I am reading "The greatest story ever told - so far" by Lawrence Krauss. He starts chapter 9, Decay and Rubble, telling how he was shocked when he realized that humans are radioactive.
When I first learned that we human beings are radioactive, it shocked me. I was in high school listening to a lecture by the remarkable polymath and astrophysicist Tommy Gold, who had done pioneering work in cosmology, pulsars, and lunar science, and he informed us that the particles that made up most of the mass of our bodies, neutrons, are unstable, with a mean lifetime of about ten minutes.
The argument that he uses is particles that make most of mass of our body is neutrons and they are unstable having a mean life of about 10 mins. He argues that within the nucleus, however, neutron is stable and that has got to do with the fact that its mass is 0.1% more than Proton. I am slightly lost in the whole argument. Can someone please help?