The particle horizon (also called the cosmological horizon, the comoving horizon, or the cosmic light horizon) is the maximum distance from which light from particles could have traveled to the observer in the universe’s age. Much like the concept of a terrestrial horizon, it represents the boundary between the observable and the unobservable regions of the universe.
A cosmological horizon is a measure of the distance from which one could retrieve information. This observable constraint is due to various properties of general relativity, the expanding universe, and the physics of Big Bangcosmology. Cosmological horizons set the size and scale of the observable universe.
In mathematical physics, the concept of quantum spacetime is a generalization of the usual image of spacetime in which some variables that ordinarily commute are assumed not to commute and form a different Lie algebra. Often only such discrete variables are called quantized.
Space-time, a four-dimensional structure (three dimensions of space and one of time) woven together into a unified fabric. Matter and energy bend and warp the fabric of space-time, and in response, the bending and warping of space-time tell matter and energy how to move. Space-time will always be as wrinkle-free as a recently ironed shirt. No holes, no tears, no tangles. Just pure, clean smoothness.
At the Quantum field level (the Planck scale), space-time is a roiling, boiling mess, an angry frothing soup of particles, constantly tearing holes in space-time and patching them up again before anyone in the macroscopic world notices.
QUANTUM GRAVITY’S INTERACTION IS THE REASON FOR THIS.
This interface blankets the universe. If this weren’t so, the universe would be pockmarked with singularities, moving the universe towards a state of collapse. Inhomogeneities would bring the whole thing down.
Low entropy was a requirement at the start. The universe underwent a period of accelerated expansion in its early stages. The origin of the cosmic structure was underway. Without inflation, life would not have happened. Inflation is a necessary effect rather than a cause.
