Originally Posted by
Hokulea
Dave - I've been on flights where the ground speed varied from 450 to 650 knots. There was no feeling of acceleration on any of those flights other than take off, ascent, descent and landing. I suspect you have your physics wrong if you think anyone on an aircraft will feel a change in velocity because it changed wrt to the ground during the cruise. The frame of reference is the aircraft, not some point on the ground.
I do have a little bit of background in physics if you had taken the time to do a little research. It's a shame; I've asked for help on this site and also offered my advice on this site, but to come across someone who 1) didn't read my posts carefully and 2) doesn't understand Newtonion physics but insults me anyway, well, that's your choice.
For the record:
1) I have read your posts carefully
2) I did not insult you, I simply pointed out that your denial ("that is absurd") of my statement that
"If you felt a deceleration (i.e. the effect of inertia), all that tells you is that your speed over the ground was reducing."
is incompatible with Newton's Laws (with which I, too, have more than a passing aquaintance).
In fact you appear to have conceded that you will feel those forces on takeoff and landing, where again it is the change in speed of the aircraft over the ground that produces the sensation you feel. The only difference between that and acceleration/deceleration in the cruise is one of degree - the physics is exactly the same, only the numbers differ.
You go on to misquote me
"you have your physics wrong if you think anyone on an aircraft will feel a change in velocity because it changed wrt to the ground during the cruise"
when I actually said that IF you feel a sensation THEN it's because the aircraft's speed is changing, not the other way round (I grant you that the sensation may be imperceptible).
I'll give you the benefit of the doubt and assume that wasn't an intentional straw man argument, but I stand by my comments.