Nuclear fusion reactions of protons with the boron isotope 11 produce less radioactivity per energy than burning coal. Since about 1973 it is known, however, that this reaction is about 100,000 times more difficult than laser fusion of deuterium tritium (DT) based on spherical compression and ignition. This is now close to be demonstrated for DT with the world’s biggest laser NIF. Alternative to the spherical laser-compression is the side-on ignition of uncompressed solid fusion fuel of 1972 which was then much too difficult. This changed now with the advent of sub-picosecond laser pulses of up to 10 petawatt power, however, only if a new measured effect of acceleration with the nonlinear (ponderomotive) force is used which needs extremely clean laser pulses suppressing pre-pulses by more than 108. This effect was predicted long ago theoretically and was proved as a fundamental property. But the discovery was not possible before the experiments by Sauerbrey (1996) and the ingeniously collected details by Jie Zhang et al (1998). Another ingredient is the hydrodynamic calculation by Chu and Bobin which needed appropriate improvements, and - if correct – may lead to an easy ignition of solid DT. As a real surprise it turned out that the proton-boron11 fusion is only about ten times more difficult [Reference: H. Hora. G.H. Miley et al., Optics Communications Vol. 282 (2009) p. 4124]. What is needed is to study alternative models than hydrodynamics parallel to specifically selected experiments.