So, if the alleged orbital speed of the Earth isn't great enough to cause shift of the Sun's position in the sky (in 24 hours) for more than just one Sun's diameter, then what consequences we should expect from incomparably slower alleged rotational motion of the Earth?
Is he trying to claim that all points on Earth won't travel 360 degrees in 24 hours?
I don't think so. I think I understood what he is saying. Rotational velocity is slower than orbital speed therefore orbital speed should have greater effect on positions of things around earth from earth. Why he thinks this is beyond me.
Maybe because 108 000 km per hour is 413 TIMES greater speed than 261 km per hour?
Perhaps (it's really closer to 414, but, whatever...), but so what? Tangential velocities, even if they seem "big" on a human scale, mean virtually nothing when great distances are involved, as here. Angular velocity does matter, always. That 261 km/hr tangential velocity at somewhere near the poles rotates you through 360° in 24 hours. That 108,000 km/hr rotates you only 1° around the Sun in those same 24 hours. 360° is
360 TIMES 1°. Which do you think will be more noticeable?
A human being is on earth and rotation causes the angle at which you see the sun to change.
A human being is on earth while hurtling around the Sun also, and why would orbital speed of the Earth (which is 413 TIMES greater than rotational speed) be less noticable than it's rotational speed? Do you really think that due to the geometrical difference between linear and circular motion, we should perceive apparent motion of the celestial objects in such drastically different manner?
Yes. It really does work that way.
Modern astronomers claim that their ancient predecessors could not have noticed stellar parallax through centuries, due to enormous distances between the Earth and the stars, doesn't that help you to understand my point?
No. Stellar parallax requires large telescopes and fairly sophisticated equipment to measure because it's small. The ancients didn't have any of that.
When the Earth rotates, what kind of motion an observer (which is placed let's say at the Equator) makes with respect to our stationary and 150 000 000 km distant star (the Sun)?
He is in fact submitted to the linear motion (from right to left), isn't he? Is this kind of motion geometrically any different comparing it with orbital motion of the Earth and with the perspective of a hypothetical observer who stands at the North Pole and watch the Sun while hurtling 108 000 km per hour?
There is no mystery here if you know a little trig. It's easy enough to calculate.
The equatorial radius of earth 6378.1 km and the perihelion distance 147,098,290 km. [nb]
http://en.wikipedia.org/wiki/Earth[/nb]
The parallax angle would be
a = 2 tan
-1(6378.1 km / 147098290 km)
= 2 tan
-1(4.3359 X 10
-5)
= 2 * 0.0024843°
= 0.0049686°
= 17.887 seconds of arc. After 12 hours.
Meanwhile, the sun is moving across the sky at about (1/4)° (900 seconds of arc)
per minute due to rotation of the Earth, and against the background stars at about (1 / 1440)° (2.5 seconds of arc)
per minute due to the motion of the Earth in its orbit. So the parallax in 12 hours is much smaller by a factor of
50 TIMES than the apparent motion in 1 minute. This will be pretty hard to detect unless you're really looking for it and have very good equipment.
Same goes for zenith stars!
What about Zenith stars? Stars are so far away that parallax due to the 150,000-km orbit of the Earth isn't detectable without good equipment; parallax due to the 12,756.2-km diameter would be totally lost in the noise with even the best equipment.
Regarding circumpolar constellations i have to ponder on this subject for a while...
Ponder if you want. They've been well understood for centuries if not millennia. I doubt you'll come up with anything that works better than a spinning spherical earth. Even if you do, you'll have to see how that agrees with other observations.
I've been away for a while. What's all this about a ZIGZAG model?