Carbon dating. Animation of how a radioactive isotope of carbon can be used to date objects containing organic matter. This is known as carbon dating or radiocarbon dating. The start of the animation shows a cosmic ray (blue) impacting a particle in the atmosphere (in this case a proton, red) to produce a neutron (yellow). This neutron then impacts the nucleus of the non-radioactive isotope nitrogen-14 (causing emission of a proton), turning it into the radioactive isotope carbon-14. This carbon-14 is taken up by plants in the form of carbon dioxide (CO2). The animation shows a mammoth eating the plants, taking up the carbon-14. A landslide kills the mammoth and the process of fossilisation begins. The carbon-14 changes back to nitrogen-14 by the emission of radiation. Over geologic time, the radioactivity due to the carbon-14 decreases in a known fashion (graph). This allows fossils and other objects to be dated by measuring the current levels of radiation due to the remaining carbon-14. The oldest objects that can be reliably measured in this way are from around 50, 000 years ago. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / EQUINOX GRAPHICS / RHYS LEWIS, AHS, DECD, UNISA |
Modell-Rechte: | nicht erforderlich |
Länge: | 01:23 Minuten |
Seitenverhältnis: | 16:9 |
Restrictions: | - |