CAMELOT FANTASIES

I am not sure how you mean. By 'unseen universe' I don't mean something still out there and not seen. I mean going inward. We live in a multidimensional Universe and we are multidimensional beings. Things materialize and de-materialize all the time. We are just not that advanced to be aware of it. Since the material Universe is a highly complex matter, it needs a very complex brain, a tool as in, to explore it but a brain is nothing more than that. A complex vehicle that mind uses in the physical world. This physical body is not needed in other realities. since they are not 'out there'.  There's nothing 'out there' that's not 'in here' first.

Things actually don't materialize unless an Observer looks at it. They all exist as wave functions of endless possibilities and it's the Observer who chooses to collapse some of these possibilities to actuality in order to experience what it desires. What we see is the emerging level - the final result. Everything is decided at that fundamental level and that's why people don't even realize that they have already decided or reacted on things even before they know it. Human brain is too slow for that kind of information. This Observer is your non-local entity, as in, it doesn't use anything to connect. It is not an energy but beyond that. It uses energies to create matter but it's own existence is non-local and fundamental. There are many realities out there created by thoughts or say, by the Observer; physical reality is only one of them. To experience all others, one needs to go inward.

Anyway, I am actually not all that interested in lucid dreams; they are still sort of out of body experience but only, you are not as conscious as you are in 'real life'. In OBEs, you are fully conscious; that's why these experiences are very different than lucid dreams. They change people's life and change them forever. Lucid dreams have no real impact on people as they still feel they are only 'dreaming'. I have first hand experience of having OBEs though that happened a few years ago, but it has changed my life for one.

Truth be told, science has no clue as to why we sleep or dream or what happens to our consciousness when we sleep.

You can't define or measure a subjective reality with an objective model. If science does intend to do that then that would be an intellectually dense attempt. In other words, in order to test the subjective world, you need a subjective model.