Deriving gravity, orbits, time dilation, and planetary behavior from mechanics alone
This series demonstrates how many quantities normally treated as fundamental—surface gravity, escape velocity, orbital speed, planetary shape, gravitational time dilation, and the apparent constancy of G—can be re-derived from density, stiffness, and geometry alone.
No force laws are assumed. No new constants are introduced. Each post uses real planetary data and mechanical reasoning to show how familiar physics emerges as a material response of a continuous medium.
Why G Appears Constant Locally (and When It Might Not) SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? 10.6 — Why G Appears Constant Locally (and When It Might Not) If gravity is a material response of a mechanical medium, a natural objection arises: Why does […]
SERIES X: Post 6 – Why G Appears Constant Locally (and When It Might Not) Read More »
Why Time Runs Faster on Mars (Revisited Mechanically) SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? In an earlier post, we noted a striking empirical fact: Clocks on Mars run faster than clocks on Earth. The difference is small—hundreds of microseconds per day—but it is real,
SERIES X: Post 5 – Why Time Runs Faster on Mars (Revisited Mechanically) Read More »
Why Small Bodies Are Spherical (and When They Aren’t) SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? Look across the solar system and a clear pattern appears: This transition is so consistent that it even has a nickname: the “potato radius.” Why does nature draw this
SERIES X: Post 4 – Why Small Bodies Are Spherical (and When They Aren’t) Read More »
Orbital Speed from Stress Balance, Not Attraction SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? If gravity is not a force pulling inward, and escape is not about overcoming attraction, then a deeper question follows: What does it mean to orbit at all? In the standard
SERIES X: Post 3 – Orbital Speed from Stress Balance, Not Attraction Read More »
Escape Velocity Without Force Laws SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? Once gravity is reinterpreted as a stored stress in a medium, a familiar quantity takes on a very different meaning: What does it mean to “escape” a planet? In the standard picture, escape
SERIES X: Post 2 – Escape Velocity Without Force Laws Read More »
Why Surface Gravity Depends Only on Density and Radius SERIES X — RECOMPUTING PHYSICS FROM FIRST MECHANICS What Can Be Derived from Density & Stiffness Alone? One of the quiet surprises of planetary science is how simple surface gravity really is. Despite very different compositions, temperatures, and histories, the surface gravity of a rocky body
SERIES X: Post 1 – Why Surface Gravity Depends Only on Density and Radius Read More »
