“another nature.”

“Everything in the spiritual world is substantial and original. This material world is only an imitation.... It is just like a cinematographic picture, in which we see only the shadow of the real thing.” 
We cannot calculate the length and breadth of even this universe, yet there are millions and millions of universes like this one within the material sky. And above this material sky there is another sky, which is called the spiritual sky. In that sky all the planets are eternal, and life is eternal, also. We cannot know these things by our material calculations.

This material manifestation is only one fourth of the whole manifestation, both spiritual and material. In other words, three fourths of the total manifestation is beyond the covered, material sky. The material covering is millions and millions of miles thick, and only after penetrating it can one enter the open, spiritual sky. Here Kṛṣṇa uses the words bhāvaḥ anyaḥ, which mean “another nature.” In other words, there is another, spiritual nature besides the material one we ordinarily experience.

But even now we are experiencing the spiritual as well as the material nature. How is that? Because we ourselves are a combination of matter and spirit. We are spirit, and only as long as we are within the material body does it move. As soon as we are out of the body, it is as good as stone. So, since we can all personally perceive that there is spirit as well as matter, we should also know that there is a spiritual world as well.

It is not possible to understand these things by experimental knowledge. The scientists can see millions and millions of stars through their telescopes, but they cannot approach them. Their means are insufficient. What to speak of other planets, they cannot approach even the moon planet, which is the nearest. Therefore, we should try to realize how incapable we are of understanding God and God’s kingdom by experimental knowledge.