Just to keep the mind in gear, playing in the electron fog.

I have some barely-formed ideas for a story, in which there will be an alien. At first I thought this would be a fairly typical Big Bruiser kind of alien of the sort that was in the Predator movies -- I have an aliens species I created that's sort of a cross between the Klingons and the Predators called the Vaikarians that I did for one of my Star Wars stories some years ago.

But there are a lot of big nasty aliens out there in the sci-fi world. And it just didn't seem right.

So I thought, maybe one of coherent energies of some form, of which I have another species called the Aoki.

Then, I thought of another of my species, the Seng, who are made of liquid metal.

Then I thought, well, why do the Seng have to be made of metal? Liquid rock, or a jelly substance of some kind, or... energy plasma. The energies and insubstantiability of the Aoki, and perhaps their dimensional shifting abilities, but a form that is at least semi-solid and a physical presence, detectable by my protagonists. The Aoki can only be seen when they are in four-dimensional space interacting on a human level, and that at only one moment in time over a cycle of possibly millions of years. But this new species would be able to interact on an indefinite basis, with only one foot, so to speak, in the higher dimensions.

I often think that one of the limitations of science-fiction is that we can't truly make up anything "alien". The starring horror of the "Alien" movies is perhaps only one of a handful of truly alien aliens in that it is not based on any earthly animal form. Reptilian, insectoid, avian, felinoid, canid, these are all based on animals we see right here on Earth, and thus familiar. We expect certain behaviors and archetypes. We forget these are indigenous forms. The universe doesn't play by our rules. So us creative types find it a challenge to come up with anything that is not based on such forms.

What would be the cultural and social dynamics of a species that has no physical form? Or of a species that doesn't even operate fully in the few dimensions we can perceive? Can humans even conceptualize such a thing?

Bubble gum for the brain.