Saturday, September 12, 2015

Part I: Introduction to Objects and EVE's Motion Model

Dear Readers, 

Over the coming weeks I will be transitioning my notes to a blog format at  Old content will become static, and new content will be transitioned to posts labeled to identify category of development.  This will enable new readers to comment on the articles and I will be able to respond to questions.  Those of you who have editorial access to the original version will continue to be allowed to comment there but I will post drafts to this blog to give everyone early access.  I will also be expanding my writing to include commentary on several other topics in the gaming community and music.  I hope you continue to enjoy this material.  

Warm regards,

S. Santorine, Ph.D.

p.s. I know that some of the equations were clipped and distorted by the embedding.  I will fix these as soon as possible.  Thank you for your patience.


  1. Hi,

    One part of this article makes me a bit surprised (perhaps my understand of used wording is off), essentially:

    Define Base Cruising Speed to be maximum ship speed without the aid of active modules such as micro-warp drives or afterburners. This speed has an aphysical aspect to it, namely that it is unaffected by mass. If, for example, you add overdrives and plates to a ship, only the overdrives affect the base cruising speed. This is nonintuitive because if EVE ships had a fixed thrust, their base speed would be affected by adding plates (mass) to the ships.

    But adding any amount of mass to a ship (whether EvE or just a generic body with fixed thrust force (that doesn't influence the mass itself) and linear drag froce) will never change its maximum speed. It will take more time to accelerate obviously, but the speed remains unaffacted.

    In context of simple EvE model, overdrives modify Vmax (so implicitly they change that ship's fixed thrust). Plates just add mass (implies slower acceleration, but thrust (and Vmax) remains the same).

    How is this aphysical or unintuitive ? It follows v(t) = F/σ(1-e^(σ*t/M)) precisely, where F would be fixed thrust, M any mass and s drag factor.

    1. Dear Unknown,

      I appreciate the notes and correction. I have updated Part I of the notes and highlighted the changes with blue additions and red strike-out deletions. You are right that changing the mass of the ship does not change the velocity, and my note now states this.

      On the other hand, I did add a paragraph discussing the 'inertia stabilizer' module and how the Force-Mass-Drag model doesn't quite fit with assumptions about ship thrust.

      Thanks again for the note, and let me know your thoughts on the changes.



  2. Dear Unknown,

    Thank you for your close look at this portion of the writing. I have to go back through this and make sure, but I think you are correct! I claimed that mass was aphysical for base velocity because I believe that there was a time when adding plates *changed* base velocity. Or perhaps I was referring AB/MWD velocity? I will review this over the coming weeks, produce a correction to the notes, and update the community. Thank you again for your readership and I hope you will continue to read.


    S. Santorine