Spaceling by Doris Piserchia

A curious novel, totally New Wave (first published in 1978).

Synopsis: Adventures and intrigues in which a 15-year-old girl finds herself involved, in a future where some humans can travel interdimensionally. In other dimensions the human body transforms into a totally different being, adapted to the new environment. For example, in a volcanic world uninhabitable for humans, the character becomes a sort of giant otter (see the hardcover edition art below).

It gets a little confusing with all the interdimensional back and forth and also for all the characters and how they come in and out of the story. At some point the story evokes or suggests to me what I assume would be an astral travel or a drug-type experience.

An interesting author, until now I had not read any of her works, but I plan to read more of hers.

The Universe Between by Alan E. Nourse

I love retrofuturism, so I love classic science fiction that is based on ideas that today may be considered outdated, partially or totally, or in concepts that have evolved to a different vision. A typical example is telepathy, with masterpieces like Dying Inside by Robert Silverberg or The Demolished Man by Alfred Bester. 

In the case that concerns us, the novel deals with… the fourth dimension! Well, as far as I know -I'm not a scientist- today the concept has evolved into a slightly (?) different thing, what we would call alternate realities due to quantum physics, and today -again as far as I know- the fourth dimension it is considered to be time itself. On the other hand, the idea of ​​a multiverse is still very much in vogue today, for example in superhero comics and movies/series.

About the novel itself, it is very entertaining and even with some moments of sense of wonder, and I must warn the reader about certain apparent anachronisms that are not such. So for me, this is one of the "good" classics, that is, worth reading even after seventy years (it was first published in 1951!). It should be noted that the great novel The Gods Themselves by Isaac Asimov, also about alternative universes and the possibility of exploiting their resources, was written twenty years later than this one.