Many people in this debate are familiar with the "problem" of Polonium halos, however this thread is not about Polonium halos, and any further mention is off topic (see PRATT CF201: Polonium Halos). Anyone wanting to talk about Polonium halos is free to start their own thread, and not clutter this one up, thanks.
quote:13. "Radiation halos" in rocks prove that the Earth was young.
This refers to tiny halos of crystal damage surrounding spots where radioactive elements are concentrated in certain rocks. Halos thought to be from polonium, a short-lived element produced from the decay of uranium, have been found in some rocks. ...
At any rate, halos from uranium inclusions are far more common. Because of uranium's long half-lives, these halos take at least several hundred million years to form. Because of this, most people agree that halos provide compelling evidence for a very old Earth.
(bold added for empHASis, part deleted not about uranium halos)
The stock YEcreationist response is that the decay rates changed, and thus all you are seeing is the result of fast decay rather than long time.
Aside from this being another PRATT (see CF210: Constancy of Radioactive Decay) which is also off topic and not part of this thread, it struck me that Uranium halos are evidence that this did not occur.
The basic radiohalo principle is simple: radioactivity produces alpha decay, and the alpha particle have a certain energy (usually measured in million electron volts, MeV) based on the familiar e=mc² formula and the conservation of energy/mass (see ref):
M1 = M2 + mp + e/c²
Thus when you have isotopes decaying into other isotopes by alpha decay, the energy of the alpha particle is unique to that decay stage because of the unique before and after mass of the decaying isotope and the constant mass of the alpha particle.
This unique energy then determines how far (on average) an alpha particle will travel before it gets stopped and absorbed into the surrounding material (and causes the ring pattern to be visible) and the result is a halo or a number of halos around decaying inclusions that look like rings, but are actually spherical, and something like this:
The halos require more than one particle to form as each one only makes a point on the ring. Thus uranium, with it's long half-life, takes "several hundred million years to form."
Now the fun part: this is based on our knowledge of physics and the physical constants that tell us how things behave in the universe, so what happens if you have fast decay instead of old time?
Not being a physicist, I am not familiar with the equations that link decay rate to decay energy, so I am going on memory, but I found this interesting tid-bit in Alpha Decay, Alpha detectors and identification:
quote:However, if the alpha has enough energy to surmount this barrier then it will regain that energy as electrostatic repulsion once it gets outside the range of the attractive strong nuclear force. One important consequence of this is that all alpha emissions have at least ~5 MeV energy. Furthermore, half-life is inversely related to decay energy.
(bold for empHASis)
Very simply put, if you change the decay rate, you change the decay energy, and the diameter of the halo changes.
There should be no characteristic uranium halos with the unique energy of uranium alpha decay from fast decay.
The existence of (common) uranium halos then is evidence that shows the physical constants have not changed while they were formed, and their formation in turn is evidence that the earth is old, at least several hundred million years old.
Enjoy.
ps - I would appreciate any of the physics mavens supplying confirmation of my rambling, and possibly provide the equation/s relating decay rate to decay energy. Thanks.
ppss - anyone that can tell what goes on in the ring formation would also help.
DATES AND DATING forum please (I am thinking this is another correlation item)
Edited by RAZD, : was "an alpha particle will travel before it decays" changed decays into "stopped and absorbed"
quote:Several micro-techniques (confocal laser-Raman microprobe, optical absorption micro-spectroscopy, high-resolution transmission electron microscopy, electron microprobe analysis) were employed in the detailed characterization of radiohaloes in biotites from two Variscan rocks from Germany. The studied biotites are intermediate members of the phlogopite-annite series with Mg/Fe2+ ratios in the range 1.6 -1.0. Radiohaloes in biotite resulted from the impact of 4He cores (α-particles) emitted from actinide-bearing inclusions. Monte Carlo simulations yielded α (238U, 235U, and 232Th series) penetration ranges in biotite between 12.5 and 37.3 μm, which are in reasonable agreement with the observed radii of radiohaloes in natural biotites. The coloration pattern of a radiohalo closely correlates with the calculated distribution pattern of point defects generated in displacive events. Calculated point defect densities in the range from < 10-5 to at most 10-2 dpa (displacements per lattice atom) suggest that there are only scattered point defects in a mainly preserved biotite lattice. This is consistent with HRTEM studies that did not reveal any indication for initial volume amorphization in the haloes. However, general Raman band broadening and intensity loss suggest that the short-range order in radiohaloes is significantly disturbed. The darkened color of radiohaloes, when compared with the un-irradiated host biotite, is caused by increased light absorption over the complete visible range due to increased point defect density. No additional color centers were found, and the absorbances of the VIFe2+, Fe2+< sup> - Fe3+, and Fe2+ - Ti4+ centers seem hardly to be changed. Both Raman and optical absorption spectra obtained from radiohaloes retain a clear orientational dependence. The results suggest that the formation of point defects rather than ionization is the main process causing the coloration of radiohaloes in natural biotites. The haloes represent an early stage of structural radiation damage, characterized by significantly disturbed short-range order but still widely preserved long-range order of the structure.
(bold for empHASis)
SO the ring would be caused by the alpha particle causing a "point defect" in the surrounding material, interrupting the normal light pattern
anyone that can tell what goes on in the ring formation would also help.
Surely it's chemical/mechanical damage. Alphas bouncing off nuclei until they run out of steam, and then stealing electrons from atoms and making new ions out at the out-of-steam radius are both going to do some damage to crystal structure in the host mineral. Enough alpha particles from a bit of uranium, and one can see the damage.
I'm betting the YEC response will sound like, "Yeah, now alpha energy and half-life correlate inversely, but back during Teh Fludde......"
"The wretched world lies now under the tyranny of foolishness; things are believed by Christians of such absurdity as no one ever could aforetime induce the heathen to believe." - Agobard of Lyons, ca. 830 AD
quote:Unlike the electric forces, whose strengths are given by the simple Coulomb force law, there is no simple formula for how the strong nuclear force depends on distance. Roughly speaking, it is effective over ranges of ~1 fm, but falls off extremely quickly at larger distances (much faster than 1/r2). Since the radius of a neutron or proton is about 1 fm, that means that when a bunch of neutrons and protons are packed together to form a nucleus, the strong nuclear force is effective only between neighbors.
In a very heavy nucleus, (c), a proton that finds itself near the edge has only a few neighbors close enough to attract it significantly via the strong nuclear force, but every other proton in the nucleus exerts a repulsive electrical force on it. If the nucleus is large enough, the total electrical repulsion may be sufficient to overcome the attraction of the strong force, and the nucleus may spit out a proton. Proton emission is fairly rare, however; a more common type of radioactive decay in heavy nuclei is alpha decay, shown in (d). The imbalance of the forces is similar, but the chunk that is ejected is an alpha particle (two protons and two neutrons) rather than a single proton.
It is also possible for the nucleus to split into two pieces of roughly equal size, (e), a process known as fission.
This is just background information, not for discussion yet.
quote:The energy of emitted alpha particles was a mystery to early investigators because it was evident that they did not have enough energy, according to classical physics, to escape the nucleus. Once an approximate size of the nucleus was obtained by Rutherford scattering, one could calculate the height of the Coulomb barrier at the radius of the nucleus. It was evident that this energy was several times higher than the observed alpha particle energies. There was also an incredible range of half lives for the alpha particle which could not be explained by anything in classical physics.
The resolution of this dilemma came with the realization that there was a finite probability that the alpha particle could penetrate the wall by quantum mechanical tunneling. Using tunneling, Gamow was able to calculate a dependence for the half-life as a function of alpha particle energy which was in agreement with experimental observations.
quote:The nuclear binding energy of the alpha particle is extremely high, 28.3 MeV. It is an exceptionally stable collection of nucleons, and those heavier nuclei which can be viewed as collections of alpha particles (carbon-12, oxygen-16, etc.) are also exceptionally stable. This contrasts with a binding energy of only 8 MeV for helium-3, which forms an intermediate step in the proton-proton fusion cycle.
I envisage it as a pyramid with each particle in contact with the other, and therefore bound by the strong force.
The illustration represents an attempt to model the alpha decay characteristics of polonium-212, which emits an 8.78 MeV alpha particle with a half-life of 0.3 microseconds. The Coulomb barrier faced by an alpha particle with this energy is about 26 MeV, so by classical physics it cannot escape at all. Quantum mechanical tunneling gives a small probability that the alpha can penetrate the barrier. To evaluate this probability, the alpha particle inside the nucleus is represented by a free-particle wavefunction subject to the nuclear potential. Inside the barrier, the solution to the Schrodinger equation becomes a decaying exponential. Calculating the ratio of the wavefunction outside the barrier and inside and squaring that ratio gives the probability of alpha emission.
Change the decay rate, and you change the energy of the alpha particle. Not a strict inverse relationship (exponential?)
Now the we can translate the above condition for the possibility of an α-decay to Qα > 0. Fig. 14 shows a diagram with Qα-values for β-stable nuclei. Positive values start to appear for A > 150.
While the energy range of alpha-decays observed in nature is relatively narrow (~ 2 - 12 MeV) the lifetimes span a range from 10 ns to more than 10^19 years. To better understand this behaviour we will investigate the mechanism of this decay a little closer. ... So we find for the decay constant:
λ = w(α)vαe-G/2R
Okay, I'm having trouble getting from Qα to λ
Translation needed.
Enjoy.
Edited by RAZD, : 10^19 not 1019
Edited by RAZD, : darn smilies
Edited by RAZD, : .
Edited by RAZD, : formula restored
Edited by Zen Deist, : fixed formula again. tried to fix link but it is subject to annual revision
Change the decay rate, and you change the energy of the alpha particle.
Which is how bismuth 209 can have a 3 MeV alpha decay - its half life is 10^19 years.
Where are the YEC's, Coragyps wonders......
"The wretched world lies now under the tyranny of foolishness; things are believed by Christians of such absurdity as no one ever could aforetime induce the heathen to believe." - Agobard of Lyons, ca. 830 AD
The stock YEcreationist response is that the decay rates changed, and thus all you are seeing is the result of fast decay rather than long time.
Makes sense if you take genesis literally you could have 3,000 to 4,000 years of accelerated decay. The sun became a light on day 1 according to some creationists 13,000 years ago. It was not a light unto the earth according to genesis for those first 3 creationists days (3,000 years) thus the sun just a star was likely like a torch in the sky could of been producing excessive amounts of gamma radiation, a much greater magnetic field, causing an acceleration of decay as part of the creation of the earth and the atmosphere until day 4 when the sun was made a light unto the earth.
It was not until day 4 that the sun according to some creationists the sun was made a light unto the earth the present slower decay rates, and the ever weakening magnetic fields of the earth.
P.S. Uniformitists assume the sun has been a star more than 13,000 years but if the young earth creationists are right and the sun became a star approximately 13,000 years ago on creation day 1 and was not a light unto the earth until day 4 you have 3,000 to 4,000 years of accelerated decay possible from their point of view happening on the earth explaining the appearance of age but not the age of the earth.
Remedial treatment of nucleur wastes are looking to gamma radiation, proton acceleration, higher magnetic fields, photons " not neutrons or alpha radiation" to accelerate uranium decay rates, to treat nuke wastes, etc...
In a few major bursts, the sun produces gamma rays with energies up to one million electron volts. The interaction of high-energy electrons, protons, and nuclei of the sun, emit the rays.
Generally speaking, the target nucleus of the radioisotope(s) to be treated is irradiated by gamma photons of an energy greater than the binding energy of the neutron in the target nucleus. This causes the irradiated nucleus to absorb the gamma rays, thereby placing the nucleus in an excited state. Upon relaxation, the nucleus ejects a neutron through the (gamma, n) reaction, thereby transmuting the element to an isotope of lower atomic mass and shorter half-life.
Using U238 as the source, this process would result in U237, half life of 6.75 days, a beta emitter which becomes Np237 an alpha emitter with a half life of 2.14E6 years (2,140,000) This doesn't accelerate the decay any where near what would be needed to reduce the age of the sun from 5 billion years to 13000 years. As for the same procedure on the infant sun, the only isotopes at this time would have been H1, H2, H3, He3 & He4. Doing the same procedure would produce
: from H1 a neutron which emits a beta to rebecomes H1 H2 becomes H1 stable, H3 becomes H2 stable, He3 becomes He2 Beta plus emiier becomes H2 stable, He4 becomes He3 stable. The only radioactive isitope created is He3 from the almost nonexistant He3 Thus no accelleration of radioactive decay. Figures from Handbook of Chemistry and Physics, edition 87, 2006
Edited by bluescat48, : spelling
There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969
Makes sense if you take genesis literally you could have 3,000 to 4,000 years of accelerated decay.
This thread is not about how you twist reality into your private mythology.
It is about Uranium halos, and why Uranium halos are (a) evidence that there has been no change to the rate of decay for hundreds of millions of years and (b) that the earth is at least several hundred million years old.
If the decay rates had changed we would not have Uranium halos, because the energy of the alpha particles would change WITH the change in decay rate, and the resulting rings would NOT be at the correct diameter, if they weren't smeared to much to see.
You don't discuss this at all, so your entire post is irrelevant, typical of your failure to deal with reality.
It is about Uranium halos, and why Uranium halos are (a) evidence that there has been no change to the rate of decay for hundreds of millions of years and (b) that the earth is at least several hundred million years old.
That I agree this is the uniformitists belief but some creationists believe accelerated decay answers the appearance of age is not evidence of an old earth.
If the decay rates had changed we would not have Uranium halos, because the energy of the alpha particles would change WITH the change in decay rate, and the resulting rings would NOT be at the correct diameter, if they weren't smeared to much to see.
Where is your evidence that accelerated decay would change the energy of the alpha particle affecting ring diameter, etc...?
The decay rate is based on the probability of decay for an atom, change the probability (increase decay) and you change the decay rate of an isotope.
Change the decay rate, and you change the time a alpha particle takes to get through the Coulomb barrier (it follows the decay curve). This changes the energy absorbed in the process, which changes the energy left over. The energy left over is what sends the alpha particle out to make the ring.
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