I have already noted (and in the book Heaven and Hell illustrated) the fact that the spiritual world and the physical world are similar to each other, the only difference being that every single thing in the spiritual world is spiritual and every single thing in physical world is physical. Because these two worlds are similar to each other, there are atmospheres, liquids, and solids in each. These are the general elements that provide the means and substances for all the infinite variety of phenomena that arise.
As for the atmospheres that we refer to as “ether” and “airs,” there are similar forms in each world, the spiritual and the physical, the difference being that in the spiritual world they are spiritual, while in the physical world they physical. They are spiritual because they come from a sun that is first emanation of the Lord’s divine love and wisdom and accept into themselves the divine fire from him that is love and the divine light from him that is wisdom, bringing each down to the heaven where angels live. They bring about the presence of that sun in everything there, from the largest thing to the smallest.
The spiritual atmospheres are distinct substances or elemental forms that arise from the sun. Since they accept the sun individually, the sun’s fire becomes a warmth that is ultimately adapted to the love of angels in heaven and spirits under heaven by being separated into a corresponding number of substances, enfolded in them, and tempered by being enfolded. The same holds true for the sun’s light.
In this respect, our physical atmospheres are like the spiritual ones. They too are distinct substances and elemental forms, arising from the physical world’s sun. They too accept the sun individually and conceal its fire within themselves, temper it, and bring it down as warmth to earth where we are; and the same holds true for light.
from Divine Love and Wisdom, Sections 173-174