[lafroste]

Thus, mass is not conserved. I expect you’ll have a tough time reconciling your theory with this.

Actually, not really. My theory also claims that mass and energy are different facets of the same thing (steam and ice). Any mechanical machination to inter convert them is fine with me.

[aNYCguy]

My theory also claims that mass and energy are different facets of the same thing

This is exactly what Special Relativity holds. Your theory doesn't conserve mass, so you might want to leave out the eyebrow-raising claim that your theory conserves mass in the future.