The article analyzes the results of experimental studies by Simon Shnol of macroscopic fluctuations of quantum processes during changes in the near-Earth gravitational field. We conclude that S. Shnol's experiments allowed us to detect gravitons and reveal the physical nature of Newtonian gravity. Based on the results of Shnol's experiments, we come to the conclusion that the carriers of gravitational field – gravitons – are virtual vector bosons with energy of 10–5–10–4 eV. Whereas the gravitational field itself is described by a tensor in a finite-dimensional vector space, the dimension of which is determined by the number N of material bodies creating this field at each point in space in accordance with Newton's law of gravitation. New views on gravity are based on two models that consider the interaction of photons of light with gravitational fields in outer space. The first model explains the physical mechanism of redshifts in the Hubble law and the formation of cosmic microwave background (CMB) with the participation of gravitons, and the second introduces into consideration the balanced circulation of baryonic matter in Metagalaxy and on this basis explains the properties of CMB radiation established in the COBE, WMAP and Planck experiments. For the Hubble constant Ho = 67 km/s/Mpc, the first model determines the average density of baryonic matter in Metagalaxy, and the second for this density obtains the average density of stars ~3 × 10–3 pc–3, and also estimates the lifetime of stars and galaxies in outer space ~1013 years.