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Writing a short story; info about naval rank structure and particle physics?


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Writing a short story; info about naval rank structure and particle physics?
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Enki
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Join Date: Nov 2004
 
2009-06-25, 13:11

Quote:
Originally Posted by sebatlh View Post
re shiny hulls and heat plates:

Yeah sure a shiny hull will be pretty easy to spot, but for defensive jobs it might be worth the extra protection.
How? My gawd think of the physical volume that needs to be scanned for differences from the background. And then layer on the energy dissipation from local stars in a cubic fashion, and the radial distance isn't only star to ship, but then ship to ship as well. A small ship fully mirrored will be visually dimmer than most of the background stars. You will have to compare long term images to discern non-system body movements, and even then you have to sort out what is comet, space-junk and crap from a ship possibility. Now add faceting to the mirror plating and wow, unless you are on a PERFECT geometry, you ship doesn't exist visually and then you have to muddle about with sloppy infrared wavelengths to do the same searches.

Don't even think about more than a couple hundred clicks for active sensor sweeps, there isn't a big enough reactor. See the sun for something that would suffice as an example of an active emitter system-wide. But you still have to do all the receiving and signal processing fast, which means you need star power plus to do the job. Not likely.

Quote:
Heatplates:
The realistic thing that everybody forgets (or choose to forget ) is, all form of powerplants generate heat. Even assuming 99% efficiency, it's still a lot of energy to get rid of. And in space, big ass radiators are the only way (venting plasma etc is no good as you run out of plasma sooner rather than later ).
So, you need to run at least some parts of the hull pretty hot. That could be used as a tactical element. Destroy those parts and your enemy needs to power down pretty soon. Also, it makes it impossible to be stealthy when running the engines/lasers/particle accelerators as part of the ship is glowing in the infrared or even visible spectra. And after a battle/manoeuvring the ship needs to cool down before it regains its stealth.
There is no stealth in space. Your heat plates are the proof of that. What you do have is VAST expanses vs teensy little ships. Even if the ship stands out like a sore thumb when you look directly at it, you actually have to look it's exact direction for long enough to actually see the little heat pump. Therein lies the problem of finding the bad-guy at the long distances you need to play relativistic battles. Finding anyone!


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Aah, the possibilities of geeky scifi battles
And the best part is that this is just normal physics (I'm including your relativistic stuff here). No startrek modulate the upper EM bands, use the main deflector dish to generate a tachyon pulse bla bla that makes no sense to anyone
None of this is normal physics, it's all good old fiction. Star Trek just tries to justify it with gold-played technobabble that has little if any realism behind it. Relativistic combat as described in this thread just leaves the technobabble out but has just as many gaping holes. Even my FTL and slow combat preferences are pure wild-assed fiction.
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Enki
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Join Date: Nov 2004
 
2009-06-25, 13:15

Quote:
Originally Posted by Kickaha View Post
Another point: a shiny hull also reflects energy back *in*... ie, it makes bleeding heat even more difficult.
Not at all. Just don't polish the inside and the smooth side will dissipate, although not as well as something tailor made for dissipation. You can also use things like piezo-electrics to drive lasers to create a heat pump out, reducing the needs for spider web cooling lattices. That particular theory has already been applied in some terrestrial science experiments needing to get items close to absolute zero.
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Kickaha
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Join Date: May 2004
 
2009-06-25, 13:23

Quote:
Originally Posted by Enki View Post
Not at all. Just don't polish the inside and the smooth side will dissipate, although not as well as something tailor made for dissipation.
Explain how something can be polished (smoothed at an atomic level) only on *one* side. The polished layer is indeed bi-reflective, hence the whole point behind black body radiation being the most emissive. A black body absorbs *and* emits energy the most, since it reflects nearly none. A perfect black body reflects zero energy - which means it also reflects zero energy back inwards, and is therefore perfectly emissive.

Want to cook your crew in the dead of space, away from stellar input? Coat the ship with IR-reflective paint and wait.

Quote:
You can also use things like piezo-electrics to drive lasers to create a heat pump out, reducing the needs for spider web cooling lattices. That particular theory has already been applied in some terrestrial science experiments needing to get items close to absolute zero.
Yes, a laser trap, used for created BECs. Not sure how well it would scale to macroscopic scales, and since this is a more or less closed system here, how would you power the laser without creating more waste heat in the overall system?
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sebatlh
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2009-06-25, 13:31

Quote:
Originally Posted by billybobsky View Post
while accurate science helps -- a good story doesn't need it.
A good story deserves a good setting
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sebatlh
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Join Date: Jun 2006
 
2009-06-25, 14:50

Enki:
People find comets with binoculars. It's easy to spot satellites with the unaided eye.
Wouldn't a shiny ship atleast be easier to spot?
I don't know which ranges Kraetos had in mind, but getting, undetected, really up close before opening the gates of hell on your opponent. Is that a bad thing?

By normal physics, I meant stuff like the stefan boltzmanns law etc. There are so many fun things one can do with the real world even in a scifi battle setting. Sure, space battles and living on different planets/solar systems require some magic devices. But, at least to me, it's more fun if those devices are kept to a minimum.
Take the transporters in star trek. Great for the original series. No need of using the shuttles and the FX that comes with that in every episode. BUT! why don't they use it as a weapon? whaaaat? (except for than sniper rifle mentioned earlier in the thread, but why use a bullet at all? Why not just beam the brain an inch to the left or something?)

And Kickaha is right. Shiny surfaces keeps the heat inside. So yeah, a shiny ship would need some parts of the hull to be black for cooling.
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709
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Join Date: May 2004
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2009-06-25, 14:59

Quote:
Originally Posted by sebatlh View Post
Enki:
People find comets with binoculars. It's easy to spot satellites with the unaided eye.
Wouldn't a shiny ship atleast be easier to spot?
Only if it's close enough to a light source (a sun in the case of a comet (heating up) and satellite (reflection)). Out in deep space it's friggin dark. "The corner of no and where" a great man once said.

So it goes.
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sebatlh
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2009-06-25, 15:24

Quote:
Originally Posted by 709 View Post
Only if it's close enough to a light source (a sun in the case of a comet (heating up) and satellite (reflection)). Out in deep space it's friggin dark. "The corner of no and where" a great man once said.
But why would one fight in deep space?
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zsummers
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Join Date: Sep 2005
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2009-06-25, 15:55

I read this thread and blew my geek wad.

Fantastic. Now I need to change pants.
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Kraetos
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Join Date: Dec 2005
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2009-06-25, 15:55

Quote:
Originally Posted by billybobsky View Post
while accurate science helps -- a good story doesn't need it.
Quote:
Originally Posted by Enki View Post
I guess there's a level of personal believability in how far someone things technology can go.
...snip...
But it's fiction so use tech however you want, but always remember -- Its the story!
I'm glad this came up. I could simply start blatantly ignoring science in certain areas. Truly accurate science in sci-fi is never going to happen because there are three basic, unavoidable scientific pitfalls all sci-fi must deal with: FTL, gravity, and inertia. (Or, at the very least, it wont happen until/if we find a way around these problems.)

Warning: wall of text. Jump to the bottom if you want the one sentence summary.

They key here isn't that one should shoot for completely "accurate" science, unless you want to write a story about ships which crawl around our solar system and either have rotating sections (which would make for fragile, clumsy, poor warships) or can't be away from port for any extended period of time without the crew's bodies deteriorating from too much zero-g.

Some authors simply ignore science completely. I don't really like this approach, because it just makes the whole thing feel fake, for lack of a better term.

Others try and cut as close as possible to realistic. The problem is with this approach is that it can severely limit story options.

Which leaves us with the middle ground. If we rank things from 1 to 10, 1 being as close to real science as possible (hard SF), 10 being completely out there (soft SF), Star Trek is about an 8, maybe even a 9, Star Wars is roughly a 7, B5 is probably a 6, Halo, Lost Fleet, and Starship Troopers are 4s (Halo is pretty heavily inspired by Starship Troopers; also, Halo is tricky since Covenant tech is much more advanced), and Battlestar Galactica (before it went totally off the wall with the religious weirdness) brings up the rear with a 2. BSG is incredibly low on the scale since, as far as I can recall, it only covers the three basics, plus the whole artificial intelligence thing, but that's not too out there. This scale doesn't take religion into account, that's really a different aspect of the story. (Worth noting: most good epic sci-fi incorporates religion in some way.)

I'm shooting for a 4.

It's not really about accurate science, it's about believable science. Remember, even Star Trek makes an attempt to justify the crazy science going on—actually, Star Trek makes more effort than most sci-fi to justify it, sometimes to a fault. (Treknobabble, I'm looking at you.)

It's about getting the right blend of real science, pseudoscience, and straight-up fantastic (whenever I say fantastic, I mean it in the literary sense) science to set the stage. Being higher on that scale doesn't necessarily mean that it's automatically bad sci-fi; I love Star Trek. It's just a stylistic choice.

This is also why I am very curious about how a naval ship works IRL since that's a relatively easy realistic touch one can toss into the story.

That said...

If you look at the some of the recent sci-fi epics—Babylon 5, Battlestar Galactica, and Halo—the story begins by being as realistic as possible w/r/t real world physics and science (relative to other sci-fi, that is), so when the sci-fi gets ratcheted up, it makes for a stronger contrast as the story moves from beginning, to middle, and end.

The real challenge is making the gradual increase in fantasticness as smooth as possible. B5 did it exceptionally well (the main series, not the spinoffs), BSG and Halo were a little rockier. Some sci-fi epics don't do the increasingly fantastic technology increase at all; arguably, this is part of the distinction between normal sci-fi and epic sci-fi.

Babylon 5 is by far the best example of this that I am aware of. (I'm only on book 2 of 6 of The Lost Fleet, but even this early it's looking like it's going to be doing the gradual increase of fantastic as well) The first two seasons felt very "real," you had an easy time believing that this could be the state of humanity in 150 years. Not necessarily because of the technology, although there is a big jump in technology over the course of the series. It had more to do with the culture that JMS depicted where humans (and a lot of the aliens) were still as stupid as they are today, and over the course of the series, everyone got a little less stupid. The third and fourth seasons rolled around and the technology got more sci-fi, and Sheridan stepped into his role as the epic hero. It slowly became clear JMS was telling a story that was about the fate of the entire universe, complete with a big plot twist right before the climax.

Babylon 5 tangent ahead:

IMO this is why Crusade and Legend of the Rangers failed to gain traction. The sci-fi level was already so high, JMS backed himself into a corner and didn't have anywhere to take it without going completely off the wall. It's difficult to believe that the Omega class and Victory class destroyers were designed by the same civilization with only 20 years between the designs, even when we take Minbari and Vorlon mumbo-jumbo into account.

Crusade was also hurt by the fact that Gideon was kind of a wimpy captain (Enterprise had this problem too—Archer was a pretty flimsy captain when you get down to it) compared to Sheridan who didn't hesitate to make the tough calls, such as sending telepaths on suicide missions.

Actually, all of Crusade's characters were kind of lackluster, and the cast was maybe half the size of B5, which limited JMS's character options. The only one I liked was Matheson, but even he was kind of iffy, and we didn't learn nearly enough about him. Compare to B5 where I liked pretty much every character. When Ivanova almost dies... gets me every time.

The less said about Legend of the Rangers, the better

Having seen both spin-offs of my all-time favorite sci-fi story get deservedly cancelled partially because they were simply weren't believable, I'm trying to avoid that pitfall in my story which is why I started this in the first place.

I could talk about Babylon 5 until my tongue fell out It really is my favorite sci-fi ever. It's biggest problem is that it's almost too epic. I've put a good deal of thought into it and have decided that if you cut out the episodes that aren't essential to the main plot, you're left with 41 episodes; basically cutting it in half. But that's nearly 31 hours of storytelling If you really want to cut the fat you can get it down to fifteen episodes but at that point it's so compressed you lose a lot of the epic feel to it.

B5 can be hard for a newcomer to get into because there are a lot of dud episodes in the first and second seasons; the only good news about that is that it makes the exceptional episodes in those seasons really stand out.

I can post some lists up if anyone has ever wanted to get into B5 but felt it was just too much of a time commitment.

We now return you to your regularly scheduled programming...

BSG did a good job but it took it a little too far with the ridiculousness at the end. The shift from the hyper-militaristic feel and "naturalistic sci-fi" to "God did it" was just too much of a leap. The first half of BSG (miniseries, seasons 1 and 2) was a totally different show than the latter half. It felt very disconnected. BSG jumped the shark after Resurrection Ship. All of the memorable episodes (33, The Hand of God, and Pegasus are my personal favorites) are before season 2.5 It's not that the final two seasons weren't enjoyable, it's just that the first two seasons were truly exceptional.

Hell, even Star Wars does something similar to this. Star Wars was one of the first sci-fi universes where everything looked worn and beaten, unlike Star Trek where the Enterprise came out of every situation spic and span. As we went from IV, to V, to VI, the force began to play a more significant role in the story. In the beginning all it did for Luke was hone his instincts when he blew up the Death Star. We get to the middle and a green midget pulls a starfighter out of a swamp and there's a ghost mentor following the hero. Finally, it culminates with a dude who could shoot lighting out of his fingers.

To succinctly sum up the above blob of 1,500 words (good lord, I need a life), believable science makes the story feel more epic, as it sets the stage as somewhere we try and adhere to the laws the universe before we throw them out the window when shit gets intense.

Logic, logic, logic. Logic is the beginning of wisdom, Valeris, not the end.

Last edited by Kraetos : 2009-06-26 at 02:00.
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Kraetos
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Join Date: Dec 2005
Location: Boston-ish
 
2009-06-25, 18:17

Quote:
Originally Posted by Enki View Post
Fusion reactors don't go boom unless they are supporting the weight of a star. Then it's the big inrush causing heavy metal fusion, not the original gaseous fusion that causes the boom. A fusion reactor in a ship would just go pffff... As the fusion looses magnetic containment the plasma looses heat exponentially fast and becomes just regular run-of-the-mill hot gas by the time it gets to containment vessel itself.
Okay, good to know. Would there be a way to intentionally turn a reactor into a thermonuclear bomb? (i.e. self destruct/kamikaze attack)

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Tradition. Humans love it. Despite whether or not it makes any sense. Also you probably need to see something for things like docking, formation flight or close proximity maneuvering for replenishment.
Neato. So now I'm thinking the bridge is closer to the outer hull and has big transparent aluminum windows all around. During combat it might recess into the hull...

Basically, non-combat operations could be conducted from there, and when it's time to fight, the bridge drops into the ship and everyone moves to CDC where there are big displays for keeping track of the battle and communicating with other ships.

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Accurate FTL jumping with longish spool-up/cycle times and slow physical speeds pretty much solve all of that. I just for the life of me can't see how there can be enough energy on demand to do any tactical maneuvering ever. Accel/decel energies for big ships would be on the order of stellar outputs for short periods. How does anyone contain that? Let alone use it. Or dampen it? Because unless you can, there is no such thing as tactical maneuvering at relativistic speeds.
Well, given that I've given my ships the ability to "blink" around a star system, maybe slowing them down and adding fighters could be interesting.

I like the idea of fighters, I really do. But I always have trouble fitting them in. I mean, wouldn't they be pretty easy targets for point-to-point lasers/particle weapons? Or anti-fighter missiles?

There's also the issue of how effective they would be against a capital ship. If you give them nukes and the ability to get through enemy defenses, then they're basically too powerful. Send in the fighters, weave through the defenses, launch your nukes and GTFO.

But without nukes, they're not really going to put a dent in the hull. I suppose the goal for fighters could be to take out the defense grid to capital ships can get close and use missles/nukes.

Why wouldn't you equip your bombers with nukes?

In BSG, we've seen Galactica and Pegasus take nuke hits and survive. Hell, there was one episode where Pegasus soaked up three or four nukes, kept fighting, and got out alive. And BSG is supposed to be one of the more grounded sci-fi 'verses.

Could a very heavily armored starship survive getting hit with multiple nukes? What would you make the armor out of? Would it be something we already know about or would I have to come up with a supermetal (i.e. duranium, tritanium) for armor plating? I have no qualms with that.

I've got shields too, so they should obviously be able to soak up nukes. Between shields and a supermetal I could just say that my ships can absorb a whole bunch of nukes before they start to take fatal damage.

What do you think would be the most interesting? (You've clearly thought about this before, too )

This thread is a blast!

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Personally I think there may be a possibility of figuring out how to use higher dimensions to move from 4-space point to 4-space point, but not finding a way to harness a tactically moving power source as dense as an entire star.
Woosh. Sounds cool, though.

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But it's fiction so use tech however you want, but always remember -- Its the story!
Hear hear!

Quote:
Originally Posted by Enki View Post
Even if the ship stands out like a sore thumb when you look directly at it, you actually have to look it's exact direction for long enough to actually see the little heat pump. Therein lies the problem of finding the bad-guy at the long distances you need to play relativistic battles. Finding anyone!
Yeah, distances always screw me up. Speeds, too.

For the sake of this idea, lets say that ships don't have inertial dampening. How fast could a ship accelerate—assuming the crew was strapped in nice and snug—without squishing them? I can see ships having warning signs and lights everywhere which are there to tell the crew to find a seat and hold on when acceleration becomes dangerous. How fast could a ship go? How fast could it turn? How about a fighter?

That's another thing I always worry about. Shouldn't a capital ship be able to move a lot faster than a fighter since it would have big honkin engines? IANA physicist (although I'm thinking I should take general physics before I graduate) so I don't quite understand how the relationship between thrust and mass works and how that would relate to big ships and fighters.

So, how close do you think opposing fleets would have to be to accurately target each other? Close enough where fighters could close the distance in a reasonable amount of time?

None of this is set in stone. I'm trying to get a feel for what laws of physics I should abide by and which ones I should magically circumvent. Sorry about all the questions, I hope I'm not bothering anyone or distracting them from doing real work

Quote:
None of this is normal physics, it's all good old fiction. Star Trek just tries to justify it with gold-played technobabble that has little if any realism behind it. Relativistic combat as described in this thread just leaves the technobabble out but has just as many gaping holes. Even my FTL and slow combat preferences are pure wild-assed fiction.
Yeah. It's all about creating interesting/plausible-sounding ways to extend physics with the right amount of "trust me, we'll figure this out in the future, 'cuz, you know, it's the future" to accommodate the story.

Quote:
Originally Posted by Kickaha View Post
A black body absorbs *and* emits energy the most, since it reflects nearly none.
So, would a small ship painted completely back with proper geometry make for a good stealth ship? (I'm thinking about a little dropship which can deliver marines to an enemy ship.)

Quote:
Originally Posted by sebatlh View Post
I don't know which ranges Kraetos had in mind, but getting, undetected, really up close before opening the gates of hell on your opponent. Is that a bad thing?
Heh, I don't have distances in mind. I'm still trying to figure that out and am completely open to suggestions

Quote:
Originally Posted by 709 View Post
Only if it's close enough to a light source (a sun in the case of a comet (heating up) and satellite (reflection)). Out in deep space it's friggin dark. "The corner of no and where" a great man once said.
Quote:
Originally Posted by sebatlh View Post
But why would one fight in deep space?
Yeah, that. Nobody is ever going to fight anywhere other than a star system. What would you be fighting over?

Quote:
Originally Posted by zsummers View Post
I read this thread and blew my geek wad.

Fantastic. Now I need to change pants.
Sorry 'bout that. I probably should have bought you a drink first

Logic, logic, logic. Logic is the beginning of wisdom, Valeris, not the end.

Last edited by Kraetos : 2009-06-26 at 02:06. Reason: AN ate my post - good thing I had it saved.
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Enki
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Join Date: Nov 2004
 
2009-06-25, 18:36

Quote:
Originally Posted by sebatlh View Post
Enki:
People find comets with binoculars. It's easy to spot satellites with the unaided eye.
Wouldn't a shiny ship atleast be easier to spot?
I don't know which ranges Kraetos had in mind, but getting, undetected, really up close before opening the gates of hell on your opponent. Is that a bad thing?
With comets and a binoculars you know EXACTLY WHERE to look. Nobody finds unknown comets with binoculars. New astrological bodies are almost always found by studying multiple photographs and finding the objects which moved in a previously unknown manner. Or a very few are found because they are so close their lighting and motion become obvious to casual observations, but they were to small and/or dark to be easily picked up through the regular photograph comparison route - your satellites fit this model.

kraetos has been talking about combat velocities of ~.1C. Moving 18,600 miles per second. Earth to the Moon in 12 seconds. 30 seconds apart the ships would be 2.5 times the Earth-Moon distance away from each other. Take a ship a half kilometer long and it will be close to the limits of the Hubble space telescopes resolution limits ("equivalent to standing at the U.S. Capitol and seeing the date on a quarter a mile away at the Washington monument.") Now give yourself no starting information on where to look, and take the Hubble Ultra Deep Field observation as a starting point for finding objects that small -- wait --
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If astronomers made the Hubble Ultra Deep Field observation over the entire sky, how long would it take?

The whole sky contains 12.7 million times more area than the Ultra Deep Field. To observe the entire sky would take almost 1 million years of uninterrupted observing.
Even making a one million time improvement in sensor tech will still make you wait a year and you only have 30 seconds to live because you are defending a fixed point, not picking an independent axis of attack. You have to be able to scan the sky a million million times faster to do it in 30 seconds. That's a tall order.


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By normal physics, I meant stuff like the stefan boltzmanns law etc. There are so many fun things one can do with the real world even in a scifi battle setting. Sure, space battles and living on different planets/solar systems require some magic devices. But, at least to me, it's more fun if those devices are kept to a minimum.
Take the transporters in star trek. Great for the original series. No need of using the shuttles and the FX that comes with that in every episode. BUT! why don't they use it as a weapon? whaaaat? (except for than sniper rifle mentioned earlier in the thread, but why use a bullet at all? Why not just beam the brain an inch to the left or something?)

And Kickaha is right. Shiny surfaces keeps the heat inside. So yeah, a shiny ship would need some parts of the hull to be black for cooling.
So that's why we keep putting shiny reflective surfaces on the outside of out spacecraft? So they can warm up? That's why if you wrap yourself up in a space blanket wrong way around you don't stay nearly as warm as if you wrap up the shiny side in? Skylab needed the solar reflector so the astronauts didn't cook, not so they would be cooked. The whole pont of the reflective surface is so you don't become a black body.

You are trying to apply the countermeasure against the near IR-visual light wavelength band, across all EM wavelength bands and that doesn't work. The hull reflectiveness is only tuned to specific wavelengths of laser weapons, that won't halt long wave infrared emission, only slow it down a bit because there is less surface area. Black bodies absorb all the energy thrown at it, then emit it in the long infrared. I really wouldn't want to live in that ship. It would be really hot for a really long time. And who said anything about perfect atomic reflectiveness? I can polish a butt-ugly block of aluminum and get 95% reflectivity and the back of it is still but ugly. You can get a little more exotic and get several 9's of reflectivity on good old sunglasses, mirrored only on the front I might add. The side that adheres to the glass is quite rough in comparison with the front surface. But that would make it hard to see anything so the layers are kept thin enough to do more like 60% reflectivity.
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Anonymous Coward
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2009-06-25, 18:46

Quote:
Originally Posted by Kraetos View Post
Neato. So now I'm thinking the bridge is closer to the outer hull and has big transparent aluminum windows all around. During combat it might recess into the hull...

Basically, non-combat operations could be conducted from there, and when it's time to fight, the bridge drops into the ship and everyone moves to CDC where there are big displays for keeping track of the battle and communicating with other ships.
In my opinion, the only reason to have the bridge manned is if you need to see something.

The submarine bridge is outside the pressure hull. Admittedly, it is always manned by the Officer of the Deck and a lookout whenever it is accessible, but that is because the sensors cannot be relied to pick up on hazards in the water 100% of the time.

Otherwise, the CONN is like the CIC in BSG, just different terminology. (That is, unless there is a separate compartment for the steering controls.) Obviously I am not a BSG watcher because in my limited experience, I cannot remember the BSG CIC giving specific maneuvering or speed orders. But with the CO or XO in control, it doesn't make sense that there would be a separate station ("control" meaning "being in charge" since when using voice communications, the area of the operations compartment with steering/diving, periscopes, radar, and fire control is known as "Control").

From a structural standpoint, I'm not sure if you want the bridge dropping into the ship. If that means a telescoping access way, those are just more joints that could fail. You could have a bridge structure that fairs into the outer hull, and it might be able to hold an atmosphere under ideal conditions, but I wouldn't want to count on it being a pressure barrier.
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Kraetos
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2009-06-25, 18:48

Quote:
Originally Posted by Enki View Post
kraetos has been talking about combat velocities of ~.1C. Moving 18,600 miles per second. Earth to the Moon in 12 seconds. 30 seconds apart the ships would be 2.5 times the Earth-Moon distance away from each other. Take a ship a half kilometer long and it will be close to the limits of the Hubble space telescopes resolution limits ("equivalent to standing at the U.S. Capitol and seeing the date on a quarter a mile away at the Washington monument.") Now give yourself no starting information on where to look, and take the Hubble Ultra Deep Field observation as a starting point for finding objects that small -- wait --
Hm, I guess that The Lost Fleet is less realistic then I originally thought. Unless the ships are truly gigantic.

Still fun to read, though

So it sounds like fictional supersensors of some sort are a must. A lot of sci-fi technologies are more about covering your ass because you know there's a gaping hole in logic with what you're trying to do.

Logic, logic, logic. Logic is the beginning of wisdom, Valeris, not the end.

Last edited by Kraetos : 2009-06-25 at 20:26.
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Kickaha
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2009-06-25, 20:46

Quote:
Originally Posted by Enki View Post
So that's why we keep putting shiny reflective surfaces on the outside of out spacecraft? So they can warm up? That's why if you wrap yourself up in a space blanket wrong way around you don't stay nearly as warm as if you wrap up the shiny side in? Skylab needed the solar reflector so the astronauts didn't cook, not so they would be cooked. The whole pont of the reflective surface is so you don't become a black body.
You'll note I said "away from stellar input". ie, deep space. Not in our neck of the woods where the solar radiation outside the protection of our atmosphere is highly significant.
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Dave
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Join Date: May 2004
Location: Bay Area, CA
 
2009-06-25, 22:54

Quote:
Originally Posted by Kraetos View Post
Hm, I guess that The Lost Fleet is less realistic then I originally thought. Unless the ships are truly gigantic.
Or makes a big splash, so to speak, when it drops out of FTL.

Unless they know you're orbiting a certain object or you transit the local star, they'll have the same amount of trouble seeing you. They'll suspect you're in a certain area, but that only narrows it down a bit. You'll have the advantage of deploying remote sensors and hiding while you wait for them to show up.

But IANASCT
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Enki
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Join Date: Nov 2004
 
2009-06-25, 23:56

Quote:
Originally Posted by Kickaha View Post
You'll note I said "away from stellar input". ie, deep space. Not in our neck of the woods where the solar radiation outside the protection of our atmosphere is highly significant.
And I've been talking about shininess as a laser countermeasure. That doesn't mater where the nearest star is. I don't want to absorb all that laser energy if I can bounce 99%+ of it off into deep space.
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Enki
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2009-06-26, 00:02

Quote:
Originally Posted by Kraetos View Post
So it sounds like fictional supersensors of some sort are a must. A lot of sci-fi technologies are more about covering your ass because you know there's a gaping hole in logic with what you're trying to do.
That's why the fantasy writers have it so easy! Magic does whatever!

Just write the good story and keep the focus off the tech, let the tech support things seamlessly in the background. You thought The Lost Fleet was good because you liked the story. That made you subconsciously willing to suspend disbelief and not examine things in detail. That's a story win right there.
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sebatlh
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2009-06-26, 07:42

Quote:
Originally Posted by Enki
kraetos has been talking about combat velocities of ~.1C. Moving 18,600 miles per second.
Doh!
I completely forgot to factor in the speed of the ships in the equation.
ooops


Quote:
So that's why we keep putting shiny reflective surfaces on the outside of out spacecraft? So they can warm up? That's why if you wrap yourself up in a space blanket wrong way around you don't stay nearly as warm as if you wrap up the shiny side in? Skylab needed the solar reflector so the astronauts didn't cook, not so they would be cooked. The whole pont of the reflective surface is so you don't become a black body.
If we want to move fast, we need a big engine. That engine, presumably, generates more heat inside the ship than the absorption of solar radiation. Or not. It all depends on how hot you run the engines at the moment and how close you are to the nearest star.
Sooo, yeah.
I guess the interesting thing in a story is if a ship somehow gets damaged so that the hull reflectivity changes (or its ability to change to change its reflectivity changes). I mean, sabotaging a ship could be as simple as painting critical parts in the wrong colour

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You are trying to apply the countermeasure against the near IR-visual light wavelength band, across all EM wavelength bands and that doesn't work. The hull reflectiveness is only tuned to specific wavelengths of laser weapons, that won't halt long wave infrared emission, only slow it down a bit because there is less surface area
I really like your idea of painting ships in specific "colours" to reflect lasers while still being able to radiate in the long wave band.
Imagine everyone having red ships because all the lasers are red. And then someone shows up with a blue laser. Instant super weapon! Could be a really good plot tool if someone needs the upper hand for a short while. (Of course it wouldn't be red and blue lasers (sounds too silly, like blueray vs dvd or something :P) but maybe lasers vs masers)
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Kickaha
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2009-06-26, 08:04

Quote:
Originally Posted by Enki View Post
And I've been talking about shininess as a laser countermeasure. That doesn't mater where the nearest star is. I don't want to absorb all that laser energy if I can bounce 99%+ of it off into deep space.
Let me try this again.

Reflective = great laser defense.

Reflective = makes venting heat that much harder because it eliminates simple radiative cooling due to also reflecting internal heat back in. Which, as you recall, was the second topic in that post chain. Both were being discussed.

And I see that here you missed the point I was trying to make, so let me try that again too:

Quote:
And who said anything about perfect atomic reflectiveness? I can polish a butt-ugly block of aluminum and get 95% reflectivity and the back of it is still but ugly.
The polished layer is how thick again? A few atoms. Is there a junction between that polished layer of atoms and the rest of the substrate? Yes. If you were to split that layer off of the substrate, what would the back side of it look like? *Polished*. There's no such thing as a one-way reflector without violating the laws of physics, ie, the second one. Look up "Maxwell's Demon".

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You can get a little more exotic and get several 9's of reflectivity on good old sunglasses, mirrored only on the front I might add.
One-way sunglasses and mirrors are still reflective in two directions, equally. The trick is that they are only partially reflective, and one side has a hell of a lot more light hitting it than the other. 60% of sunlight being bounced back at you is blinding, 60% of the light on the inside surface is nominal. The 40% being transmitted from the outside is enough to see because of the photon density - the 40% being transmitted from the inside is swamped by the external reflexivity. Same reflection both ways.

The layer of material that is doing the reflection is extremely thin - and the backside of that thin layer is just as reflective as the front, since reflectivity is a property of the atomic arrangement. If the atoms are arranged such that they reflect one way, they will reflect on the other side as well.

You are correct that can have materials that are frequency-specific reflective, and if you could create one that was IR-transparent, but weapon-reflective, that would work - up until the point that you're around a source of IR, such as a star, nuclear blast, or heck, when your opponent realizes they can just cook you with an IR laser. Or, of course, the weapon frequency changes, and you're hosed... oh HEY - Kraetos, there's a hard sf detail for you - doppler shifted weapon blasts no longer being reflected by armor plating because it's too frequency-specific. This indicates that broad-spectrum reflectivity is needed.

Go back and read sebatlh's post before mine, the one I responded to - two topics were being discussed, I simply highlighted an interaction between them.

Edit: *lol* sebatlh, you beat me to it.
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Banana
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2009-06-26, 08:12

While we're talking space combat, I have to wonder about the hull breach. It seems to be a common occurrence on Star Trek that a hit ship has a breached hull and you see people running under the slowly closing gates. Maybe throw in a little smoke & fumes for visual effects.

But, really?

The pressure difference between inside and outside is pretty significant, IINM, and I can't help but think that if there was a pinhole hole, it'd turn into something even more worse. Furthermore, even if it could be contained, I wonder if it can stay that for an indefinite time; seem to me it'd just keep deteriorating.

Am I mistaken in imagining that subs has it easier than spacecraft because subs is keeping the pressure out while spacecraft has to keep the pressure in, no?
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sebatlh
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2009-06-26, 09:02

Quote:
Originally Posted by Kraetos
Quote:
Originally Posted by Kickaha
A black body absorbs *and* emits energy the most, since it reflects nearly none.
So, would a small ship painted completely back with proper geometry make for a good stealth ship? (I'm thinking about a little dropship which can deliver marines to an enemy ship.)
Stealth in space works the same way as stealth in the air.

Don't emit stuff in the general direction of enemy sensors.
Don't reflect energy back from active enemy sensors (radars/laserscanners)

In space, the part of your ship facing the enemy needs to be the same temperature as the background radiaton (what is it, black body radiation of ~4 Kelvin?) *or* whatever is directly behind it not to stick out. And you should also control the intensity.

So cold as hell and paint the hull the right shade of grey.
Geometry wise I guess looking at anything stealthy today is good inspiration.

OR, jump to the far side of venus, wait until the orbit is just right (can take a while ) and then just keep the sun in you back and enemy straight ahead
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sebatlh
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2009-06-26, 09:18

Quote:
Originally Posted by Banana View Post
While we're talking space combat, I have to wonder about the hull breach. It seems to be a common occurrence on Star Trek that a hit ship has a breached hull and you see people running under the slowly closing gates. Maybe throw in a little smoke & fumes for visual effects.

But, really?

The pressure difference between inside and outside is pretty significant, IINM, and I can't help but think that if there was a pinhole hole, it'd turn into something even more worse. Furthermore, even if it could be contained, I wonder if it can stay that for an indefinite time; seem to me it'd just keep deteriorating.

Am I mistaken in imagining that subs has it easier than spacecraft because subs is keeping the pressure out while spacecraft has to keep the pressure in, no?
Subs have it a bit easier because water doesn't leak as easily.
Otherwise the pressure difference is *much* greater when diving than atmosphere - space.
Normal pressure is about 1000hPa (14.5 psi)
On 10 meters depth, the pressure is 2000hPa
20 meters - 3000hPa
etc.

So, just looking at the forces that the hull needs to handle, diving is a lot worse.
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Banana
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2009-06-26, 09:34

I really need to brush up on my physics, but yes you are right, the absolute difference is likely to be higher underwater than in space. I perhaps shouldn't have used the difference, but what I was thinking of how the hull would react. If we have a hole in a sub's hull, it'd get flooded and that compartment is now equalized. The pressure upon the rest of sub would also apply compressive force which also conveniently makes it easier to contain the leak if the hull is well designed.

But in space, it's the reverse; instead of the hole getting plugged by the force outside, we have to plug something in the hole and plug it well so it doesn't get dislodged and leak any further.

Let's see if rephrasing the question would help: If spacecraft are more likely to suffer tensile force compared to sub suffering from compressive force, does it means it would be more problematic to design a hull that doesn't fail under tensile force instead of compressive force?

Edit: Maybe to help, I'm thinking of how an egg can withstand compressive force when pressed on the ends even though the shell itself is fragile. I do not know of similar behavior where the force is tensile instead of compressive.
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sebatlh
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2009-06-26, 10:19

Good point about compressive versus tensile forces and how a subs hull kind of tightens up when the pressure increases.

I don't know but I don't think it makes that much of a difference.

But I agree. Hull integrity often seems to be more of an afterthought in sci-fi. At least in star trek
As long as the warp engines are online, everything is ok
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709
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2009-06-26, 10:37

Quote:
Originally Posted by sebatlh View Post
But why would one fight in deep space?
I don't know. Trade routes?
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Dave
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2009-06-26, 10:44

Quote:
Originally Posted by sebatlh View Post
Hull integrity often seems to be more of an afterthought in sci-fi. At least in star trek
As long as the warp engines are online, everything is ok
I think it comes off that way because every door is air-tight (or at least it looks like they are, and they would be if I was designing a ship), so a hole in the hull merely disallows you use of that room. Of course, if the holes are of sufficient size, you might tear apart the ship doing something that otherwise wouldn't be a problem. Interestingly, Star Trek's warp drive, at least the way I understand it, doesn't really stress anything other than the warp engines, which is why everything is ok as long as they're online.
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Banana
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2009-06-26, 10:49

Quote:
Originally Posted by Dave View Post
I think it comes off that way because every door is air-tight (or at least it looks like they are, and they would be if I was designing a ship), so a hole in the hull merely disallows you use of that room. Of course, if the holes are of sufficient size, you might tear apart the ship doing something that otherwise wouldn't be a problem. Interestingly, Star Trek's warp drive, at least the way I understand it, doesn't really stress anything other than the warp engines, which is why everything is ok as long as they're online.
Now that's another thing I've been wondering. I know that in space, the shape of ship doesn't matter as much as there's much less resistance, friction and drag to account for (and they do so with deflector shields). But... if the warp engines are in the nacelles, and thus propelling from there, wouldn't they be pushing the nacelles forward, rather than the ship itself, which means the nacelles would be dragging the rest of ship... stress glamour on the thingy that holds the nacelles to the rest of ship, no?


Kraetos, my apologies for asking questions in your thread. Curiosity kilt the cat, I swear!
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Kickaha
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2009-06-26, 11:05

Quote:
Originally Posted by Banana View Post
Now that's another thing I've been wondering. I know that in space, the shape of ship doesn't matter as much as there's much less resistance, friction and drag to account for (and they do so with deflector shields). But... if the warp engines are in the nacelles, and thus propelling from there, wouldn't they be pushing the nacelles forward, rather than the ship itself, which means the nacelles would be dragging the rest of ship... stress glamour on the thingy that holds the nacelles to the rest of ship, no?


Kraetos, my apologies for asking questions in your thread. Curiosity kilt the cat, I swear!
Nope - no stresses, because it's not a propulsion, as in application of force against the surrounding space and matter. It creates a warp bubble around the ship, and then moves the bubble sort of *around* space.
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billybobsky
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2009-06-26, 11:35

Although that theory has been shown to violate QM at the event horizon...
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sebatlh
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2009-06-26, 11:43

Quote:
Originally Posted by billybobsky View Post
Although that theory has been shown to violate QM at the event horizon...
Care to elaborate?
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