Comment by Gravityloss
Comment by Gravityloss 6 months ago
The point is that the gravity interactions are time reversible. Not so with friction etc.
Comment by Gravityloss 6 months ago
The point is that the gravity interactions are time reversible. Not so with friction etc.
You don't understand my point. If we watch purely gravity interactions, the video can be reversed and you wouldn't be able to detect it.
If a meteor crashes into the moon, there's other effects than gravity that makes the video not reversible. Ie it's not only gravity.
That's the point.
In other words, if a comet approached the moon at high speed, missed and slingshotted in another direction, it would be traveling away from the moon, but the video would be time reversible and you couldn't be able to detect it. Gravity only interaction.
I think you don’t understand my point.
Someone wrote “If you saw an apple spiral out of a black hole, wouldn't you suspect that you were watching a reversed video?”
I replied “If you saw a comet coming from the sun, or a meteorite coming from the moon, etc. you would also find that suspicious.”
I don’t know what part do you object to (if any).
> If a meteor crashes into the moon, there's other effects than gravity that makes the video not reversible.
If a meteor (or an apple) is still in a crashing trajectory when you stop recording there are no effects other than gravity. The video is reversible - it just looks weird when you play it in reverse (because the meteor seems to be coming from the Moon and the apple seems to be coming from the black hole if you try to imagine where they were before).
Well yes for example if there was a cannon firing an apple from the moon, then it would travel the same trajectory, just in reverse.
But we know there are no apple firing cannons on the moon.
Ie if an object was coming from the moon and its past trajectory intersected with the moon's surface, you could say "this is reverse video".
Sure, nothing in the laws of physics prevents a celestial body from distancing itself from the Sun or from the Moon. But it would like suspicious! Wouldn't you suspect that you were watching a reversed video?