Gravity is the result of warped space-time. Matter affected by gravity is the result of experiencing a change in uniform motion. Change in momentum lags behind a change in velocity. Matter on the surface of the Earth is applying pressure on the core: anything put under pressure radiates heat (longwave energy). Einstein gave us the answer to gravity, warped space/time. And he told where to look for it, the bending of light in a gravitational field. On May 19, 1919 astronomer Arthur Eddington took a photograph of a constellation that lined up behind the Sun during a solar eclipse, and it confirmed Einstein's prediction of light bending in a gravitational field. The background star images moved away from the Sun as if you were viewing the constellation through a huge positive lens. Einstein described the mechanics of this observation by imagining a series of elevators rising from the Sun’s surface; light enters the elevator at a higher level on the far side, and then it exits at a lower level on the side closest to us. Space and time are both warped. Time is slower, and the fabric of space is longer.

You don’t see space and there is no moving scenery to establish you're moving toward the core of the Earth but gravity is merely a change in uniform motion, Light redshifts when coming from a massive star. Light from each element has spectral lines that are unique to that element because elements have their own electron arrangements in their electron energy shell levels. Light is absorbed and emitted in the electron shells, if there is not an electron available to radiate a specific color there will be a black line in the spectrum that will identify light from that element. To redshift means that light will be longer in wavelength. Think of it as the light that has been emitted by an object moving directly away from you, the light will doppler shift. If you think of a second as the distance that light can travel in a second that is now a greater distance, which equates to a slower time in that location.