Ryan_m_b said:
If its soft science fiction just use a technobabble explanation like nemo has above, it's nonsense but its not the focus so it doesn't matter.
That rather depends upon how you define soft v hard SF and what role "technobabble" necessarily plays in SF. As we have no supporting FTL theories at the moment, anything that involves FTL necessarily uses "technobabble" as an explanation unless it ignores theory all together - however, a lot of authors do speculate and in some instances their stories actions can hinge around particular aspects of their hypothetical drives. With regard to the "Casimir Dark Boundary Drive" and looking at the SF Grading criteria given below ...
The Casimir Effect itself is "Present Day" theory and includes repulsive as well as attractive forces.
Dark Energy is currently thought to represent ~73% of the total mass-energy in the Universe and also falls into the "Present Day" category.
Nano-scale technology is real and in use.
The speculative element of the drive is the existence of device that allows the Casimir effect to take place at some boundary between our normal mass-energy dimension and the dark energy field. Many SF stories explicitly name the underlying future theories that allow the technology / effect they are using; the "Einstein-Korobov String Rotation" theorem is such a story device and hints at both general relativity and string theory, with the drive name perhaps implying a Domain Wall involvement.
As also mentioned, the Casimir effect is also a mechanism that has been looked at in relation to wormholes (eg,
http://arxiv.org/pdf/hep-th/0510232v2.pdf ). See this paper from NASA's Eagleworks ...
http://ntrs.nasa.gov/search.jsp?R=20110023492 which links to
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110023492_2011024705.pdf for some other, less speculative, ways of using quantum vacuum effects (the paper specifically mentions Earth-Saturn transit times of 70 days).
Consequently, using the criteria and examples given below, I estimate that the Casimir Dark Boundary Drive falls into the Plausibly Hard category.
The other thing to bear in mind that a story is not limited to being totally hard or soft; for example, the plot may hinge upon quite realistic biology but not be too fussed about how people get between planets or stars (everybody knows about warp drives so no need to explain (Murray Leinster springs to mind, or many of Niven's Known Space stories and the Banks' Culture). The Medium category is where a lot of my favourite stories lie. A device need not be overly plausible under current technology if it captures the imagination and makes one think "what if ..?"
However bare in mind what Drakkith said about how long it would take to get to said speed, I think at 1G acceleration it would take around a month to get to 0.1c and in that time you would cover about 45 trillion kilometres, around 6500 times the distance between Pluto and the sun. If you want to lower that distance you'll have to up the acceleration but to get to anything useful (I.e. less than solar system sizes) you're probably going to have to up it to hundreds/thousands of G.
I think about 10 times Pluto's orbital radius to get to 0.1 c at 1 g, and just under 1 day at roughly 80 g to get to Saturn at nearest approach (allowing for a brief "cruise" phase at 0.1 c). A 1 g trip to Saturn should take about 8 days and get up to ~ 0.01 c.
As with all SF, very hard or very soft, you should explore the full ramifications of your speculative plot devices to make sure they are consistent and don't break the story.
Consistency's good, but working out the full ramifications of real devices and theories is daunting enough, let alone fictional ones. Getting rid of the 'obvious' (undergrad level) errors may be a reasonable level to aim for ...
Anything above 20gs for a significant amount of time is deadly to a human so you're going to need to throw in a workaround for that acceleration like inertial negation or crew uploaded to computers.
'crew upload' introduces the philosophical subject of identity plus the subject of 'crew download' (eg, what is being downloaded into what and how?).
Other things you're going to have to consider is
Jon's Law/Burnside's Advice. The technology to propel spacecraft at significant fractions of the speed of light means that doomsday devices are now common place. Consider that a 1000 tonne spacecraft (just over twice the mass of the international space station) traveling at 0.1c has a kinetic energy of 4.5e20 joules which is 2000 times more powerful than the most powerful nuclear bomb ever built. Crank it up a bit and instead of a ship bolt one of these SuperDrives to a 100m3 block of ice and you've got a weapon more powerful than the asteroid that wiped out the dinosaurs. The implications here are problematic, let in super propulsion to your setting and suddenly every spacecraft is a potential weapon of mass destruction. That poses serious problems for any science fiction setting with mass civilian space travel.
It only poses problems for a setting which involves it - some SF tackles it head on and describes the defences (or lack of them), some SF notes the threat but just states the existence of defences whilst the majority of (good) SF I've read gets on quite well with the assumption that nobody does that kind of thing (by analogy, a heavy goods vehicle or tank can do a lot of damage in the wrong hands, but the overwhelming majority of us drive along the roads without the slightest concern that the lorry in the other lane is going to deliberately or accidentally slam into our lane).
Lastly the problem of energy rears its head: if your 1000 tonne ship can gain 4.5e20 joules of kinetic energy where did that energy come from? Assuming an impossible near perfect energy to momentum device you'd have to plug in at least those 4.5e20 joules which is the mass-energy equivalent of 100 tonnes. Now your hypothetical reactor is a weapon of ultra mass destruction as well...
Or you could use one of a number of "Medium" devices which either tap into some external power source (eg, quantum vacuum energy) whilst using the on-board systems as exciters/catalysts.
You could just ignore all this and focus and hope that readers won't pick up on it but in my experience science fiction readers are quite voracious in how they pick apart settings. That doesn't mean don't do it by all means but it might be good to carefully put in place reasonable limitations to the plot devices you use.
Agreed. It's worth asking, however, how many people have some knowledge of the Soft Star Wars and Star Trek and compare that figure to the number who've can tell you anything about some of the Hard SF ...
lpetrich said:
Grading Science Fiction for Realism goes into gory detail about the "scientific" hard-vs.-soft dimension.
- "Present Day Tech" -- Cutting edge Present Day Tech, some developments and speculation, but nothing major that has not been attained today (so no AI). Basic space exploration, very near future -- Technothrillers, Allen Steele's Orbital Decay
- Ultra Hard (Diamond Hard) -- Plausible developments of contemporary technologies - AI, Constrained Nanotech, DNI, Interplanetary colonisation, Genetically engineered lifeforms. Nothing that conflicts with the laws of physics, chemistry, biology etc as currently understood -- William Gibson, Neil Stephenson, Kim Stanley Robinson's "Mars" Trilogy, Robert Forward
- Very Hard -- Plausible developments of provocative contemporary ideas, but nothing that conflicts with the known laws of physics, information theory, etc - Assembler Nanotech, Nano-Goo, Uploads, Interstellar colonisation, Relativistic ships, vacuum-adapted life -- Greg Egan, Linda Nagata, Greg Benford's Galactic Center series, Stephen Baxter's Manifold Series, GURPS Transhuman Space
- Plausibly Hard -- The above but with the addition of some very speculative themes, some of which may well turn out to be impossible, others may be possible. Requires some modification of current understanding, but nothing that is logically impossible, or has been conclusively proved to be impossible (so no FTL without time travel) - Wormholes, Reactionless Drive, Sub-nanotech (Femto-, Plank, etc), Domain Walls, exotic matter, FTL drive with time travel, etc. -- Stephen Baxter's Xeelee universe, Greg Bear's Forge of God series, Orion's Arm
- Firm -- As realistic as the above categories were it not for unrealistic/impossible plot devices (e.g. FTL without time travel paradoxes), although these are kept to a minimum as much as possible -- Asimov's "Foundation" Series, "Giants" series by Hogan, Vinge's A Fire Upon the Deep and A Deepness in the Sky
- Medium -- Similar to the above but with a larger number of unrealistic plot devices; e.g. FTL without real explanation (or with pseudo-explanation), alien biota in some instances very similar to terragen life, psionics, a great many alien civilizations. However still preserves plot and worldbuilding consistency, and the science is good and consistent -- Niven's "Known Space" series, Robert Heinlein's Starship Troopers, Banks' "Culture" novels, David Brin's "Uplift" series, Frank Herbert's Dune, Traveller RPG
- Soft -- A number of unscientific themes - e.g. aliens as anthropomorphic "furries", handwavium disintegrator guns, Alien Cultures and psychology all extremely uniform, and so on. However, still retains story consistency -- Various TV series: Babylon 5, Farscape, Andromeda, Matrix, StarGate for the most part
- Very Soft -- As above but either even more unscientific elements (humanoid of the week, lifeless planets with breathable atmosphere, etc), and story with less consistency -- Various TV and movie series; for the most part the Star Trek Canon and Star Wars Canon
- Mushy Soft -- As above but even more unscientific (alien races never before encountered speak perfect English without a translator, animals too large to stand in Earth gravity (Godzilla), weapons that make energy beams without putting energy in, interstellar travel without FTL or centuries long voyage, mutants with super energy powers, etc) -- Godzilla, Comic Book Superheros, badly written TV sci fi, elements of some franchises
