Sunday, April 16, 2017

Frigates of EVE: A New Physics Model



 Like many of you, I will be ordering the "Frigates of EVE" book from the EVE-Online store. Max's talk about the PEG at FanFest is here.  As many of you know from communicating with me in person, I have not participated in lore discussions, as I only work with models that have predictive value -- having a story about how it fits into the history of the game has been a secondary consideration.  Having said that, I had a few brief thoughts on this, since it involves the physics of EVE and I am notorious for working and writing on this subject. 

 First, based only on the presentation at FanFest we have learned that anything that warps, cloaks or is anchored in New Eden is powered by one or more power enhanced generators (PEG) which each create a 'subspace singularity'.  The details may be more carefully revealed in the book, but I infer that acceleration or anchoring effects arise from either a relativistic mass effect or from an interference pattern that can be tuned to either constructive or destructive interference.  Of course, I will wait to read the chapter itself before deciding if I add any value to the communication on this model.  

 Second, the model does not alter the first-order differential equations that govern ship motion which I presented in Chapter I and in all my subsequent blog postsThe justification for the 'inertia' coefficient now is explained by the presence of a subspace singularity.  Thus, drag is produced on any EVE ship that can warp and/or cloakNone of the applied physics work that I have presented will need to be fundamentally revised, although changes to vocabulary would be helpful for lore enthusiasts.  We can still use all of the tools that I have presented and developed to analyze subwarp ship motion and ship-to-ship interactions like orbits and bumping.  

 Third, the presentation of the PEG model is encouraging because it shows that CCP recognizes the importance of the physics model that underlies ship motion in EVE online.  They have invested in explaining the root cause for its most distinguishing phenomena and are committed to itWhat attracts me to the classical explanations of EVE's model is that it lends itself well to predictive models, player intuition and the many tools that have been developed for linear systems analysis.  If this PEG model makes EVE's linear drag mechanics palatable to the lore community by explaining why there is maximum velocity for certain objects in space, then I am enthusiastic about receiving it.  

 Finally, the model presented at FanFest 2017 answers some questions about how the New Eden universe works but it also raises questions and opportunities for future additions to the game.  One of the obvious opportunities that has presented itself is to imagine ships that do not include any PEGs and therefore do not produce a subspace field.  Such ships would be limited only by the speed of light, or whatever other governing particle/energy is constituent to New Eden.  I do not yet know if this is discussed in the Frigates of EVE physics chapter, but I certainly hope we consider this opportunity.  I discuss some of the properties of such ships belowI look forward to this addition to EVE.  


PEG-Free Ships
 Imagine the interesting role such ships would play.  While these ships would not be able to warp or cloak, they could be launched from stationary structures, citadels or even large ships.  They would have finite capacitor energy but they would be able to accelerate continuouslyIf we assume relativistic effects for the motion of such a craft, their maximum velocity would be limited only by the speed of light, and the amount of energy that you could carry in the form of fuel.  You would not be able to pilot them with a pod because pods include PEG devices.  A cockpit would certainly be possible, or they could be piloted by a drone computer of some sort.  It seems that this is likely the motion model for the Valkyrie ships?  During the Paschal holiday, I took a few moments to think about the energy bounds of these hypothetical PEG-free ships.

Without an infinite source of energy, we have to imagine that such ships would have to carry their energy with them.  They cannot rely upon the infinite PEG energy that slowly recharges a capacitor.  Lets also suppose that we wanted them to carry armaments comparable to a frigate, requiring it to be a similar mass to a frigate and similar energy requirements.  With finite fuel limitations, EVE pilots would want to use such ships for tackling ships near stations and other deployment locations.  So, the capability to use warp scrambling and webbing technologies would be desirable.  

The most energy dense fuel I can think of today is antimatter.  I wont go into ideas on how you could make use of antimatter for propulsion and self-containment at this time, but I am confident that 23,000 years from now these issues would be have been well addressed.  So, we have a ship with a mass of 106 kg, that needs the energy to accelerate continuously for, lets say, an hour of flight time before docking to refuel.  


Now, I'm not advocating that PEG-free ships be able to approach the speed of lightAs readers are no doubt aware, reaching velocities approaching the speed of light begins to require an exponential more energy (see Figure 04-17-a).  I have highlighted the 6000m/s datapoint on the figure to show that there is significant region to improve EVE ship velocity without requiring ship mass to be overwhelmed with antimatter fuel mass requirements. 

Figure 04-17-a: Energy needed to accelerate an object with mass 106kg to a velocity, v.  Note that for velocity to reach the speed of light, you would need infinite energy, which is not shown.


Figure 4-17-b: Mass of fuel needed to accelerate a mass of 106kg to relativistic velocities is shown.  Achieving 10% to 20% of the velocity of light could be done without impacting overall ship mass. 



Figure 4-17-b above shows that we can achieve millions of meters per second in velocity powering our frigate propulsion with antimatter annihilation instead of with PEGs. I am willing to concede that antimatter containment and propulsion are constrained by thermodynamic efficiency limits even 23,000 years from now, but even with less than 50% efficiency the total fuel mass is plausible for a PEG-free frigate. As an aside, if such a frigate were limited to the fuel energy density of today's technology, i.e. liquid hydrogen with 142MJ/kg, the mass requirements for relativistic velocity would be staggering and unworkable.


So if we aren't practically limited by maximum velocity, might we be limited by maximum acceleration? Lets assume the rate of acceleration is limited to the highest acceleration of the most agile ship in EVE, which recently was a microwarp drive fitted Dramiel capable of roughly 100G acceleration. Of course, depending on how long your memory is, you know that ships in EVE actually have had much higher accelerations in the distant past.  In the age of speed-fits, prior to the Dominion rebalance, dedicated interceptor fits could achieve 800G of acceleration, with a top speed of 24,000m/s. So, we know that velocities in that range are workable in the EVE engine. 

In my October 2015 poast, I updated the notes on fundamental limitations of orbits. In that note, I showed that close in orbits are limited by acceleration, not velocity, so deploying a PEG-free frigate for high angular velocity tackling would be far superior to PEG ships. For on-grid tackling near stations or capitals, PEG-free ships would be unmatched for tackling or skirmishing. Sustained acceleration of 800G would allow a orbit angular velocity of 3 radians per second, an order of magnitude higher than we can achieve with existing PEG ships.

From a lore perspective, you might imagine that the fluid in a pod could protect the pilot from acceleration to some degree. Indeed, if the fluid inside a PEG-fitted pod can protect a pilot from this sort of acceleration, we can imagine a PEG-free pod that would provide similar protection. Experiments on humans did not reveal a specific short-term acceleration limit for the human body. I suspect that the many years of technological development and modifications of the body that are inherent in implants would have vastly extended the capability of a pilot's body.

In summary, now that we know how PEG ships work, I look forward to the inclusion of PEG-free ships to EVE. I for one will be purchasing the Frigates of EVE book, and reviewing the motion model chapter with keen interest in places where we can make predictive improvements in how ships behave in strategic situations. If the physics chapter includes a proposal for PEG-free ships, then I will consider this model complete.

I hope you have enjoyed these quick thoughts about Frigates of EVE and the physics model presented at FanFest 2017. My next post will be the first of a two-part offering that explores a very different topic in EVE, one that is not related directly to motion or applied physics but instead asks how we make decisions in combat. Thank you for your readership and for comments on this work.


 
S. Santorine



 

(Just another link,
 to make you think,
 about exhaust versus thrust.