One theory which can no longer be taken very seriously is that UFOs are interstellar spaceships.
Interpretation
The idea that UFOs are spaceships from other planets is no longer credible.
In this quote, Arthur C. Clarke suggests that the theory of UFOs originating from distant planets lacks serious consideration among scientists. This reflects a broader skepticism towards claims that lack empirical evidence and urges a critical approach to understanding phenomena that captivate the imagination.
In practice
In a science class discussing the scientific method, this quote can highlight the importance of evidence in forming theories.
Nowhere in space will we rest our eyes upon the familiar shapes of trees and plants, or any of the animals that share our world. Whatsoever life we meet will be as strange and alien as the nightmare creatures of the ocean abyss, or of the insect empire whose horrors are normally hidden from us by their microscopic scale.
As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self-destroying.
It has yet to be proven that intelligence has any survival value.
The best measure of a man's honesty isn't his income tax return. It's the zero adjust on his bathroom scale.
It was the mark of a barbarian to destroy something one could not understand.
My favorite definition of an intellectual: 'Someone who has been educated beyond his/her intelligence'.
Natural gas emits only half the carbon dioxide of coal when burned, but if methane leaks when oil companies extract it from the ground in a sloppy manner - methane is far more potent a greenhouse gas than carbon dioxide - it can wipe out all the advantages of natural gas over coal.
I hate crowds and making speeches. I hate facing cameras and having to answer to a crossfire of questions. Why popular fancy should seize upon me, a scientist, dealing in abstract things and happy if left alone, is a manifestation of mass psychology that is beyond me.
For me, the level at which natural selection causes the phenomenon of adaptation is the level of the replicator - the gene.
A discovery is like falling in love and reaching the top of a mountain after a hard climb all in one, an ecstasy not induced by drugs but by the revelation of a face of nature that no one has seen before and that often turns out to be more subtle and wonderful than anyone had imagined.
Science is best defined as a careful, disciplined, logical search for knowledge about any and all aspects of the universe, obtained by examination of the best available evidence and always subject to correction and improvement upon discovery of better evidence. What's left is magic. And it doesn't work.
I was taught over and over again that the accumulation of random mutations led to evolutionary change - led to new species. I believed it until I looked for evidence.
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