Radiocarbon dating provides a range, often spanning 200 years or more, rather than an exact date for a site.

采用放射性碳技术来测定一处考古遗址的年代，得到的并不是一个准确日期，而是一个时范围通常为200年或更久远的数值。

Many aspects of a white dwarfs mechanics, including how long it will last, are thought to depend on its magnetism. But it is hard to measure.

人们认为白矮星演化过程的诸多方面都决定它的磁性，包括演化持续的时。但其磁场一直难以测定。

There have been many artefacts found over time in archaeological dig sites, that based on carbon dating should not have existed during that time.

长时以来在古迹中，土了很多古代遗物，基碳-14年代测定的方法本不应该存在那个时代。

According to radiocarbon dating, this was made sometime between 50 BCE and 275 CE.

根据放射性碳年代测定，这件物品的制作时大约在公元前50年至公元275年之。

To date the new artifacts, the team used a technique called optically stimulated luminescence, or OSL, which reveals the last time a mineral was exposed to sunlight.

为了测定这些新文物的年代，研究团队使用了一种称为光释光测年法的技术， 该技术可以揭示矿物最后一次暴露在阳光下的时。

When we date these flood basalts, we see that  many of these eruptions align with mass extinction events.

当我们对这些洪水玄武岩喷发进行年代测定时，发现许多喷发事件与大规模灭绝事件在时上相吻合。