有關化石、半衰期、化石年期如何計算，其準確性及影響因素？

Carbon-14 dating is not the only dating technique. It has a disadvantage that only ancient objects that contain carbon can be dated using this technique. For objects like ceramics, or rocks, carbon-14 dating technique is not applicable.

Carbon-14 dating relies very much on the ratio of radioactive carbon-14 to stable carbon in the natural environment. But there is no guarantee that such ratio has not alterd throughout a long period of time.

A more widely used dating technique (especially in Hong Kong) is "thermoluminescence dating". It makes use of nuclear counting technique to estimate the age of an acient object from the amount of natural radiation absorbed.

Apart from the above two techniques, other dating methods include electron spin resonance, fission track, archaeomagnetism, uranium-thorium dating....etc.

The web-page cited below gives an account of various dating methods, you could have a look on it,

http://www.mnsu.edu/emuseum/archaeology/dating/