This radioactivity can be used for dating, since a radioactive 'parent' element decays into a stable 'daughter' element at a constant rate.
The rate of decay (given the symbol λ) is the fraction of the 'parent' atoms that decay in unit time.
India has had a long religious history of contemplating nothingness.
Marcus du Sautoy, a professor of mathematics at the University of Oxford, believes that this is why the concept of zero might have been influenced through cultural practices. “Much ado about nothing: ancient Indian text contains earliest zero symbol.” The Guardian, 13 Sept.
There may be more information on why The Bakhshali Manuscript comes from three different time periods but, an official report of the results have not yet been published. Researchers do know that the document was found in 1881 by a farmer in Bakhshali, a small village in Pakistan, buried in a field.