent explosions called 00:25:46.500 --> 00:25:49.400 supernovae. I remember reading that they're incredibly 00:25:49.400 --> 00:25:52.259 dense, like a teaspoonful would weigh billions 00:25:52.259 --> 00:25:54.670 of tons. That's right. They're only about 10 00:25:54.670 --> 00:25:57.750 to 20 kilometers across, but they pack more mass 00:25:57.750 --> 00:26:00.549 than our sun into that tiny space. And their 00:26:00.549 --> 00:26:03.049 gravity is so strong that atoms are crushed, 00:26:03.630 --> 00:26:05.869 forcing electrons and protons to combine into 00:26:05.869 --> 00:26:07.710 neutrons. That's why they're called neutron stars. 00:26:07.970 --> 00:26:09.710 They're essentially a giant ball of neutrons. 00:26:09.750 --> 00:26:11.910 So how is that similar to an atom? Well, in an 00:26:11.910 --> 00:26:14.519 atom, you have the nucleus. which is held together 00:26:14.519 --> 00:26:17.119 by the strong force, right? And in a neutron 00:26:17.119 --> 00:26:20.680 star, you have this giant ball of neutrons, also 00:26:20.680 --> 00:26:23.339 held together by the strong force, but it's gravity 00:26:23.339 --> 00:26:25.759 that's providing the pressure to overcome the 00:26:25.759 --> 00:26:28.680 neutron's tendency to repel each other. So in 00:26:28.680 --> 00:26:30.619 a way, you could say that a neutron star is like 00:26:30.619 --> 00:26:33.400 a giant nucleus, but instead of being held together 00:26:33.400 --> 00:26:36.460 by the strong force directly, it's gravity that's 00:26:36.460 --> 00:26:39.440 driving the interaction. So, similar in the sense 00:26:39.440 --> 00:26:41.519 that the strong force is involved, but different 00:26:41.519 --> 00:26:44.160 in scale and in the role of gravity. Exactly. 00:26:44.519 --> 00:26:46.240 And there's a lot we still don't know about neutron 00:26:46.240 --> 00:26:48.500 stars, like what exactly happens in their cores. 00:26:48.900 --> 00:26:50.839 Some scientists think they might be made of even 00:26:50.839 --> 00:26:53.559 more exotic stuff, like a quark -gluon plasma, 00:26:53.839 --> 00:26:55.720 which is what the universe was like in the first 00:26:55.720 --> 00:26:57.779 fraction of a second after the Big Bang. Wow, 00:26:57.779 --> 00:27:00.500 that's wild. So, neutron stars are like a glimpse 00:27:00.500 --> 00:27:02.779 into the extreme conditions that existed in the 00:27:02.779 --> 00:27:05.579 very early universe. Okay, this next question 00:27:05.579 --> 00:27:08.579 is truly mind -boggling. What if the entire universe 00:27:08.579 --> 00:27:10.839 is just an atom? That's a really fun thought 00:27:10.839 --> 00:27:13.339 experiment, and it highlights how much we still 00:27:13.339 --> 00:27:15.859 don't know about the true nature of reality. 00:27:16.680 --> 00:27:19.200 It plays on the idea of scales, like how atoms 00:27:19.200 --> 00:27:21.779 are tiny compared to us, and we're tiny compared 00:27:21.779 --> 00:27:23.559 to planets, and planets are tiny compared to 00:27:23.559 --> 00:27:26.039 stars, and so on. So could the whole universe 00:27:26.039 --> 00:27:28.000 be just a tiny part of something even bigger? 00:27:28.920 --> 00:27:31.539 It's a very old idea, going back to ancient philosophers. 00:27:32.180 --> 00:27:34.380 The article mentions a few theories, like the 00:27:34.380 --> 00:27:36.759 one -electron universe and the multiverse theory. 00:27:36.910 --> 00:27:38.710 Yeah, those are some interesting takes on this 00:27:38.710 --> 00:27:40.990 question. The one -electron universe is this 00:27:40.990 --> 00:27:43.349 wild idea that there's only one electron in the 00:27:43.349 --> 00:27:45.269 whole universe, and it's zipping back and forth 00:27:45.269 --> 00:27:47.990 through time, creating the illusion of all the 00:27:47.990 --> 00:27:50.609 electrons we see. That's wild. And what about 00:27:50.609 --> 00:27:53.269 the multiverse? The multiverse idea suggests 00:27:53.269 --> 00:27:56.150 that there might be many, maybe even an infinite 00:27:56.150 --> 00:27:58.970 number of universes, all existing alongside each 00:27:58.970 --> 00:28:01.630 other. And maybe our universe is just one tiny 00:28:01.630 --> 00:28:05.779 bubble in this grand cosmic foam. And in some 00:28:05.779 --> 00:28:08.160 versions of the multiverse, each universe could 00:28:08.160 --> 00:28:10.920 be like an atom in a larger structure. So it's 00:28:10.920 --> 00:28:13.180 like a never -ending nesting doll of universes. 00:28:13.859 --> 00:28:15.980 Exactly. But it's important to remember that 00:28:15.980 --> 00:28:18.099 these are just theories, ideas that people have 00:28:18.099 --> 00:28:21.220 explored. There's no scientific evidence to support 00:28:21.220 --> 00:28:23.720 them yet, although there are some physicists 00:28:23.720 --> 00:28:26.690 trying to find evidence for the multiverse. It's 00:28:26.690 --> 00:28:28.569 definitely fun to think about, though. Absolutely. 00:28:29.029 --> 00:28:30.930 And these questions about the ultimate nature 00:28:30.930 --> 00:28:33.710 of reality, they push us to think beyond our 00:28:33.710 --> 00:28:36.650 current understanding and to imagine possibilities 00:28:36.650 --> 00:28:39.390 that might seem crazy at first. Alright, let's 00:28:39.390 --> 00:28:41.650 get a bit more personal now. What happens to 00:28:41.650 --> 00:28:44.130 our atoms after we die? Do they just disappear? 00:28:44.470 --> 00:28:47.269 Not at all. One of the fundamental laws of physics 00:28:47.269 --> 00:28:50.950 is the conservation of matter. It basically says 00:28:50.950 --> 00:28:53.529 that matter can't be created or destroyed, only 00:28:53.529 --> 00:28:56.569 transformed. So the atoms that make up your body, 00:28:56.630 --> 00:28:58.990 they've been around for billions of years, cycling 00:28:58.990 --> 00:29:00.849 through the universe, and they'll continue to 00:29:00.849 --> 00:29:03.029 exist long after you're gone. So where do they 00:29:03.029 --> 00:29:05.690 go? Everywhere. They become part of the environment. 00:29:05.730 --> 00:29:07.750 They're taken up by plants and animals. They 00:29:07.750 --> 00:29:11.190 might even end up in space. Think about it. The 00:29:11.190 --> 00:29:13.509 water in your body That's mostly hydrogen and 00:29:13.509 --> 00:29:16.089 oxygen, right? When you die, that water will 00:29:16.089 --> 00:29:18.269 eventually evaporate, become part of the atmosphere, 00:29:18.690 --> 00:29:21.230 maybe fall as rain, be taken up by a plant, and 00:29:21.230 --> 00:29:23.170 eventually end up in someone else's glass of 00:29:23.170 --> 00:29:26.250 water. Or, it could be split apart by sunlight, 00:29:26.529 --> 00:29:29.230 and its hydrogen could escape into space, eventually 00:29:29.230 --> 00:29:32.190 becoming part of a star -forming nebula. That's 00:29:32.190 --> 00:29:34.329 pretty amazing to think that our atoms can be 00:29:34.329 --> 00:29:37.710 part of this vast cosmic cycle. It is. And it's 00:29:37.710 --> 00:29:39.410 not just water, it's everything that makes up 00:29:39.410 --> 00:29:41.910 your body. The carbon, nitrogen, phosphorus, 00:29:42.130 --> 00:29:44.289 calcium, all of it gets recycled and reused in 00:29:44.289 --> 00:29:46.730 countless ways. So even though we die, our atoms 00:29:46.730 --> 00:29:48.910 live on, becoming part of the world around us 00:29:48.910 --> 00:29:51.130 and beyond. Exactly. In a way, we become one 00:29:51.130 --> 00:29:53.190 with the universe, our atoms dispersed across 00:29:53.190 --> 00:29:55.890 space and time. Okay, last question, and it's 00:29:55.890 --> 00:29:59.230 a big one. Do atoms last forever? That's a question 00:29:59.230 --> 00:30:01.230 that has puzzled philosophers and scientists 00:30:01.230 --> 00:30:03.910 for centuries. On the one hand, we know that 00:30:03.910 --> 00:30:06.509 matter is conserved, so atoms don't just disappear. 00:30:06.970 --> 00:30:09.730 But on the other hand, we see things changing 00:30:09.730 --> 00:30:12.630 and decaying all the time. So is anything truly 00:30:12.630 --> 00:30:15.009 eternal. The article talked about radioactive 00:30:15.009 --> 00:30:18.269 decay, where unstable atoms break down over time. 00:30:18.529 --> 00:30:21.430 Right. Some atoms, particularly heavier ones, 00:30:21.769 --> 00:30:23.890 are inherently unstable because they have too 00:30:23.890 --> 00:30:27.390 many or too few neutrons in their nuclei. And 00:30:27.390 --> 00:30:29.930 over time, they undergo radioactive decay, emitting 00:30:29.930 --> 00:30:31.869 particles and energy until they reach a more 00:30:31.869 --> 00:30:34.890 stable configuration. So some atoms are definitely 00:30:34.890 --> 00:30:37.500 not forever. True. And there's even a theory 00:30:37.500 --> 00:30:40.259 that protons, those seemingly stable particles 00:30:40.259 --> 00:30:42.799 in the nucleus, might actually decay over incredibly 00:30:42.799 --> 00:30:45.480 long time scales, like billions of times the 00:30:45.480 --> 00:30:47.619 current age of the universe. If that's true, 00:30:47.880 --> 00:30:48.920 then even the most basic.