The word 'efficiently' here means up to polynomial-time reductions . This thesis was originally called Computational Complexity-Theoretic Church–Turing Thesis by Ethan Bernstein and Umesh Vazirani (1997). The Complexity-Theoretic Church–Turing Thesis, then, posits that all 'reasonable' models of computation yield the same class of problems that can be computed in polynomial time. Assuming the conjecture that probabilistic polynomial time ( BPP ) equals deterministic polynomial time ( P ), the word 'probabilistic' is optional in the Complexity-Theoretic Church–Turing Thesis. A similar thesis, called the Invariance Thesis , was introduced by Cees F. Slot and Peter van Emde Boas. It states: "Reasonable" machines can simulate each other within a polynomially bounded overhead in time and a constant-factor overhead in space .  The thesis originally appeared in a paper at STOC '84, which was the first paper to show that polynomial-time overhead and constant-space overhead could be simultaneously achieved for a simulation of a Random Access Machine on a Turing machine. 
By Jesse Colombo
All great bubbles start out as legitimate and compelling economic growth booms. The .’ Roaring Twenties bubble started as a growth boom based on the commercialization of radio, automobiles and mass production. Japan’s 1980s bubble grew out of their post-war economic miracle that was spurred by ground-breaking advances in electronic technology and manufacturing. The Dot-com bubble evolved out of the Information Age boom that revolutionized society in an incomprehensible number of ways. The fact that all of these booms started out legitimately didn’t prevent them from developing into bubbles that popped disastrously in the end. The China Bubble is no exception to this pattern, starting out as a boom based on successful economic reforms and modernization that helped to lift hundreds of millions out of poverty, while eventually devolving into an orgy of wild real estate speculation, reckless construction of empty cities to create economic growth and materialism mania. Even if China’s long-term growth thesis remains intact, the same was also true of the US in 1929; China could conceivably experience a Great Depression of its very own when its bubble pops.
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