# Hypothetical: How would spot a time traveller? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [July 27, 2016, 11:21pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069 "2016-07-27T23:21:23Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![JacobSwan](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@JacobSwan](https://boards.straightdope.com/u/JacobSwan)\ **Post date:** [July 28, 2016, 9:43am UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/21 "2016-07-28T09:43:23Z")
I have vague memories of a short sci-fi story with this premise. The time detective spots the traveller because he doesn’t pull his trouser legs up when he sits down. In the future people don’t wear trousers and aren’t used to pulling the legs up to avoid wrinkles. Does anyone remember what story this was? ---
**Author:** ![cmkeller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmkeller/32/118_2.png) [@cmkeller](https://boards.straightdope.com/u/cmkeller)\ **Post date:** [July 28, 2016, 10:20am UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/22 "2016-07-28T10:20:54Z")
I’d look at classified ads for one with four lines that spell “ATOM” as an acrostic. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [July 28, 2016, 12:30pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/23 "2016-07-28T12:30:37Z")
Ted Kennedy got busted as a time traveler in 1998: [![](https://img.youtube.com/vi/AggeSjZwx6s/hqdefault.jpg "Sammy Sooser Mike McGwire #shorts") ](https://www.youtube.com/watch?v=AggeSjZwx6s) ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [July 28, 2016, 1:14pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/24 "2016-07-28T13:14:27Z")
Depending on how far time was traveled, seems like their accent/vocabulary would give them away. ---
**Author:** ![Aspidistra](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aspidistra/32/3894_2.png) [@Aspidistra](https://boards.straightdope.com/u/Aspidistra)\ **Post date:** [July 28, 2016, 1:17pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/25 "2016-07-28T13:17:06Z")
> [@Chihuahua](#): > > So I’m guessing you would have to start with a list of wealthy and powerful people, and then investigate their backgrounds until you found one that looked like pure dumb luck. Holy crap! _It’s started already!_ ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 28, 2016, 1:34pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/26 "2016-07-28T13:34:15Z")
Depending on their apparent age and where they were born and raised they may be missing a smallpox vaccine scar. ---
**Author:** ![Pantastic](https://avatars.discourse-cdn.com/v4/letter/p/3bc359/32.png) [@Pantastic](https://boards.straightdope.com/u/Pantastic)\ **Post date:** [July 28, 2016, 2:09pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/27 "2016-07-28T14:09:33Z")
> [@Mijin](#): > > I think this would do it, but in a slightly subtler way; interview someone using a lot of contemporary cultural references and language, and sprinkle in a few deliberate mistakes. > I think with a well-designed test you could tell the difference between someone who’s lived up to 2016 but is not up to date on the latest fads, and someone who’s just arrived and is trying to blend in. I think you’re vastly overrating how tuned in to pop culture most people are; you’re going to get a lot of false positives with this technique, and the time traveler is more likely to have studied up on background info than a random person. People have stuff that they keep up with, but very few people actually stay on top of all of the current trends. You’d probably peg half the people on this board as time travelers with that test, for example. ---
**Author:** ![4d3fect](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/4d3fect/32/9728_2.png) [@4d3fect](https://boards.straightdope.com/u/4d3fect)\ **Post date:** [July 28, 2016, 3:42pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/28 "2016-07-28T15:42:47Z")
You’d be able to tell by the shimmering halo surrounding the body. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [July 28, 2016, 3:47pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/29 "2016-07-28T15:47:48Z")
Also you can just ask them. Time travelers aren’t allowed to lie if you ask them if they are a time traveler. Oh wait, that’s undercover cops, nevermind. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [July 28, 2016, 4:23pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/30 "2016-07-28T16:23:49Z")
> [@RivkahChaya](#): > > How far in the past or future could someone travel and still expect one’s immune system not to be overwhelmed by sudden contact with unfamiliar pathogens? Would there just be something like “time-traveler syndrome,” where you have a runny nose, the trots, and be a little run-down for a couple of days, while you caught up, or could you catch something really bad? One assumes that travel to fourteenth century Europe would require a little fibbing at the doctor in the 21st century beforehand to procure some antibiotics to have in hand, and lots of hand sanitizer and a flea collar probably wouldn’t hurt. Hard to say, especially since some kind of technological artificial immunity (like nanotech antigens) seems more plausible than time travel as far as future inventions go. ---
**Author:** ![Don\_t\_Panic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/don_t_panic/32/398_2.png) [@Don\_t\_Panic](https://boards.straightdope.com/u/Don_t_Panic)\ **Post date:** [July 28, 2016, 4:38pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/31 "2016-07-28T16:38:36Z")
The way I understood the OP (or rather, one way): If we look at our past history, are there events in it that might have been caused or influenced by clandestine time travel? If such historical events exist, would we even be able to tell? How do we spot them? For the record: No, I personally don’t think that there are any. There’s a simple test: Does Hitler exist in our timeline? If he does, there’s no time travel shenanigans in it. As we know, the first thing any time traveler does is to kill Hitler. If your timeline doesn’t have Hitler, you might have time travelers, and you should be able to find them in the historical record. Look for any reported incidents of mysterious and heavily armed visitors queuing up outside a house in Braunau am Inn, Austria-Hungary, at around the year 1900 or thereabouts. ---
**Author:** ![Hampshire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hampshire/32/4887_2.png) [@Hampshire](https://boards.straightdope.com/u/Hampshire)\ **Post date:** [July 28, 2016, 6:04pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/32 "2016-07-28T18:04:18Z")
They would speak English but you wouldn’t be able to understand it. Using phrases like “How would spot…” ---
**Author:** ![Chihuahua](https://avatars.discourse-cdn.com/v4/letter/c/dec6dc/32.png) [@Chihuahua](https://boards.straightdope.com/u/Chihuahua)\ **Post date:** [July 28, 2016, 6:17pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/33 "2016-07-28T18:17:39Z")
> [@Martian Bigfoot](#): > > The way I understood the OP (or rather, one way): If we look at our past history, are there events in it that might have been caused or influenced by clandestine time travel? If such historical events exist, would we even be able to tell? How do we spot them? > > For the record: No, I personally don’t think that there are any. There’s a simple test: Does Hitler exist in our timeline? If he does, there’s no time travel shenanigans in it. As we know, the first thing any time traveler does is to kill Hitler. > > If your timeline doesn’t have Hitler, you might have time travelers, and you should be able to find them in the historical record. Look for any reported incidents of mysterious and heavily armed visitors queuing up outside a house in Braunau am Inn, Austria-Hungary, at around the year 1900 or thereabouts. This is more what I had in mind. You might be looking through archives and see a headline that says, “Unidentified man kills Austrian baby. Police have no motive.” Now, it would be strange that it was an unsolved and apparently random crime, but since WW2 never happened in your universe, you would have no way to know its real significance. Right? ---
**Author:** ![Urbanredneck](https://avatars.discourse-cdn.com/v4/letter/u/ea5d25/32.png) [@Urbanredneck](https://boards.straightdope.com/u/Urbanredneck)\ **Post date:** [July 28, 2016, 6:18pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/34 "2016-07-28T18:18:01Z")
> [@Martian Bigfoot](#): > > The way I understood the OP (or rather, one way): If we look at our past history, are there events in it that might have been caused or influenced by clandestine time travel? If such historical events exist, would we even be able to tell? How do we spot them? > > For the record: No, I personally don’t think that there are any. There’s a simple test: Does Hitler exist in our timeline? If he does, there’s no time travel shenanigans in it. As we know, the first thing any time traveler does is to kill Hitler. > > If your timeline doesn’t have Hitler, you might have time travelers, and you should be able to find them in the historical record. Look for any reported incidents of mysterious and heavily armed visitors queuing up outside a house in Braunau am Inn, Austria-Hungary, at around the year 1900 or thereabouts. I dont know because I’ve often thought that our computers have developed so fast over just the past few years makes me wonder if somebody is showing some future stuff to a group of engineers. I mean we went from tube technology in Eniac to chips to microchips and computing power keeps doubling and improving. Granted this is part of the plot for "Terminator and was also a plotline for a Star Trek Voyager episode. ---
**Author:** ![The\_Other\_Waldo\_Pepper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_other_waldo_pepper/32/12370_2.png) [@The\_Other\_Waldo\_Pepper](https://boards.straightdope.com/u/The_Other_Waldo_Pepper)\ **Post date:** [July 28, 2016, 6:25pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/35 "2016-07-28T18:25:53Z")
> [@Martian Bigfoot](#): > > For the record: No, I personally don’t think that there are any. There’s a simple test: Does Hitler exist in our timeline? If he does, there’s no time travel shenanigans in it. As we know, the first thing any time traveler does is to kill Hitler. Isn’t the handwave in DOCTOR WHO that some events are fixed points in time and can’t be altered, while most others are fair game? So if offing Hitler would change history so dramatically that time travel is never invented, it’s impossible – but you could still make it so Biff Tannen gets punched out by George McFly, or is handed a sports almanac from the future, or whatever; those changes are minor enough. ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [July 28, 2016, 6:45pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/36 "2016-07-28T18:45:51Z")
They’re holding the mouse like a microphone and saying, “Hello computer!” ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [July 28, 2016, 7:07pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/37 "2016-07-28T19:07:38Z")
The time traveler’s computer has Windows 8. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [July 28, 2016, 7:18pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/38 "2016-07-28T19:18:32Z")
> [@Chihuahua](#): > > This is more what I had in mind. You might be looking through archives and see a headline that says, “Unidentified man kills Austrian baby. Police have no motive.” Now, it would be strange that it was an unsolved and apparently random crime, but since WW2 never happened in your universe, you would have no way to know its real significance. Right? Author Jack Finney’s protagonist causes the time travel inventor’s parents to not meet and cause the project to have never happened. Members of the time travel project begin “remembering” things that did not happen. One of them travels back to prevent the protagonist preventing the parents meeting. A tangled web, and a darn confusing one at _times_. There is that darned word again! ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [July 28, 2016, 8:24pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/39 "2016-07-28T20:24:47Z")
> [@Urbanredneck](#): > > I dont know because I’ve often thought that our computers have developed so fast over just the past few years makes me wonder if somebody is showing some future stuff to a group of engineers. I mean we went from tube technology in Eniac to chips to microchips and computing power keeps doubling and improving. > > Granted this is part of the plot for "Terminator and was also a plotline for a Star Trek Voyager episode. Space travel seems to be a lot more within the grasp of cultures with technology similar to ours, than time travel, so if Von Damiken stuff is proven legitimate, my money is on space travelers. There seem to be two factors working from opposite ends, that militate against time travel: The obvious philosophical limitations, and the high risk that some time traveler screws up so bad, the results wold be abundantly visible. Like, we, as space travelers, completely ignore the consideration of hiding the fact that we were there. Why wouldnt time travelers do the same, and leave flags and shit all over the place. ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [July 28, 2016, 10:35pm UTC](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069/40 "2016-07-28T22:35:01Z")
> [@Martian Bigfoot](#): > > The way I understood the OP (or rather, one way): If we look at our past history, are there events in it that might have been caused or influenced by clandestine time travel? If such historical events exist, would we even be able to tell? How do we spot them? > > For the record: No, I personally don’t think that there are any. There’s a simple test: Does Hitler exist in our timeline? If he does, there’s no time travel shenanigans in it. As we know, the first thing any time traveler does is to kill Hitler. > > If your timeline doesn’t have Hitler, you might have time travelers, and you should be able to find them in the historical record. Look for any reported incidents of mysterious and heavily armed visitors queuing up outside a house in Braunau am Inn, Austria-Hungary, at around the year 1900 or thereabouts. [Everybody kills Hitler on their first trip](http://www.abyssapexzine.com/wikihistory/) [Previous page](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069.md?page=1) [Next page](https://boards.straightdope.com/t/hypothetical-how-would-spot-a-time-traveller/761069.md?page=3)