If you are looking for an interesting read on the subject of origins and existence beyond what we can fathom, then I can recommend a book by R.C Sproul called Does God Exist?. It is available on Amazon as a free kindle book.

It is only about 90 pages long. The author goes through a series of viewpoints from Rene Descartes, Immanuel Kant, etc looking at the possibilities for existence outside and beyond the "visible" universe.

He employs logical philosophical methodology (laws of origin, contradiction, absurdity)as he goes through and tests each of the arguments.

I am in the process of reading it through again and and each time I pick out something new.

Here is list of chapters to give you a flavour.

1. The Case for God
2. Four Possibilities
3. The Illusion of Descartes
4. Self-Creation, Part 1
5. Self-Creation, Part 2
6. Self-Existence
7. Necessary Being
8. The God of the Bible vs. the God of Philosophy
9. Kant’s Moral Argument
10. Vanity of Vanities
11. The Psychology of Atheism

I hope you find it useful