spacetime channels in spin foam

High quality printing on a stiff substrate. Size and framing variable – up to customers wish. The price of 400 euro applies to high-quality prints of the size of about 60 x 60 cm2, on stiff substrate.

Loop Quantum Gravity (LQG) is one of the most important theories aimed at unifying all (four) basic forces. Built with a powerful theoretical apparatus, it is also S-F at its best. In a fascinating way, Dr. Jim Baggott describes this in his book “Quantum Space……”(2018) [and citations therein].

LQG is a ‘no background’ theory, just like the General Relativity and at the same time the quantum one. Here, the unification of the forces demands that the space must be quantized, just like energy. In LQG the base for the description of the space are closed lines of gravitational forces (loops of the order of the Planck length (~ 10^-35 m)) bound in two-dimensional so-called spin networks.

The ’empty’ space is made up of multi-layer (already three-dimensional) spin networks, creating the so-called “Spin Foam”. The relative movement of the network layers ‘creates’ time.

In LQG, the intersection points of the loops forming the network define the positions of quanta of the (empty) space.

In turn, ‘open loops’ of forces (i.e. ‘strings’ (this is one of the contact points with the String Theory)) here represent fermions, i.e. charged particles of matter in spacetime. They can be also interpreted as free ends of the loops or breaks in the spin networks. These lines of forces can theoretically ‘penetrate’ through hypothetical spacetime tunnels (of the sizes of the Planck scale), which means the possibility of particle movement in the entire spacetime through a tunneling mechanism, where the speed of light is not a limit. Also, in this model, the particles are created as if from gravity itself (the theory ‘automatically unified’). Further, it was proven in the frame of this theory that fermions and spacetime tunnels can be treated equivalently.

LQG is not complete yet and is continuously evolving. In addition, there is no idea yet how it can be verified experimentally. However, it seems now to be the most serious candidate for ‘theory of everything’. I tried to put impressions from reading in present graphic works.