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1:07:50new celestial discovery, a cosmic gamecher for star formation theories? >> Yeah. So they're claiming, you know, it's been all over the news. They're claiming that this is a new type of object. Okay. It's a compact, gas-rich starless object. And it's a totally different thing in our cosmic zoo. You know, we got galaxies, we got stars, we got planets, and now perhaps a totally different animal altogether. >> Okay. >> Okay. That's very rare >> cuz we we've been staring at the night sky for a while. >> Right. Right. >> So, a new type of object is is quite interesting right? >> Yes. >> That that definition doesn't fit into
1:08:31another bucket. >> Yes. Yes. And what's really important about this new type of object is it's confirming a lot of theories about dark matter that we have. There were some holes in that theory that this is sort of filling and at the same time it's raising some new questions. Okay. >> As almost all new stuff does. Yes. Right. So let's start at the very beginning. We're going to start at the big bang and we're going to start with something called lambda CDM >> in the bening >> there. There it is. Lambda CDM is cold dark matter. That's the prevailing cosmological model that we have for all the stuff that is in our universe. Not a lot of normal matter, a lot of dark matter. So I think 85% of stuff that is
1:09:12gravitationally influenced is dark matter. Only 15% is normal matter. And then we don't have to talk about dark energy which is a whole other thing. You know that's actually even more than dark matter, right? But let's not get into that. Let's just talk about stuff that is influenced by gravity. So in the very beginning there was the big bang. The big bang expanded into it didn't expand into space. Space itself expanded. Let me catch myself when I say that. Right. >> The comments would have gone crazy with that. >> Yeah. Yeah. So, 300,000 years after the Big Bang, we formed atoms. That's when we got our cosmic microwave background. And then we had our first stars, our first galaxies, our first black holes.
1:09:53And through all of this, dark matter was also expanding with all of the berionic matter. That's the ordinary matter, stuff of atoms, quarks, electrons, things like that. And at some point the first stars began collapsing. They started blowing up. The dark the black holes started creating a mess, right? They started creating ultraviolet radiation. And all of this time what was happening was this ultraviolet radiation was heating up the intergalactic medium to a temperature of approximately 10 the 4. So 10,000 Kelvin, 10,000° C. Okay,
1:10:35>> it's pretty cool. Pretty cool. >> Pretty cool. And this was happening around 400 million years after the Big Bang. This is called the reionization epoch because what's happening now is all of the hydrogen that's in our intergalactic medium is getting bathed in this UV radiation. Okay? And this whole time dark matter is just doing its thing. Okay? So all of the hydrogen, which is the berionic matter, is getting bathed in UV radiation. Meanwhile, the UV radiation is not at all interacting with the dark matter. That's the point of dark matter. It does not interact with light, hence it's dark. Okay? So, dark matter has been collapsing this whole time. And when dark matter collapses, it forms clumps. Okay? >> Okay. These are called halos. And the
1:11:17clumps happen at all different scales. If we look out at the dark matter halo function, the mass function that we see see today, that function is something that we call scale free. So instead of the size of the dark matter halos sort of collapsing as an exponential where there's some like fundamental scale constant of that exponential, this thing is a power law which means as we get to smaller and smaller sca like scales of halos, there should be more and more of these dark matter halos. So there should be a halo for the Milky Way that is as big as the Milky Way. And at the center of this dark matter halo is the our normal Milky Way. But then around this Milky Way, there should be a bunch of
1:11:58different tiny clumps. And around those tiny clumps, there should be even smaller clumps. And around those, so on and so forth. It's it's kind of this like self referential fractally system. >> It's like the Russian dolls. >> Yes. Exactly. But the smaller the Russian doll, the more there should be. That's key. >> Okay. >> Okay. >> Yes. Yeah. >> Okay. Interesting. Okay. So, now let's think about what would happen with these halos right? The bigger the halo, there should be galaxies inside, right? We don't actually see all that many halos. >> Mhm. >> That's kind of a problem. Okay. >> Yeah. >> Now, there could be a solution about why
1:12:39we don't see a bunch of small halos. Okay. And that has to do with the nature