Real Space Battles?

[Onyx]

Isn't Skade's ship (I assume this is the battle we are talking about) damaged in an attempt to exceed the speed of light? And thus allowing Clavain to get to Resurgum before being overtaken? I don't have my copy of the book at hand. Well I do sort of, but it's in the garage somewhere in a box.

Skade is the one being pursued, and Clavain is trying to kill her or board her ship, rather than just trying to get there first.

 

[Venusian Broon]

Skade is the one being pursued, and Clavain is trying to kill her or board her ship, rather than just trying to get there first.

My memory thinks that Clavain was trying to get to the cache weapons first in Resurgum and not (as a primary goal) trying to kill Skade or board her ship. (Clearly though he doesn't want her there first, as then she would get them. Hence the fighting.) But again I could be mistaken, as it's been some time since I've read it and it's more-or-less unavailable to me

So Skades ship was self-damaged, allowing Clavain to leapfrog/arrive at Resurgum first, then he initiates an attack on the Nostalgia for Infinity to try and get control of the weapons. I'm pretty sure that's what happens. My memory isn't that bad, is it? (Must be age!)

 

[Onyx]

My memory thinks that Clavain was trying to get to the cache weapons first in Resurgum and not (as a primary goal) trying to kill Skade or board her ship. (Clearly though he doesn't want her there first, as then she would get them. Hence the fighting.) But again I could be mistaken, as it's been some time since I've read it and it's more-or-less unavailable to me

So Skades ship was self-damaged, allowing Clavain to leapfrog/arrive at Resurgum first, then he initiates an attack on the Nostalgia for Infinity to try and get control of the weapons. I'm pretty sure that's what happens. My memory isn't that bad, is it? (Must be age!)

That's about right, it is just that Clavain and Skade never acknowledge that the turnover point is going to be an issue and that Clavain just needs to wait until Skade decelerates to stop her. The FTL attempt takes place before the halfway point.

And maybe that's all that was necessary to say about it - the FTL thing headed the other plot point off before it mattered. I just was left with the impression in several Reynolds sub-light books that allowing yourself to be chased was a reasonable tactic without decel being addressed.

 

[Venusian Broon]

That's about right, it is just that Clavain and Skade never acknowledge that the turnover point is going to be an issue and that Clavain just needs to wait until Skade decelerates to stop her. The FTL attempt takes place before the halfway point.

And maybe that's all that was necessary to say about it - the FTL thing headed the other plot point off before it mattered. I just was left with the impression in several Reynolds sub-light books that allowing yourself to be chased was a reasonable tactic without decel being addressed.

I'll think about it overnight and maybe have an attempt to sketch out the mathematics tomorrow. For my own curiosity.

My thinking is that:

Assuming that both ships were the same - and they both had the inertia device - if the goal was to reach Resurgum, both would have to start deceleration at, more-or-less, the same point. Therefore, if that was the case, Skade's ship should always, assuming she actually didn't half-scuttle herself, be ahead of Clavain - although the gap between them would drop as soon as she applied deceleration. (Although, Skade because she started first, would always have been expanding the gap ahead of Clavain during the first acceleration phase)

If the goal had been for Clavain, behind, to get to Skade, ahead, then, presumably he could continue accelerating a little beyond the 'Resurgum deceleration point' and allowing him to pass her on-route, and I suppose having a close up attempt at destroying her*. But, he would then have overshoot the destination system and have to turn around, costing valuable time. If he failed to significantly damage or miss Skade's ship in the attempt then Skade would definitely arrive in the system well before him.

Have I missed anything?

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*And presumably giving her a close up attempt at destroying him, but also would it be a very fleeting chance as the velocity differential between the two craft might be quite large?

 

[Onyx]

I'll think about it overnight and maybe have an attempt to sketch out the mathematics tomorrow. For my own curiosity.

My thinking is that:

Assuming that both ships were the same - and they both had the inertia device - if the goal was to reach Resurgum, both would have to start deceleration at, more-or-less, the same point. Therefore, if that was the case, Skade's ship should always, assuming she actually didn't half-scuttle herself, be ahead of Clavain - although the gap between them would drop as soon as she applied deceleration. (Although, Skade because she started first, would always have been expanding the gap ahead of Clavain during the first acceleration phase)

If the goal had been for Clavain, behind, to get to Skade, ahead, then, presumably he could continue accelerating a little beyond the 'Resurgum deceleration point' and allowing him to pass her on-route, and I suppose having a close up attempt at destroying her*. But, he would then have overshoot the destination system and have to turn around, costing valuable time. If he failed to significantly damage or miss Skade's ship in the attempt then Skade would definitely arrive in the system well before him.

Have I missed anything?

----------------------------------------------

*And presumably giving her a close up attempt at destroying him, but also would it be a very fleeting chance as the velocity differential between the two craft might be quite large?

Neither ship needs to get to Resurgum by a certain deadline, so the contest is really just to get to the cache weapons first and take them. So if Clavain doesn't decelerate on schedule, he will bring his larger ship and well equipped army within striking distance of Skade at whatever closing velocity he chooses after she starts to decelerate. When he gets to Skade and eliminates or captures her ship, then he can overshoot Resurgem and turn around at his leisure. And even though his velocity will be higher as he passes Skade, their actual distance in space will just get closer since she started decelerating first. So there really isn't a downside to attacking Skade after midpoint.

The other possibility is that Skade keeps he acceleration up to stay ahead of Clavain. At this point she loses because after they pass Resurgem Clavain's ship is now closer and can decel and turn around before she can. Or, he can use all the shuttles at his disposal to decel a force into Resurgem as they pass by.

There's no way for a lighter armed and equipped lead ship to actually win.

 

[Parson]

There's no way for a lighter armed and equipped lead ship to actually win.

True, if you bar luck and/or a possible innovation in tactics, armament, or negotiations.

 

[Onyx]

Finally watched the video - I get the argument, but I think the host is kind of missing the forest for the trees. All of the science he talks about is accurate, but that doesn't mean that the underlying fictional science in a given SF world doesn't consistently support the depiction of space war shown. As the video references, lasers have considerable range in space, which should put the combatants far apart. But lasers are unguided weapons that achieve their effectiveness in part by how long they can be directed on a target. As the range increases, the slightest movement of the target causes the laser - which isn't self correcting - to 'wander' all over a target that is moving in any way not predicted by the program aiming the laser. Just rotating the ship distributes the laser damage over a much larger area. And when the range is great enough the ability to predict where a purposely evasive ship is located moment to moment becomes nearly impossible.

That's just supposing that lasers are good space weapons. In a vacuum, things that are delicate on earth - like mirrored surfaces - hold up pretty well. You can also more effectively distribute laser reflecting chaff or ice crystals and take advantage of ablative surface coatings to absorb the lasers - like a coating of easily renewable surface ice.

The heat problem is another one of those things that sounds onerous until you realize that current spacecraft have really primitive heat handling mechanisms little different than AC. But there are technologies like thermoelectric generators that use the Seebrook Effect to turn ambient heat directly into electricity - much like a solar cell converts light into current. Once converted, the electricity could be used to run the ship, turned into laser energy, excitation of propulsion fuel or simply stored in capacitors. And such devices provide another possible protection against lasers.

The range problem also is subject to all sorts of mitigating factors. Can you actually detect stealthed ships at longish ranges? In zero G, how do you tell inflatable decoys from enemy ships? How close do you need to be to both accurately target AND effectively hit a randomly evading ship?

There's also other constraints. During the Vietnam War, the US fielded sophisticated long ranger interceptors capable of shooting down enemy jets via radar and guided missles - and then US foreign policy required pilots to visually identify enemy aircraft, which gave the more primitive but maneuverable MIGs an advantage over the new F4s. Fill in your own analogous political or social limitations.


The other SF factor in what we see depicted on screen is the nature of propulsion systems and their underlying principles. Most SF movies depict reactionless space drives that seem to use no significant fuel. It is a presumption that an X-wing isn't interacting with the universe to produce motion in a way that is more like getting traction on an atmosphere than the simple thrust vector model of reaction mass space ships. I'm not talking about science, but fictional science - the kind that allows 10 ton fighter to operate in and out of atmospheres for mulitple trips without fuel or service. Who are we to presume that strict Newtonian rules apply?


People interested in SF should be open minded to the speculative possibilities that fiction opens up - including the ability to end up with seemingly primitive combat due to overwhelming technological barriers. A great example are the combatants in Dune who are reduced to fighting with knives because of the incredible effectiveness of Shields and the taboo of setting off nuclear blasts if a laser hits one.