Thanks, Jonathan. This is the first time I've seen the original HG Wells text that you linked. I had thought mistakenly that you had meant the various film adaptations.

At first, I was going to post this in the comic book thread but on second thought decided to post it here for the time travel because I had a question about a particular time travel principle. In the Flash magazine,a time traveler from the 98th century named Kryad came back to Flash's era in order to forcibly extract the super speed from The Flash. Kryad needed the speed force in order to fight a Menace in his era of the 98th century. In the ensuing battle,Flash thwarted Kryad. But then he also wanted to help Kryad because the future century was in peril. Since extracting the speed force from The Flash would be fatal, The Flash proposed a different solution. In other words they time traveled back to when Barry Allen had that remarkable accident which gave him the super speed. Turns out that when Barry Allen was drenched in those chemicals that gave him the super speed, Barry had thrown away the drenched lab coat into an outdoor trash can. So Flash had Kryad use his futuristic devices to extract the speed force from the chemical mixture that the lab coat was drenched in.
The question I had was that when Kryad travels with The Flash, the Flash becomes just a ghostlike image, intangible, in the time stream. Flash explains that he has become ghostly and intangible because two of him cannot exist at the same time. So the Flash can remain as only an observer. That's why he had to get Kryad to retrieve the lab coat from the trash can.
That brings me up to my question, that is, about two of the same person Unable to occupy the same time. That was the point made in the Flash story. Yet I remember an episode from the TV series Time Tunnel where Tony went back in time and met his childhood self. In that episode, Tony was not intangible at all so he could interact with his childhood self. And there was also a Twilight Zone episode where the same happened, namely an interaction with a childhood counterpart.
So I wonder--Was the Flash story more plausible than those two other examples?

Any time travel theory is as plausible as any other until we get time travel and find out what the rules are. An argument can be made that the you that you meet in the past can be considered a different person because he occupies a different point in your time stream. Spider Robinson, in his Callahan’s series, follows the premise that there can’t be to of you in the same moment in time. But you don’t get to be an observer, you just can’t go there.

welcome. When trying to imagine what such a thing might look like - I get stuck at "what would the story look like to observer X" i.e. how it would look to someone watching a video of a thing which travels. The "I don't remember event (a) so this thing might or might not be part of my narrative." seems to push the idea to "many worlds" and scary extra dimension(s) and no distance formula. <- that distance formula problem has sat with me like Poe's Raven.

The OP was, what would you do if you had time travel? Asimov’s may had a story where someone was sent to Ancient Greece and given the task (with the gold necessary) to have certain famous, but missing, documents copied, the copies placed in clay jars and hidden away in a cave. He then goes back to the present and gets them dug out. (In the ensuing time, some of them were still lost!)

I would take modern equipment and record missing things. Copy the Liberty of Alexandra, as well as all the missing Dr. Who’s and famous magicians performances!

There was a series from England that tuned the idea of time travel inside out! It was called “Sapphire and Steel.” Time is a malignant force that’s always trying to break through to the present! Joan Lundrum and David McCullum were the two agents who travel around the countryside, battling Time’s attacks, trying to keep everything running smoothly.

Ed, Stephenson's latest book "The Rise and Fall of D. O. D. O." also uses that story element. Douglas Adams had his Professor Chronitis doing that trick with a salt shaker.
If you travel to what you believe to be our past - can you return to our common present? Doesn't that get awkward the second time you try and return to that past and that moment? Do you see your earlier trip? How quickly does this become "All You Zombies"? An extreme case of subjective continuity comes with "Yesterday was Monday" - which was picked by by Stephen King for "The Langoliers" and a Twilight Zone episode called "A Matter of Minutes". Or Stross's story "Palimpsest" if you're really brave.

There are dramatic conventions in place which support that kind of story. For example every time we open to page 5 and look at panel 2 it will have the same contents. We don't need to fret over whether the panels are in the correct order or depicting the same characters between panels. The illusion of subjective continuity within the premise of a fantasy story is taken as stronger than our suspended disbelief in the characters.

It’s a philosophical debate whether you return to the “same” present or not. In “The Man Who Folded Himself,” David Gerrold has his character interact with his other selves in time. This appears to be a multiple timeline concept as one of the characters goes insane and plots to kill the others. When he’s locked up, none of the others seems to worry that they’re going to follow his path. (One even states that he’d gone down the same route, but they’d gotten to him sooner, before he got that bad.)

Gerrold also has his character in an ongoing game of five-card stud with himself, and has him seduce himself!

One last point is that the character finds an alternate him who’s female! The two of them conceive a child and (I confess, I got totally lost here) each one goes back to their timeline with the child, but the character’s child is a son and the alt-character’s child is a daughter.

I read that sequence three times and still didn’t understand it.

In his “Callahan” series, Spider Robinson has had a number of time travelers. The first one did it the hard way, one day at a time, isolated from the world in a South American jail. By the time he was released, the world had changed so much in ten years, he just couldn’t understand it.

That time travel with probability story has become "mainstream" worldview. It's been argued that if you reset the world to what it was a billion years ago and then watched as time rolled forward - you'd get a very different world of outcomes a billion years into that history.

Let's say on Monday you go to your magic collection room, take a pack of cards out of your prop box, count down ten cards and look at the eleventh card. Then on Tuesday you use your time machine to pop back into that room on the day before (Monday) but a few minutes earlier. You take out your pack of cards, practice a color change or something displacing one card from the top to the bottom of pack. You replace the pack in the case, then press the "return" button on your time machine to return to Tuesday. Okay, what card did you look at? Presumably on Tuesday before you traveled you'd recall the card you saw on Monday.

Maybe things are free to be wherever/whenever as long as they are unobserved?

At first, I had intended to post this in the comics thread because it concerns the Infinity War. But then I decided to post it here because of the Infinity War's use of the Time-stone. After the shock at seeing so many characters being killed off in the movie, it seems likely that they could be all Resurrected by using the Time-stone. After all, we've seen it done already in the X-Men movies when Professor Xavier died but was resurrected by Wolverine's time travel. Do you think that will happen in the Infinity War's 2nd half?

There are so fee who have died forever in the Marvel Universe. Aunt May and Simon Williams. Actually not sure if they stayed dead.

But of course they will resurrect them. Black Panther 2, the next Spiderman movie and such depend upon it.

Doctor Strange used the time-repeat idea successfully, so that's a fine option. They also have the "What If" comicbook story approach - could have Stan Lee appear as author/editor who dismisses the part one climax as "too busy" and resets the story to some point before. Open season.

Reset to 1961 and have the Fantastic Four appear at the end?

Talking about making changes, there is a comic book series called "Astro City," which tries to restrict its heroes to some degree.

One is a time traveler who comes back to the past to stop the Challenger disaster. he develops temporary amnesia, but remembers his mission at the last moment and saves the crew.

When he reactivates his time machine to go back, there's nothing there! It's just a void as reality has gone down a different path. He comes back to our present (his past) and sets up a life as a super hero called "Samaritan." (He's obviously a Superman pastiche) The depressing part is that, rather than be a "mild mannered reporter," he's a fact checker who uses his super tech to do his work for him while he files around the world stopping disasters (afraid of what the next "Challenger" might do to the timeline!) He dreams of just being able to fly for the sheer pleasure of it!

There's a webcomic called "Something Positive," which has NOTHING to do with time travel! But the creator USED to make a super hero strip called "Super Stupor," which presented a dark vision of the comic book tropes we take for granted.

One of the heroes was a sullen guy named "Time Puncher," he could literally punch time and change the past. One person demands he change the past of this guy's favorite hero ("Spider Monkey,") and is unhappy with the results. He insists that Time Puncher did something wrong and wants him to fix it! Time Puncher does his thing and ends up erasing the original guy from existence! His partner looks at him and says;

"Don't you ever worry about paradox?"

"Nah," says Time Puncher. "I got a crèam for that!"

* adult content warning *
http://www.superstupor.com/sust02132009.shtml

Interesting how the Time-stone has been added to the lore of the Eye of Agamotto. Also that the word, Agamotto, as the name of an actual sorcerer was, at first, used Only in the What If magazine so it was not canonical at first.

The only time I ever saw Doctor Strange use time travel in his magazine was when he rescued Cleopatra, but in doing so, he had to use his astral body. Apparently the occult form of time travel is not as advanced as the scientific form such as Doctor Doom's because Von Doom's Machine can transport the actual physical body as well.

This brings up the question. Have there been any other stories where time travel was done via astral form like Doctor Strange? Since Ed has accumulated so many time travel stories, maybe he knows of some.

Sorry, I can’t think of any stories where the traveler is in an astral form.

Remember the first time traveler meeting Shakespeare? Asimov’s magazine did another where James Moriarty leaves a letter for Sherlock Holmes explaining that he’d escaped Holmes all those years because he had access to a “time bicycle!” The machine breaks down on him in mid-journey and strands him, not only in Shakespeare’s England, but actually onstage during a performance of Macbeth!” He appears at the moment the “Third Murderer” is supposed to appear, and recites the Third Murderer’s lines. After the production, Will thanks him for his contribution, stating that he felt SOMETHING belonged in that point of the script, but he hadn’t been able to think of what and now, he’d use Moriarty’s contribution. So, Moriarty is now stranded in the past, but will join Shakespeare’s troupe. He finishes the letter to Holmes with this thought; “And so, my dear Detective. When the Third Murderer’s lines were first read, they were spoken from memory. I ask you, who wrote them?”

I'm okay with ret-conning the current canon into a "what if" in the main brand every now and then. As the Watcher said - stating the "what if" as point in canon for the start/end branch of narrative. Do all roads lead to Rome? Does it matter who shows up in Samara?

To the OP, of course there are many events I'd like to inspect. But to change... that Bradbury story has be less than comfortable about what awaits on the return trip.

There is a teen-age Superboy story where the villain "gets rid" of Superboy by sending Superboy into the future. The bizarre consequence of that is that at the same time, his Adult counterpart of Superman is flung back automatically into his teenage time period.

To make a long story short, Superman manages to get at the villain's time-machine and re-sets it to send people back into the past. The re-set sends the villain back into the past one-hour before he had shot the ray at Superboy. After that,it will be as though none of the things that happened today ever occurred.
Before Superman leaves to go back to his own time, he writes a letter and leaves it with Superboy's foster parents so that they can forward the letter to the teenage Superboy when he returns. The letter that Superboy reads, tells the identity of the villain so Superboy can capture him. But Superboy is left with a mystery because the letter is written in his own handwriting and he cannot figure out when and how he wrote it.

The point to be made here and what I found interesting is that the story tries to resolve the discrepancy that two of you cannot exist in the same time. That's why Superboy's arrival in the future automatically sent his adult counterpart of the future back into the past where Superboy had left. The sticky wicket of two of you in the same time was resolved by way of the time-switch.

Doctor Who season 11 starts 10/7/18 - global simulcast with BBC England. USA afternoon and repeat 8pm EST

Jonathan, now that you mentioned Doctor Who, I just noticed something in the current JLDJustice League Dark series that reminds me of the Time Lord's Tardis. As you know when you enter the Tardis, its interior is much more spacious as compared with its exterior appearance. It's done also in the current JLD with Doctor Fate's obelisk, his Tower in Salem that serves as his secret abode. Inside that obelisk, the interior is as spacious as a castle. Because as part of Doctor Fate's occultism, the Tower's interior functions as supernatural nexus for extra dimensional travel and communication.