As you move down the periodic table the elements become more and more unstable.
Current science will
tell you that after the big bang had cooled enough the universe was filled with hydrogen and helium.
From this, the first stars formed. These are thought to be thermonuclear
powerhouses that convert these elements through nuclear fusion into large atoms.
This has a limit and beyond iron the elements cannot be fused in this manner.
The remaining, and there are many, elements are created in explosive events like supernova
which would have enough energy to create these larger elements.
The problem is that these larger elements at a certain point become unstable
and will want to decay to lighter ones. This means that there are some exotic heavy elements
that will generally only last for a relatively short period of time.
So when Physicists uncovered a pair of large,
still radioactive isotopes in samples of deep-sea crust pulled from 1500
metres below the pacific ocean it raised some interesting questions. Let’s find out more…
According to the current scientific view, the Solar System formed from a cloud of gas
and dust that collapsed to form the star and planets. This initial cloud may well
have contained some of these elements but most of them should have decayed into more stable formed
long before they were extracted from the sea bed.
The two isotopes they discovered were iron 60 and plutonium 244. Iron 60 is very unstable
and has a half life of 2.6 million years and will decay to nickel. Finding this iron in
the crust would imply a relatively recent delivery of iron from some cosmic event.
Iron 60 has appeared in rock samples before,
and it has also been seen in some of the samples brought back from the lunar surface.
The other isotope they found was plutonium 244,
an isotope with a half-life of just over 80 million years.
What the scientist discovered was two distinct influxes of iron 60 which must
have arrived within the past 10 million years. both samples were accompanied
by a small but significant quantity of Plutonium 244 each in a similar ratio.
Finding them together adds more detail than finding either part.
The amount of Plutonium in them is lower than would be expected if supernova were primarily
responsible for their production, pointing to contributions from other r-processes.
In nuclear astrophysics, the rapid neutron capture process, also known as the r-process, is a set of
nuclear reactions that is responsible for the creation of approximately half of the atomic
nuclei heavier than iron. The r-process entails a succession of rapid neutron captures by one or
more heavy seed nuclei, typically beginning with nuclei in the abundant speak centred on iron. the
captures must be rapid in the sense that the nuclei must not have time to undergo
radioactive Decay before another neutron arrives to be captured. this sequence can continue up to
the limit of stability of the Increasingly neutron-rich nuclei. This process must
therefore occur in locations where there exists a high density of free neutrons. Early studies
theorized that 10 ^ 24 neutrons per centimetre cubed would be required. this amounts to almost
a gram of free neutrons in every cubic centimetre, an astonishing number requiring extreme locations.
It is only possible for an atom to absorb so many
neutrons this is known as the neutron drip line. so a heavy element such as plutonium 244
Cannot be instantly formed from neutrons alone. it requires many Cycles adding neutrons
and then allowing it to decay to a stable structure before you continue this process.
Exactly how this particular sprinkle of alien dust ended up very deep
inside a crust is never really properly explained.
The lead scientist stated "the story is complicated,
possibly this plutonium 244 was produced in a Supernova explosion or it could be leftover
from a much older but even more spectacular event such as a neutron star detonation.
They speculate the production of iron 60 is compatible with two
of four Supernova events going off between 160 and 330 light-years away.
Of course, there is a totally different way of looking at this. the fact that they find these
elements within the crust of the Earth May in fact points to the fact that the current
model for the creation of elements is incorrect. Rapid neutron capture seems rather far-fetched
and requires conditions that almost seemed inaccessible.
It requires either a neutron star to explode releasing lots of neutrons or Supernovae. And for
this to come in waves to allow for the gradual build-up of the atom from iron with neutrons!
If we consider the structured atomic model then we can see that it may be possible but
these elements were created in situ inside the crust. We know from sapphire that
electrical transmutation is possible. So could electrical events running through the
crust cause the fusion of other elements in the crust creating some of these heavier isotopes.
One potential reaction could be calcium-40 fusing with oxygen 16 producing iron 56.
calcium can also be found with a 2% abundance in the form of calcium 44.
an alternative reaction would therefore be B&B calcium 44 + oxygen 16 produces iron 60.
this would constantly Decay and therefore would drop in abundance.
The rate of decay is also something that is currently assumed to be steady
but some experiments do show that this rate is variable.
This means that when they date the Iron 60 to 10 million years
this may be totally wrong. The question is whether these processes occur all the time or whether it
takes a cataclysmic discharge event to create these larger isotopes, especially plutonium 244
Now this is nothing new. When we looked at the abundance of elements
and where they are found we asked the question why do we find so many
heavy metals in veins. We saw there that the current model for how metals end up in veins
and are only ever found in the crust was fatally flawed. Most metal veins contain a collection of
different metals and almost always end in the heavier elements particularly uranium.
Most of these veins take up the shape of a discharge channel.
So it really should not come as a surprise to find these elements locked away in the
crust. The whole topic around the abundance of certain elements and the question of where the
elements come from is something that I would like to dig into deeper in the near future.