The 21 cm line of neutral hydrogen serves as a signature of neutral hydrogen. This line is redshifted and from the lower bound for the redshift one can deduce the time when "Dark Ages" ended. The popular article tells (see this) that the recent study using Murchison Widefield Array (MWA) radio telescope by Jonathan Pober and collaborators gave an unexpected result. Only a new lower upper bound for this redshift emerged: the upper bound corresponds to about 2 meters (see this). The conclusion of the experiments is optimistic: soon the upper bound for the redshift should be brought to light.
In TGD based view about cosmology and astrophysics (this) one one can formulate two questions.
- One can ask whether there were any "Dark Ages" at all!
- An alternative question is wheter the "Dark Ages" at distant past are prevailing anymore! This would be like asking whether the Hitler of thirties is the Hitler we know anymore. The point is that in TGD framework one must distinguish between subjective time and geometric time and this leads to some rather dramatic modifications of the prevailing view about time. The following arguments encourage a positive answer to the first question and negative answer to the second question.
The answer to the first question relies of TGD based view about nuclear physics solving anomalies of standard nuclear physics and leading to a new view about stellar evolution.
- In TGD framework the formation of stars could have preceded by a pre-stellar period during which dark fusion giving rise to dark proton sequences - dark nuclei - at monopole flux tubes happened: this is Pollack effect in biology. This would have been "cold fusion" period in the stellar evolution and would have occurred spontaneously at low temperatures. It would have already produced abundances, which are not far from modern ones and one of the recent surprises is that the abundances at very early period are already near to modern ones.
- The model predicts also the possibility of neutral states for which electrons are at flux tubes parallel to dark proton flux tubes and have the same scaled up size (due to non-standard value of heff=nh0, which is smaller by factor about 1/2000) as dark protons. In solar interior dark protons would have Compton size of electron so that heff for them would be about 2000 times higher H=M4× CP2 than h. Also smaller and larger value of heff are possible. For blackholes the protons at flux tubes would be ordinary: heff=h.
- The transformation of dark nuclei having much smaller binding energy would have liberated nuclear binding energy and the resulting photons having energy up to gamma ray energies would have ionized the neutral hydrogen.
- In ZEO Universe consists at the level of imbedding space H=M4 × CP2 of a fractal hierarchy of CD= cd× CP2, where cd is causal diamond of M4. CDs have interpretation as a hierarchy of sub-cosmologies. Each CD defines a correlate for a conscious entity and increases in size in each "small" state function reduction (SSFR) defining a counterpart of weak measurement. The flow of experienced time corresponds to the increase of distance between tips of CD. Second boundary of CD is however fixed - passive - as also members of state pairs at it defining zero energy states. The active boundary recedes farther away from the passive one. This gives rise to the arrow of time for given life of CD.
- In a "big" (ordinary) state function reduction (BSFR) the roles of boundaries of CD change. Active becomes passive and vice versa. The arrow of time changes. Self dies and reincarnates with opposite arrow of time. The simplest possibility is that the size of CD can decrease in BSFR meaning that the formerly passive boundary becomes much nearer to active. In this case CD begins to grow from a small size: self has "childhood". In this case it can happen that self never reaches a size larger than some upper bound and lives again and its life. Each life is more evolved since the extension of rationals involved with space-time surface increases in statistical sense in BSFR. This is nothing but Karma's cycle but in all scales.
- At the level of stars this would mean that star could undergo evolution as Karma's cycle also in cosmological remote past as an object located at fixed point of H. The abundances would be more or less the same as for modern stars. This would explain the mystery of stars older than the Universe and solve also other time anomalies of the standard cosmology. This explanation is consistent with the first one and actually the first one is needed to explain abundances of nuclei heavier than Fe and the light nuclei Li, B, Be much higher than predicted by standard model.
For a summary of earlier postings see Latest progress in TGD.