Generic EM Drive Information
This is a location for assorted information concerning EM Drives. Likely applies to all current experimental efforts.
Conservation of Energy Violation
Doctor White has proposed that the EM Drive is capable of producing constant thrust at a constant power output. User frobnicat has shown (in the following text and image) that if this were to be true, then the EM Drive could be utilized as a source of unlimited energy. [1] This of course constitutes a violation of Conservation of Energy.
"As often remarked : for any propellantless device yielding "given constant thrust for given constant power" (ie. a definite thrust/power ratio) there is a velocity relative to a power feedback loop system above which net power surplus can be generated (indefinitely, wear apart). This velocity is simply the inverse of the thrust/power ratio : V (m/s) = power (W) / thrust (N)." -frobnicat [2]
On the assumption that the results provided by the various experimenting groups are valid, then one of the following two options as provided by user deltamass[3] and clarified by user frobnicat [4] must be true. The options are as follows:
Option 1: Energy is conserved, but there is a preferred rest frame. In essence, the drive has a maximum change in velocity (a decreasing acceleration curve) that it can impart irrespective of its starting velocity. The idea of a preferred rest frame is at odds with general relativity.
Option 2: An apparent breach of conservation of energy is possible, where the mechanism by which conservation of energy is maintained is as yet unknown. An example of a possible solution to this problem is that the drive could in some way be emitting tachyons.[5]
Mode Shape
See calculations pertaining to the relationship between thrust and mode shape at Notsosureofit's post and Rodal's response.
The mode-shape to frequency relation is very sensitive to the exact geometrical dimensions of the cavity. [6]
