An example of an historical scientific notion which would now be considered an alternative conception:
"…Roberval, first enunciated the theory of universal gravitation – applying it to matter everywhere – though he did not discover any law regarding the variation in the strength of this gravitational force as it operated at various distances. He saw a tendency throughout the whole of matter to cohere and come together; and on his view the moon would have fallen into the earth if it had not been for the thickness of the ether within the intervening space – the fact that the matter existing between the earth and the moon put up a resistance which counterbalanced the effect of gravity."
Herbert Butterfield (1957) The Origins of Modern Science 1300-1800 (New Edition: Revised and enlarged). G. Bell and Sons Ltd., London.
