TL 9-10 air combat in the "Caliph" setting

[warellis]

Also, isn't the issue that contra-gravity seems to only be for small vehicles like aircars, and hasn't been upscaled for spacecraft?

It could be there is difficulty in upscaling it.

[Anthony]

It's possible to have effects that mostly look like contragravity without violating conservation of energy -- it just means that energy requirements depend on velocity. That makes it decently useful for aircars (and other things fulfilling a similar role to helicopters) but very slow at getting to orbit.

[David Johnston2]

Originally Posted by seasalt

Which brings me back to the original problem. How do you avoid the fact that every battlesuit and civilian aircar is suddenly a planet-killing superweapon capable of blowing the earth apart like a shotgun to a canteloupe? A global war is the central premise of the setting! Are we assuming that nobody considered building kinetic kill vehicles? The real problem is it doesn't NEED to be planet-killing - kinetic projectiles with high-acceleration reactionless drives can be scaled to any power you need, from taking out a single city on downwards, and even with lasers there is NO POSSIBLE WAY to defend against them.

So overhyped. What's the reason why they can't detect an object taking years to accelerate on a collision course for their target? Assuming that is, that they have the power reserve to maintain that continuous acceleration?

[Varyon]

Originally Posted by seasalt

Which brings me back to the original problem. How do you avoid the fact that every battlesuit and civilian aircar is suddenly a planet-killing superweapon capable of blowing the earth apart like a shotgun to a canteloupe?

By making it so they aren't. Here are some options.

Vacuum: Aircars and battlesuits may be Sealed, but that doesn't mean they're automatically vacuum-rated. There's also the concern of keeping the pilot fueled (with food, water, and oxygen) for the long time necessary to accelerate to a WMD-level velocity (potentially avoidable with a robot, but those either need flight corrections - meaning communications, meaning they can be hacked* - or to be sufficiently-advanced to do the course corrections on their own). Note also that such vehicles are designed assuming there will be an atmosphere into which to dump their waste heat, and thus will rapidly overheat in the vacuum of space. You'll need to have an expert extensively modify your vehicle before it can become capable of surviving long enough to reach the turnaround and then come back.

Power: As noted by others, there's a concern of if such a vehicle will have enough power reserves to accelerate the whole time. I could easily see such vehicles having a bank of supercapacitors that power them, recharging either by hooking into a municipal power grid or by waiting a good while for their (undersized relative to their energy requirements) miniature fusion reactor to recharge them. This will allow for good accelerations in the short term, but either no or low acceleration over the long term... and high long-term acceleration is what you need to generate a WMD in a short timescale.

Orbital Defense: A space battlesuit or a souped-up aircar isn't going to match the performance of a dedicated combat spaceship. When someone sees such a vehicle trying to set itself up to become a WMD, they can just scramble space fighters to follow it and blast it to pieces well before it reaches the turnaround. And that's assuming the monitoring station can't just lase it directly - as noted above, these things are going to be having enough trouble keeping their own heat in check without an external source dumping more into them.

Speed Limit: Reactionless drives already break physics, giving them some sort of speed limit that is below the WMD point could be an option. If you want stargate-carrying probes to use the same drive, you could potentially link the speed limit to distance from the nearest star, have a higher speed limit when heading away from a nearby star (something-something solar wind), or similar.


*As an aside, while it's common to think any type of communication renders a vehicle hackable, that's not quite true. Load your vehicle up with some One Time Pads, then send any necessary instructions encrypted using such an OTP. As the name implies, you can only use each one once, but you can load a lot into a small amount of disk space. OTP won't work very well for real-time communication, but "send damage report," "engage this target," "return to base," "self-destruct," etc would all be options.

[seasalt]

Originally Posted by warellis

Also, isn't the issue that contra-gravity seems to only be for small vehicles like aircars, and hasn't been upscaled for spacecraft?

It could be there is difficulty in upscaling it.

They were apparently able to deliver stargates with automated "probes" that accelerated to, and decelerated from, near lightspeed to the point that they reached a dozen or so extrasolar systems within 20 years.

Originally Posted by Fred Brackin

Actually no. ...
A 1 ton (metric) aircar with thrust only equal to 1/6th G with lift provided by contragravity needs 6 years and "only" delivers 43 gigatons. It won't hit the surface of Earth either. It'll go FLASH! as soon as it hits the upper atmosphere which will be very bad for living beings of that hemisphere and probably mess up the atmosphere as a whole but it won't treat the planet as a shotgun does a cantaloupe.

Huh. This is interesting. I see that the Atomic Rockets article on the "dirt cheap planet crackers" problem with including reactionless drives in your fiction was a little overhyped, granted these things are still "planet killing" weapons in the sense of wiping out the biosphere.

[QUOTE=Anthony;2460042]Actually, it pretty much will. A couple megawatts isn't much. If necessary, use expendab

[warellis]

Originally Posted by seasalt

They were apparently able to deliver stargates with automated "probes" that accelerated to, and decelerated from, near lightspeed to the point that they reached a dozen or so extrasolar systems within 20 years.

And in 4e, as I recall, that got retconned to just be them putting the finishing touches on a Stargate that hasn't been activated yet and is apparently Caliph's first one.

[seasalt]

Originally Posted by warellis

And in 4e, as I recall, that got retconned to just be them putting the finishing touches on a Stargate that hasn't been activated yet and is apparently Caliph's first one.

Whoah, hold up! There's a 4E update to the setting? Where is that? I can't find it!

Agh... let me guess. The Pyramid magazine? I.e. totally inaccessible for nonsubscribers even if they were willing to pay for a PDF? Sigh..

[David Johnston2]

Originally Posted by seasalt

Whoah, hold up! There's a 4E update to the setting? Where is that? I can't find it!

Agh... let me guess. The Pyramid magazine? I.e. totally inaccessible for nonsubscribers even if they were willing to pay for a PDF? Sigh..

Actually it's just in Infinite Worlds, although there isn't much material on it.

[warellis]

Originally Posted by seasalt

Whoah, hold up! There's a 4E update to the setting? Where is that? I can't find it!

Agh... let me guess. The Pyramid magazine? I.e. totally inaccessible for nonsubscribers even if they were willing to pay for a PDF? Sigh..

No, in GURPS Infinite Worlds.

There's no real difference besides the fact that a Stargate in trans-Neotunian orbit is being built, and the corporation building it has claimed it may have contacted aliens, instead of in 3e where there already is interstellar travel to another star system via the Stargate.

[Rolando]

the danger of introducing cheap reactionless is not air cars or air bicicles, but having cheap reactionless means someone in a garage (maybe a big one with some extra funds, but still relatively small and cheap) may make an automated WMD.

An almost solid armor missile with ablative heat shields to enter atmosphere and reactionless rockets plus small fusion engine will do. It may be done small enough and maybe with stealth to help it get close.

You may make a few dozen of them if you want a serious threat.