Cosmic crashes forging gold: Nuclear reactions in space do produce the heaviest elements

Sep 09, 2011
Where did gold form? For a long time, the cosmic production site of this rare metal - here are shown natural gold nuggets from California and Australia - and of other very heavy chemical elements has been unknown. New theoretical models now confirm that it could be forged in the merger events of two neutron stars. Credit: Natural History Museum, London

(PhysOrg.com) -- Collisions of neutron stars produce the heaviest elements such as gold or lead. The cosmic site where the heaviest chemical elements such as lead or gold are formed has most likely been identified: Ejected matter from neutron stars merging in a violent collision provides ideal conditions. In detailed numerical simulations, scientists of the Max Planck Institute for Astrophysics and affiliated to the Excellence Cluster Universe and of the Free University of Brussels have verified that the relevant reactions of atomic nuclei do take place in this environment, producing the heaviest elements in the correct abundances.

Most heavy are formed in nuclear fusion reactions in stars. Also in the centre of our Sun, hydrogen is “burned” to create helium, thereby releasing energy. Heavier elements are then produced from helium if the star is more massive than our Sun. This process, however, only works up to iron; further fusion reactions do not yield any net energy gain. Therefore heavier elements cannot be produced in this fashion. Instead, they can be assembled when neutrons are captured onto “seed”-nuclei, which then radioactively decay.

This involves two main processes: the slow neutron capture (s-process), which takes place at low neutron densities inside stars during their late evolution stages, and the rapid neutron capture (r-process), which needs very high neutron densities. Physicists know that the r-process is responsible for producing a large fraction of the elements much heavier than iron (those with nuclear mass numbers A > 80), including platinum, , thorium, and plutonium. However, the question of which astrophysical objects can accommodate for this r-process remains to be answered.

“The source of about half of the heaviest elements in the Universe has been a mystery for a long time,“ says Hans-Thomas Janka, senior scientist at the Max Planck Institute for and within the Excellence Cluster Universe. ”The most popular idea has been, and may still be, that they originate from supernova explosions that end the lives of massive stars. But newer models do not support this idea. “

Violent mergers of neutron stars in binary systems (see background information on neutron stars) offer an alternative scenario, when the two stars collide after millions of years of spiralling towards each other. For the first time, scientists at the Max Planck Institute for Astrophysics and the Free University of Brussels have now simulated all stages of the processes occurring in such mergers by detailed computer models. This includes both the evolution of the neutron star matter during the relativistic cosmic crashes and the formation of chemical elements in the tiny fraction of the whole matter that gets ejected during such events, involving the nuclear reactions of more than 5000 (chemical elements and their isotopes (see background information on isotopes)).

”In just a few split seconds after the merger of the two , tidal and pressure forces eject extremely hot matter equivalent to several Jupiter masses,“ explains Andreas Bauswein, who carried out the simulations at the MPA. Once this so-called plasma has cooled to less than 10 billion degrees, a multitude of nuclear reactions take place, including radioactive decays, and enable the production of heavy elements. ”The heavy elements are `recycled' several times in various reaction chains involving the fission of super-heavy nuclei, which makes the final abundance distribution become largely insensitive to the initial conditions provided by the merger model,“ adds Stephane Goriely, ULB researcher and nuclear astrophysics expert of the team. This agrees well with previous speculations that the reaction properties of the atomic nuclei involved should be the decisive determining factor because this is the most natural explanation for the essentially identical abundance distributions of the heaviest r-process elements observed in many old stars and in our solar system.

The simulations showed that the abundance distribution of the heaviest elements (with mass numbers A > 140) agrees very well with the one observed in our solar system. If one combines the results of the simulations and the estimated number of neutron star collisions in the Milky Way in the past, the figures indicate that such events could in fact be the main sources of the heaviest chemical elements in the .

The team now plans to conduct new studies to further improve the theoretical predictions by refined computer simulations that can follow the physical processes in even more detail. On the other hand, observational astronomers look out for detecting the transient celestial sources that should be associated with the ejection of radioactive matter in neutron star mergers. Because of the heating by radioactive decays, the ejecta will shine up with almost the brightness of a supernova explosion — albeit only for a few days. A discovery would mean the first observational hint of freshly produced r-process elements in the source of their origin. The hunt is on!

Explore further: How baryon acoustic oscillation reveals the expansion of the universe

More information: Stephane Goriely, et al., r-process nucleosynthesis in dynamically ejected matter of neutron star mergers, The Astrophysical Journal, 10. September 2011; doi:10.1088/2041-8205/738/2/L32

Related Stories

The importance of fundamental measurements

May 04, 2011

At the Radioactive Isotope Beam Facility (RIBF) of the RIKEN Nishina Center for Accelerator Science in Wako, a research team has measured the time it takes for 38 extremely rare isotopes to decay by half. ...

First evidence for a spherical magnesium-32 nucleus

Feb 02, 2011

Elements heavier than iron come into being only in powerful stellar explosions, supernovae. During nuclear reactions all kinds of short-lived atomic nuclei are formed, including more stable combinations – ...

Making massive stars

Sep 10, 2010

Massive stars -- those with more than about eight times the mass of the sun -- are arguably the most important actors in the universe. Much hotter and more luminous than the sun, they live only hundreds of ...

A supernova that's super different

Jun 03, 2011

A researcher at the Harvard-Smithsonian Center for Astrophysics believes that a new kind of supernova is at work in recent observations of bright but short-lasting stellar explosions that don’t appear ...

Recommended for you

The Great Cold Spot in the cosmic microwave background

Sep 19, 2014

The cosmic microwave background (CMB) is the thermal afterglow of the primordial fireball we call the big bang. One of the striking features of the CMB is how remarkably uniform it is. Still, there are some ...

Mystery of rare five-hour space explosion explained

Sep 17, 2014

Next week in St. Petersburg, Russia, scientists on an international team that includes Penn State University astronomers will present a paper that provides a simple explanation for mysterious ultra-long gamma-ray ...

User comments : 46

Adjust slider to filter visible comments by rank

Display comments: newest first

antialias_physorg
3.8 / 5 (13) Sep 09, 2011
This process, however, only works up to iron; further fusion reactions do not yield any net energy gain. Therefore heavier elements cannot be produced in this fashion.

I've always been a bit bothered by this statement. I know that for fusion to heavier elements you need more energy than you get out. But a sun is not an entirely homogeneous body: It vibrates, it has hotspots, ... in short: there are areas where the energy density is higher and where therefore fusion to heavier elements could take place (with the attendant reduction of energy from these peak energy density zones). Much like we pump in energy for fusion experiments here on Earth.

Especially during a (super)nova event such unbalanced regions should be available for production of some heavier elements. When the hydrogen/helium fusion the contraction creats a shockwave with significantly higher energy density before it bounces' and the star throws off its outer layer.
TheGhostofOtto1923
3 / 5 (10) Sep 09, 2011
in short: there are areas where the energy density is higher and where therefore fusion to heavier elements could take place
In order to know whether this statement has any merit at all you would have to analyze potential conditions and compare them to energies needed to form the heavier elements, for a wide range of stellar types, to determine whether this was actually possible or just farting in bathtub water.

Have at it.
omatumr
1.7 / 5 (18) Sep 09, 2011
1. Neutron capture makes most isotopes of elements heavier than iron.

a) Slow neutron-capture, the s-process, made the more stable isotopes
like Xe-128, Xe-130.

b) Rapid neutron-capture, the r-process, made heavier isotopes,
like Xe-131, Xe-132, Xe-134 and Xe-136

c) The p-process, (p,gamma) or (gamma,n) for (in,out) process, made lighter isotopes,
like Xe-124 and Xe-126

2. In 1972 the first evidence was reported that these products were unmixed when meteorites started to form ["Xenon in carbonaceous chondrites", Nature 240, 99-101 (1972)]

Paper: www.omatumr.com/a...ites.pdf
Data: http://www.omatum...Data.htm

3. In 1983, Nature acknowledged error in model of Solar System's birth

http://tallbloke....1983.pdf

4. By 1993 analyses had shown that

a) Products of r- and p-process were trapped in carbon
b) Products of s-process were trapped in silicon carbide

Data: www.omatumr.com/D...Data.htm

O Manuel

antialias_physorg
3.8 / 5 (8) Sep 09, 2011
Since gravity of collapsing stars of 3-10 times the mass of the sun can be enough to form neutron stars (which is already way beyond the energy needed for fusion to heavier elements) it's not unreasonable to assume that parts that did not quite make it could fuse to heavier elements, is it?

i.e.:
- parts that were not quite dead center during the collapse and were blown off during the formation of a neutron star or
- parts of stars that don't have the mass to form neutron stars but came close

There seems to be a process (r-process) in type Ib, Ic and II supernovae that could do this type of nucleosynthesis.

The main argument is: we can do fusion here on Earth to stable elements while having a negative Q factor (pumping in more energy than we get out). Why should this not be possible in stars at some locations?
Nanobanano
1.9 / 5 (21) Sep 09, 2011
Why would these rare/trace metals, if created in distant stellar mergers, appear on earth (or meteors) in nuggets ranging from milligrams to kilograms in size?

How the hell do you explain an solid object the size of your fist escaping the surface of merging neutron stars? If it was in some sort of particle or plasma form, why didn't it disperse in a conical projection, instead of becoming a solid nugget?

Finally, why is it that gold deposits mysteriously appear very heavy in some confined locations, and not at all eslwhere?

You should tend to find "gold dust" everywhere, rather than absurd concentrations deep within ores in mountains and such.

After all, we don't see rocks, ores, or even molecules coming out of the Sun or other stars. We only see IONS and cosmic ray particles.

Besides, anything with enough velocity to escape a neutron star merger (a significant fraction of the speed of light) would punch a hole straight through a planet and keep going.
Nanobanano
1.3 / 5 (15) Sep 09, 2011
Addtionally, if Gold was created in this manner, shouldn't there be some sort of forensic evidence?

You should find something like, oh, microscopic neutronium inclusions inside of the Gold nuggets, or at least "somewhere" in the ores surrounding the Gold...After all, if it formed from the merger of neutron stars, the some of the neutronium should have escaped and travelled with it, and subsequently get deposited in meteors and other gold-rich ores on earth and other planets.

So where did the missing neutronium go? There should be at least as much neutronium as Gold in planets and meteors, if not a great deal more. What happened to it?
antialias_physorg
4.5 / 5 (17) Sep 09, 2011
[q}Why would these rare/trace metals, if created in distant stellar mergers, appear on earth
As noted in the artile: Stuff gets ejected (no matter whether you subscribe to the r-process supernova or neutron star impact theory)

How the hell do you explain an solid object the size of your fist escaping the surface of merging neutron stars?

The earth was (and is to large part still) molten. Under such an environment heavy elements will naturally separate from less dense ones yb less dense stuff floating to the top. In a partialy molten state (i.e. with some rock already fairly solid) you can get cavities into which stuff pools. Pretty much like a smelter oven.

After all, we don't see rocks, ores, or even molecules coming out of the Sun

We're not at the stage where our sun is currently going (super)nova (lucky for us). The sun is currently not producing these heavy elements (or in only very small amounts).

antialias_physorg
4.7 / 5 (14) Sep 09, 2011
Besides, anything with enough velocity to escape a neutron star merger (a significant fraction of the speed of light) would punch a hole straight through a planet and keep going.

The speed of ejecta from a neutron star merger is not limited towards the low end. And if it's in the form of individual atoms then it won't punch through anything.

Current models assume that supernovae seeded hydrogen clouds with heavier elements (i.e. the shockwaves impacted on these clouds). Some time afterwards the clouds collapsed to form starsm and planets of their own (so the velocities of any ejecta are already slowed down to the average velocity of the cloud)

microscopic neutronium inclusions inside of the Gold nuggets

Neutron star matter is not stable when you take the crushing gravity away (i.e. when eject this stuff from the neutron star). It decays quickly into 'ordinary' matter.
macsglen
1.8 / 5 (10) Sep 09, 2011
"Finally, why is it that gold deposits mysteriously appear very heavy in some confined locations, and not at all eslwhere?

You should tend to find "gold dust" everywhere, rather than absurd concentrations deep within ores in mountains and such.

After all, we don't see rocks, ores, or even molecules coming out of the Sun or other stars. We only see IONS and cosmic ray particles."

Same goes for any heavy metal. Why didn't all these heavy elements sink to the Earth's core during the planet's formation? Indeed, the majority of the crust is lighter material (like the slag in a blast furnace), but why is it so inhomogenous?

This goes to a greater phenomenon: moons of our gas giants seem to favor like materials: some mostly water, others mostly hydrocarbons -- where you'd expect a more even distribution of material. Very mysterious.
antialias_physorg
4.3 / 5 (12) Sep 09, 2011
Indeed, the majority of the crust is lighter material (like the slag in a blast furnace), but why is it so inhomogenous?

Because the Earth isn't a still ball of molten slag. There are dynamic heat and material exchange system (plumes rise from deeper down to the top in some places which can transport all sorts of material that separates out when it cools).

E.g. if you have a volcano spewing out magma then anything that got transported up will not sink down to the core. It will pool and the less dense material will float up top and the more dense material will collect in depressions.

Add to that stuff that gets deposited later on through meteorites and you have a number of mechanisms that can give you surface (or close to surface) materials of most any type in largish chunks..

Yes, MOST of the heavy metals will sink down (this is why the Earth has an iron core, after all) - but only in a still, isotropic, non-dynamic model will you get a perfect separation into layers.
Skultch
4 / 5 (2) Sep 09, 2011
Yes, geology is dynamic and brings cool stuff to the surface. I've heard gold can be brought to the surface in the same conditions where quartz is brought up. There's a ton of quartz just laying around in my neck of the woods. People stopped panning for gold around here decades ago, after most of the mining stopped. If I ever get some free time (doubtful) I might do a little panning in curvy streams where tiny, semi-buoyant nuggets might have settled in the banks.
omatumr
1.3 / 5 (24) Sep 09, 2011
The earth was (and is to large part still) molten.


Bunkum!

Only Earth's upper mantle melted!

It's iron core formed first, from iron meteorites that condensed near the neutron star (pulsar) remains of the supernova that gave birth to the solar system [Science 195, 208-209 (1977)].

See experimental data from analysis of

a) Lunar soils (1972)
www.omatumr.com/D...ata1.htm

b) Carbonaceous meteorites (1972)
www.omatumr.com/D...Data.htm

c) Carbonaceous meteorites (1975)
www.omatumr.com/D...Data.htm

d) Diverse meteorites (1976)
www.omatumr.com/D...Data.htm

e) Solar wind (1983)
www.omatumr.com/D...Data.htm

f) Iron meteorites (1991)

g) Meteorite inclusions (1993)

www.omatumr.com/D...Data.htm

e) Jupiter (1995, data released in 1998)
www.omatumr.com/D...Data.htm

http://www.youtub...IFmZpFco

I regret that it took 40 years to recognize that the AGW model of Earth's climate and the SSM model of the Sun are also "Bunkum."
omatumr
1.2 / 5 (20) Sep 09, 2011
f) Iron meteorites (1991)

www.omatumr.com/D...Data.htm


Today suppressed experimental observations are melting forty years of false science dogma on PhysOrg.com than ice is melting in Greenland!

OM

thales
5 / 5 (12) Sep 09, 2011
I'm surprised no one mentioned the recently discovered evidence that much of the heavy elements found in the crust was likely deposited during the Late Heavy Bombardment by meteorites.

http://www.scienc...2044.htm
Jeddy_Mctedder
1.5 / 5 (12) Sep 09, 2011
to me the simplest explanation is that these elements have been around since the big bang created them and have not deteriorated since then into lower atomic number elements.

i am a huge believer in science, but cosmology and atomic physics, still run into the fact there is a great unknown, and that is what were the physics of the early universe, and what was and is the physics of the universe today---as physical rules may not only change through time, but be different in different localities of the universe.

so i always take cosmology with a grain of salt. and i NEVER have believed the theory of supernova making most of the heavy elements, nor did i ever believe 15 years ago in high school that "JUNK DNA" served no purpose in the cell and was mostly just useless. that was intuitively obvious to me then for many reasons. namely, that organized junk must have a non-random explanation.

sometimes, doubt is a good thing in science,, scientific rigor does not make up for lack of data
that_guy
5 / 5 (7) Sep 09, 2011
Therefore heavier elements cannot be produced in this fashion.

I've always been a bit bothered by this statement. I know that for fusion to heavier elements you need more energy than you get out. But a sun is not an entirely homogeneous body

You may be partially right, but basically in stars, you only yield trace amounts of an element above a particular number. The reason why bigger stars don't fuse past iron while still alive, is that when they start taking energy out of the system, it increases density, which increases gravity, which helps fuse more iron...etc etc. it sets off a chain reaction that very quickly causes the star to explode.

Especially during a (super)nova event such unbalanced regions should be available for production of some heavier elements.

? It's widely assumed that supernovas produce heavier elements as well. i don't understand what you're trying to say. This article is saying that the neutron star process could create more.
that_guy
5 / 5 (6) Sep 09, 2011
I'm surprised no one mentioned the recently discovered evidence that much of the heavy elements found in the crust was likely deposited during the Late Heavy Bombardment by meteorites.

http://www.scienc...2044.htm

Anti-alias did in fewer words.

@nano - you're assuming that the process is uniform, when it is anything but. When you have these cataclysmic scenerios, you have heavy elements of all sizes being created, some decay, some don't. It will naturally be very mixed...just like your coffee and cream and sugar. and then, you dismiss every process that occurs between said event, and it getting to the earth.

You did have one point correct though. the elements are initially somewhat evenly distributed, and one reason a nonreactive element like gold is harder to find, is not because it is rare, but because there are fewer natural processes that will concentrate it.
KBK
1 / 5 (1) Sep 09, 2011
so..this meas that Dr. Joe Champion..is vindicated?
that_guy
5 / 5 (7) Sep 09, 2011
so..this meas that Dr. Joe Champion..is vindicated?

Nope. He believes all stars have neutron cores and make all the elements. This article states that neutron star collisions add more elements. The processes are completely different, and only bear a slight superficial resemblance to oliver chester's theories.

On the other hand, I'm not sure that you're not just being sarcastic or just trolling with that comment :)
KBK
1.6 / 5 (5) Sep 09, 2011
A bit of each. I'm illustrating that a tickle and push can work just as well as a slam . Thus overly misguided physicists and their dreams of going to the exact place their history dictates.

The depth of the history in and of science dictates the exact opposite is the truth and reality.

The arrow of science must be under and in constant correction, otherwise truth will never be found or known.

If this is not done, it becomes dogma and law (no laws in science, please), not true science. This sad misnomer that science has become, that is.

In each realm of conceptual existence, there are leaders and followers and--the given bell curve. Never allow the bell curve of human relational frailty to be attached to attempts of hypothesis and truths in science.

This is the major failure point of those who investigate science, for the most part.

In truth, it's the basic lack of understanding their own psychology and it's originating physiology-which twists meaning and the basis of thought.
TheGhostofOtto1923
2.5 / 5 (8) Sep 09, 2011
Indeed, the majority of the crust is lighter material (like the slag in a blast furnace), but why is it so inhomogenous?

Because the Earth isn't a still ball of molten slag. There are dynamic heat and material exchange system (plumes rise from deeper down to the top in some places which can transport all sorts of material that separates out when it cools)...
Geology is after all a complex science with a long history of exploration and study. The mechanisms of material concentrations and ore deposits are in general well-known and I myself would only tend to acknowledge this and shuttle doubters toward the proper informed sources, rather than presume to infer that I myself knew something about the science involved when in fact I was also just conjecturing:
http://en.wikiped...wiki/Ore
http://en.wikiped.../Geology

-hope this helps-
TheGhostofOtto1923
2.8 / 5 (9) Sep 09, 2011
KBK
1.6 / 5 (9) Sep 09, 2011
the generalist is required to solve these complex multi-faceted considerations.

The specialist is natively ---blinkered, by very definition.

It seems as if science, as a concept and human group, has somehow worked very hard to kill the Renaissance man, the genralist who can pull all the bits together.

I wonder why that is?

It should be a question on your mind, if it is not, then you might be a bit too linear. Thus...blinkered.

Be careful. It isn't even remotely an abstract objective externalized push ---through desire and expectations.

Half the equation lives in the person.

Your reach is exactly synonymous with your psychological process. Never forget that.'Physician, heal thyself'.
KBK
1.5 / 5 (8) Sep 09, 2011
To those who give me low ratings, I thank you for proving my point, via your reactive--actions. Steering though your past is no way to reach a new future.
omatumr
1.3 / 5 (16) Sep 09, 2011
to me the simplest explanation is that these elements have been around since the Big Bang created them and have not deteriorated since then into lower atomic number elements.


Sorry. No Big Bang, nor any of the fudge factors (Dark Energy, Dark Matter, etc) used to prop up that story.

When examined in the light of experimental observations given above, the following models melt than Greenland ice melts under the bright glare of Al Gore's TV camera!

a.) The Big Bang model of the universe
b.) The AGW motel of Earth's climate
c.) The SSM model of the Sun
d.) K/M's model of society*

*Kissinger/Mao's Model To Save the World
http://dl.dropbox...oots.pdf

The Universe is infinite and cyclic**.

**"Is the Universe Expanding?" The Journal of Cosmology 13, 4187-4190 (2011)

http://journalofc...102.html

Oliver K. Manuel
barakn
5 / 5 (9) Sep 09, 2011
The earth was (and is to large part still) molten.


Bunkum!

Only Earth's upper mantle melted!

Surely you're aware that seismology has shown a molten outer core? No?! OMG. Oh, wait, that's not surprising. Helioseismology also discredits your theories and it's well known you ignore that evidence.
RealScience
4.8 / 5 (6) Sep 09, 2011
Nano - surely you jest. The neutron star merger doesn't produce nuggets of gold, it produces gold nuclei. And contrary to Star Trek doomsday machines, neutronium isn't stable away from the massive pressures of a neutron star. Under normal pressure neutrons have a half-life of 17 minutes unless stabilized by protons.

Jeddy - The older the stars, the poorer they are in heavy elements, which is reasonable evidence that the heavy elements have been created since the big bang (the older stars are much too cold to destroy the stable heavy elements).
(However I agree with your intuition on 'Junk DNA'. DNA is the disk drive, RNA is the processor; when people first figured out how to read DNA they knew that most of the information was in the DNA - so they ignored RNA as merely and intermediate for making proteins (mRNA). But the complex interactions that control the reading of the DNA are almost all in RNA.)
Husky
5 / 5 (1) Sep 09, 2011
if we assume that indeed a spray of golddust is ejected by violent neutronstar merger and here on earth compacted into nuggets by plate tectonics processes, then this could be verivied by samplinh the moon for gold ore, without significant tectonics then, moongold should be found as widely dispersed dust rather than concentrations of lumps, if however large nuggets are found, then its back to the drawing board for either neutron merger theory or the theory about the formation of the moon
Osiris1
1 / 5 (1) Sep 09, 2011
Baawwwww! I wanna know where to find element 115, Unumpentium, so I can sell it to the Air Farce at Nellis, home of Area 51. They need it for fuel for their F117's, or at least ONE of them!
RealScience
5 / 5 (2) Sep 09, 2011
Husky - Gold from either a supernova or a neutron star merger would be spewed as hot atomic nuclei. In the supernova case these would have cooled and acquired electrons and been incorporated into dust grains on hitting matter previously ejected by the same star. In the neutron star merger case this would likely take place in interstellar gas and dust clouds.
But in either case the many of dust grains would have been melted within our solar system, as the nickel/iron meteorites show. Gold would have been concentrated in this process, and it could have separated out enough to form lumps.
So I would expect enriched gold regions on the moon around craters that were from nickel/iron asteroids, and I wouldn't be too surprised by lumps.

Osiris1 - My first thought on reading the neutron-star merger hypothesis was that this would be neutron-rich enough to create elements in the island of stability. Element 115 would have decayed by now, but perhaps some heavier elements are stable enough.
that_guy
5 / 5 (1) Sep 09, 2011
if we assume that indeed a spray of golddust is ejected by violent neutronstar merger and here on earth compacted into nuggets by plate tectonics processes, then this could be verivied by samplinh the moon for gold ore, without significant tectonics then, moongold should be found as widely dispersed dust rather than concentrations of lumps, if however large nuggets are found, then its back to the drawing board for either neutron merger theory or the theory about the formation of the moon


Obviously you know little about the process. Plate techtonics do not create nuggets.

There are many processes that affect elemental concentrations, but the end conclusion you had I believe is correct, that you will find little or no gold nuggets on the moon. Gold 'nuggets' are primarily created through a water based process to my knowledge.
omatumr
1.3 / 5 (16) Sep 09, 2011
The earth was (and is to large part still) molten.


Bunkum!

Only Earth's upper mantle melted!

Surely you're aware that seismology has shown a molten outer core? .


Surely you are blind to experimental data that show Earth accreted heterogeneously, beginning with its iron core [1]!

The data and conclusions were published in a first-class, peer-reviewed research journal ~30 years ago.

"The noble gas record of the terrestrial planets", Geochemical Journal 15, 247-267 (1981).

http://www.omatum...eGas.pdf

http://philosophy...ore.html
that_guy
5 / 5 (8) Sep 09, 2011
Surely you're aware that seismology has shown a molten outer core? .


Surely you are blind to experimental data that show Earth accreted heterogeneously, beginning with its iron core [1]!

The data and conclusions were published in a first-class, peer-reviewed research journal ~30 years ago.

"The noble gas record of the terrestrial planets", Geochemical Journal 15, 247-267 (1981).

http://www.omatum...eGas.pdf

Evidence published by YOU Oliver? With links to YOUR own blogs? I'd point out that just because a journal publishes a paper does not make it correct, obviously because they publish so many competing theories. Also, YOUR theory stated here is obsolete in the face of much data gained since you published YOUR paper, in what appears to be a japanese geochemical journal that was 3 years old, looking for american scientists to publish to enhance its standing. They failed.

You're absolutely ridiculous.
Nanobanano
2 / 5 (3) Sep 09, 2011
Nano - surely you jest. The neutron star merger doesn't produce nuggets of gold, it produces gold nuclei.


I know that, back up and read what I said again.

I asked how a gold nugget could have been formed, when the material should have been ejected and dispersed over a broad area/volume of space, and NOT concentrated as a nugget.

The question of how a fist sized nugget could be ejected from a neutron star was more rhetorical than anything else.

Of course it's monatomic nuclei: positive ions and cosmic rays.

The question still remains how, if the gold was created in this manner, how does it end up in highly concentrated nuggets? Anywhere? Not just on earth, but in meteors, etc.

Supernova nebulae expand at thousands of km/s, which is a couple orders of magnitude faster than individual planets or stars move. Heavy metals ejected from a supernova or neutron star merger could not have matched velocity with the Sun's local environment, except in head-on collisions.
TheGhostofOtto1923
2.1 / 5 (7) Sep 09, 2011
Obviously you know little about the process. Plate techtonics do not create nuggets.
-But then people just can't resist the urge to speculate...

"Gold deposits are formed via a very wide variety of geological processes. Deposits are classified as primary, alluvial or placer deposits, or residual or laterite deposits. Often a deposit will contain a mixture of all three types of ore.
Plate tectonics is the underlying mechanism for generating gold deposits. The majority of primary gold deposits fall into two main categories: lode gold deposits or intrusion-related deposits."

-Sorry dude. Check out the links I posted. This is also for terrestrial deposits. I suppose planetary scientists have additional mechanisms postulated for lunar deposits. Try GOOGLE.

@nano
Close your mouth and open your brain. Do a little reading. This is explained by experts in the links I posted.
Nik_2213
5 / 5 (2) Sep 09, 2011
IIRC, gold gets concentrated from its few-atom dispersal by slow geothermal processes, precipitating along fault lines when pressures reduced...
Isn't there a group of gold-mines in US MidWest where the gold is distributed as sub-microscopic flecks in the 'intrusions' around relict volcanic sites ? The assay is high enough to be pay-dirt, but there's narry a nugget in sight...

OT: IMHO, there's no point arguing with Om-- Just post a kind warning for newbies. Terrestrial and Helio-seismography have falsified his key tenets, leaving him in Fred Hoyle's unhappy position of a great scientist side-tracked by later data...
RealScience
5 / 5 (3) Sep 09, 2011
Nano - the nuclei slowed down running into atoms / molecules in gas/dust clouds, and got captured on dust grains.
Our sun was formed from a dusty cloud collapsing, likely triggered by a supernova shockwave. The dust would already have had some heavy elements, and a supernova shockwave (the fast ejecta slamming into a slow-moving cloud) could have added more.

Some of the sun's cloud's dust aggregated into big balls - planets and asteroids large enough to melt themselves, and dense iron and siderophiles (including gold) sank to form a core. The asteroids solidified relatively quickly, being smaller. Some of the big asteroids hit each other, and their shattered cores became nickel-iron meteorites. We do not know if they have nuggets or just dispersed gold (earthly nugget production involved water, heat and pressure). Some of these asteroids hit earth after its own core had formed and so stayed in the crust. See geology books or wikipedia for nugget formation on earth.
Clear enough?
RealScience
5 / 5 (1) Sep 09, 2011
Nano - For earth-based nugget formation, I agree with Otto - Google: gold nugget formation geology, and then read the dozen links.
marraco
not rated yet Sep 09, 2011
Why would these rare/trace metals, if created in distant stellar mergers, appear on earth (or meteors) in nuggets ranging from milligrams to kilograms in size?...

Possibly, on early stages of planetary systems formation, lots of small planets grow, and destroy by colliding.

Those protoplanets probably melt by accumulated heat caused by natural fission, and then reorganize in layers of different density.
that_guy
3.8 / 5 (4) Sep 09, 2011
@Nano - Please read Ghost's post about gold deposits.

Then read what I posted about gold nuggets.

Please note that gold deposits, and the formation of nuggets are two seperate things. That said, Hopefully you find your answer.

Just because something is formed from supernovas or from colliding neutron stars doesn't mean it doesn't have any variation in concentration. It also doesn't mean that there won't be processes in the last 6 billion years that might concentrate and layer it in various ways.

If you have further questions, this is not the forum to take them to, you should do some research and find out how it's done, rather than question something that you apparently have little interest in actually knowing.
extinct
1 / 5 (6) Sep 09, 2011
gold can be made from other metals such as lead, mercury, silver, copper, etc and an electrical current, to put it simply. alchemy has been lost through time but it's still a very real thing for the few who pursue it, and no, i'm not one of 'em, but go look at the before and after pics and the descriptions... if you can put up with all the typos... drjoechampion dot com
Crazy_council
1 / 5 (1) Sep 10, 2011
would the planet collision have created enough energy, when earth was reformed and the moo was created. Should there be gold on the moon,
omatumr
1 / 5 (7) Sep 10, 2011
Evidence published by YOU Oliver? With links to YOUR own blogs? I'd point out that just because a journal publishes a paper does not make it correct, obviously because they publish so many competing theories. Also, YOUR theory stated here is obsolete in the face of much data gained since you published YOUR paper, in what appears to be a japanese geochemical journal that was 3 years old, looking for american scientists to publish to enhance its standing. They failed.

You're absolutely ridiculous.


What do you disagree with?

Heterogeneous accretion of the Earth was proposed by two well-known geochemists at Yale University in 1969 ( Karl K. Turekian and S. P. Clarke, Jr) [1] and confirmed by two stable isotope geochemists in 1981 [2].

1. "Inhomogeneous accumulation of the Earth," Earth Planet. Sci. Lett. 6, 346-348 (1969)

2. The noble gas record of the terrestrial planets", Geochm J 15, 247-267 (1981)

http://www.omatum...eGas.pdf
Parsec
not rated yet Sep 11, 2011
Since gravity of collapsing stars of 3-10 times the mass of the sun can be enough to form neutron stars (which is already way beyond the energy needed for fusion to heavier elements) it's not unreasonable to assume that parts that did not quite make it could fuse to heavier elements, is it?

i.e.:
- parts that were not quite dead center during the collapse and were blown off during the formation of a neutron star or
- parts of stars that don't have the mass to form neutron stars but came close

There seems to be a process (r-process) in type Ib, Ic and II supernovae that could do this type of nucleosynthesis.

The main argument is: we can do fusion here on Earth to stable elements while having a negative Q factor (pumping in more energy than we get out). Why should this not be possible in stars at some locations?
The s-process is what your talking about, and does exactly this. But the products are extremely dilute.
macsglen
not rated yet Sep 11, 2011
GhostOtto -- thanks very much for the links on ore deposition. Very informative.
hush1
1 / 5 (1) Sep 17, 2011
http://www.howstu...n486.htm

Excerpt:
"So how big does a meteoroid have to be to make it to the surface of the Earth? Surprisingly, most of the meteoroids that reach the ground are especially small - from microscopic debris to dust-particle-size pieces."

http://www.scienc...abstract
http://www.boulde...breakup/
http://www.google...;cad=rja

Excerpt:
"About 40,000 tons of extraterrestrial matter
fall to Earth each year."

.1)If the Earth is in radiative equilibrium, then the earth exhibits stable global temperatures.

.2)If you considered dust accreditation as universal for all heavenly bodies, then a body with a condensed matter equilibrium appears unlikely.

3.)Our global condense matter net balance is...?