Empirical evidence for two arrows of time

The scientists in Perimeter Institute for Theoretical Physics Canada and European Space Agency Planck Collaboration have published in Physical Review D, 2025 evidence that the Universe has two arrows of time. The findings give a totally unexpected support for the notion of zero energy ontology (ZEO) of TGD predicting that two arrows of geometric time are possible and that roughly one half of the Universe has both arrows of time. I did not believe that one of the most dramatic predictions of TGD would get empirical support so soon. TGD predicts a fractal Universe and this means testable predictions in all scales and support for the TGD is indeed emerging in all scales. For instance, a scale hierarchy of standard model physics is predicted and there are indications for it at LHC.

In TGD, the view about the arrow of geometric time is more complex than in the framework of standard cosmology. The arrow of geometric time is associated with a given causal diamond (CDs) analogous to a sub-cosmology in a Russian doll cosmology defined by a hierarchy of CDs with increasing size scales. A given CD can have both arrows of time and the arrow of time changes in the TGD counterpart of ordinary quantum measurement.

It must be emphasized however that the meaning of the arrow of time used by the researchers is based on CPT as a symmetry. The proposal is that CPT would relate the two Universes with an opposite arrow of time: CPT would not be a trivial operation anymore. On the other hand, the time reversal in the sense of TGD inspired theory of consciousness does not reduce to time reversal as a discrete symmetry although one cannot exclude the possibility CPT – and TGD based views are closely related

TGD view means roughly the following. In quantum field theories there are two vacua as states annihilated by annihilation resp. creation operators. In the original picture of Dirac all positive/negative energy states of fermions would be filled for these two vacua.

In TGD, the chance of the arrow of geometric time taking place in the TGD counterpart of the ordinary state function reduction, changes the roles of these operators. These operators act at the opposite 3-D light-like boundaries of CD carrying ordinary 3-D quantum states as building blocks of what I call zero energy states.

Very roughly, the interpretation of zero energy states would be as pairs of ordinary 3-D quantum states defining initial and final states of time evolution. ZEO is forced because the classical time evolutions fail to be strictly deterministic: this is absolutely essential for the non-triviality of quantum TGD and also for the TGD inspired view of consciousness. The mild non-determinism forces us to introduce additional discrete degrees of freedom implying that one must allow 3-D seats of classical non-determinism as carriers of quantum numbers identified as cognitive degrees of freedom not present in standard physics.

The sequence of quantum jumps giving rise to the analog of repeated quantum measurements gives rise to a flow of consciousness at the level of a given CD. The change of the arrow of time means the death/falling asleep of self at a given level of self hierarchy. Sleep is a basic example of this at our level. In cosmic scales stars older than the Universe can be explained by ZEO. Stars older than the Universe is an example of possible consequences of ZEO in cosmic scales.

See for instance, https://tgdtheory.fi/public_html/articles/zeoagain.pdf, https://tgdtheory.fi/pdfpool/ZEO.pdf and https://tgdtheory.fi/public_html/articles/3pieces.pdfdtheory.fi/public_html/articles/3pieces.pdf .