Bad science ideas

Just a few thoughts on ideas that might seem cool in a science-fictiony way but that will not quite achieve what's expected of them.  Don't get the wrong idea, I'm all for technology progressing; it's given us modern medicine, flight, the internet, electricity, transportation, and space flight just to name a few examples.  But with advancing technology comes ethical questions, and of course questions of direction. If all of our technology were devoted to ever more lethal weapons of mass destruction, that would not be a good thing, again as an example.

But even the technology itself can be subject to questions of efficacy.