I would also like to recall that energy conservation is connected to Poincare invariance, or the invariance of the physics laws under translations (which are part of the Poincare group). This is not "nothing" as you claim.

Well, the "nothing" part is derived logically from Hive account@pjheinz statement:

For energy, conservation is enforced by gravitational fields.

I followed the following logic:

1. gravity is considered to be a 'fictituous' or ' apparant force';
2. 'apparent' forces do not involve "any physical interaction between two objects";
3. gravity is therefore considered to consist of non-physical interactions between an object and the absolute nothingness of empty spacetime itself;
4. empty space time is "no thing", nothing.

Hence the sort version, completely in line with Tesla' s reasoning:

energy conservation is enforced by nothing

Regards,

Hive account@lamare