Posted on 12/08/2015 11:01:44 AM PST by sparklite2
[This article is much more interesting than its headline]
Several years ago it was discovered that the early Solar system contained a significant amount of plutonium-244. Considering its short-lived cycle, plutonium-244 that existed over four billion years ago when Earth formed has long since decayed but its daughter elements have been detected. Plutonium is a radioactive element. Its longest-lived isotope is plutonium-244 with a lifetime of 120 million years. Detection of plutonium-244 in nature would imply that the element was synthesized in astrophysical phenomena not so long ago (at least in Galactic time scales) and hence its origin cannot be too far from us.
But recent measurements of the deposition of plutonium-244, including analysis of Galactic debris that fell to Earth and settled in deep sea, suggest that only very small amount of plutonium has reached Earth from outer space over the recent 100 million years. This is in striking contradiction to its presence at the time when the Solar system was formed, and that is why the Galactic radioactive plutonium remained a puzzle.
The Hebrew University team of scientists have shown that these contradicting observations can be reconciled if the source of radioactive plutonium (as well as other rare elements, such as gold and uranium) is in mergers of binary neutron stars. These mergers are extremely rare events but are expected to produce large amounts of heavy elements.
The model implies that such a merger took place accidentally in the vicinity of our Solar System within less than a hundred million years before it was born. This has led to the relatively large amount of plutonium-244 observed in the early Solar system.
(Excerpt) Read more at dailygalaxy.com ...
Interesting point.
If the Earth is unique, or at least very rare, then that is an answer to “why aren’t they here” about extraterrestrial intelligence.
On the other hand there doesn’t seem to be a direct or indirect connection between the prevalence of heavy metals and the formation of life or the development of intelligence.
Good, so if we just figure out how to merge neutron stars and harvest the heavy metals we should be able to keep nuclear plants running indefinitely.
"Neutron stars pack their mass inside a 12.4 miles diameter.
They are so dense that a single teaspoon would weigh a billion tons"
Agreed. I don’t know what the impact would be, but when you think about it, how many movie aliens have you seen that wore gold bling?
These had loads of bling -
Flash Gordon
http://www.imdb.com/title/tt0080745/
if gold, silver and platinum are rare because the forces that produce heavy elements are unusual, why is lead so cheap?
Thanks sparklite2.
It’s their various properties that make them especially valuable.
Lead is the decay product of 2 isotopes of uranium and one of thorium. My guess would be that it is more plentiful than these because the half-lives of the parent isotopes had expired prior to their placement in the Earth and solar system.
The Hebrew University study might suggest as well why these parent isotopes are as abundant in this system as they are.
Interesting hypothesis, sparklite2. Thanks for posting.
Couldn't prove it by me. Priced fishing sinkers lately? They're about triple what they were a few years ago.
I believe their rarity makes them valuable. All the gold ever mined would fit in a good sized barn.
GOLD
Besides its obvious beauty for jewelry and other decorative uses...
Physical and chemical properties:
Gold has unique physical chemical characteristics that made it very valuable.
Gold is the most malleable and ductile of all the metals.
One ounce of gold can be drawn into more than [50 miles] of thin gold wire.
One ounce of gold can be beaten into a sheet covering 9 square meters and 0.000018 cm thick.
Gold has an electrical resistivity of 0.022 micro-ohm and a thermal conductivity of 310 W m-1. hence, it is very efficient for the transmission of heat and electricity.
Gold has the highest corrosion resistance of all the metals and it is corroded only by a mixture of nitric and hydrocloric acid. Gold is a noble metal because it does not oxidize.
Scarcity:
The mentioned characteristics are enough to make a very useful and desired metal; thus, a very valuable one.
Besides, it is important to consider that gold is rather scarce. It is estimated that the whole gold of the planet equals a total of 168,180 tonnes or 5,407,112,558 ounces.
To visualize this imagine, let’s imagine a single solid gold cube with edges of about 19 meters. This is about three meters shorter than the length of a tennis court.
http://sciengsustainability.blogspot.com/2013/05/why-is-gold-so-valuable.html
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“Gold’s atomic number of 79 makes it one of the higher atomic number elements that occur naturally in the universe. It is thought to have been produced in supernova nucleosynthesis from the collision of two neutron stars[4] and to have been present in the dust from which the Solar System formed. Because the Earth was molten when it was just formed, almost all of the gold present in the early Earth probably sank into the planetary core. Therefore, most of the gold that is present today in the Earth’s crust and mantle is thought to have been delivered to Earth later, by asteroid impacts during the late heavy bombardment, about 4 billion years ago.
Gold resists attacks by individual acids, but it can be dissolved by aqua regia (nitro-hydrochloric acid, literally “royal water”). The acid mixture causes the formation of a soluble gold tetrachloride anion. Gold metal also dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. It is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in items, giving rise to the term acid test; it dissolves in mercury, though, forming amalgam alloys, but this is not a chemical reaction.
This metal has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history. In the past, a gold standard was often implemented as a monetary policy within and between nations, but gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard was finally abandoned for a fiat currency system after 1976. The historical value of gold was rooted in its medium rarity, easy handling and minting, easy smelting, corrosion resistance, distinct color, and non-reactivity to other elements.
A total of 183,600 tonnes of gold have been mined in human history, as of 2014.[5] This is equivalent to 9513 m3 of gold. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry.[6] Gold’s high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to its continued use in corrosion resistant electrical connectors in all types of computerized devices (its chief industrial use). Gold is also used in infrared shielding, colored-glass production, gold leafing, and tooth restoration. Certain gold salts are still used as anti-inflammatories in medicine.”
https://en.wikipedia.org/wiki/Gold
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