The short answer is that when our Sun dies, another Sun won't take its place.
The thing that defines the Sun's life right now is the fact that nuclear fusion is taking place at its core. The gas cloud that originally formed the Sun had enough total mass that it could get hot and high-pressure enough at its core to fuse hydrogen into helium. That's the first level of fusion, transforming the simplest atom in the Universe into the next-simplest, and it's what has to happen in order for a new star to form. While that's happening, there's a nice, steady system that's regulated by gravity trying to pull the Sun's matter closer together on the one hand and the pressure from the energy of fusion trying to push everything apart on the other. When those two forces balance in a star, we call that equilibrium. The Sun is in equilibrium right now, while its core is fusing hydrogen into helium.
The reason the Sun will die is that it will use up all its core hydrogen. After that happens, the equilibrium will be disrupted, and things will start to change. The Sun will go through several phases before it eventually ends up as a carbon-oxygen white dwarf star surrounded by what astronomers call a "planetary nebula" -- a terrible name, as it has nothing whatsoever to do with planets -- but throughout all of it the remaining hydrogen in the outer parts of the Sun will be pushed outward (forming part of the nebula and eventually dispersing completely).
I keep going on about hydrogen because *that* is what you'd need to try and form another Sun where the old one was -- except that the Sun will die because it no longer has enough where it needs to be, and the rest of it in the outer parts will be driven away by the energy of the collapsing core before the core reaches the white dwarf phase. It couldn't become another Sun anyway until you'd gotten rid of the white dwarf to make room for a hydrogen core instead. That bit is important because if you keep adding material onto a white dwarf it will eventually explode, which wouldn't be so good for the earth. And if you've got a civlization powerful enough to move something as dense as a white dwarf, you've got the technology to just find another star and go there instead.
If you're a baby civilization like us and you need the Sun to come back to life, well, the only examples of dead stars coming back to activity are unusual events that take place in binary systems where two stars orbit each other and one star feeds the other enough material to re-ignite fusion or otherwise trigger some kind of event. But, first, those events can be extremely violent (ref: exploding white dwarf, above). Second, because we don't currently have a secondary star in our solar system, if one were to suddenly arrive it would seriously disrupt the gravitational stability of our entire system and we might end up either in a new orbit very inhospitable to life, or flung out of the system completely, with no star at all to orbit. We don't expect either to happen, which is good, but what that means is we've just got to deal with the Sun we've got.
Note: our Sun is about 4.5 billion years old, and it's in the middle of its life. So we have a little while before we have to worry about its death!
This is a great question, and my Official Scientific Answer is: we don't know. We don't even know if it's meaningful to talk about it in those terms. It's possible that there is one Universe and it had a beginning and there was nothing to talk about in the nothingness that existed before t = 0, so asking it may be like asking "what did grandma do before she was born?" (Like that, but way, way more contradictory.)
But it's also possible that there are many universes -- which makes the word universe a bit ironic -- and that they exist in some sort of higher-dimensional space where universes can pop into and out of existence depending on whether they have the right conditions to thrive ("conditions" would be stuff like the amount of matter, the values of the gravitational constant and other physical constants, etc.). There are various theories about this, and a good Google term is "multiverse". There are people who simulate what this might be like and have produced YouTube videos showing their simulations. The ones I've seen kind of look like bubbles forming and unforming and sometimes overlapping.
The trouble with theories on topics like these, though, is that for something to be properly called a theory in scientific terminology, it needs to make testable predictions. And it's pretty hard to test a prediction about what might have happened before time began, or about what happens outside the Universe! We don't currently have any way to observe anything outside our Universe, and if a multiverse did exist we might be "far away" (whatever that means) from any other universes anyway. Even if we did happen to overlap with another universe, as far as we can tell we wouldn't really interact: it's not like there would be galaxies from both universes colliding with each other or anything. It'd be a bit more like a TV signal, if every channel was a universe. If you grew up only watching one channel on a TV with no knobs or buttons and never had a TV guide, you might not even know any other channels existed. Unless science finds the equivalent of the remote control, we may just never know what else is on.
Unless, that is, there's interference between the channels, the sort you sometimes get on an old TV that's receiving signal from an antenna. Maybe a universe overlapping with ours would leave some kind of echo on our own? There are people looking for it, but I really don't think we even know enough about this field of science to even give an educated guess as to what they'll find.
I have some questions. Black hole questions: Have we ever found out what is inside a black whole? Where do you think all of the things that can get sucked up in there go? Do you think Einstein's theory is right, could there be worm holes? Random questions: Is there anyway we could live without the sun? OH AND THIS QUESTION... So there are many different solar systems right, they have planets orbiting around them right, so would there be other earths out there somewhere because there are so many planets and solar systems its hard to think about!?
is our sun dies, is it possible for another sun to form and take the vital place of our sun?
ReplyDeleteHi Kennedy,
DeleteThe short answer is that when our Sun dies, another Sun won't take its place.
The thing that defines the Sun's life right now is the fact that nuclear fusion is taking place at its core. The gas cloud that originally formed the Sun had enough total mass that it could get hot and high-pressure enough at its core to fuse hydrogen into helium. That's the first level of fusion, transforming the simplest atom in the Universe into the next-simplest, and it's what has to happen in order for a new star to form. While that's happening, there's a nice, steady system that's regulated by gravity trying to pull the Sun's matter closer together on the one hand and the pressure from the energy of fusion trying to push everything apart on the other. When those two forces balance in a star, we call that equilibrium. The Sun is in equilibrium right now, while its core is fusing hydrogen into helium.
The reason the Sun will die is that it will use up all its core hydrogen. After that happens, the equilibrium will be disrupted, and things will start to change. The Sun will go through several phases before it eventually ends up as a carbon-oxygen white dwarf star surrounded by what astronomers call a "planetary nebula" -- a terrible name, as it has nothing whatsoever to do with planets -- but throughout all of it the remaining hydrogen in the outer parts of the Sun will be pushed outward (forming part of the nebula and eventually dispersing completely).
I keep going on about hydrogen because *that* is what you'd need to try and form another Sun where the old one was -- except that the Sun will die because it no longer has enough where it needs to be, and the rest of it in the outer parts will be driven away by the energy of the collapsing core before the core reaches the white dwarf phase. It couldn't become another Sun anyway until you'd gotten rid of the white dwarf to make room for a hydrogen core instead. That bit is important because if you keep adding material onto a white dwarf it will eventually explode, which wouldn't be so good for the earth. And if you've got a civlization powerful enough to move something as dense as a white dwarf, you've got the technology to just find another star and go there instead.
If you're a baby civilization like us and you need the Sun to come back to life, well, the only examples of dead stars coming back to activity are unusual events that take place in binary systems where two stars orbit each other and one star feeds the other enough material to re-ignite fusion or otherwise trigger some kind of event. But, first, those events can be extremely violent (ref: exploding white dwarf, above). Second, because we don't currently have a secondary star in our solar system, if one were to suddenly arrive it would seriously disrupt the gravitational stability of our entire system and we might end up either in a new orbit very inhospitable to life, or flung out of the system completely, with no star at all to orbit. We don't expect either to happen, which is good, but what that means is we've just got to deal with the Sun we've got.
Note: our Sun is about 4.5 billion years old, and it's in the middle of its life. So we have a little while before we have to worry about its death!
4th hour would like to know: What came before the Big Bang?
ReplyDeleteThis is a great question, and my Official Scientific Answer is: we don't know. We don't even know if it's meaningful to talk about it in those terms. It's possible that there is one Universe and it had a beginning and there was nothing to talk about in the nothingness that existed before t = 0, so asking it may be like asking "what did grandma do before she was born?" (Like that, but way, way more contradictory.)
DeleteBut it's also possible that there are many universes -- which makes the word universe a bit ironic -- and that they exist in some sort of higher-dimensional space where universes can pop into and out of existence depending on whether they have the right conditions to thrive ("conditions" would be stuff like the amount of matter, the values of the gravitational constant and other physical constants, etc.). There are various theories about this, and a good Google term is "multiverse". There are people who simulate what this might be like and have produced YouTube videos showing their simulations. The ones I've seen kind of look like bubbles forming and unforming and sometimes overlapping.
The trouble with theories on topics like these, though, is that for something to be properly called a theory in scientific terminology, it needs to make testable predictions. And it's pretty hard to test a prediction about what might have happened before time began, or about what happens outside the Universe! We don't currently have any way to observe anything outside our Universe, and if a multiverse did exist we might be "far away" (whatever that means) from any other universes anyway. Even if we did happen to overlap with another universe, as far as we can tell we wouldn't really interact: it's not like there would be galaxies from both universes colliding with each other or anything. It'd be a bit more like a TV signal, if every channel was a universe. If you grew up only watching one channel on a TV with no knobs or buttons and never had a TV guide, you might not even know any other channels existed. Unless science finds the equivalent of the remote control, we may just never know what else is on.
Unless, that is, there's interference between the channels, the sort you sometimes get on an old TV that's receiving signal from an antenna. Maybe a universe overlapping with ours would leave some kind of echo on our own? There are people looking for it, but I really don't think we even know enough about this field of science to even give an educated guess as to what they'll find.
Could the milky way galaxy possibly be swallowed by a black hole ever? Is there black holes big enough to be capable of doing that?
ReplyDeleteI have some questions.
ReplyDeleteBlack hole questions: Have we ever found out what is inside a black whole? Where do you think all of the things that can get sucked up in there go? Do you think Einstein's theory is right, could there be worm holes?
Random questions: Is there anyway we could live without the sun? OH AND THIS QUESTION... So there are many different solar systems right, they have planets orbiting around them right, so would there be other earths out there somewhere because there are so many planets and solar systems its hard to think about!?