It is sometimes very useful to become very critical about own ideas. Usually this leads to considerable progress. At this time I became very critical about the notion of twistor space in TGD.

Twistor lift of TGD involves representation of space-time surfaces as 6-surfaces in twistor space of H having structure of S2 bundle over space-time surface resulting in dimensional reduction. These 6-surfaces would be holomorphic and thus minimal surfaces represented in terms of polynomials having same degree as the corresponding M8 octonionic polynomial by number theoretic universality.

I have assumed that what I call geometric twistor space of M4 is simply M4× S2. It however turned out that one can consider standard twistor space CP3 with metric signature (3,-3) as an alternative. This option reproduces the nice results of the earlier approach but the philosophy is different: there is no fundamental length scale but the hierarchy of causal d…

**Criticizing the notion of twistor space of M4**Twistor lift of TGD involves representation of space-time surfaces as 6-surfaces in twistor space of H having structure of S2 bundle over space-time surface resulting in dimensional reduction. These 6-surfaces would be holomorphic and thus minimal surfaces represented in terms of polynomials having same degree as the corresponding M8 octonionic polynomial by number theoretic universality.

I have assumed that what I call geometric twistor space of M4 is simply M4× S2. It however turned out that one can consider standard twistor space CP3 with metric signature (3,-3) as an alternative. This option reproduces the nice results of the earlier approach but the philosophy is different: there is no fundamental length scale but the hierarchy of causal d…