Imagine ships, boats, sailors made of ace. Here, in the model all is water in different states. In the universe all is made of space in different states. There is nothing extra. In the next figure you can see the explanation of group and phase velocities of boats-photons, as they rearrange in groups.
Space simply vanishes in the massive objects.
The bigger the object, - the more energy it receives on every one unit of its mass. The Sun and other stars consume so much energy, that they shine in a visible range. And we mistakably think that thermonuclear sources warm the Sun, or radioactive decays warm the planets from inside. One of the processes of transition of energy from vanishing vacuum to massive body is excitingly very simple and is new opened consequence of the special theory of relativity. That process is calculated and described in the section Sun Energy.