I read this book in the mid 80's, and what I remember of it, is that time travel has been discovered (invented if you will), but it only works one way. It's possible to send poeple back in time, but it's impossible to go forward. That which has been sent back can't even be brought to its original time again.    This would seem fairly useless, but for one thing, namely imprisonment. The main character is, as far as I can remember, the leader of a group of prisoners. They regularly search they're surroundings for time junk1, which is what they call stuff that was sent back during early stages of testing the time travel. I also distinctly fossils of trilobites being mentioned.    One day a man arrives on The Anvil1, which is what they call the device (platform, scaffold, or whatever) where new prisoners and supplies appear. He claims to be a prisoner, but for some reason the main character gets suspicious of this new man, and starts following him. And in the end it is revealed that this man is an agent of the government, and that they have discovered a way to go forward in time, and that it has been decided that they have all been pardoned, and that they are free to return home. However, the main character decides to stay and he is employed as a guide to time tourists.    1Time junk and anvil are direct translations from my native language to English, but it's perfectly possible that those are not the names used in an official English version.
121452
This book (pre-1980s?) is about people who are exiled to the distant past for serious crimes. However, men and women are exiled to different time periods. So all men are sent to a certain time, but are separated from the women (who are sent to another period).
65670
I read this in the early 1990s when I was a teenager and I have no idea whether it was old or new at the time.  Changing your body involves going in to a tank of liquid. People wear bodies of many and various different types (probably chosen mainly for fashion reasons) but certain body types are prohibited although I don't really remember any of the reasons why.  The main character is persuaded by someone to change his body to an illegal type. Perhaps he becomes involved in some kind of secret underground organization. The new body is of a type that he has never seen before. The main thing that I remember about it is that it has a panel of lights built into the chest and after he has learned how to he is able to communicate with other people in bodies of this type at incredible speed by flashing these lights.  I've spent considerable time web searching with no joy whatsoever. I'd love to re-read this book... the image of the flashing-chest-array communication has been stuck in my head ever since I read it but I can't remember whether anything else about it was noteworthy.
81711
I read a story several years ago in which aliens come make first contact with Earth, and a bunch of scientists set to work trying to establish communication with them in various fields. The main character is a linguist and her team is working to try to figure out their written language, which doesn't have any sort of linear structure and can be read starting from any place.  It contains some explanation of quantum physics as an analogy for how they view time.  In the end, it turns out that the aliens don't perceive time in a linear fashion, and sort of see the future on equal terms with the past, etc. The main character learns to see time this way by studying their language, and the story is interspersed with her talking about what her child is going to do / is doing / has done.  I think I read it in a science fiction magazine but I'm not sure about this part.
88398
I read this in English in the late 70s in primary school. What I remember:  Two boys are somehow caught up in a time travel scenario. I think their father may have been the inventor of the time machine. Their initial journey takes them back about 200 million years. They meet an animal they identify as a cynogasaurus. At least, that's what my memory told me. Google tells me my memory may be playing tricks and they met a  instead. It was definitely cynogsomething. They somehow jump forward to caveman times with the cynogasaurus/cynognathus in tow. They befriend a similarly-aged kid who's a member of a particular tribe, possibly the leopard tribe. The leopard tribe are enemies of the zebra tribe. It's possible I've got both animals wrong. Each tribe has a sacred animal. Disputes between the tribes are settled by their sacred animals fighting. Somehow the kids have caused the death of &quot;their&quot; tribe's sacred animal so they offer the cynogawhatsit, which the cave-people call Nog, in its place. Nog wins the fight and stays on as the sacred animal when the kids leave.  Edit: I thought it may have been Lester Del Rey's &quot;Tunnel Through Time&quot;, the subject of a few queries here over the years. The cover looks familiar and some details match. However two comments have verified that it doesn't feature the cynog* creature, sacred animals or the fight, which are what I recall about the book.
9678
I read a book a while ago in which a device is invented which opens up "tunnels" back through time. These tunnels cannot be traveled through, but can be used to view what happened in the past. I believe it starts out narrating the invention of the device, then skips ahead to after it is widely in use. There is another device created, a cloak of sorts,  which hides the user from the view of someone using the tunnel device. Does this ring a bell with anyone?
101387
I originally read this in the 1980s or 1990s; the author was considered up-and-coming at the time, but not really well-known.  The two main characters were a 'courier' and a wealthy student:   the 'courier' wasn't a messenger so much as an escort into the 'hidden worlds'. The hidden worlds were only accessible through a tunnel on the blasted world; this led to a world of high-tech that was treated as magic; from there, there was another tunnel to a world of real magic (by invoking sprites/imps/demons/etc).  the wealthy student was ostensibly studying the hidden worlds, her real purpose was to study the courier/escort. She was also trying to get away from a smothering bodyguard, who managed to follow them into the hidden worlds.    The denouement involved a revelation that there was a fourth world, where the demons invoked on the third actually came from, and there was a subplot involving a character trying to bring a demon into the high-tech world.
75941
So, I read this book in the mid-nineties (no idea if it was new or not).  I can't recall the title (obviously), but relevant plot points:  It starts off like the Narnia series, where a young (tween) sister and brother are sent to live with relatives in a country estate.    If I recall correctly, the girl was older, and the boy was more of a child, she was closer to being a teen (or actually being a teen). I remember specifically that he was referred to as having baby fat still, and being more childish than her.  They discover salmon swimming in the pool, and there was an old woman. Turns out she was a druid who had turned a man into a salmon for (reasons). Both he and her are from the ancient past (you know, when druids were more common), and the guy starts to resemble the famous Irish hero Finn MacCool.  I am pretty sure he was called Finn also, but I don't think they ever gave him a last name in the book, so I'm pretty sure it's not the eponymous book "Finn MacCool" which I saw later on.    The druid takes the kids and young man back in time with her, and they live in the woods for a while having adventures.  I don't recall all of them, but I do recall that Finn had to catch and eat the "salmon of wisdom" or similar, and burned his thumb in doing so, which made him think he had to stick his thumb in his mouth to think.    Eventually the kids were returned to their own time, leaner and harder and more tan, and the boy faced up to some bullies and didn't let himself get pushed around (evidence of his character development, I suppose).    I thought it'd be a fun book for my daughter, but can't for the life of me remember the name to find it.
80394
I read a story some years ago (probably about 35) in an monthly sci-fi anthology...  It's set in a prison.  The main character is a psychopath who has sessions with a psychiatrist - in these sessions he always blames a person in his earlier life for his condition: uncle, father, mother, sibling... each time returning to his cell - time travelling to his earlier life and killing that person...   Example: He blames his father for leading him into bad ways - goes back in time and kills his father. Next session he blames his mother (and the fact that he grew up with no father in his life) - goes back in time and kills his mother.  Next session he blames a carer (and the fact that he grew up an orphan) etc...  The story had a very clever dénouement, which is hidden in a spoiler section below.  I would love to read this again - any ideas?    Edited to add: I hope I have explained the format sufficiently - the point is, the psychiatrist helps him to identify where he began to go off the rails and who in his life was responsible. Later when he is alone in his cell he goes back in time (the mechanism for this is not explained - it's as if he can will himself to go to that time) and kills the person identified as responsible.  When he attends his next session: his reality, his history, is different so another person has to be identified as the cause of his problems... the story has a Groundhog Day feel to it...  The final paragraph, the end of the story, has him       sitting once again in front of the Psychiatrist and as if it is suddenly dawning on him he looks up slowly, 'realising' that all his problems started when he first came to see this psychiatrist!  Thus leaving the reader in no doubt who will die when he later travels back in time to just before his first session with the psychiatrist...
51529
Long, long ago(ca mid-90's), back when I first got into reading books in digital form, I came across one that started quite promisingly. Unfortunately I was easily distracted back then, and have no recollection of name or author. But I think the opening is curious enough to have a chance at recognition.  It features a female protagonist that serves as a mage's assistant, the position of apprentice reserved for males. this annoys her. finding upon reporting to work one day that she has been reduced to transport mule for something the mage need transported, she is none too pleased when, upon mishandling a scroll or similar, she finds herself rather better built for swordplay than spellcasting. I also believe the case in this particular instance was that she somehow learned that her master was dead, leaving her with nothing to do but make the delivery. If anyone can tell me the name of the book, I'd be ridiculously grateful.
28185
The Book is about an earthship exploring the frontiers that I read as a kid (80's). All the stories are told by the same character but different encounters and events.    The first story is about the crew exploring the planet in a number of separate ships when one of them is taken over by a telepathic alien. As the ship returns however the surprise is sprung on the alien that the Mother ship is Computer controlled. Another is the ship shrinking and then finding after its shrunk beyond the atom that it comes back in as gigantic compared to the Universe in a closed loop.   Hopefully that's enough to trigger a memory.
72128
YA Time travel/teleportation novel. Plot required using helmet (or other head gear)... but only for training. A young kid (less than sixteen?) finds he can either teleport or time travel (I don't exactly remember which one). He is given a helmet, and told that if he wears it, he will be able to travel wherever he thinks.  Later in the story, he is told he can actually do it whenever he wants, without requiring the helmet. The helmet was purely for training his mind.  The "gift" would eventually disappear as the person got older.  I remember reading this novel in my school library around eight years ago...
55533
I just watched the movie  and started pondering time travel.  While pontificating and stretching my limited remembrance of AP Physics, science documentaries, and YouTube videos I remembered the laws of Conservation of Energy and Mass.  Would that not make time travel impossible?  You can't send something elsewhere in time as you would be destroying energy and/or mass, by removing it from the current time.  And it would be impossible to arrive elsewhere in time, as you would be creating energy and/or mass.  I know this is theoretical and a real answer can't be found till someone invents a time machine.  I'm just curious as to what people think of that.
97241
I have little recollection when I read this, but it started with people observing indications of some special engine use many lightyears away, and it led them to 'reverse-engineer' the traces to create their own drive.  Had the usual tropes of international crew-selection for first-voyage.  Somewhere in the travel, they encounter a sentient star or quasar.  When they get back hundreds/thousands of years later, they arrive to an uncaring Earth that no longer pursues space-travel.
45378
It might be a short story or it might be a novel. It must be before 1972 because I read it in my youth and I am OLD.  The following is very impressionistic.  There is a multidimensional/not of this Earth/alien artifact-like tunnel.   Picture a long, perhaps transparent, storm drain like structure sitting in a field but with an opening on only one end.  It is the subject of a lengthy investigation/exploration that has cost many lives. An instrumented investigator enters the "tunnel" and makes the exact movements that his predecessors have made, advancing until he must do something original at which point he survives and a new "move" is added to the list of correct moves or he is destroyed and a "move" is added to the list of things to be avoided at that point.  I remember absolutely nothing else about the work except that (I hope central) feature.
72354
I've read this book about 15 years ago, but I think it's older than that.  In the story people use some sort consciousness transfer technology to travel to distant solar systems. So basically an alien from planet A would want to visit Earth, and you would like to visit the planet A, by mutual agreement you'd transfer your mind into the alien's body and alien's mind would be transferred into your body.  So the main character decides to travel and swaps bodies with an alien. However, he/she isn't able to return back to his/her own body and instead is transferred to another alien's body and so on. As the story progresses the protagonist jumps from body to body until he/she slowly loses his/her own identity.  Also the story is written in a funny/light tone.   I've read this story in Russian but I am sure that it was translated. The story was a part of collection of short sci-fi stories.
28890
I think I read this story in Omni magazine in the '80s.  It's about two lovers who discover that whenever they're touching each other, time stops for everyone and everything else. Time just stands still outside of their bedroom - like hitting pause on a VCR.  I do remember one small detail: these two people tried to experiment with this ability, and they discovered that they could prepare meals, and that they would stay hot while time was paused. They experimented in other ways, too, though I cannot recall how.  Sometimes my searches turn up a story about two lovers who are time travelers - there is jealousy and some paradoxes - but the story I am thinking of is not a story about time travel, at least not directly.  I've tried googling for it, but the search terms (e.g. "lovers touch time stops") are so non-specific that all I get are false hits. I've tried looking here both using Search and Similar Questions. No joy.
42573
A man living in an underground city gets on his local subway train and keeps traveling, station after station, just to see where it goes.    Nobody has ever done this before. The staff on the train (who only each work a small section of train line) are interested in his journey, and allow him to continue.  The train passes through thousands of miles of continuous underground city, past contaminated and bricked-up areas, past thousands of stations, and finally after many months or perhaps years, comes back to where he started.  He realizes the world or universe is all city, entirely urbanized and occupied by people, all the way to the core, and can estimate its diameter. He also becomes concerned that the city-world may be slowly choking on its own toxic wastes... more and more areas are being walled-up and sealed off, and the whole civilization may eventually die.  As far as I can remember there is no mention of "sky" or even of a "surface" to a planet. Even the idea of "outside" is absent, if I remember correctly.  It's not clear if it is set in a large converted planet, or if the entire universe is city.   It was written in English. I read it in the 1980s, and it felt like it could have been written any time from the 1930s to about 1970s. It was almost certainly part of an anthology.