> Playing time backwards long enough would see the earth disassembled into rocks, dust and gas, repelling each other and indeed flying off into <far away>.
No, playing time backwards long enough would see a hot earth exploding into rocks, dust and gas that are attracting each other - just the initial velocity is large enough and attraction is not strong enough to stop them from flying out into <far away>. They would be slowing down when flying off, not accelerating as if they were repelling each other.
They would then be joined by the dissolving sun and form a cloud of dust which some time later (i.e. earlier) would converge (because the dust is attracting itself) into some earlier massive star(s) out of whose remains our solar system was formed.
If an asteroid hits the earth, the gravitational potential energy (of an attractive gravity) gets turned into kinetic energy as it accelerates when approaching the earth and afterwards into heat as it impacts it; playing time backwards, the heat gets turned into kinetic energy, which then gets turned into gravitational potential as it distances itself from earth.
No, playing time backwards long enough would see a hot earth exploding into rocks, dust and gas that are attracting each other - just the initial velocity is large enough and attraction is not strong enough to stop them from flying out into <far away>. They would be slowing down when flying off, not accelerating as if they were repelling each other.
They would then be joined by the dissolving sun and form a cloud of dust which some time later (i.e. earlier) would converge (because the dust is attracting itself) into some earlier massive star(s) out of whose remains our solar system was formed.
If an asteroid hits the earth, the gravitational potential energy (of an attractive gravity) gets turned into kinetic energy as it accelerates when approaching the earth and afterwards into heat as it impacts it; playing time backwards, the heat gets turned into kinetic energy, which then gets turned into gravitational potential as it distances itself from earth.