147 votes
Accepted

What realistic way could limit an FTL drive to only travelling between stars?

A guy named Arioch has a webcomic called Outsider (highly recommended, BTW) with a simple and elegant solution to this problem. Ships in that universe use a drive that jumps them through hyperspace, ...
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  • 1,296
121 votes
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How to prevent superluminal traveling idiots from wrecking half of the universe?

But in most stories, FTL doesn't actually follow Newton's 1st law; everybody knows that once your hyperdrive fails, you're dead in the water. Otherwise, the Enterprise could hit warp 9.9 and easily ...
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  • 3,132
88 votes
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Are there any ways to allow some form of FTL travel without allowing time travel?

As you said, any FTL drive is implicitly a time machine. Let’s review the reasons why. As a prerequisite you need to understand spacetime and the ideas of space-like and time-like intervals. first ...
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  • 68.5k
83 votes
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Law enforcement in FTL civilization

Use real world examples? Criminals could 'run away' to the Americas or wherever in the 1600s. In that case, how would the Spanish crown capture them? What about outlaws that fled to the territories ...
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  • 84.2k
78 votes

Would 'cheap' FTL make powerful telescopes obsolete?

1000 times the speed of light means you can visit something 500 lightyears away in a one-year round trip. 5000 lightyears would take a decade and you are still not even leaving our galaxy. In contrast ...
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  • 10.9k
77 votes

How to prevent superluminal traveling idiots from wrecking half of the universe?

1. Space is mostly empty If you pull the trigger on this, you're ruining someone's day, somewhere and sometime Well, not necessarily. There's so much empty space between anything interesting in the ...
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  • 3,559
73 votes

How much would we learn from observing an FTL starship fly by?

Hmm. Let's try to understand what we actually see. "Deep space telescopes notice as an object appears out near the orbit of Jupiter": That's either one biggg object, or at least a veeery luminous ...
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  • 73k
70 votes

Why are certain spaceships capable of warp at a moment's notice while others require some preparations?

The older Warp drives are ballistic. Like a bullet fired from a gun. You have to set the direction and impulse at the beginning, and thus need to have your settings exactly right, or you miss your ...
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  • 25.9k
66 votes
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If an FTL spacecraft entered Earth orbit, how long would it take for humans to build a FTL spacecraft?

It depends on how far from the current production possibilities frontier this technology is. There are several possibilities, depending on the technology gap: It is like the Apollo Moon mission to ...
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65 votes
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Does knowing a technology exists make it develop faster?

I would think so. Innovation is probably the hardest bit and duplication is much easier. We see it with computers all the time now. Some small company comes up with a new idea that is "obvious" and ...
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  • 1,191
62 votes

How would two ships travelling at light speed communicate with one another?

It is impossible for the ship to travel at the speed of light, it can at best travel close to the speed of light. The difference matters. There is nothing really stopping two ships travelling at a ...
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  • 42.9k
61 votes
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How can I justify a Type III civilization using planetary jump drives instead of FTL starships for galactic commerce and travel?

There are two broad reasons why the jump drives are only used on planets. The first reason is that some property which planets have but spaceships lack is required for the jump drive to work ...
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  • 2,121
58 votes
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Why are certain spaceships capable of warp at a moment's notice while others require some preparations?

The Dreadnoughts are taking advantage of a breakthrough in FTL communication technology, and they continue to sync with the networks and plot the coordinates while already at warp. For this to work, ...
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  • 6,931
57 votes

How can I justify a Type III civilization using planetary jump drives instead of FTL starships for galactic commerce and travel?

Jump drives are just plain huge The reason they move entire planets around instead of smaller ships is because, by the time you've put all necessary equipment for a functioning jump drive into your ...
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55 votes

Why are certain spaceships capable of warp at a moment's notice while others require some preparations?

It still takes 72 hours, a tiny tweak in the order of events makes it seem instant. After a few decades of CEOs cutting talent from the engineering department and using the savings to pay their own ...
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  • 43.3k
55 votes
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How long can it really take to calculate a hyperspace jump?

An arbitrary example of a calculation with suitable complexity, that matches the complexity of a hyperdrive jump, which cannot be pre-calculated but which can be calculated and shared to multiple ...
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  • 25.9k
54 votes

What realistic way could limit an FTL drive to only travelling between stars?

It is common to require that FTL only operate at some distance from large mass. So, the ship must withdraw (say) beyond the orbit of Neptune before engaging. Likewise, ships will arrive at this ...
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  • 68.5k
52 votes

What plausible reason could I give for my FTL drive only working in space

The traditional answer to this question is "FTL drives don't work within gravity wells", which is sometimes justified by saying that they require a region of "flat" spacetime to operate reliably. If ...
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51 votes
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Interstellar war without co-ordination, is fine timing important at these scales?

This is a fascinating question that will have a substantial impact on your story. I love it! Let's get some basic observations out of the way, which will include some restatement of your limitations....
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49 votes

If an FTL spacecraft entered Earth orbit, how long would it take for humans to build a FTL spacecraft?

Impossible to answer. I'm using the answer format rather than a comment to get enough space to explain. FTL travel will probably require a paradigm shift in science. The necessary theoretical hints ...
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  • 97.3k
49 votes

What might stop people from destroying navigation satellites that are used for FTL plotting?

Their area is not included in the FTL grid. Your satellites are sitting in the depth of space where there is no reason to stop (besides, the exact location won't be public knowledge). So any ...
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  • 39.5k
45 votes
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What are plausible faster than light methods for a far advanced civilization that aren't a warp drive

Let's set the technobabble aside You can name your drive/engine/motor/causal-difference-generator anything you want. It's important (don't ignore it), because what you're really going to do is choose ...
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44 votes

Effects of being hit by an object going at FTL speeds

I'm not sure on what happens when the spear reaches its FTL speed, but you're going to have issues while the spear is accelerating to FTL speed. Because it is constantly hitting something, namely &...
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43 votes

What realistic way could limit an FTL drive to only travelling between stars?

Make the aiming difficult If the lowest precision of coordinates you can aim at still has an error margin greater than the typical size of a solar system your method would not be usable for ...
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39 votes

What might stop people from destroying navigation satellites that are used for FTL plotting?

The FTL beacons are stars. Artificial pulsars to be precise. Some were already pulsars and their rotation speed adjusted and a couple were made from scratch. This was no mean feat, even in your ...
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  • 273k
38 votes

Ridiculously Fast Supercomputer

So the elephant in the room is the halting problem. Consider a program like this: while (true) { } // do nothing forever cout << "Finished" << endl; ...
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  • 129k
38 votes

Standardisation of Time in a FTL Universe

Is there a theoretical method of inferring a "universal" time that FTL travellers can use for their clocks to maintain a constant time? Generally, no. There is no universal time, period. Relativity ...
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  • 1,893
38 votes

How much would we learn from observing an FTL starship fly by?

Obviously exciting things: FTL is possible without the need for chunks of exotic matter than weigh more than the visible universe. Interstellar travel appears to be possible and practical. There ...
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37 votes

FTL travel is impossible. How is interstellar trade possible?

I think you've got yourself in a bit of a corner. Without FTL, trading would be nomadic rather than what we think of today - think the old Silk Road, or traveling peddlers. It'll be people whose ...
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  • 1,213
36 votes
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How to resolve the transporter conundrum in a FTL spaceship?

The real answer is "whatever you want." We have no known physics for what happens past the speed of light, so you are writing your own rules. However, if we are to use our own intuitive laws to try ...
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