Big Bang was this almost uniform but not quite areas which formed these clumps which pulled in more gas and pulled in clumps and more and more and piled on. You get some crazy instability happening and it spits out galaxies but you also said that it spits out some really big stars along the way. Now these something's gonna happen to this stuff. Yes we got this galaxy made up of the very first stars that formed but some of these stars are going to die because as we'll talk about later massive stars have a very short life span and when they die they might explode as a supernova or blow out winds so you've got a picture like this one which is a revenant of a star a fairly massive one that's went bang at some point and so this is the gas or the material that has come from that exploding star now going up into the region of a galaxy. So what you've got is a whole series of stars that come to their end of their lives in various ways squirt gas out and the gas mingles around the galaxy and in this simulation we can actually see this whole process and here's a galaxy which has been simulated by our colleague Mark Trump helps here at ANU and what we're seeing is that it modeled all the different stars at form and some of them die and they squirt out gas and the gas swirls around and eventually coalesces into new gas clouds. So some of these big stars form early on they live as a short time as we'll talk about later explode but then gravity starts to pull it back together again much like what happened with the big bank. Yes so most of the gas doesn't escape from the galaxy the gas has got pretty strong gravity so it holds the gas in so all the gas that comes from these exploding stars mingles with the gas that was already there and maybe even more gas falling in from the big bang. So now you're kind of mixing gas. Yes so as you go closer in you can see a very complicated procedure where gas clouds turn into stars which explode and squirt more gas out and in turn mixes with other gas and swirls around and forms more stars and this whole evolutionary process goes on for billions of years producing the Milky Way galaxy that we see today and indeed you can see some of these gas clouds in space so here we have artist impression of the Milky Way across some random desert landscape and if you look at it most of the white you're seeing here is stars yep but there are these dark channels. And the dark areas you know have long been thought by some people to be the absence of stars but actually people now know and people even historically like Aboriginal people in Australia have noticed that these dark patterns are not necessarily the absence of stuff. That's right they're actually areas where this interstellar dust is blocking the light from background stars so there's background stars behind it and there's dust which is essentially building blocks of new stars blocking the light in front. That's right. Well this is quite an amazing photo Paul I have to say that photographer is probably good who did it. Well thank you very much as I took my very elderly SNR camera behind the Tuskeboard Mount Strommelow. Now the point of this picture is once again we see the Milky Way and the dark clouds going through it dust and gas and these dark clouds which have been made by gas that's been squirted out of stars and swirling in space are some of the most beautiful things in the world of astronomy so let's just luxury eight in some of the pictures here. Well this is what people like I mean people see these photos and they're still breathtaking to us right we still like to look at it. And it's why I got into astronomy with you but yeah this is actually such a critical part of the stellar process right it's actually in these beautiful areas that it's the beginning of a star's life. Yes so if you want to go right back to the beginning of our sun or back to the bank it's going to be in some of these clouds of gas particularly a dense opaque cloud called a giant molecular cloud and we can see a simulation or you see actual examples of giant molecular clouds this is the most famous one this is the Orion Nebula. That's right so famous you name your child on that. That's right but it's also one that you can slightly see with your eyes if you have a small telescope. And very easy with a pair of binoculars. And let zoom in on it so here's a simulation with a NASA put together showing an actual flight into the middle of the Orion Nebula. And what we have here is a giant molecular cloud that formed stars in the middle and some of these stars are very bright. And they've blown a hole in one side and we're about to fly down that one side. In fact stars are still forming here but you can't see them in these images actually forming behind all of dust further back from what we can see what we're actually actually seeing is the edge of the stars and exposed themselves at the front. So it's like the Milky Way where we have those dark dust lanes and the light bits around it but there's actually another layer in front that we're staring at. That's right I used to do a field trip with my astronomy students here and would use the radio telescope at Tid bin Villa and map molecular missionals from the submit find all the cause a little bit off from where the visible light is. So here we're flying down the channel in the middle of these things but actually beneath us in the opaque dust is actually where the real action is going on which can't be seen at visible light wavelengths but can be seen at radio or far and for red wavelengths. And so this is essentially the the the nursery the beginnings the birth of some of these what will be new stars. Yes so this has already formed new stars. We can look at a simulation of our formation of one of these classes. This is a simulation from a few years ago from so we have a kind of a generic molecular cloud. So it gave a roughly spherical molecular cloud and gave it some initial turbulence. If it was perfectly uniform we'll just shrink down to steam but of course these things are very irregular you saw all the picture. That's right they did start as perfect spheres as it was really complicated as you'd imagine given the raw stuff blowing out of supernovae and stars and swirling gas and you can see we now zoom in it shrinks again. This is similar to what happened after the Big Bangman Galaxy's formed it's a gravitational instability only now it's on the scale of a few light years rather than a few million light years. So but it's still the same process you get that gravitational stability it pulls more gas in which is more so it pulls more gas in and you get that clumpiness. That's right. Now the trouble with most simulations of the set is actually they form stars too fast and too effectively they basically turn the entire chart molecular cloud into stars very quickly and we know that doesn't actually happen most chart molecular clouds only do us a small fraction of their mass to stars and most it stays in the form of gas and it takes much longer than the basic theories say. So the basic theories are too efficient at producing stars. What we do see is we get these lumps or proper lids and these actually form a spinning discs which we can see. So what you do is you get a star in the middle and a spinning disc of gas around it and the gas funnels into the middle to form the star and the left over bits of dust and gas will form the planets. So this is an image from Alma the sensitive submilimeter telescope in Chile. That's right. So what we're seeing I guess in this disc is we're seeing that clump at the center from the star and then we're seeing the bits on the outside. It should be forming the planets eventually and we're talking much more about those in the planets course. Here's an artist impression of these things again a lot of the gas has gone to the center forming the sun and it got small amounts around the outside which are forming the planets and comets and asteroids and other things like this. And so it's kind of because of the similar origin that as we talk about later that they all have about the same age in a solar system the stars and the planets are roughly the same age. Yes and they formed it about the same time you got the whole cloud that shrank down formed the spinning disc much like we're talking about for galaxies earlier only much smaller and the middle bit turns into the sun and the outer bits turn into planets. But there is complication here when you look at these things often instead you see the disc but you also see stuff being squirted out in opposite directions like you can see here. That's right I mean these are quite really large-scale jets shooting out of this central spinning stellar industry. I think it looked quite stunning I mean this is like a goya painting or something like this. And what we think is happening is once you're made and it's going on so magnetic fields and turbulence so just like the corona you've got the magnetic fields which are probably trapped in this giant molecular cloud and as it shrinks down you just imagine lots of rubber bands from the roof to the floor of this room and I put my arm around them and start swirling around they get wound up really tight and they go twang speaking technically I'm squirt stuff out in both directions. So as that magnet that magnetism that magnet fields get wound and then they release they squirt out how some material and details are extremely obscure not very well understood because it's magnetic fields and magnet which we've already talked about as being really complicated. But I guess the point here is we see it we can physically see with our telescopes that this is actually happening or something like it. And this is probably one of the two reasons that stops formation being too good. One reason is you get these very bright stars like the ones in the middle here whose radiation blows away the gas. So you have these really bright energetic stars and they kind of blow some gas out so that limits some of this stuff that can turn into stars. But here's our modern simulation of star formation and this one now includes the effect of this radiation blowing gas away and the jets being fired out. Okay so these two processes we've just talked about now budgeted it. Yes so you can see the different things are forming. And so this is a couple million years. Yes this is 2.4 million years and we're going to look at it from the direction and then we're going to zoom in and see what's going to keep on going. And we'll start seeing particular jets these jets being squirted out and that disrupts the gas around a particular area and that's then slows down the star formation because the gas that was going to fall in gets blown away by the jets or by the radiation. And so and that's kind of why these initial simulations were too efficient. They weren't taking that into account. Yes so this is our overall understanding of what's happening here that we start obviously the Big Bang. We hit slight lumps. They collapse the form of galaxies. The stars of the galaxies explode and produce gas. This produces giant molecular clouds. These beautiful dense glass clouds. These intern collapse because of their gravity. They're rather complicated ways. Form these spinning discs of gas. The protoplanetry or proto solar disc. And it's out of this that both the sun and the earth formed.