While I can't claim credit for it since my late father thought of it here's my entry-a bridge across the Atlantic Ocean. I think we were discussing ways to cross the ocean without flying which would be faster than ship. I mentioned that even by car it would still take two days to cross. His idea to reduce the crossing time was to have the cars running on conveyor belts moving at 100 mph or so. :laughing: This would cut the crossing time by more than half. Of course, I mentioned what a hair-brained scheme the whole idea was. The power to run the conveyors would have been enormous, it would have been impossible to anchor a bridge in water that deep, you would need refueling and rest stops, the whole thing would cost ten times the GNP of the US, etc. He still thought it was a great idea. :lolsign:
The funny thing about all this is that a variation on the theme may well be practical in about 20 or 30 years as we run out of fossil fuels. Some have proposed a maglev running in an evacuated concrete tube. The tube would be bouyant but anchored to the ocean bottom via cables. It would be roughly 100 feet under sea level. Maglev trains would traverse NYC to London in under an hour while using two orders of magnitude less energy than flying. Cost is estimated in the hundreds of billions but it would save many times that in energy costs. Land for airports would be freed up for housing. Noise and pollution from airliners would be a thing of the past. It would be way safer than flying.
Sometimes an outlandish idea isn't so bad after all if it can be refined into something practical.
