Spin foam

With the concept of spin- foam ( engl. spin foam), ( also called loop quantum gravity LQG ) of the theory of loop quantum gravity comes, the whole time- evolving spin networks is understood. A spin- network thereby changing according to the loop quantum gravity its node lines structure abruptly, ie quantized time. This will see the loop quantum gravity theorists changes the quantum state of spacetime. The " foamy " structure revealed only on the tiny scales of the Planck scale, ie on the characteristic length scales of only cm.

Spin- foam and quantum foam

Both the quantum foam ( engl. quantum foam), and the spin- foam describe physical phenomena that take place at the Planck scale. However, it involves fundamentally different things. While the quantum foam is curved, foam-like space-time of the quantum vacuum at a given time, the spinning foam is not 'real'.

In the loop quantum gravity each time step is discrete. Therefore, the spin- network exists in a moment in one, and in another moment immediately in the other ( vice knüpften ) form. Only if you mentally connects these individual networks from time t1 to time t2 and t3, etc. further, one can speak of a " foam-like structure."

Figuratively speaking, results from this modeling form a kind of ' ghosting ', as we know from older (tube ) video cameras, or about of photographs in which to set very long exposure times so that moving lights at night photographed strip-like streaks of light in the photo (cf., bar -track recording ). Also, "real" counterpart in nature exists as for these streaks of light in the photo is not so is also the image of the spin foam only to illustrate the internal dynamics of the spin network in the theory of loop quantum gravity.

• Quantum field theory