Dear Forum, I am filmmaker from Berlin and despite physics focus back in high school I am really bad at it. I am trying to get my head around some ideas I am working on and would kindly ask you for some tiny calculations. I hope this is OK and maybe even fun for someone here? So my questions are: The earth spins at a speed of 465,1 m/s (A) at the equator, right? How fast would the Earth spin at the equator if it would be tidal locked to the Sun (B)? If the negative acceleration from A to B would take 20 years how many m/s slower the Earth would spin in a year? Would the negative acceleration be linear or exponential if one passing object would "steal" the rotational energy through its own gravitational force. Like the moon does for example but much heavier of course. What mass would such an object need to decelerate the Earth like this if it passes let's say about the distance of the moon? I know it is nonsense. But fun to think about it! I thank you so much.