"There is one great difference between the Astral Light and the Akasa which must be remembered. The latter is eternal, the former is periodic. The Astral Light changes not only with the Mahamanvantaras but also with every sub-period and planetary cycle or Round. . . .
"The Akasa is the eternal divine consciousness which cannot differentiate, have qualities, or act; action belongs to that which is reflected or mirrored from it. The unconditioned and infinite can have no relation with the finite and conditioned. . . . We may compare the Akasa and the Astral Light . . . to the germ in the acorn. The latter, besides containing in itself the astral form of the future oak, conceals the germ from which grows a tree containing millions of forms. These forms are contained in the acorn potentially, yet the development of each particular acorn depends upon extraneous circumstances, physical forces, etc." (TBL 75-6; also IU 1:197).
The astral light is the tablet of memory of earth and of its child the animal-man; while akasa is the tablet of memory of the hierarchy of the planetary spirits controlling our chain of globes, and likewise of their child, each spiritual ego. The astral light is simply the dregs or lowers vehicles of akasa. Gautama Buddha held only two things as eternal: akasa and nirvana. In the Chandogya Upanishad (7:12:1-2) akasa (ether, space) is equated with Brahman.

"There is one great difference between the Astral Light and the Akasa which must be remembered. The latter is eternal, the former is periodic. The Astral Light changes not only with the Mahamanvantaras but also with every sub-period and planetary cycle or Round. . . .
"The Akasa is the eternal divine consciousness which cannot differentiate, have qualities, or act; action belongs to that which is reflected or mirrored from it. The unconditioned and infinite can have no relation with the finite and conditioned. . . . We may compare the Akasa and the Astral Light . . . to the germ in the acorn. The latter, besides containing in itself the astral form of the future oak, conceals the germ from which grows a tree containing millions of forms. These forms are contained in the acorn potentially, yet the development of each particular acorn depends upon extraneous circumstances, physical forces, etc." (TBL 75-6; also IU 1:197).
The astral light is the tablet of memory of earth and of its child the animal-man; while akasa is the tablet of memory of the hierarchy of the planetary spirits controlling our chain of globes, and likewise of their child, each spiritual ego. The astral light is simply the dregs or lowers vehicles of akasa. Gautama Buddha held only two things as eternal: akasa and nirvana. In the Chandogya Upanishad (7:12:1-2) akasa (ether, space) is equated with Brahman.