Before Present BP years is a time scale used mainly in archaeology , geology , and other scientific disciplines to specify when events occurred before the origin of practical radiocarbon dating in the s. Because the "present" time changes, standard practice is to use 1 January as the commencement date epoch of the age scale. The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. Some archaeologists use the lowercase letters bp , bc and ad as terminology for uncalibrated dates for these eras.
If you want to know how old someone or something is, you can generally rely on some combination of simply asking questions or Googling to arrive at an accurate answer. This applies to everything from the age of a classmate to the number of years the United States has existed as a sovereign nation and counting as of But what about the ages of objects of antiquity, from a newly discovered fossil to the very age of the Earth itself? Sure, you can scour the Internet and learn rather quickly that the scientific consensus pins the age of of the planet at about 4. But Google didn't invent this number; instead, human ingenuity and applied physics have provided it. Specifically, a process called radiometric dating allows scientists to determine the ages of objects, including the ages of rocks, ranging from thousands of years old to billions of years old to a marvelous degree of accuracy.
The analysis was done in the frame of an ORF TV documentary, and the public announcement was made during a press conference on 8 December The radio-carbon dating was performed by the University of Arizona, and described in some detail in an internal report. It has been publicly presented at several occasions 1 , but I am not aware of a published paper on this topic. The present page is meant as an explanation of the relevant aspects of this analysis, for non-experts.
The Shroud of Turin , a linen cloth that tradition associates with the crucifixion and burial of Jesus , has undergone numerous scientific tests, the most notable of which is radiocarbon dating , in an attempt to determine the relic 's authenticity. In , scientists at three separate laboratories dated samples from the Shroud to a range of — AD, which coincides with the first certain appearance of the shroud in the s and is much later than the burial of Jesus in 30 or 33 AD. The idea of scientifically dating the shroud had first been proposed in the s, but permission had been refused because the procedure at the time would have required the destruction of too much fabric almost 0.