You can throw a tennis ball to a friend on a moving train and it will behave as if the train is still.
Now try doing it when the train is going around in a circle, the ball will always end up to the left of where it should have landed.
In physics when something travels in a circular path it's angular velocity is constantly changing. The object may have a constant speed but it is constantly changing direction to get a circular path.
Going around a corner in a car at a constant speed still makes the passengers move to one side.
Yes, we do also have that force applied to us as we orbit the sun.
So if the earth is circling the sun it's angular velocity should be constantly changing so we should feel it
No.
In your image, the centrifugal force is clearly very great in relation to the very short distance. The centrifugal acceleration experienced by the kids on the carousel, people in the car, and the ball on the train are all influenced by the radius of the turn. Because that turn is relatively sharp, their forward momentum is preserved more by inertia so they exert more force away from the center, so centripetal force (seat for the carousel, seat belts for the car, nothing for the ball) presses just as much.
Their change in momentum is very noticeable because it's very sharp--and they feel it in the
pressure provided by the centripetal force's reaction. A physical presence is noticeable; we don't have any object directly pushing us and Earth towards the sun. In addition, if you traveled 100 miles per hour forward and decelerated backwards instantly, your guts would get jerked around everywhere and you very well could die. If it weren't for that tangible and/or particularly
sudden physical force, for example the kids being held in by their seats, it wouldn't be noticeable.
And anyway, we have a turning radius of 93 million miles and turn at a speed of 2*pi/365 radians/day. Earth's orbit is hardly sharp or rapid, astronomically speaking. In addition, every part of us is
uniformly accelerated in towards the Sun, so not one organ or nerve ending would feel any different regardless of how fast we accelerate.
That's a fine answer, but what exactly do you mean by:
"This means the weight of an average-size person weighing 700N at g0 (mass ~ 71.4 kg) would change from 700.42N at noon to 699.58N at midnight due to the acceleration of the Earth moving in its orbit. Would you expect to feel that?"
I don't think it's very clear.
This is the difference in gravitational force from the Sun depending on whether you're on the side of Earth facing it or facing away.
He said the weight changes from noon to midnight
There should be an experiment to measure this
Read his post. His point is that it's virtually unnoticeable. That's a tenth of a percent increase.