In his 1950 book Worlds in Collision, Immanuel Velikovsky argued that the planet Venus had been a molten ball of fire only a few thousand years ago. At that time, he said, Venus also displayed some of the characteristics of a comet, sporting a massive tail of gasses and debris which would eventually come to form the planet’s atmosphere. Given that ancient peoples had witnessed Venus as a red-hot fireball, Velikovsky predicted that the planet would still be extremely hot on the surface.
Such a claim went very much against the grain of thinking at the time. In 1950 almost everyone imagined Venus to have a surface temperature not unlike that of the earth. Books and articles by scientists and lay people regularly appeared suggesting the planet might contain life and perhaps even civilizations. Soviet and American space probes in the 1960s answered the question decisively in Velikovsky’s favor. Venus was ultimately found to have a mean surface temperature of 463 degrees Celsius, hot enough to melt lead and almost hot enough to emit light (525 degrees Celsius). This came as a great surprise to establishment astronomers and it prompted a concerted attempt on their part to explain the data. At no point however did they (with a couple of honorable exceptions) give any credit or recognition to Velikovsky for his accurate prediction.
The advent of the Space Age in the 1960s in fact proved Velikovsky correct in a large number of his predictions, which in turn prompted a renewed interest in his work in academia and popular literature. This in spite of a concerted campaign of denigration by the scientific establishment in the 1950s. By the early 1970s then Velikovsky was enjoying a renewed period in the limelight; so much so that one sneering article at the time was entitled, “Velikovsky rides again!” It was clear to the gatekeepers of orthodoxy that something had to be done. Where space exploration had proved Velikovsky correct, other explanations of the data were sought as a matter of priority.
One of the central figures in this effort, and one of the most public faces of the gatekeeping establishment, was Carl Sagan. In 1974 Sagan chaired a symposium at Cornell University designed allegedly to investigate Velikovsky’s theories in the light of recent discoveries in space. In reality, the meeting was nothing of the sort: It was, rather, a carefully prepared attempt to discredit the maverik writer and to nip in the bud his burgeoning popularity among the younger generation. Despite assurances to the contrary, Velikovsky was not permitted to enlist as speakers scientists sympathetic to his work, and in the end all the papers delivered - with the exception of his own - were critical of his work. The proceedings of the symposium were published in a book three years later entitled “Scientists Confront Velikovsky” and was, as the title suggests, little more than a hatchet job.
Sagan’s own paper at the symposium and a chapter of the aforementioned book was entitled “Venus and Velikovsky”, and in this he attempted simultaneously to debunk Velikovsky’s hypotheses regarding Venus and to explain how he nevertheless managed to predict its great heat. For Sagan, the latter was pure accident and had nothing to do with any worth in Velikovsky’s thinking. In this paper Sagan reiterated arguments first put forward in 1969 by Andrew Ingersoll (“The Runaway Greenhouse: A History of Water on Venus”) that the planet was hot because at some time in the distant past water on the surface had evaporated, causing a buildup of clouds, which in turn eventually massively increased the planet’s temperature. Interestingly, it is known that carbon-dioxide (which comprises virtually all of Venus' atmosphere) is an extremely ineffective greenhouse gas and would not be capable of producing such a “runaway” greenhouse effect. As such, the existence of large amounts of water on Venus at some time in the past had to be hypothesised. (These latter facts are never made clear to the public).
Sagan expanded on this theme of a “runaway” greenhouse on Venus in his 1980 book Cosmos, a work that was widely read and hugely influential. As yet, however, no one had imagined a greenhouse effect on the Earth. That step was taken in June 1988 when another student of Venus’ climate, James E. Hansen, turned his attention to the Earth and bluntly announced that “the greenhouse effect has been detected [on Earth] and is changing our climate now.” The 1980s was a decade of increasing environmentalism and Hansen’s announcement fell on fertile ground. Later that year the Intergovernmental Panel on Climate Change was established and the ball was set in motion.
It will be obvious that I regard the greenhouse theory, whether runaway or stay-at-home, as extremely poor science. It was only dreamed up in retrospect after the discovery of Venus’ great heat, whereas Immanuel Velikovsky, who saw Venus as a very young planet, and who had correctly predicted the true conditions on its surface without any reference to greenhouse effects, has been denigrated and ignored by establishment academia. This is in violation of the fundamental scientific principle which states that the truth of a hypothesis is gauged by its ability to generate accurate predictions. Velikovsky, who spoke of a solar system in chaos just a few thousand years ago, made dozens of predictions which subsequently proved to be accurate. His claims should therefore have been seriously explored rather ignored. Establishment academia stands condemned.