I've always been fascinated by topics that skirt the edges of what is known, that are our the very frontiers of science - or perhaps beyond the frontiers, in the region of pseudo-science or fantasy. All of accepted science was at one time beyond what was known, what was considered legitimate knowledge. Every theory we now accept was once heresy or worse. Some of the things we consider outlandish, bizarre, ridiculous - some of them may eventually find acceptance. Of all the contending theories and notions, only a tiny fraction are likely to ever find their way into what we would call science - and we have no reliable way of predicting which ones make it and which don't.
Here I bring up some of these topics, either ones that may some day be conventional science, or ones that were once considered likely candidates but have now fallen into disfavor.
The topics range from the ridiculous to the sublime. Old chestnuts such as attempts to devise perpetual motion machines are now mostly considered wholly untenable. There are other topics such as UFO's that, while not widely accepted by the scientific community, still have a large following of interested people. Other topics are even more potentially acceptable - such as the idea of "cold fusion." While cold fusion is not presently accepted, there have been some experiments that have appeared to support the idea. Whether cold fusion ultimately joins the canon of well-accepted science remains to be seen.
Since I can't predict the future, and since I'm not omniscient, I can't say with certainty which, if any, of these topics will ever become accepted. It may be that none will. It is almost certain that very few will find acceptance.
Despite this limitation, I can at least ask questions and make observations of what current science tells us about the topics. Naturally if a subject is going to overturn or revise some scientific tenets, then relying on current scientific knowledge to decide potential new theories is not reliable. However, it is the best tool we have for now. I am likely to be wrong about some of these things, though for some I feel highly confident that my understanding of the topic is likely to be correct. I am about as certain as it is possible to be that perpetual motion is not feasible under any circumstances. For it to exist would require such a thorough rewriting of scientific knowledge that it would become unrecognizable. Possible in theory, but nothing I'd lose any sleep over.
A topic such as the possibility that UFO's are extraterrestrial visitors is highly doubtful in my opinion, but I am nowhere near as confident about this opinion as I am about perpetual motion. The difference is that perpetual motion violates what we know about the Universe. UFO's, while presenting difficulties, don't actually violate laws of nature.
The demonstration that no possible combination of known substances, known forms of machinery, and known forms of force can be united in a practicable machine by which men shall fly for long distances through the air, seems to the writer as complete as it is possible for the demonstration of any physical fact to be. - Astronomer Simon Newcomb, 1906
I am mindful that many others - often highly respected scientists - have dismissed new ideas as ridiculous, only to be proven wrong within their own lifetimes. I suppose this ought to make me reluctant to make statements that are too definite, or that ridicule an idea. But that wouldn't be any fun, so I'll pontificate to my heart's desire and risk becoming yet another laughingstock in the history of scientific prophets. Perhaps some day one of my own wrong-headed statements will find its way into an amusing quotation.