Dating methods1 Carbon-14 dates are determined from the measured ratio of radioactive carbon-14 to normal carbon-12 (14C/12C). Used on samples which were once alive, such as wood or bone, the measured 14C/12C ratio is compared with the ratio in living things today. The date is calculated by assuming the change of 14C in the sample is due entirely to radioactive decay. It is also assumed that carbon has been in equilibrium on the earth for hundreds of thousands of years.
Wrong dates are usually caused by assuming a wrong initial 14C/12C ratio, contamination or leaching. Samples from before the Flood, or from the early post-Flood period, give ages that are too old by tens of thousands of years. This is because the Flood buried lots of 12C-rich plants and animals. This would result in a lower 14C/12C ratio, which is wrongly interpreted as great age.
Thermoluminescence (TL) dates are obtained from individual grains of common minerals such as quartz. When such grains are heated, they emit light, and this is related to the radiation ‘stored’ in the crystal structure. It is assumed that the radiation was slowly absorbed from the environment, building up from zero at a certain time in the past (perhaps when the grain was last exposed to sunlight). A date is calculated by measuring the light emitted from the mineral grain when it is heated, and measuring the radiation in the environment where the grain was found.
Unfortunately, there are many unknowns and many assumptions need to be made, including the amount of radiation ‘stored’ in the mineral at a certain time in the past, that the change in radiation has only been affected by the radiation in the environment, that the radiation in the environment has remained constant, and that the sensitivity of the crystal to radiation has not changed. All these factors can be affected by water, heat, sunlight, the accumulation or leaching of minerals in the environment, and many other causes.
Optically-stimulated luminescence (OSL) dates are based on exactly the same principle as TL. But instead of heating the grain, it is exposed to light to make it emit its ‘stored’ radiation. The calculated date is based on the same assumptions, and affected by the same uncertainties, as for TL.
Electron-spin resonance (ESR) dates are based on the same principles as TL and OSL. However, the ‘stored’ radiation in the sample is measured by exposing it to gamma radiation and measuring the radiation emitted. The measuring technique does not destroy the ‘stored’ radiation (as does TL and OSL), so the measurement can be repeated on the same sample. The calculated date is based on the same assumptions, and affected by the same uncertainties, as for TL and OSL.
Thorium-uranium (Th/U) dates are based on measuring the isotopes of uranium and thorium in a sample. It is known that uranium-238 decays radioactively to form thorium-230 (through a number of steps, including through uranium-234). The dating calculation assumes that the thorium and uranium in the sample are related to each other by radioactive decay. Furthermore, before a date can be calculated, the initial ratios of 230Th/238U and 234U/238U need to be assumed, and it is also assumed that there has been no gain or loss of uranium or thorium to/from the environment—i.e., that the system is ‘closed’. However, the bone and soil must have been ‘open’ to allow these elements to enter and accumulate.
Protactinium-uranium (Pa/U) dates are based on similar principles as Th/U dating, but use uranium-235 and protactinium-231 instead. The isotope 235U decays radioactively to form 231Pa. Again, it is assumed that the isotopes in the sample are related to each other by radioactive decay. Also, the initial ratio of 231Pa/235U has to be assumed, and it is assumed that there has been no gain or loss of uranium or protactinium to/from the environment—i.e., that the system is ‘closed’. Again, any bone sample containing uranium must have been ‘open’ to allow it to accumulate in the first place.
Reference Details about dating methods may be obtained from such sources as: Smart, P.L. and Frances, P.D. (Eds.), Quaternary Dating Methods—A User’s Guide, Quaternary Research Association, Technical Guide No. 4, Cambridge, 1991, or Faure, G., Principles of Isotope Geology, 2nd edition, John Wiley & Sons, New York
http://www.answersingenesis.org/creation/v26/i1/game.asp
As for the 'law of physics' being changed by a 'capricious agent', on the contrary, it is because God is not capricious that we can count on nature to be constant (Gen.9:22)
There is nothing in any 'natural' law that shows that Evolution is correct or even possible.
You had to 'imagine' another Universe to get this one.
Indeed. That means he can be safely removed from the equation. This is one reason that methodological naturalism was adopted.
As for your quote from AiG, they seem to be missing the fact that every dating method is cross verified with others and calibrated according to the conditions of the samples. The scientists who collect the samples and the scientists who run the tests are well aware of the potential problems and adjust to take them into account.
Surely you don't believe that all of the geophysicists, geologists, physicists, astronomers, astrophysicists, biologists and chemists that prepare and perform dating are dumber than the authors at AiG?