Hydrogen, or perhaps high energy nitrogen polymers:
http://pda.physorg.com/lofi-news-nitrogen-pressures-energy_139662206.html
what possible future nuclear fuel
I think the fuel cell
I will fuel.
It is a means for fuel storage. Simply put it keeps fuel clean and contained to be used in the future.
nothing
Yes
Petroleum is a fossil fuel, it has no future only a geological past, once is is used it is gone.
water, electric, air.
uranium-235 your welcome :)
The next possible nuclear fuel is actually Thorium, but will likely remain Uranium
The Air Force has experimented with biodiesel in some of its airplanes - jet fuel is very similar to diesel.
Yes :d