1. If solar energy could provide 10% of all energy needed, this still would be of a gigantic volume and a very profitable big business; there seem to be fundamental limits, however, that the concentrated low cost main energy for producing the fertilizers for feeding the present or even growing population cannot come from solar energy.
2. G. Cooperstein, S.A. Goldstein, D. Mosher, R.J. Barker, J.R. Boiler, D.G. Colombant, A. Drobot, R.A. Meger, W.F. Oliphant, P.F. Ottinger, F.L Sandel, S.J. Stephanakis, and F.C. Young, Laser Interaction and Related Plasma Phenomena, H. Schwarz et al. eds. (Plenum, New York, 1981) Vol. 5, p. 105.
3. H. Hora, Atomkernenergie 40, 289 (1982).
4. F. Aebi, Hilterfingen (private communication, 1982).
5. M.L.F. Oliphant, P. Harteck, and Lord Rutherford, Proc. Roy. Soc. A144, 692 (1934).