The theories of General Relativity and Newtonian gravity are contradicted by the "Pioneer anomaly." That anomaly or effect consists of the Pioneer slowing down more than expected as it left the solar system. "Dubbed the Pioneer Anomaly, the unexplained force appears to be acting against NASA’s identical Pioneer 10 and 11 probes, holding them back as they head away from the Sun."<ref>http://www.space.com/scienceastronomy/070327_scitues_pioneeranom.html</ref> Of course, it begs the question to describe the cause as an "unknown force," as the relativity and Newtonian models may be fundamentally incorrect views of nature. | The theories of General Relativity and Newtonian gravity are contradicted by the "Pioneer anomaly." That anomaly or effect consists of the Pioneer slowing down more than expected as it left the solar system. "Dubbed the Pioneer Anomaly, the unexplained force appears to be acting against NASA’s identical Pioneer 10 and 11 probes, holding them back as they head away from the Sun."<ref>http://www.space.com/scienceastronomy/070327_scitues_pioneeranom.html</ref> Of course, it begs the question to describe the cause as an "unknown force," as the relativity and Newtonian models may be fundamentally incorrect views of nature. |