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What would be a fair energy requirement (in Watts) for a hyperspace engine to support 1T at 1c? This is how the system works:

  1. Gravity affects your ship, so you have to compensate for that (or take the risk that you crash on reentry). The ship has to avoid stars and planets in normal space even though the ship is in hyperspace.
  2. It's not infinite-speed, it takes time (speed and energy follow a square law with increases in speed needing the square of the energy, so 2c would be four times as much power).
  3. You require constant power or you will drop out of hyperspace or slow down (if it's only power reduction).

I want to make ftl practical for interstellar transportation, at 5-10c, but not overly cheap: you can't do it for fun (unless you're rich). Electricity costs are 5c/Kwh (at current rates, in credits it will be different)

Mathmagician
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    How is it faster than light at 1c? You might also want to specify that you're talking about ftl travel. – Annonymus Aug 12 '16 at 06:14
  • When you mean FTL are you referring to Alcubierre drive ? If not, does your world follows General Relativity ? – Chinu Aug 12 '16 at 06:19
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    Current physics says that energy required to accelerate approaches infinity as speed approaches c. So it all comes down to making things up in a way that works for your story. – Euphoric Aug 12 '16 at 06:19
  • Also 1c is far from practical. Even the closes star would take years to reach at 1c. That means this FTL will be limited to "humanity" as whole sending "seedships" randomly out and not expecting their return. – Euphoric Aug 12 '16 at 06:34
  • May I suggest my answer to the question Science-based FTL drive? "Speed increases follow a square law for energy increases" implies that your universe is described by something other than special relativity, so you need to tell us how it works. Also please note that $1c$ is, by definition, not faster than light, but only equal to the speed of light (to whatever precision your $1$ is). – user Aug 12 '16 at 09:35
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    I'm voting to close this question as off-topic because without knowing more about how this universe works, it is impossible to answer the question as asked. – user Aug 12 '16 at 09:37
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    It looks like the OP's FTL drive is neither Newtonian nor Einsteinian if velocity increases according to the square of increases in energy. This suggests if this drive consumes one unit of energy at 1% of lightspeed it will only require ten units of energy to travel at 100% of lightspeed. This also suggests the drive has to be constantly activated for its motion. This is Aristoltean physics. The reason that it is a FTL drive is that presumably it isn't limited to less than lightspeed velocities. At 100 eu, its velocity will be 10 c. Not quite physics as we know it. – a4android Aug 12 '16 at 12:10
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    Welcome to Worldbuilding, Matthew! Your question about FTL travel is a sensitive topic here. Can you please clarify your speed & energy rule? if your question is about estimating what the energy consumption should be at a given speed, then we should be able to devise an answer. Your FTL drive is a fictional contrivance not based on the usual science of vehicle dynamics. This has confused the commenters. You may need to edit your question to make it clearer. – a4android Aug 12 '16 at 12:19
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    @a4android What you are saying makes sense, but at this point, we are guessing. Matthew, please [edit] your question and tell us more about how your drive system works, because as described, it doesn't resemble anything in our world. We can probably help you sort out the energy requirements and the effects of those, if only we know the constraints of the system we are working with. If you don't feel comfortable expressing it as formulae, give us some example data points plus what goes into the calculations, and someone might be able to derive a nicely fitting formula. – user Aug 12 '16 at 16:03
  • @MichaelKjörling Thanks for saying it made sense. An educated guess at best. Pity it was wrong. But them's the breaks. Yes with more detail, there's no reason why an answer can't be given. – a4android Aug 13 '16 at 05:24
  • Matthew, you edited your question. I edited some more to, hopefully, clarify a few more points. If I'm wrong, please fix the question. I have one suggestion for an answer. 1 kilowatt of power per kgm, or 1 MW per metric ton. That's a fair bit of power to move a ship at 1 c. Trips will take years and power must be sustained for the duration. Other answers will improve on my ballpark figure. – a4android Aug 13 '16 at 05:28
  • It seems like you are proposing a solution to a problem that you are facing. Perhaps this would be easier if you stepped back and described the parameters of the problem more. Then describe your partial solution. Then ask for help with the details. – Brythan Aug 13 '16 at 15:42
  • @a4android I'm thinking about making travel at 5-10c practical. That would make trips faster. – Mathmagician Aug 14 '16 at 02:29
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    Matthew, your hypothetical FTL drive makes sense in that velocity range. Basically it gives FTL travel for any given power setting. Yje more power the faster ships go. However, you just need to choose a suitable power consumption per kgm for a given speed and that gives the answer you want. Set the cost of power which then determines the economics and practicality of FTL travel in your world. Go for it! – a4android Aug 14 '16 at 09:53
  • «Electricity costs are 5c/Kwh (at current rates, in credits it will be different)» now you’re just being silly. – JDługosz Aug 15 '16 at 06:19

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Basic lesson in Newtonian physics:

  • It does not take any energy to maintain a velocity.
  • It takes energy to change your velocity.

This is Newton's First Law of Motion.

So why do you need to feed energy to your bike/car/train/airplane to maintain velocity? This is because friction is providing a resistive force on your vehicle. Force times distance travelled equals energy, and that changes your velocity. So to combat the detrimental influence of friction, that conceptually bleeds you of energy, you need to provide more energy.

In space, this does not apply. You have (almost) no friction in space. So once you reach a certain velocity, you do not need any energy to maintain it. Hence when you ask for "energy consumption at 1c", the answer is 0. If you have reached 1c and you are coasting, you do not consume any energy.

But you do need to put in energy to reach your velocity. And this is where Einsteinian physics trips up your question, because you need an infinite amount of energy to reach 1c. And not even a Kardashev Type III civilization can do that.

MichaelK
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    Presumably his ftl drive isn't a rocket and doesn’t work by simply “going faster” in the normal way. – JDługosz Aug 15 '16 at 06:16
  • @JDługosz And? What does that have to do with the question? – MichaelK Aug 15 '16 at 06:20
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    That's my question to you! Your reply has nothing to do with a “hyperspace engine”. He postulates that it takes power to keep operating. Pointing out that newnonion motion doesn't is beside the point. He postulates a ftl drive. Pointing out that normal motion can't reach ftl is beside the point. – JDługosz Aug 15 '16 at 06:26
  • @JDługosz Well then he better come up with some physics for this hyperspace engine as well. All fine and well that he postulates an engine that runs on applied phlebotinium ( http://tvtropes.org/pmwiki/pmwiki.php/Main/AppliedPhlebotinum ) but unless he also lays down the parameters for this engine, then he cannot expect an answer on a question like this. It is not our job to invent physics for his imaginary engine. – MichaelK Aug 15 '16 at 06:32
  • I agree: it is not answerable as asked. That’s a common issue that often gets lumped under POB now, where the answer is “it’s up to you!”. – JDługosz Aug 15 '16 at 14:05