# TGD view of the gravitational hum

The revolution in cosmology is continuing. The latest breakthrough was announced yesterday (see this and the popular article this).

Scientists from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) have now officially made the first detections of the gravitational wave background. This gravitational hum was not detected by Earth bound instrument. Rather, they make themselves manifest as periodic changes of the spinning rates of pulsars with the frequencies of the gravitational waves involved. The corresponding periods are extremely long and measured in millions of years. In LIGO experiment the periods are measured as fractions of second.

The wavelength of the oscillations makes itself visible as correlations between the variations of the spinning rates for pulsar having relative distances of millions of light years. The wavelength of the oscillations is measure in millions of light years. This scale corresponds to a typical distance between galaxies which is few Mpc, pc= 3.26 ly. It is difficult to imagine any other explanation for the correlations except gravitational waves.

This motivates the hypothesis that pairs of galactic supermassive blackholes could generate the gravitational radiation. Or possibly groups of them. There are candidates for these pairs but no established pair.

TGD suggests a somewhat different hypothesis.

- TGD predicts quantum gravitational coherence in astrophysical scales characterized by gravitational Planck constants h
_{gr}= GMm/β_{0}characterizing big mass M and small mass m. β_{0}=v_{0}/c<1 i velocity parameter. the equivalence principle is realized as independence of gravitational compton length λ_{gr}= GM/β_{0}= r_{s}/2β_{0}on mass m. For the Sun gravitational Compton length is 1/2 of Earth radius. If the TGD proposal, which explains Cambrian explosion in terms of rapid increase of the Earth radius by factor 2, this scale is the radius of Earth before the explosion (see this). For Earth the scale is .45 cm and the size scale of a snowflake, which is a zoomed version of the unit cell of the ice crystal: a fact which still remains a mystery.

For the galactic black hole scale is about 1.2×10^{7} km=1.2× 10^{-2} light seconds and corresponds to a frequency of about 100 Hz, the upper bound of EEG frequencies by the way (which might put bells ringing!). For β_{0}=1 Λ_{gr} happens to correspond to the radius of the lowest Bohr orbit for Sun Λ_{gr} in Bohr orbit model for planetary orbit (another bell ringing!) and defines only a lower bound for the quantum coherence scale.

There would be a fractal hierarchy of them. Could the galactic supermassive blackholes form tessellations of this kind analogous to lattices in a condensed matter system. The natural wavelength for the gravitational waves propagating as gravitational lattice vibrations in the tessellation having galactic blackholes at its points would correspond to a multiple of the lattice constant, defined by the distance between neighboring galactic supermassive blackholes.

What is important is that by quantum coherence the scattered amplitude is proportional to N^{2} rather than N, where N is the number of atoms in the lattice, now galactic blackholes in the tessellation. This could explain why the observed effect is larger, maybe much larger, than expected.

Scientists from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) have now officially made the first detections of the gravitational wave background. This gravitational hum was not detected by Earth bound instrument. Rather, they make themselves manifest as periodic changes of the spinning rates of pulsars with the frequencies of the gravitational waves involved. The corresponding periods are extremely long and measured in millions of years. In LIGO experiment the periods are measured as fractions of second.

The wavelength of the oscillations makes itself visible as correlations between the variations of the spinning rates for pulsar having relative distances of millions of light years. The wavelength of the oscillations is measure in millions of light years. This scale corresponds to a typical distance between galaxies which is few Mpc, pc= 3.26 ly. It is difficult to imagine any other explanation for the correlations except gravitational waves.

This motivates the hypothesis that pairs of galactic supermassive blackholes could generate the gravitational radiation. Or possibly groups of them. There are candidates for these pairs but no established pair.

TGD suggests a somewhat different hypothesis.

- TGD predicts quantum gravitational coherence in astrophysical scales characterized by gravitational Planck constants h
_{gr}= GMm/β_{0}characterizing big mass M and small mass m. β_{0}=v_{0}/c<1 i velocity parameter. the equivalence principle is realized as independence of gravitational compton length λ_{gr}= GM/β_{0}= r_{s}/2β_{0}on mass m. For the Sun gravitational Compton length is 1/2 of Earth radius. If the TGD proposal, which explains Cambrian explosion in terms of rapid increase of the Earth radius by factor 2, this scale is the radius of Earth before the explosion (see this). For Earth the scale is .45 cm and the size scale of a snowflake, which is a zoomed version of the unit cell of the ice crystal: a fact which still remains a mystery.

For the galactic black hole scale is about 1.2×10^{7} km=1.2× 10^{-2} light seconds and corresponds to a frequency of about 100 Hz, the upper bound of EEG frequencies by the way. For β_{0}=1 Λ_{gr} happens to correspond to the radius of the lowest Bohr orbit for Sun Λ_{gr} in Bohr orbit model for planetary orbit (another bell ringing!) and defines only a lower bound for the quantum coherence scale.

There would be a fractal hierarchy of them. Could the galactic supermassive blackholes form tessellations of this kind analogous to lattices in a condensed matter system. The natural wavelength for the gravitational waves propagating as gravitational lattice vibrations in the tessellation having galactic blackholes at its points would correspond to a multiple of the lattice constant, defined by the distance between neighboring galactic supermassive blackholes.

What is important is that by quantum coherence the scattered amplitude is proportional to N^{2} rather than N, where N is the number of atoms in the lattice, now galactic blackholes in the tessellation. This could explain why the observed effect is larger, maybe much larger, than expected.

The dark gravitational radiation would propagate along the monopole flux tubes connecting galactic blackholes to astrophysical objects such as stars in other galaxies.

^{3}but only 4 regular uniform honeycombs. For two of these the unit cell is a dodecahedron, for 1 of them it is an icosahedron and for 1 of them it is a cube. Note that in Euclidian 3-space one has just one regular honeycomb consisting of cubes.

There are also more general uniform honeycombs involving several cell types. There is a unique honeycomb for which all cells are Platonic solids, icosa-tetrahedral (or more officially, tetrahedral-icosatetrahedral) honeycomb for which the cells are tetrahedrons, octahedrons, and icosahedrons. All faces are triangles and I have proposed a universal realization of the genetic code in which genetic codons correspond to the triangular faces of icosahedra and tetrahedra (see this). See the for instance the articles Magnetic Bubbles in TGD Universe: Part I and Magnetic Bubbles in TGD Universe: Part II.

For a summary of earlier postings see Latest progress in TGD.

Source: http://matpitka.blogspot.com/2023/06/tgd-view-of-gravitational-hum.html