Carbon 14 dating equipment
A new way to carbon-date old samples has been developed by physicists in Italy.Unlike current methods, which involve large and costly laboratory equipment, the new technique can be performed using portable and low-cost equipment.Archaeology and other human sciences use radiocarbon dating to prove or disprove theories.Over the years, carbon 14 dating has also found applications in geology, hydrology, geophysics, atmospheric science, oceanography, paleoclimatology and even biomedicine.Because the laser light is injected into the cavity in advance and switched off during the measurement, SCAR is not affected by fluctuations in laser intensity.Another benefit of the technique is that the multiple reflections ensure that the light interacts with the gas for a much longer time than if the laser were just fired through a sample.This new method is based on infrared laser spectroscopy, which probes the quantized vibrational modes of molecules.A specific type of molecule will absorb infrared light only at energies corresponding to its vibrational modes.
When an organism dies, it stops taking in carbon, so the number of carbon-14 atoms decreases with a half-life of about 5730 years – a timescale that makes it ideal for investigating human history.Radiocarbon, or carbon 14, is an isotope of the element carbon that is unstable and weakly radioactive. Carbon 14 is continually being formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen 14 atoms.It is rapidly oxidized in air to form carbon dioxide and enters the global carbon cycle."It is an incredibly sensitive measurement of a very small quantity of this very rare isotope," says David Nelson, atmospheric scientist at Aerodyne Research in the US.However, he points out that the technique benefits from the fact that carbon dioxide "has an extraordinarily strong infrared line strength.