Olavi Kajander of the University of Kuopio in Finland notices ultrasmall particles inside many mammalian cells; about 50 nm in size, they are about a tenth the size of the smallest known ordinary bacteria; Kajander later hypothesizes that they are living organisms that thrive in urine and cause kidney stones to form by precipitating calcium and other minerals around them; in this case, they would be alien organisms in the sense that they use a radically different biochemistry than what is known.
