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A realistic jump/wormhole ship.


SpaceMouse

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So, similarly to my old warpship thread, I wanted to get idea's going about what it would take to build a ship capable of jumping via some form of stabilized wormhole. Based on my limited knowledge, this might be more realistic but, it's a topic that seems to get seldom discussed.

The closest we've probably seen was in Interstellar and there they had a conveniently stable one to go through.

Thoughts? Science? Cold-hard reality?

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First of all, discussing about jump/ wormhole ship in real-life scientific viewpoint is hard. We have very little information about how to teleport (jumping is basically teleport), and especially, about wormhole, since we haven't even send a probe there, we don't even know if it leads to somewhere, so all current information about them is purely from observation, speculation and theoretical calculations

Second, the laws of physics simply prevents it. Unless you have infinite energy and some plot-device level of propulsion technology, we simply ain't going anywhere. Gravity, orbital mechanic, energy requirements, spaceship design, material and most importantly heat dissipation, is the problem that must be overcome before we even started thinking about this. Even without "Jumping" shenanigans (which is basically teleport, if we want to be literal), the idea of interstellar travel in respectable amount of time using cold hard science is still beyond our reach, judging by our current technology. If we're talking about "conventional" propulsion techniques (i.e. rockets of one sort or another, whether chemical, nuclear, anti-matter, or whatever else), even approaching lightspeed would require more energy per second than all of Earth's industries use per year. While this may be explained by advances in technology, the general formulas for velocity and acceleration are such that as you approach the speed of light, the energy needed to accelerate anything with non-zero mass increases asymptotically. In other words, you need an infinite amount of energy (and an infinite amount of time) to accelerate to the speed of light. It isn't just an engineering challenge — it is fundamentally impossible.

The idea of jump/ warp/ wormhole ship first appears during the age where sci-fi writers started to write speculative fiction about what lies beyond our sky. At first, they wrote about going to moon, then going to venus. After the space race, we started exploring other planets, and they naturally went nuts since those celestial bodies out there does not look like what they imagined/ speculated before, so they changed their setting to another star, but since the distance involved is literally astronomical (pun intended), and audience simply want to see the story progress to somewhere interesting in space (which is very very far when we're talking about distance in space), a plot device for travel was invented, and thus the concept of jump drive, warp, FTL and recently, wormhole portal was born. Jumping/ warping/ wormhole mechanic is poorly explained in the sci-fi story. They are simply plot device for moving between star systems, since without such progression, the plot of space sci-fi won't go anywhere

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I would expect any warp drive theory not sooner than a slow one-way interstellar ship arrives to aplha/Proxima Centauri, founds there a scientific base, and starts interstellar physical experiments and astronomical observations with 4 l.y. wide interferometers.

All we have now - 100 AU with primitive tools. Too ridiculously to understand physical laws at scale of a galaxy.

Spoiler

Unless we find a cave with Proto-Indoeuropean paintings describing how to build an Engineers' warp drive.

 

Edited by kerbiloid
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If you wrap by wormhole, you will need a very small craft. I am not sure about this, but it may be smaller than an atom.

If you are willing to wrap by other means, scientists have been able to teleport individual atoms by quantumn entanglement and superposition. Theorectically we can teleport even larger stuff, but our current technology is unable to provide the energy and precision required.

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1 hour ago, Xd the great said:

If you are willing to wrap by other means, scientists have been able to teleport individual atoms by quantumn entanglement and superposition. Theorectically we can teleport even larger stuff, but our current technology is unable to provide the energy and precision required.

Quantum Entanglement only allows you to remotely alter the state of particles, not teleport anything. And even worse you can‘t use this to transmit information either.

Edited by Canopus
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1 hour ago, Canopus said:

Quantum Entanglement only allows you to remotely alter the state of particles, not teleport anything. And even worse you can‘t use this to transmit information either.

Well, lets say two particles are entangled and are both in a superposition. If we reveal one of the particles, the other one reveals itself at the same time. No delay.

If we use this to transmit the state of the particle we want to teleport, we can do it.

The rest is to use energy to recreate the particle with the given state. In the whole process, the orig9nal particle is destroyed.

So I guess it is possible to teleport stuff.

In fact, quantum communication, or the above method I have discussed, is currently being developed as a way to prevent hackers intercepting transmission.

 

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On 6/23/2018 at 7:18 AM, SpaceMouse said:

Cold-hard reality?

The reality is we have no idea how this would work, so speculation on what a "realistic" design is not possible.

On 6/23/2018 at 8:22 AM, SpaceMouse said:

My understanding was it might actually be easier that all the complexities of warping space but, if that's the cold hard science...

"warping space is easier than creating a wormhole" makes very little sense as a statement, may as well say that using the force is easier than using telekinesis.

All current hypothetical "warp" drives (whether they be alcubierre flavour, wormhole flavour, the spice melange flavour etc) are imaginitive speculation (and often mostly imagination and little speculation - the interstellar ship was designed on aesthetics and homages, not any science. Its the wormhole and blackhole effects that got all the science on that film) based on maths at the fringe of testable physics, there are no known methods of making things move faster than light, at the moment. This is not to say that there is no indication that it might one day be possible, but talking about realistic drives is waaaaaaaaaaaaay out of scope. Waaaaay.

 

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To the OP -- Robert L Forward wrote a combination pop sci / fiction book where he addressed many theoretically possible (at least with the data available at the time he wrote it) methods of FTL communication, transportation, time travel, etc.

Note, he wasn't claiming any of them are actually true. Just that the math seemingly allowed for them. I believe it was called Indistinguishable from Magic. It dates back to 1995, though (Forward died in 2002), so it could be 20 years out of date in terms of modern thinking about such subjects.

Forward was one of the few people who actually knew the physics and the math and was also not afraid to look silly by talking about stuff like this. Usually the serious scientists don't want to look crazy and the crazy people don't actually know what they are talking about.

Edited by mikegarrison
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37 minutes ago, kerbiloid said:

Probably it will stay correct, but even if not - the sky won't fall on the ground, just there will appear another theory, more stable, free of its weak places (if any).

Theories aren't mushrooms. They don't just appear regularly after rain. Your approach sabotages the principle which we use to arrive at a theory. We take observations, we fit a model to it, and we see how well that model does against other observations. We adjust, and we continue. Theory shouldn't just explain the known phenomena. That's pointless. Theory should predict new phenomena. If I'm building an airplane, I need to know that the wings don't snap off. And I need to have a very high margin of certainty. So I take my model, throw in any uncertainties I can't account for, such as random fractures in the materials, and I get how thick I need to make critical parts to prevent failure with a 99.999...% guarantee.

Now we take our current model. We make predictions, and they are perfect within our capacity to measure across the board. We take most pessimistic estimate of the odds, and we arrive at how certain we are about conclusions. Something that's going to have a lot of moving parts, like planetary trajectories, will have high uncertainty. We don't know the value of G all that well, we aren't tracking all objects in the system, and there can always be a rogue gravity wave. So you can't be too certain. But if you take something that follows as theorem from core principles, then you just take raw certainty in these principles. And as we've stated, that's a ridiculous number now.

But then you say, "What if it isn't? We'll do better." How? You've just taken the only thing that actually let us arrive at a theory - ability to establish degree of uncertainty - and thrown it out of the window. If you are saying "It could be wrong," you are saying, "All of physics can be entirely wrong," because you are putting huge error bars on base assumptions. Everything that follows will be worse. How the hell am I supposed to figure out tolerances on an airplane, if you can't even give me certainty on principles it's based on.

You can replace bad models, mechanisms we've misunderstood, and it will only impact things that were being modeled this way. You can't just discard the core of what all of your knowledge is based on, and then just shrug it off, saying we'll do better. You've just discarded the only way to get better. You are actively sabotaging the very means of obtaining knowledge by insisting on going by gut-feeling rather than theory on something so fundamental.

37 minutes ago, kerbiloid said:

Not that I've failed, but do you already know, what is dark matter? Or your interpretation of its qualilites (let it be a hundred of them) matches your assumptions better than other interpretations?

Has rest mass. Has no other charges. This fully describes a particle, and literally the only thing that matches interpretation. Again, you're getting stuck on it being called "dark matter". The name is purely historical at this point. An electron has exactly the same description, except due to its other charges, I can also comment on some intrinsic DoFs. None of these are relevant for a particle that doesn't interact other than via gravity. What exactly are you expecting? What color it is and what it tastes like? That's not how you describe a particle.

Do you understand distinction between empirical measurements and theoretical framework? If I gave you a ruler and asked you to measure circumference of the moon, are you going to claim that you can't do it because you don't understand how to use a ruler, and expect a better way to use a ruler to come along?

37 minutes ago, kerbiloid said:

But still can't explain exactly the antimatter disbalance or build a working fusion reactor. And the fission reactors are protected not with forcefields, but with several meters of concrete.

Nor does it allow for unicorns! Why do you think that the ultimate theory has to allow for the specific magics that you expect it to? Some problems are just hard, no matter the complexity of the theory. Did General Relativity make it easier to compute interplanetary trajectories? Hell no. Again, emergent behavior is not inherently evident from underlying physics. We've had GR for nearly a century. Still don't know internal ground state of a rotating black hole. That one's just math, no physics involved. Equations are known, we just can't solve them. No "improvement" to theory will make that better, because the problem is entirely mathematical. We have pretty much exact equations for hydrogen atom. Certainly the best understood system. What do we know about metallic hydrogen? Pretty much nothing.

Real physics is hard. Having simple fundamental equations doesn't make it easier. Just the opposite, usually.

Oh, and we have numerous explanations for matter-antimatter imbalance. We just can't test any of them, because it sort of already happened. If you'd like to start a new universe, I can tell you what to look for. Would be great help.

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Since the concept of warp/ wormhole / FTL travel is born from Sci-fi stories, Here's a bit of info to explain the scale of technical impossibility of "game-breaking technology" of interstellar travel in sci-fi when explained using hard science:

The common scenario of sci-fi interstellar travel goes like this: "Let's say the idea of a spaceship carying 10 times its empty weight in fuel sickens you. You want the space aboard your space ship to house your colorful characters, dazzling weapons, holodecks, shopping malls, and other fun and excitement — not deck after deck full of boring old propellant. And you want to allow for long patrols without having to refuel at every destination. So, you equip your spaceship with a gravity manipulation Reactionless Drive that allows her to accelerate without throwing material out of her tailpipe."

But hold on. There's a problem:

First, if you allow them to accelerate without pushing anything, they are now violating one of the most basic laws known to physics: the conservation of momentum. In the real world, you can't apply a force to an object in one direction without causing an equal-and-opposite force on some other object. Rockets fly up because their exhaust flies down. Jumping up pushes the Earth ever-so-slightly downward; falling back to the ground afterward pulls the Earth ever-so-slightly up. By letting your space ship violate this basic law, you're saying that momentum is not always conserved. What other circumstances in your universe will cause momentum not to be conserved? Do the laws of Newton simply get held in abeyance every time someone switches on a gravity generator? Are there natural phenomena that accomplish the same thing?

Second, are you also violating the conservation of energy? A 1000 tonne spaceship traveling 1/10 of the speed of light has a kinetic energy of 450 quintillion Joules, equal to 100,000 megatons of TNT. That energy had to come from somewhere. Did it come from burning some sort of fuel on board your space ship, to power the generators? If you used the thermonuclear fusion of hydrogen into helium as your fuel source, and you managed to create a fusion reactor technology that's nearly 100% efficient, you'd have to burn at least 350 tonnes of hydrogen to obtain that much energy, which is a third of your spaceship's own mass. (This isn't as bad a mass-ratio situation as if you'd used a plain-old momentum-conserving fusion rocket, but it's still pretty significant.) And you'll have to burn just as much again to slow your space ship back down at the end of your trip. If this is too much for you, and you decide your reactionless gravity drive simply works by tapping into the magical gravity waves of the universe and surfing along them with only minimal power requirements, then your space ship's kinetic energy is being created "ex nihilo". You've got yourself a free energy machine! Just strap your space ship to one end of a long lever, strap the other end to a huge electric generator, and fly in circles. You can generate enough energy to power your entire civilization this way, with no cost in natural resources. This will play absolute havoc with the setting's economy. You'll have to throw away that whole story about space empires' war over Space Oil.

Third, if any 1000 tonne space ship can easily accelerate to a tenth of light speed, then every two-bit spaceship owner has in his possession a weapon of mass destruction. Those 100,000 megatons of TNT-equivalent kinetic energy will act like 100,000 megatons of actual TNT if they strike a planet. Want a future populated by plucky tramp space-freighters and sneaky space pirates? It ain't gonna happen if every ship is a Hiroshima-on-steroids waiting to happen. Every spacecraft captain will be on too short a leash. Any spacecraft that even looks suspicious will be killed before it can become a threat. (And, yes, all fast-moving spacecraft, and even stationary spacecraft, will eventually be detected — there ain't no Stealth In Space.) Any technological marvel that sidesteps the Real Life roadblocks facing space travel has the potential for unintended consequences. Thermonuclear torchships? They've got the same "spaceship = weapon of mass destruction" problem that reactionless drives do, albeit on a more manageable scale.

FTL Travel is one of the bigger thorns in the side of the Hard SF genre. Special Relativity makes it absolutely clear: it is physically impossible to accelerate an object with any kind of mass so that it's moving faster than the speed of light. Even accelerating an object to the speed of light would require an infinite amount of energy. However, we've also pretty much established that there are no other technological species on any planet in the Solar system other than Earth. If we want to have space adventures involving high-tech aliens, we'll have to travel to other star systems, and the distances involved are so enormous that it would take years to get from one star to another if you were limited to sub-light speeds. Science Fiction writers have had to compromise, and allow some means of travelling faster-than-light which didn't turn their universe into something totally unrecognizable to a modern reader. Therefore, the ability to move faster-than-light has received more attention in SF than any other fantastic concept.

The very worst problem with FTL travel (or even just FTL Radio) is a certain niggling consequence of Time Dilation. When travelling at any speed, even a brisk walk, relative to somebody else, you'll see his clock move slower than yours — but he'll see your clock move slower than his. This way-counterintuitive state of affairs means that some distant events in the universe which are in your future are in the other guy's past, and vice-versa. Without FTL travel, though, this isn't a problem. Einstein and Minkowsky established that for any event that's in Oberver A's future and Observer B's past, no matter how far in Observer A's future the event is, it will always be far enough away that any light-speed signals from this event would not reach Observer A until the event was also in Observer A's past. When plotted on a space-time graph, the signals from the event would stretch out in spacetime in a "light cone," which guarantees that the signal will not reach any observer in the universe until the event is in that observer's past. To put it another way, let's say that in Observer A's reference frame, Event 1 occurs before Event 2, but in Observer B's reference frame, Event 2 occurs before Event 1. Light cones maintains causality by ensuring that, if Observer A would find out about Event 1 before Event 2, Observer B cannot find out about Event 2 before information about Event 1 is theoretically available to him. By going faster than light, even just FTL Radio, you can receive information about events that are in your own future. You can perceive Event 2, which was caused by Event 1, before Event 1 actually occurs in your reference frame. In other words, Time Travel.

How do veteran SF writers handle the time travel consequences of FTL travel? Most of them don't. They simply sweep it under the rug and hope no one will notice. Those authors who do address it often end up with bizarre universes where wars are fought before they've even started, and characters can shoot their own grandfathers. The other main problem with FTL travel is what it can do to life in SF universe even without time travel. If your space pirates can just jump into hyperspace at the first sign of trouble, you'll never have any exciting space battles. If you can ram a planet or another spacecraft while travelling at FTL speeds, you risk turning even the tiniest FTL shuttlecraft into a planet-killer that will put even the largest, fastest slower-than-light kamikaze to shame.

The last problem with FTL travel is more practical: we don't know how to do it in Real Life. Every attempt to come up with a way to do so has run into intractable problems. Quantum entanglement can occur instantaneously across vast distances, but it can't convey any actual information faster than c. The Alcubierre space warp requires the energy output of an entire sun just to create, and there's no guarantee that you could actually make the space warp move — and even if you could, there's even less of a chance that it could move faster than c. Wormholes, if they even exist, will spontaneously collapse faster than it's possible to traverse them. 

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On 6/28/2018 at 8:24 AM, ARS said:

First, if you allow them to accelerate without pushing anything, they are now violating one of the most basic laws known to physics: the conservation of momentum. [...] Second, are you also violating the conservation of energy?

First of all, it's important to keep in mind that these are the same thing. System that violates conservation of momentum in one coordinate-system necessarily violates conservation of energy in another and vice versa. This is because energy and momentum are components of a 4-vector known as 4-momentum. They are related the same way that space and time are. Distinguishable, but inseparable.

Second, and more interesting point is that while these quantities are strictly conserved, change in velocity does not need to result in change of momentum or change in energy! Certainly, in classical mechanics, p = mv and E = mv2. So change in velocity requires reaction mass and expended energy. If you are using a conventional rocket, you're stuck with this.

But the moment you step away from classical mechanics, things get more interesting. I won't go into details of Quantum, because they get complicated, but it's worth mentioning that there is concept of mass shell, and only on-shell particles follow the above rules. Off-shell particles can travel in direction different than their momentum vector suggests. Of course, off-shell particles have limited range and life time, and are most commonly found in various interactions. E.g. photons in electromagnetic interactions are off-shell.

The more relevant caveats come from General Relativity. Here, momentum picks up a contribution from frame dragging. A very naive analogy is swimming in the river. You have to expend energy to move relative to the water, but if the current changes, you can speed up or slow down with it without doing any work. This is sort of how Alcubierre warp drive works. Ship goes from rest to moving, but it does so because it's local frame accelerated, not the ship itself. Consequently, ship's momentum and kinetic energy stay the same. Now, this still takes a huge amount of energy to warp the space-time, but that energy, at least in theory, is recoverable.

So for example, you might power your ship with a kugelblitz - a miniature black hole made up of light. Let it evaporate in a miniature nova, redirect all this energy into curving space-time, and your ship is now in warp. When ship drops out of warp, the energy of the space-time curvature is released, and redirected back into a single point to create a new kugelblitz.

Obviously, I'm glossing over many, many details. We have no idea how to manipulate these quantities of energy, and Alcubierre drive itself has very serious limitations preventing us from building even a proof of concept. But it can work!

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