I'm developing a better guess about the nature of precognition and shared dreaming that's making more sense to me than the thoughts I had about it previously....

The 'astral plane' is a mental projection. The reason some people get premonitions during astral experiences is that information about the future is available in the present physical world but in a way that is not generally recognized. The idea is that there are no 'random' events in the future, physically it is deterministic. It can't be determined according to the principles of classical physics, so we treat it as random. But the information is there in the quantum states. The imagination can exercise or feel that information, so to speak, it is built into how the mind works. In doing so it can feel what will happen, and also reorient it in a way that can alter what follows.

Maybe there there's also some exotic matter involved besides normal matter and its properties (which I think also isn't understood as well as is commonly supposed). But that invisible matter doesn't match the 'astral plane' idea very well. The reason I think the astral plane is a projection, is the kinds of mistakes that are made with premonitions, or even shared dreaming experiences, seem to me to make a lot of sense if these experiences involve the exercising of a neural network that involves quantum information that's causally connected to future events.

Formerly, I was experimenting with the idea that the information is being accessed in 'parallel worlds', but I couldn't get it to work very well. I think my imagination was confused by the sci-fi idea of parallel worlds. Now I think that actually the information isn't in other physical worlds, its encoded in the quantum states in our world. If there are other worlds also, they're not as directly involved.

I'm not explaining this very thoroughly, and it's vague in my mind anyway. But I'm feeling fairly confident that these ideas are in the right direction. They're a lot more self-consistent and in much better agreement with my experience than with anything I've been able to understand using the 'higher worlds' or 'finer states of matter' ideas, or the more modern 'many worlds' idea.

The 'astral' idea hasn't made sense to me except as a projection for 20 years. But talking recently about the topic with other people helped get me over the 'many worlds' mental block, after which it became a lot easier to see how the projection would work. When some people say that something is a projection, they mean that its illusory or not real. I don't mean it that way. There is information in it that is real.