Barnes Wallace had something to say when Concorde was proposed. He said it was silly trying to do long haul flights with a sort-of-traditional aircraft. He said if you want to go from London to Sydney you can do it in 4 hours, sub-orbital. Take off and use 80% of your fuel to get into a low orbit. Then you just glide round the globe at umpteen thousand miles an hour and you can do it much more economically and quicker. No one believed him, of course. The RAF declined Frank Whittle's jet engine which he invented and built in 1937. "It hasn't got a propeller, it will never work". Whittle built the first one in Lutterworth, where I live, and there are still bits of evidence of it. He built it on a trolley on the first floor of a brick industrial unit. He thought "Hang on, if it works, it will shoot across the room. I had better tie it down". so he put a steel plate on the outside of the brick wall and a bolt through to the inside where he attached a chain to the trolley. He fired up the engine and it worked, shooting across the room and tore a 6ft diameter hole in the wall. The different mortar from the repair is still visible. After that he went outside and sunk a big length of steel in the ground and anchored his test engines to that. It is still there.