I think this should be something you can answer for yourself by looking at human media and news over the lasy 100 years. I find it hard to belive you haven't ever noticed anyone seriously saying we may possibly have FTL sometime in the future. Incidentially I think I read on HackerNews that Sam Altman has been talking about building Dyson Spheres in the future. I suppose they're not forbidden by the current laws of phyisics either, but I don't know if I would call them a realistic technology.