I was wondering if our governments hide us some knowledge. Military industry for sure, but What about physics? Is all the knowledge public? I include in my question biology. I am sure that the richest people in this planet are investing right now hundreds or thousands of billions researching how to be immortal and I'm sure they are not publishing obviously the results of these investigations. Science at this moment in time provides enough tools to investigate this topic: there are supercomputers able to calculate anything, and a massive biological and chemical knowledge. What do you think?