One of the points I was trying to make about efficiency was that it was a diminishing return game. Even if you did invest in pulling the absolute Carnot-hugging efficient engine out of the hat, you really only reduce consumption rates (and by less than half at most). You can't become more and...
Of course, it may be whether you're working off of a thermal efficiency definition, or some other efficiency metric. Efficiency requires qualifiers to mean something - relation to what idealized scenario?
"The internal combustion engine we are adicted to is only 30% efficient which in my opinion is a gross waste. "
Actually, though I don't have the reference, I believe my old thermodynamics textbooks had the maximum possible efficiency for a compression driven (diesel) IC engine at about 80%...
PS - my prediction is that we'll mine harder and harder oil deposits than middle eastern light crude oil (the current proven reserves) (shale oil ect) and thus extend the gasoline supply out 100 years or so more than is currently predicted.
After that, it depends on the politics and science of...
Until you can drive a loaded truck 200 miles with alternative X, it isn't viable. Economies need to move mass from point A to point B - they don't run on micro-machines.
Also, until we have a massive multi-terawatt expansion in our energy producing grid, (in something other than gas power...
One approach to pushing an asteroid out of the way would be to have a nuclear rocket vehicle (such as a NERVA engine) match velocity with it, "land" on the side and apply thrust.
There may be ways to rig a nuclear explosive to dump the radiation energy into a propellant tank and produce...
Hmm. I've read about this before. Manufacturing propellant on the surface allows you to get away with much less propellant for the round-trip.
However, it means depending on remote equipment to operate correctly to fuel the return flight. I wouldn't launch the manned mission until a supply of...
