Surprisingly, Thomson did not send Joule a copy of his paper, but when Joule eventually read it he wrote to Thomson on 6 October, claiming that his studies had demonstrated conversion of heat into work but that he was planning further experiments. Thomson replied on 27 October, revealing that he was planning his own experiments and hoping for a reconciliation of their two views. Thomson returned to critique Carnot's original publication and read his analysis to the Royal Society of Edinburgh in January 1849, still convinced that the theory was fundamentally sound. However, though Thomson conducted no new experiments, over the next two years he became increasingly dissatisfied with Carnot's theory and convinced of Joule's. In February 1851 he sat down to articulate his new thinking. He was uncertain of how to frame his theory and the paper went through several drafts before he settled on an attempt to reconcile Carnot and Joule. During his rewriting, he seems to have considered ideas that would subsequently give rise to the second law of thermodynamics. In Carnot's theory, lost heat was absolutely lost but Thomson contended that it was "lost to man irrecoverably; but not lost in the material world". Moreover, his theological beliefs led Thompson to extrapolate the second law to the cosmos, originating the idea of universal heat death. Compensation would require a creative act or an act possessing similar power, resulting in a rejuvenating universe (as Thompson had previously compared universal heat death to a clock running slower and slower, although he was unsure whether it would eventually reach thermodynamic equilibrium and stop for ever). Kelvin also formulated the heat death paradox (Kelvin’s paradox) in 1862, which uses the second law of thermodynamics to disprove the possibility of an infinitely old universe; this paradox was later extended by Rankine. In final publication, Thomson retreated from a radical departure and declared "the whole theory of the motive power of heat is founded on ... two ... propositions, due respectively to Joule, and to Carnot and Clausius." Thomson went on to state a form of the second law: In the paper, Thomson supported the theory that heat was a form of motion but admitted that he had been influenced only by the thought of Sir Humphry Davy and the experiments of Joule and Julius Robert von Mayer, maintaining that experimental demonstration of the conversion of heat into work was still outstanding.