Relative dating involves radioactive isotopes Married wife live sex chat
The intensity of all types of radiation from a point source follows an inverse-square law in relation to the distance from its source.
Like any ideal law, the inverse-square law approximates a measured radiation intensity to the extent that the source approximates a geometric point.
Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles.
Typical alpha particles (α) are stopped by a sheet of paper, while beta particles (β) are stopped by an aluminum plate.
The lower-energy, longer-wavelength part of the spectrum including visible light, infrared light, microwaves, and radio waves is non-ionizing; its main effect when interacting with tissue is heating.
This type of radiation only damages cells if the intensity is high enough to cause excessive heating.
This is an important distinction due to the large difference in harmfulness to living organisms.
A common source of ionizing radiation is radioactive materials that emit α, β, or γ radiation, consisting of helium nuclei, electrons or positrons, and photons, respectively.
If the source of the ionizing radiation is a radioactive material or a nuclear process such as fission or fusion, there is particle radiation to consider.