Hi Cougar

You stated the following.
"Snowflake, what degree do you have in what field? I'm not saying that people with advanced degrees are always right, but I'm saying that if you don't have a PhD in astronomy and you want to tell someone who does that he's wrong, you better first check all possibilities that it might be YOU who is wrong."

Facts are facts, BA is wrong in this case, he was hasty and made a mistake.

(I also have received in the past superior grades in at least as many advanced dynamic college courses in mechanics at both the undergraduate and graduate level as BA (most likely). (Engineering major, multiple fields.) The dynamics courses at the graduate level fall more into stability issues, but they also include celestial mechanics. This level of education is not necessary to describe acceleration or deceleration. The concepts are found in high school physics texts. )

Snowflake