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Re: Astronomy and Age of Precious Metals on Earth
Posted: Sun Aug 25, 2013 10:30 pm
by Propsector
BMAONE23 wrote:
Ah the Midas Bacterium...That golden touch
This article carries this sentence. "Solid gold is mainly formed through geological processes in large veins underground."
Who is correct, the geologists or the astrophysicists?
Re: Astronomy and Age of Precious Metals on Earth
Posted: Sun Aug 25, 2013 10:37 pm
by neufer
Propsector wrote:BMAONE23 wrote:
Ah the Midas Bacterium...That golden touch
This article carries this sentence. "Solid gold is mainly formed through geological processes in large veins underground."
Who is correct, the geologists or the astrophysicists?
The question should be:
Who is correct, the geologists or the microbiologists?
Re: Astronomy and Age of Precious Metals on Earth
Posted: Mon Aug 26, 2013 5:46 am
by Chris Peterson
Propsector wrote:This article carries this sentence. "Solid gold is mainly formed through geological processes in large veins underground."
Who is correct, the geologists or the astrophysicists?
The astronomers are looking at a mechanism that explains the delivery of atoms of gold to the surface and outer crust of the Earth. The geologists and biologists are looking at mechanisms that concentrate those atoms into veins. Different questions. They can all be correct.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Mon Aug 26, 2013 1:58 pm
by ErnieM
BDanielMayfield wroteL
P.S. It is now thought that something even more exotic could be required to build heavy elements like Au and Pu; a supernova caused by the collision of two neutron stars. This may sound like it might be an impossibly rare event but it does occur fairly regularly. This is because binary stars are very common and because the neutron star state is a common condition that massive stars can collapse into after going supernova. Two neutron stars in a tight orbit will be drawn toward each other until they collide. So, it could be that it may take a series of THREE supernova explosions to form Gold!
(See the news bystander has colected for us here :
http://asterisk.apod.com/viewtopic.php?f=31&t=31783)
P.S.S. The explosion caused by the collision of two neutron stars is only 0.1 to 0.01 as powerfull as the average supernova, and 1,000 times as powerful as a typical nova, so they are calling these kilonovas. But they still rock. One kilonova is reported to be able to produce 10 of our Moon's worth of gold!
Universe is under 13.77B years old. Milky Ways is 13.2B years old. Solar System is 4.6 B years old expected to last another 4+B years more or 9-10B years before our Sun turns into a hot white dwarf.
This leaves 8-9B years for the series of THREE supernova, or a TWIN supernova THIRD supernova, or ONE kilonova plus (TWO supernova or nova or ONE of each) events to occur and give birth to GOLD on the Solar System. Do I have these numbers right?
Did all these occur in the Milky Way? Or did any of these events saw their beginning in one or two of several dwarf galaxies that merged forming the Milky Way?
Besides the Solar System, each of these events also would have created a black hole. Where are these THREE black holes now?
Re: Astronomy and Age of Precious Metals on Earth
Posted: Mon Aug 26, 2013 2:23 pm
by neufer
ErnieM wrote:
Universe is under 13.77B years old. Milky Ways is 13.2B years old. Solar System is 4.6 B years old expected to last another 4+B years more or 9-10B years before our Sun turns into a hot white dwarf.
This leaves 8-9B years for the series of THREE supernova, or a TWIN supernova THIRD supernova, or ONE kilonova plus (TWO supernova or nova or ONE of each) events to occur and give birth to GOLD on the Solar System. Do I have these numbers right?
Besides the Solar System, each of these events also would have created a black hole. Where are these THREE black holes now?
The 2 supernova are probably the consequence of a massive binary star system in which the core collapse of both stars end up producing neutron stars (not black holes). The neutron star binary then radiates of gravitational wave until they collide creating and ejecting elements heavier than iron/nickel while presumably leaving behind a single black hole.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Tue Aug 27, 2013 1:40 pm
by ErnieM
Neufer wrote:
The 2 supernova are probably the consequence of a massive binary star system in which the core collapse of both stars end up producing neutron stars (not black holes). The neutron star binary then radiates of gravitational wave until they collide creating and ejecting elements heavier than iron/nickel while presumably leaving behind a single black hole.
From this one could infer that extra-solar systems with rocky planet(s) are the product of this process. If the process also gave birth to a black hole, where are these black holes now? How far is the Solar system from its "mother" black hole? Is 13.2B years long enough for it to evaporate? Can the size of the black hole be calculated from the total mass of the Solar system?
Re: Astronomy and Age of Precious Metals on Earth
Posted: Tue Aug 27, 2013 1:59 pm
by Chris Peterson
ErnieM wrote:From this one could infer that extra-solar systems with rocky planet(s) are the product of this process. If the process also gave birth to a black hole, where are these black holes now? How far is the Solar system from its "mother" black hole? Is 13.2B years long enough for it to evaporate? Can the size of the black hole be calculated from the total mass of the Solar system?
Planetary systems usually form in dense nebulas, with a high stellar density including many massive stars. Nearby supernovas are probably common. If black holes result, they could be anywhere- except for the small percentage with accretion discs, they are generally not detectable.
Since the birth of the solar system, we have made many orbits around the galaxy. It's as if we were in a big blender. Stars that formed alongside ours could be dispersed throughout the galaxy (although I'd expect most to be in a similar radial zone). Probably, locating any components from our zone of formation, whether evolved stars or remnant neutron stars or black holes, is impossible.
Certainly, no stellar mass black hole has ever evaporated, as this requires a time much greater than the age of the Universe, by many, many orders of magnitude.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Tue Aug 27, 2013 2:46 pm
by neufer
http://en.wikipedia.org/wiki/Futurama wrote:
<<Nibbler is Leela's pet Nibblonian, whom she rescues from an imploding planet and adopted in the episode "Love's Labours Lost in Space". Lord Nibbler masquerades as an innocent, cute and unintelligent pet during most of the series. In reality, he is highly intelligent and capable of communication, but tries to avoid suspicion while he goes about his mission of protecting the Earth in general and Fry in particular from the evil Brainspawn. Nibbler's feces consist of dark matter (as the feces of all of those of his species do), which can be used as starship fuel. It is an extremely dense material, "each pound of which weighs over ten thousand pounds", according to Professor Farnsworth.>>
Re: Astronomy and Age of Precious Metals on Earth
Posted: Wed Aug 28, 2013 12:27 pm
by ErnieM
Chris Peterson wrote:
Planetary systems usually form in dense nebulas, with a high stellar density including many massive stars. Nearby supernovas are probably common. If black holes result, they could be anywhere- except for the small percentage with accretion discs, they are generally not detectable.
Since the birth of the solar system, we have made many orbits around the galaxy. It's as if we were in a big blender. Stars that formed alongside ours could be dispersed throughout the galaxy (although I'd expect most to be in a similar radial zone). Probably, locating any components from our zone of formation, whether evolved stars or remnant neutron stars or black holes, is impossible.
Certainly, no stellar mass black hole has ever evaporated, as this requires a time much greater than the age of the Universe, by many, many orders of magnitude.
All matter in a dense nebulae including its black hole(s) and any amount of dark matter are bound by gravity. So are the stars and planetary systems that formed from the same nebulae. Together they orbit the galaxy as a local group in the same radial zone.
The list of nearest stars (
http://en.wikipedia.org/wiki/Nearest_star), could all be siblings of our Solar system. The black hole(s) formed in the original nebulae must also be in this locality and serving as the locality's center of gravity, the center where local members orbit around.
Our black hole(s) will be detected and found by gravity wave detectors of the future? Only question is not IF but WHEN, before evaporation.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Wed Aug 28, 2013 1:52 pm
by Chris Peterson
ErnieM wrote:All matter in a dense nebulae including its black hole(s) and any amount of dark matter are bound by gravity. So are the stars and planetary systems that formed from the same nebulae. Together they orbit the galaxy as a local group in the same radial zone.
No, this is not the case. The material in a nebula is only very loosely bound gravitationally. Some of the nebular mass is concentrated into stars as they are formed, and some is lost as the stellar radiation pressure causes it to dissipate. Gravitational perturbations very early on eject stars (that is, they are tweaked into hyperbolic orbits with respect to the center of mass of the nebula contents, including other stars). So there is no reason at all to think our solar system is anywhere near other stars that formed in the same stellar nursery, and we don't have enough information about the precise location and dynamics of all the galactic material to integrate very far backwards to find where things actually were long ago. In fact, this is probably an inherently unsolvable problem.
The list of nearest stars (
http://en.wikipedia.org/wiki/Nearest_star), could all be siblings of our Solar system. The black hole(s) formed in the original nebulae must also be in this locality and serving as the locality's center of gravity, the center where local members orbit around.
There's little reason to think the nearest stars are siblings. Most differ significantly in age. Also, there is no reason to expect any original black holes to have remained local, nor to expect them to contribute significantly to any local center of gravity. Keep in mind these would simply be stellar mass black holes. Dynamically, they are no different from stars, but stars are far more abundant.
Why would you expect stars formed in a nebula to be orbiting a black hole formed by a supernova in that nebula? If they weren't orbiting the star that exploded (and generally, why would they be?) they won't be orbiting it after it becomes a black hole, and has even less mass than it started with.
Our black hole(s) will be detected and found by gravity wave detectors of the future? Only question is not IF but WHEN, before evaporation.
"Our" black hole, or any stellar mass black hole, cannot be distinguished gravitationally from any star. Gravity wave detectors cannot detect ordinary black holes. Detectable gravity waves are formed by the collision of black holes, or by processes around supermassive black holes. These are completely different things.
Keep in mind that the shortest evaporation time for any type of black hole known to actually exist is something like 60 orders of magnitude longer than the age of the Universe. For all practical purposes, we can consider stellar mass black holes to last forever.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Wed Aug 28, 2013 5:07 pm
by ErnieM
Chris Peterson » Wed Aug 28, 2013 1:52 pm
No, this is not the case. The material in a nebula is only very loosely bound gravitationally. Some of the nebular mass is concentrated into stars as they are formed, and some is lost as the stellar radiation pressure causes it to dissipate. Gravitational perturbations very early on eject stars (that is, they are tweaked into hyperbolic orbits with respect to the center of mass of the nebula contents, including other stars). So there is no reason at all to think our solar system is anywhere near other stars that formed in the same stellar nursery, and we don't have enough information about the precise location and dynamics of all the galactic material to integrate very far backwards to find where things actually were long ago. In fact, this is probably an inherently unsolvable problem.
Viewed from Orion, I wonder about the shape of the "asterism or constellation" our Sun is a member of. Are the stars in constellations we see from Earth not bound by gravity? I imagine they are because the shapes they take are cyclical from our perspective. If so, how and when did this happen? Did they just randomly happen to catch each other as they travel in their respective hyperbolic orbits? Are the stars in the same constellation of same age and properties? Even if they are not, this does not mean they come from different nurseries.
There's little reason to think the nearest stars are siblings. Most differ significantly in age. Also, there is no reason to expect any original black holes to have remained local, nor to expect them to contribute significantly to any local center of gravity. Keep in mind these would simply be stellar mass black holes. Dynamically, they are no different from stars, but stars are far more abundant.
By siblings, I don't mean twins. If the original black holes did not remain local, were they also kicked out and took the hyperbolic trajectory wandering alone in the galaxy? As these black holes are of stellar mass, any chance there could be black holes with solid rocky planets? They would be pretty hard to see. So we will never know.
Why would you expect stars formed in a nebula to be orbiting a black hole formed by a supernova in that nebula? If they weren't orbiting the star that exploded (and generally, why would they be?) they won't be orbiting it after it becomes a black hole, and has even less mass than it started with.
What would determine the mass of the resulting black holes? From wikipedia : "A stellar black hole (or stellar mass black hole) is a black hole formed by the gravitational collapse of a massive star.[1] They have masses ranging from about 3 to several tens of solar masses.[2] The process is observed as a supernova explosion[citation needed] or as a gamma ray burst[citation needed]. These black holes are also referred to as collapsars."
"Our" black hole, or any stellar mass black hole, cannot be distinguished gravitationally from any star. Gravity wave detectors cannot detect ordinary black holes. Detectable gravity waves are formed by the collision of black holes, or by processes around supermassive black holes. These are completely different things.
Keep in mind that the shortest evaporation time for any type of black hole known to actually exist is something like 60 orders of magnitude longer than the age of the Universe. For all practical purposes, we can consider stellar mass black holes to last forever.
Galileo;s telescope has evolved and gave us the Hubble. Whose is to judge what future gravity/black hole wave detectors can do. Since these stellar black holes are very long lived, there is time for new detectors to evolve. No need to rush.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Wed Aug 28, 2013 5:42 pm
by neufer
ErnieM wrote:
Viewed from Orion, I wonder about the shape of the "asterism or constellation" our Sun is a member of.
- Whatever the shape our Sun wouldn't be a pare of it since it would only about a 12th magnitude star.
ErnieM wrote:
Are the stars in constellations we see from Earth not bound by gravity? I imagine they are because the shapes they take are cyclical from our perspective.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Wed Aug 28, 2013 9:23 pm
by Chris Peterson
ErnieM wrote:Are the stars in constellations we see from Earth not bound by gravity?
No, they are not.
Are the stars in the same constellation of same age and properties? Even if they are not, this does not mean they come from different nurseries.
They are typically of very different ages, which does mean they didn't originate together. Stellar nurseries are very short lived- a few million years at most. That's the longest possible age spread for stars born from the same nebula. A random collection of stars making up any constellation (and for the most part, they are random) typically range in age over several billion years.
By siblings, I don't mean twins. If the original black holes did not remain local, were they also kicked out and took the hyperbolic trajectory wandering alone in the galaxy? As these black holes are of stellar mass, any chance there could be black holes with solid rocky planets?
Sure, you'd expect any black hole or neutron star remnants to be ejected just like any star. Indeed, even a small lack of isotropy in the forces produced during the supernova could eject the remnant, with no need for additional gravitational perturbations. In terms of dynamics, there's no reason a black hole couldn't have planets around it. Whether they could survive a local supernova is questionable. Some kind of later captures might be more likely.
What would determine the mass of the resulting black holes?
They will be the mass of the original star, less the mass-energy equivalence released in the supernova, less the mass of the ejected material. Typically a few solar masses for a massive star.
Galileo;s telescope has evolved and gave us the Hubble. Whose is to judge what future gravity/black hole wave detectors can do. Since these stellar black holes are very long lived, there is time for new detectors to evolve. No need to rush.
It doesn't matter how good they are. The point is, a black hole doesn't generate gravity waves, and in terms of gravity itself, is indistinguishable from a star.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Sat Aug 31, 2013 8:26 am
by ErnieM
Chris Peterson wrote:
No, this is not the case. The material in a nebula is only very loosely bound gravitationally. Some of the nebular mass is concentrated into stars as they are formed, and some is lost as the stellar radiation pressure causes it to dissipate. Gravitational perturbations very early on eject stars (that is, they are tweaked into hyperbolic orbits with respect to the center of mass of the nebula contents, including other stars). So there is no reason at all to think our solar system is anywhere near other stars that formed in the same stellar nursery, and we don't have enough information about the precise location and dynamics of all the galactic material to integrate very far backwards to find where things actually were long ago. In fact, this is probably an inherently unsolvable problem.
Stars in a hyperbolic orbits must be going at velocities high enough to escape the gravity of the nebula. At such a high velocity, the star's gravity would not be strong enough to hold on to it's the planetary matter. If our Sun went through this, where did it acquire the material that formed our solar system? Are the matter in our Solar system from the same nebula that gave birth to our Sun?
Re: Astronomy and Age of Precious Metals on Earth
Posted: Sat Aug 31, 2013 8:43 am
by Chris Peterson
ErnieM wrote:Stars in a hyperbolic orbits must be going at velocities high enough to escape the gravity of the nebula. At such a high velocity, how a given star hold on to its planets or planetary matter?
The velocities required are not large. That's what it means to be loosely bound. For example, material in our own Oort cloud is in orbit around the Sun, but only loosely bound gravitationally. It requires only a few meters per second velocity change to radically change their orbits, often into hyperbolic ones. We observe that in the occasional long period comets on their way around the Sun and forever out of the Solar System.
In any case, planets are usually strongly bound to their parent stars. Where the stars go, they go as well. There is no mechanism that would result in stars losing their planets or protoplanetary discs simply because they are flung out of a nebula by some perturbation.
If our Sun went to this, where did it acquire the material that formed our solar system?
Stars form their planetary systems (or at least, their protoplanetary discs) while still within their parent nebula. It is that nebula that supplies both the material making up the star, as well as the material making up its planetary system.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Sat Aug 31, 2013 1:06 pm
by BMAONE23
I would imagine that the process of gravitational binding to create both a planetary system and its parent star happen rather simultaneously, as once the star begins its lifelong fusion process, solid material begins to migrate outwards and away from the star. Once the star "Lights up" its growth process is pretty much complete though the remaining material will still continue to add mass to planetary bodies.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Tue Sep 03, 2013 12:54 pm
by THX1138
In any case, planets are usually strongly bound to their parent stars. Where the stars go, they go as well. There is no mechanism that would result in stars losing their planets or protoplanetary discs simply because they are flung out of a nebula by some perturbation.
Focusing in on the word usually in the above first sentence for a moment.
I’ve read someplace that there is some whom believe Uranus might very well be a planet that formed someplace else and was later captured by our sun. (It’s backwards orbit and etc being a foundation for that belief) I think? In any event what would be the possible mechanism by which the planet didn’t follow it’s parent star / how could it of gotten kicked out to of ended up orbiting our star, if that is indeed the case???
As usual I spent most of this weeks check on my bike, women and beer and the rest I just wasted
Re: Astronomy and Age of Precious Metals on Earth
Posted: Tue Sep 03, 2013 2:12 pm
by Chris Peterson
THX1138 wrote:I’ve read someplace that there is some whom believe Uranus might very well be a planet that formed someplace else and was later captured by our sun.
I don't know anybody who thinks this is likely at all. The evidence is rather overwhelming that it was formed along with the other planets- its composition is as expected, and its circular, ecliptical orbit would be unlikely for a capture.
In any event what would be the possible mechanism by which the planet didn’t follow it’s parent star / how could it of gotten kicked out to of ended up orbiting our star, if that is indeed the case???
It is estimated that a significant number of protoplanets get ejected from their parent system. This happens because orbiting systems of more than two bodies are inherently unstable. With time, bodies settle into semi-stable orbits (as in our own system), but while they are doing that all sorts of resonances develop with transfer angular momentum between them and can easily result in new, hyperbolic orbits and the ejection of planets.
Ejections are likely common. Captures not.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Thu Sep 19, 2013 4:45 pm
by ErnieM
Neufer wrote:
ErnieM wrote:
Viewed from Orion, I wonder about the shape of the "asterism or constellation" our Sun is a member of.
Whatever the shape our Sun wouldn't be a pare of it since it would only about a 12th magnitude star.
A very humbling picture.
Imagine if there was an advanced civilization on the Orion system searching for other civilization, our Sun won't even make the list of possible candidate.
Re: Astronomy and Age of Precious Metals on Earth
Posted: Thu Sep 19, 2013 4:52 pm
by Chris Peterson
ErnieM wrote:Imagine if there was an advanced civilization on the Orion system searching for other civilization, our Sun won't even make the list of possible candidate.
Sure it would. Magnitude 12 is pretty bright, so our system would be easily studied. We identify all sorts of candidates for systems similar to our own that have apparent magnitudes much dimmer. When looking for systems harboring life, apparent magnitude isn't a factor at all.
