Energy Dissipation

It's all downhill but sometimes by interesting routes


Here's an example of the effects of conservation of angular momentum. Consider an object orbiting the Sun about where the Earth is. If you want to put the object into the Sun, you'd think that just aiming toward the sun and turning on the rockets would be enough - but it's not. Because angular momentum is conserved, the closer the object gets to the Sun, the more its path tends to divert away from the Sun. In the rotating frame of reference, this manifests as an effective potential energy wall that goes to infinity as the orbiting object approaches the Sun. In order to crash the object into the Sun, it's necessary to use the rockets to decrease the object's angular momentum - or, rather, to transfer angular momentum from the object to the rocket exhaust, so that the object ends up in the Sun, while the exhaust ends up in a higher orbit (or escapes the sol.

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