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can a rail gun be converted into a "High Velocity Pulse Engine",to be used as a "Jump Drive" to achieve light speed capabilities.

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    $\begingroup$ what do you mean by 'pulse engine'? A rail gun can be used for propulsion without conversion (although it's usually called a 'mass driver' when used for this purpose). $\endgroup$ – Hobbes Jan 16 '19 at 11:08
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    $\begingroup$ Simple answer from a physics perspective is no. A rail gun is just a way to propel mass. There is no way to use carried mass to accelerate to light speed. In fact there is no possibility of even getting close. Have a look at relativity and the force required to accelerate a body as it gets faster... $\endgroup$ – Rory Alsop Jan 16 '19 at 12:08
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    $\begingroup$ Related: space.stackexchange.com/questions/16610/… - but the 'light speed' part makes this one different and the answer a no-brainer 'no'. Railgun / mass driver could be used as a reaction engine but it wouldn't be anywhere close to relativistic speeds. $\endgroup$ – SF. Jan 16 '19 at 13:30
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No. Railgun could be used as a common reaction engine with specific impulse of order of 700 seconds, which is a respectable number but nothing coming anywhere close to relativistic velocities and already worse than existing ion engines. There's nothing in the concept of the device that could suggest it could be made it into a 'jump drive'.

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  • $\begingroup$ how about some kind of magnetic kenetic engine where the magnetic are working against each other then suddenly released to produce some type of pulse $\endgroup$ – royce davies Feb 2 '19 at 3:42
  • $\begingroup$ OK.Has a railgunn every been fired into vaccum or in 0 gravity eg, space to test this,Also could a nuclear powered celled turbine be used as fuel sourse instead ov convensional methods of propulsion $\endgroup$ – royce davies Feb 2 '19 at 4:00
  • $\begingroup$ @roycedavies: No. These don't affect the principles of its operation though. The only things you'll encounter is problems of controlling recoil, cold welding, heat dissipation and similar headaches that are typical to migrating any technology to space use. What do you mean by celled turbine? $\endgroup$ – SF. Feb 3 '19 at 0:47
  • $\begingroup$ can uranium be contained in a type ov battery cell as space is cold enough to control the cooling ov the cell.maybe it could power some kind gyroscopic magnetic pulse drive $\endgroup$ – royce davies Feb 4 '19 at 3:28
  • $\begingroup$ @roycedavies: Radioisotope Thermoelectric Generators can give out around 100-300 watt. Cooling in space is much more difficult than you picture it: space is cold, but it's also a very good thermal insulator, draining heat really slowly. And you are not producing any net thrust without ejecting reaction mass. If you eject one of the magnets (to lose it in space forever) you're getting some thrust... not much. If you stop it from escaping, all you gained on ejecting is lost on stopping it. $\endgroup$ – SF. Feb 4 '19 at 9:06
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In my opinion it would not be practical to use it anyway. Please correct me if I am wrong: In my oppinion the terminal velocity is not as big issue as the time period over which we need to build the momentum. If human body cant take more than 1,2 g in the long run it is not practical to build engines that can accelerate faster than that. So the question is which drive is the most efective to achieve acceleration of 1,2g for longest periods of time. But that is just my opinon. I will be happy to discuss.

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  • $\begingroup$ It would take a year to achieve ~80% of speed of light (100% if taking Lorenz Contraction making the target closer into account, speed calculated as distance at start of travel divided by time of travel as perceived by the crew) at 1g. The limiting factor is the Tyranny of Rocket Equation. At 700s of specific impulse the spaceship need to expend 3bln times its own weight in propellant to reach half of speed of light. $\endgroup$ – SF. Jan 17 '19 at 8:28
  • $\begingroup$ what if the space craft mass was greater would this reduce the g-force impact on the human body say in a smaller craft $\endgroup$ – royce davies Feb 2 '19 at 3:38
  • $\begingroup$ @roycedavies: 3bln times own weight. No matter if the craft is big or small, heavy or light, if it accelerates fast or slowly, the impact on human body is moot because you're not reaching a speed that would reach Proxima in a thousand years. $\endgroup$ – SF. Feb 6 '19 at 0:07

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