From the link - "Isaac Newton had a cause for acceleration (force) but none for inertia." Funny, because physics explains that all objects of mass have inertia

From the link - "Isaac Newton had a cause for acceleration (force) but none for inertia." Funny, because physics explains that all objects of mass have inertia. Heavy objects traveling at speed have inertia. Faster speeds? More Inertia. Heavier objects? More inertia, and we can calculate inertia : I = mr2. I doubt that this author has any credibility for anything related to physics.