Help clear out all the unanswered questions!

Welcome to NameThatMovie, a Q&A site for movie lovers and experts alike.

Guidelines

- Please italicize complete works, like so: Jaws, for movies, TV shows, etc. and use quotations for partial works, which are only part of a complete work, like so: "Hey Jude", for songs, episodes, segments, etc.

- When referencing a movie title or actor's name etc., please place next to it (or below it), the corresponding URL from IMDb or Wikipedia. Please use canonical URLs.

Preferred answer format example.
(answer format and depth of information provided may vary from question to question and different question/discussion types)


- If you're not at least above 50% positive about an answer or are just asking follow-up questions or providing general information, please post it as a comment instead.

- While we're happy to have R language and references, please treat each other PG.

- Only the person who asked the question may decide if an answer is the "Best Answer" or not.

If you're here asking a question please be courteous enough to pick a Best Answer (by clicking on the star next to the correct answer) or at the very least follow up.

If you find the answer yourself elsewhere you can post the answer to your own question.

Remember that this is a community, you could very well help someone else that is also looking for the same thing.

Thank you and have fun!

More tips and tricks for using NTM.

Points

20 - Best Answer
05 - Posting/Selecting an Answer
01 - Asking a Question

Looking for name and author of a science fiction book about alternate worlds or timelines

I read this book a couple of years ago and can't remember the name or the author (also not sure if it was just one book or series - if it was more than one book then it would be 2 or at most 3 books) - anyway the plot is about a group of people finding an alien ship or machine that contains these doorways into alternate or paralell worlds.  If I recall correctly I think there were a couple of these ships/machines found and one was in South America although that was later in the story.The aliens are nowhere to be found so the people start exploring the ships and find the doorways. After going thru one of the doors they find that they can't get back to their original  timeline or world and they keep trying to find out how to get back.  Also they find artifacts and machines left by the misssing aliens who created these ships/machines and try to find out about them. One part that I remember - After the world at large has found out about the ships/machines - one way they use the doorways are as prisons by  sending criminals thru the doors and sending supplies thru and just let these criminals sort things out amongst themselves.  I know this is really vague. I usually download most of the books I read and then delete them from my e-reader. Any help is appreciated.
asked Dec 28, 2016 in Name That Book by jbr549 (47 points)
edited Dec 28, 2016 by jbr549
Maybe :Doorways in the Sand" by Roger Zelazny.

'...Humanity is not alone in the cosmos. The aliens have given a precious relic to the people of Earth: star-stone. The harmony of the galaxy is at stake when they discover the disappearance of their star-stone.
Likeable Fred Cassidy is an eternal undergraduate. All he thinks he knows about the star-stone is that it came to Earth in an interplanetary trade for the Mona Lisa and the British Crown jewels.
Then Fred is accused of stealing the cosmic artifact, and he is pursued from Australia to Greenwich Village and beyond, by telepathic psychologists, extraterrestrial hoodlums and galactic police in disguise; as he enters multiple realities, flipping in and out of alien perspectives, through doorways in the sand...'
Thanks but that's not it. I haven't read Doorways in the Sand  but have read other books and stories by Zelazny. He's one of my favorite authors. I'll have to get a copy of Doorways - sounds interesting.
Yes that's the book I was trying to remember. Thanks CarlosCM for the link.
...