I'm not part of any group or organization.
when i thought about inertial frames, i concidered the GAPS between the frames, they should be constant in size or width.

its NOT TIME & SPACE but the SPACE BETWEEN TIME..
Everything moves through time but at different speeds or acceleration.

4 dimentional ==== SPACE in this example equals this room.

------- ME **moving frame to frame faster giving the ability to move around CHAIR.
------- ME **moving UP & DOWN between the chairs frames-------------------
frame>>>(12/24/2000 @ 10pm)>>>frame ----CHAIR moving slower frame to frame ----
frame>>>(12/24/2019 @ 10pm)>>>frame ----CHAIR moving slower frame to frame

ME and CHAIR occupy the same SPACE & TIME but at different speeds between frames