Attacking Darius:

kzt wrote:The Honorverse in general, not just spiders or RMN drones, totally violates the laws of thermodynamics. So you can't really argue 'science' here. David hasn't even provided any real in-universe explanation.

Yes and no.

Yes, there are plenty of violations of known laws of Physics, including Thermodynamics, as we understand them. That could be an argument for allowing a perfect closed system that did not need to radiate any energy.

But no, in this particular case, textev says it must expel some energy because it isn't a perfect system. Therefore, at least this portion of the Second Law is still in force.

tlb wrote:Perhaps I am, but the point is that it will always be the case that the heat generated in a closed system will build up to a point were some will have to be dumped outside. There is simply no way to turn all heat into useful energy, in this example it takes extra energy to pump heat from one room to another.

kzt wrote:The Honorverse in general, not just spiders or RMN drones, totally violates the laws of thermodynamics. So you can't really argue 'science' here. David hasn't even provided any real in-universe explanation.

It's like barricade. All plot, no logic.

There are still some vestiges of science, in particular the need to radiate waste heat in a way that does not attract attention. There is no suggestion that all heat can be made to perform useful work, in the end there is still waste heat left over.

I have a background in Physics, but ended up not making a career out of it; so I recognize the problem inherent in almost all science fiction. The boundaries are that the author wants to write about future marvels, that we would not be able to create today, particularly in what is called hard science fiction; indeed our current understanding of the laws of nature would suggest that they are not even possible. So the author is forced to adopt a modified set of laws which allow those future marvels to work. We go along with the changes, if we like the stories that are being told; it helps if the author is consistent in the application of those laws.

When locked genes were first introduced in the stores, I remember that there were many posts from biologists saying that was not the way genetics worked. It was not crucial to the story if they had been correct about the way things worked in our world, since the author was not bound by that in the world of the story. As it happens, the creation of locked genes has been demonstrated in insects; but for now that technique does not work as well in higher animals.

The laws of nature in the Honorverse are not exactly those of our world, in some cases they are quite different. But if they are applied consistently, then we can argue about whether something (such as perpetual motion) is within the author's boundaries. Note that sails drawing energy in a gravity wave is not an example of perpetual motion, since it will stop with the heat death of the Honorverse.

Jonathan_S wrote:We don't get much detail about how the tractors work, but we know it needs at least 3 rows of them to work properly; and I'd assume that's because each can only pull in a straight line -- so to go forward you'd need to pull at least trilaterally so there was no net sideways force, only a net forward force. (But even to get that the angle of the tractor beams needs to be able to change, at least somewhat. If the angle couldn't change then attempting to pull forward would fail because you can't tow yourself forward from fixed points without shortening the beams - but shortening beams that are projecting somewhat off to the sides means changing the geometry of their angles.

It might not be. My theory is that two sides would have been enough to get movement, but three is better and four is overkill. Your own explanation would allow for moving with just two, because they are parallel to each other. But it might be unstable, because no system is perfect, so it requires more work / energy to keep it going.

Three is probably just the most efficient design, because each tractor is additional mass and cost. You may get a more energy efficiency per tractor with four sides, but the added mass and/or cost makes the total operating cost lower than three sides.

I'm basing this on the three phases of electricity we use. There's nothing preventing a tetraphasic or hexaphasic design, but triphasic is just the most efficient one.

I have no idea how long the tractor is. We know it has "insanely short range" for a weapon; less than a grav lance (so presumably below 100,000 km). But we don't know how much less. It could well be much shorter than 150 km -- however 150 km is far an SD is inside it's wedge; so my point was if it was 150 km (or less) then spider ships should be able to operate in (at least) as close a formation as SDs do.

BTW, I wasn't talking about ships flying in formation like SDs do. I was thinking of ships being insanely close to each other to block each other's heat exhausts and capture that energy, as cthia was suggesting. This isn't in the range of 100 km; this is going to be less than 1 km.

That's why I said "like a train."

ThinksMarkedly wrote:It might not be. My theory is that two sides would have been enough to get movement, but three is better and four is overkill. Your own explanation would allow for moving with just two, because they are parallel to each other. But it might be unstable, because no system is perfect, so it requires more work / energy to keep it going.

If we assume that the tractors on the spider stick straight away from the ship with an angle toward the front, then you would need three sets in order to maneuver in three dimensions. Two sets on opposite sides of the ship would only allow you to maneuver in a plane.

tlb wrote:The laws of nature in the Honorverse are not exactly those of our world, in some cases they are quite different. But if they are applied consistently, then we can argue about whether something (such as perpetual motion) is within the author's boundaries. Note that sails drawing energy in a gravity wave is not an example of perpetual motion, since it will stop with the heat death of the Honorverse.

Right, there's a difference between drawing energy from a source we don't have access to (we have no idea if it even exists) and therefore have no idea how it would work, and a perpetual motion machine or, worse, a machine with efficiency above 100%.

We can try and poke holes at whether the laws as presented even make sense. The case of Zero-Point Energy as shown in many a Sci-Fi universe (like Stargate) is a case in point. It helps that currently Quantum Physics and Relativity disagree on the value of the vacuum energy by 120 orders of magnitude.

My Honorverse version of this are the wedges. If it's so insanely easy and cheap to accelerate things out of gravity wells, then you can generate power with them too by dropping weights down gravity wells. Star Trek transporters would be too: transport water uphill or weights to orbit, then generate power by their acceleration back down to the planet.

This may be splitting hairs for some. For others, it's part of what attracts us to the stories.

It sends the waste heat out the tractors to hyperspace.

tlb wrote:If we assume that the tractors on the spider stick straight away from the ship with an angle toward the front, then you would need three sets in order to maneuver in three dimensions. Two sets on opposite sides of the ship would only allow you to maneuver in a plane.

You could always use thrusters to change the ship's attitude and thus change your plane of acceleration. But I as thinking that the tractors actually have a 3D cone of attack so they could change the direction vector with the spiders.

However, this would not be as efficient as having 3 keels and therefore the ability to change the vector by changing the intensity of the tractors instead of their angles. In fact, if you don't need to gimbal the tractors for direction control, then the tractors should be cheaper / less massive too. Going from 2 keels to 3 might mean 50% more tractors, but a much smaller fraction of increase in mass. You would get no such comparable reduction when going from 3 to 4.

kzt wrote:It sends the waste heat out the tractors to hyperspace.

Well, sure, that's the "gravity sump" trick for the compensators. But it doesn't seem like this is possible because we know the ships do have waste heat in n-space.

It might become possible in the future.

ThinksMarkedly wrote:My Honorverse version of this are the wedges. If it's so insanely easy and cheap to accelerate things out of gravity wells, then you can generate power with them too by dropping weights down gravity wells. Star Trek transporters would be too: transport water uphill or weights to orbit, then generate power by their acceleration back down to the planet.

This may be splitting hairs for some. For others, it's part of what attracts us to the stories.

Do you mean the wedge or contra-gravity? It is easy, because of the magic batteries that power contra-gravity trays and pulsers and so on. I hope it is not a plasma capacitor. Being easy is not the same as energy free, we can presume that there are power requirements.

Star Trek transports actually use energy (hence the word "Energize"), so you are not going to generate excess energy that way.

Can't use thrusters. Thrusters will be visible.