Questions tagged [time-travel]

For questions relating to travel in time. Such travel may involve FTL travel; consider also using the [faster-than-light] tag.

Filter by
Sorted by
Tagged with
-1 votes
1 answer
55 views

A device to negate time dilation believability

In this setting spacecraft are able to approach the speed of light and are equipped with a device to negate the time dilation, this allows things to go horribly wrong if this device fails plot wise. ...
user avatar
  • 317
1 vote
2 answers
64 views

Post scarcity economy via time travel/alternate universes

I'm imagining a world where it's possible to travel back in time, but doing so creates an alternate universe rather then changing your past. There is some high, but manageable, cost the first time ...
user avatar
  • 31k
7 votes
3 answers
693 views

What would be the best time period, in the age of the dinosaurs to send two people back to for maximum survival?

I'll give you a bit of context and understanding. What's happened is that two people are investigating a scientist who was believed to be involved in suspicious practices and they end up discovering ...
user avatar
-8 votes
2 answers
133 views

Is it really possible to travel back in time? [closed]

There have been many time travelling questions here, but I am not sure if this one specifically has been asked. Is it really possible to travel back in time and is it theoretically possible? This ...
user avatar
  • 234
7 votes
5 answers
370 views

What physical effects would 3000 years have on the physiology of humans on Mars?

This is my first ever question on here. I've seen a few posts on Martian physiology but since the answers on here are answered so well and by so many I thought I'd be more specific. How would human ...
user avatar
4 votes
1 answer
77 views

Surviving time travel using black holes or wormholes

Operating under the assumption that it is possible to use a black hole or wormhole to travel forward in time by a relatively small amount of time (e.g. 2,000 years) without travelling a significant ...
user avatar
6 votes
6 answers
863 views

Can the 1980s US government recreate a smartphone?

Inspired by this question. A time traveller appears in two situations in the year 1985 in front of Steve Jobs and other Apple high ups in front of few federal and us army officials The time ...
user avatar
  • 1,742
1 vote
7 answers
147 views

What would be the advantage of a device that can only let a person travel forward in time? [closed]

Context The Helix Corporation is an evil mega-corporation where everything they make always has some sort of strange twist to it. Their latest product was the Relativity Rocket Alarm Clock. It was ...
user avatar
6 votes
5 answers
216 views

Paradox Free Time Travel: What Are the Implications of the “One More Ball” Thought Experiment? [closed]

Note: this question uses third-party worlds and events to illustrate the point, but it is not in any way about them, therefore this question is not off-topic. I have had an interest in time travel. ...
user avatar
  • 2,013
9 votes
4 answers
2k views

How to estimate size of ketamin dose to sedate a T. rex.?

To mark the anniversary of our company we have decided to introduce to our VIP guests a once in a lifetime opportunity to get intimate with the dinosaurs, we will put the animal to sleep so the guests ...
user avatar
  • 46k
31 votes
9 answers
7k views

What can we eat in the late Cretaceous?

Suppose there is a team of explorers sent back in time 66 million years ago somewhere before the K-T event took place, the mission is to spend no more than 3 months to retrieve a blood sample from a ...
user avatar
  • 46k
3 votes
0 answers
107 views

A High School student time travelled through a certain time in Medieval Ages how would he/she survive? [closed]

Since it's the Medieval Age can mean any time period and any place you can suggest which place and time the student can most likely survive with limited skill. How would a person with high-school ...
user avatar
1 vote
2 answers
183 views

What might a time travel facility be called? [closed]

In the real world one may catch a train at a station, a flight from an airport, a bus from a depot, a boat from a port or terminal. If one were to travel through time inside a time machine what would ...
user avatar
5 votes
4 answers
198 views

Chemical component that would be dangerous (existential threat) when liquid, but safe if it evaporates?

The story I am writing takes place in a world where someone invented time travel. This technology, and the control of anti matter is only available for the creator (and the protagonist that helps him)....
user avatar
  • 121
0 votes
2 answers
78 views

Ideas from the future changing the past [closed]

There is a thesis that I rather support, claiming that most inventions where done when done not because of lack of creativity, but because the technology or society were not ready for them. But I ...
user avatar
4 votes
3 answers
123 views

Ideal Settlement Location for Time Travelers [closed]

If a group of time travelers dedicated to travel back 10 million years and settle a humanless earth, where might they decide to found this first colony? Assume that these temporal colonists are well ...
user avatar
2 votes
5 answers
195 views

Effectiveness of a modern-built Q-ship in the Napoleonic Wars

Let us suppose that at the beginning of the Napoleonic Wars, we have a 5th-rate ship similar in appearance to the 38-gun HMS Lively with a displacement of approximately 820 tons, and a top speed under ...
user avatar
  • 45.5k
6 votes
2 answers
209 views

Hacking the simulation to do time travel (with quantum computers?)

I am trying to come up with a plausible speculative physics explanation for a story I am writing where the conceit is that phsyicists discover the universe is a simulation. The idea is that the ...
user avatar
6 votes
5 answers
996 views

"Busted" from the past

Imagine someone claimed she was from Mesopotamia, one of the earliest civilization and had time travelled 5000 years into the future which is now our current modern day, she was completely naked so ...
user avatar
  • 46k
7 votes
6 answers
439 views

If a time traveler from the near future went back in time to kill Hitler and failed, could the nazis reverse engineer modern tech with 1940's tech?

Suppose someone went back in time to kill Hitler and fails and some modern tech falls into nazi hands. What modern technology could they realistically reverse engineer with 1940's tech? I'm leaving ...
user avatar
1 vote
2 answers
127 views

What is the earliest that a time-traveling electric vehicle of current era could be recharged?

Taking modern gas engines into the past is hard because the fuel isn’t refined enough and damages the engines. But electricity has been the same since time began, limited by human capacity to produce ...
user avatar
  • 24.9k
2 votes
5 answers
116 views

What tests might someone do to assess possible brain damage from time travel? [closed]

I have a character who travels in time, but after making major jumps (like 100 years forward), she begins experiencing side effects—first nose bleeds, but the symptoms begin to increase to things like ...
user avatar
  • 490
2 votes
2 answers
117 views

Interstellar Space Travel via Time Travel

Building upon the questions from @States Time travel from stationary position? and @Travis Time travel from stationary position?, would it be possible to travel to other star systems within our galaxy ...
user avatar
  • 677
31 votes
20 answers
9k views

What would be the most effective role to place 150-300 modern soldiers in during the Civil War? [closed]

So, let’s say 300-ish modern American Soldiers/Marines are sent back to the civil war. They lack any heavy weaponry, but overall this is what their armament consists of: 250 of them have basic M4 ...
user avatar
  • 11.1k
3 votes
4 answers
215 views

How could a time paradox caused by a manufactured deity fail to produce a full retcon of history?

The Leviathan https://villains.fandom.com/wiki/Scarlet_King is an entity formed as the manifestation of the tension between the modern world and the pre-modern world and the rage it creates. ...
user avatar
  • 38.2k
6 votes
7 answers
419 views

How can controlling the flow of time prevent you from altering history?

The Leviathan is an ancient deity that exists outside the mortal plane. It seeks to enter the human world, which is separated from him by an all-enclosing barrier protecting it. However, the ...
user avatar
  • 38.2k
15 votes
12 answers
3k views

What's needed for a solar powered past?

The person in the story falls through a plot hole into the early 1800 years. Like, steam engines are still new and ineffective, but industrialization is nothing foreign anymore. Light bulb, car & ...
user avatar
  • 3,313
31 votes
13 answers
5k views

How long will it take for a medieval human to adapt to our current world?

Meet Henry, he is a sharp and quick-witted rich young adult from the High Medieval Ages(1000-1347). He can be described as someone with decent adaptability skills, though not much He found a time-...
user avatar
2 votes
8 answers
359 views

What would really happen if an adult's mind was dumped into his five year old self's brain?

We’ve all read those Isekai mangas... or at least I have... but how realistic would they really be put into practice? Say a normal average dude suddenly gets caught in some weird temporal event that ...
user avatar
-5 votes
3 answers
182 views

Can we use shrink rays to go back in time? [closed]

I researched muons, the Higgs boson, and quarks, and at least one of them can be used for a shrink ray. I'm not asking if we could build a shrink ray, I know it is possible to build one. I'm asking if ...
user avatar
  • 91
3 votes
7 answers
395 views

Is this time travel scheme internally consistent?

I know there are similar questions, but not similar enough, and in fact, I don't remember seeing this kind of time travel in fiction. Before I start, it doesn't matter how the time machine works in ...
user avatar
  • 1,377
3 votes
1 answer
240 views

"cloaked" stars and gates viable to stop causality paradoxes

So I was lying in bed this moring(summer break, yaaaay) when it suddenly occurred to me that most causality paradoxes are caused by the exchange of information, so if when moving FTL no information ...
user avatar
1 vote
0 answers
70 views

Will we ever be able to understand history with 100% accuracy [closed]

Asked the same question on History SE and was directed here. Link with the context is here And this is the question: First of all, I am not a historian or anything of the like, but this question was ...
user avatar
0 votes
2 answers
198 views

Proving to the past that I am from the future [closed]

Let's say I've been able to travel in time and I am back in the past (just by a few years or even centuries). I do not have any modern gadgets or even modern clothes, just me and my 21st century mind. ...
user avatar
4 votes
6 answers
216 views

Create a machine to detect a signal sent from the future [closed]

Suppose the inhabitants of my world wish to build a time machine capable of receiving information sent from the future. It is only necessary to build the receiver; building the transmitter can be ...
user avatar
  • 157
7 votes
4 answers
292 views

Implications of post-cognition on societies

There are fictions where we can travel to the past, but it often raises causality paradoxes. There are others where we can see into the future, and it has also some implication on free will. But what ...
user avatar
  • 173
1 vote
2 answers
158 views

What kind of building structures could a group of eleven people make whilst stranded on a tropical island?

I'm just curious to know what kind of structures a group of people would make on a tropical rainforest island. Context After an incident in the beginning the story these eleven young people (young ...
user avatar
  • 362
17 votes
9 answers
4k views

What disease could my time traveler find a definitive 'cure' for, without recognizing the specific disease

I've been toying with a story of person sent to a alternate reality that mirrors medieval Europe, but not necessarily with identical history/countries. The time traveler would earn the trust/support ...
user avatar
  • 31k
1 vote
5 answers
599 views

How can I implement time travel on a somewhat realistic way?

Requirements for answer: -hypothetically can work (I don’t care if it’s hard or energy expansive) Made by Mankind Can be used at any time preferably works for going to the past it’s enough if I ...
user avatar
28 votes
19 answers
8k views

How can I hide my island in the 1600s?

I have time traveled to the past on an oriental country in southeast Asia. I want to hide my island from European colonists using some technology available in both the future and the past. Would ...
user avatar
  • 297
-1 votes
2 answers
96 views

Reconcile time travel paradox using entanglement

Imagine a crazy nut with exceptional intelligence managed to sent radiowave signals across multiple timelines, 10 years into the past and the future. That messages contained a blueprint of a time ...
user avatar
  • 46k
0 votes
2 answers
132 views

Would this time-travel scenario work? [closed]

In a novel I am writing one of the antagonists travels to Earth because at the end of the novel, he travels back in time and brings himself to Earth. I'm sorry that it's a little confusing. ...
user avatar
25 votes
10 answers
6k views

Time traveling Bitcoin buying

One of the most common answer tropes to the "start-your-life-over-at-x-age-with-all-your-current-memories"-question is people saying that they'd buy Bitcoin or invest in Stock XYZ that they ...
user avatar
  • 19.8k
52 votes
18 answers
12k views

How could a lost time traveller quickly and quietly determine they've arrived in 500 BC France?

A time machine malfunctions and spits a traveller from ~2015AD out in 500BC northern France. With nothing but the clothes on his back, and minimising contact with the locals (as that may risk altering ...
user avatar
  • 537
8 votes
4 answers
407 views

How could medieval nobles standing improve by having someone from 2021 as an accountant?

I remember reading in another question about Time Travel here on the forum, with the subject of your being stuck in medieval time. That if you where lucky, you could have a good life serving your ...
user avatar
  • 353
2 votes
1 answer
109 views

A SWAT van with Raptors attacking it? [closed]

I want to know if a SWAT Lenco BearCat van that got teleported to a different world where a group of a few dozen raptors starts attacking the van. Would the van be able to survive about eight hours ...
user avatar
0 votes
6 answers
579 views

battleship vs pirate ships [duplicate]

So I was thinking of a scenario where a fleet of 5 warships got sucked into a portal that dumps them in a glitch in time. They were dumped into an ocean world where pirates of the Caribbean-ish keep ...
user avatar
22 votes
6 answers
3k views

Robbing the past to pay the future: Where do the resources go? How to balance the books?

In the future, the world is in a parlous1 state. Earth people of the future (let us call them Futurians as in the answer by DWKraus) are desperate but they still have a number of time portals in ...
user avatar
5 votes
4 answers
261 views

How much trouble would a great depression era rural county have with settling a late cretaceous Montana/Wyoming?

I have a very specific setting in mind that can be pretty much summed up as "Wild West with Dinosaurs". However, I'm still trying to figure out the details of just how the people native to a ...
user avatar
11 votes
8 answers
2k views

Is it murder if I stop a person's parents from meeting?

Suppose time-travel is common. There is someone who I want to eliminate for nefarious purposes of my own. If I go back in time and kill that person, then surely it's murder, but what if I go back and ...
user avatar

1
2 3 4 5
11