On bad time travel, another way to go wrong is to have events mutable, but for it to be impossible for things to have gone wrong without having first, well, gone wrong. Star Trek: Voyager, that paragon of bad scifi writing, has my favorite example:

The Voyager comes across a devastated planet, and since everybody’s dead they can take a look-see without going all Prime Directive at the natives. A first look tells them that, strangely, Federation technology was involved in the disaster. The away team goes down, plays with the anomaly that made things go boom, and end up in the planet’s past, just before the boom happened. Wacky hijinks ensue, and the folks stuck in the past eventually realize that what they were about to do to get back is what caused the population’s destruction, don’t do it, and time resets. Epilogue: Voyager spots a pre-interstellar culture, invokes the Prime Directive, and continues on its merry way.

Yes, that’s right. They only went to the planet because… in an earlier loop they went to the planet. Which if they hadn’t gone to, they’d never go to. Yeah. Another example of ST: Voyager’s favorite early plot: wring your hands over a horrible problem, wait fifty minutes doing nothing effective about it, and discover that the horrible problem wasn’t.

My wife gets frsutrated when TT stories come up. She starts overthinking the “if XX didn’t happen, then why would ZZ have gone back in time to change AA”? I’ve tried to walk her through it, but no luck so far.

I think one of the best uses of TT in television was in Babylon 5. First “something” moves backwards in time. Years later our heroes are responisble for that something moving in time. Only to discover that it had all happened already (in a predestination type situation). In fact, some of the most important parts of Babylon 5’s history only exists BECAUSE of the TT. Very well done, and very cohesively told.

Ah, rant over. See you guys online.

Lol.

Oh, and when you mentioned time travel and Jack the Ripper, I immediately thought of the Time Scout series by Robert Asprin and Linda Evans. From what I remember when I read it, time travel was again through set portals, but nobody knew where a portal went until you’d been through it, and you could never occupy the same time as another version of yourself. If you did, you just went poof. i.e. if I went through one portal to April 1st, 1981, and then came back to the present, and then later took a portal to March 31st, 1981 and stayed for more than a day, I would cease to exist at the point my past self entered the past for the first time. Paradox was not allowed. Anyway, I recommend the series.

Time Scout series

* Time Scout (1995)
* Wagers of Sin (1995)
* Ripping Time (2000)
* The House that Jack Built (2000)
gmazeroth´s last blog ..Hallow’s End Ball

She has another time-travel story, “The Doomsday Book”, which I also recommend. Here though the time travel is only minor part of the story, with global pandemics being the main focus. Much less light-hearted, what with the Black Death and all, but still an excellent story.
Ratshag´s last blog ..Gone Fishin’

I heartily recommend it if you like time travel stories.

I have 2 separate time travel stories rolling around in my head that I will eventually write.