An admission + asking JohnMartin for some help

[Yttrium]

Think about it. If a man stands on the equator and sees stars (X) and geosynchronous satellite (A) at 23:00 in January . Then six months later a man stands on the equator at the same location on earth at 23:00, he will see stars (Y) and geosynchronous satellite (A). Stars (X) and (Y) will be 180 degrees apart. So too the geosynchronous satellite will initially have its rear face stars (X), then six months later have its rear face (Y). As the geosynchronous satellite has turned 180 degrees in 6 months then the geosynchronous satellite has twisted in space. The twisting in space requires a torque not accounted for in the Newtonian model.

So you just completely ignored what I said about Earth's rotational period, then. I'll just chalk that up to your cognitive dissonance.

Add Time of Day to the cluelessness list.

[JohnMartin]

I've thought about it, and concluded that you are a blithering idiot who has forgotten that the Earth rotates the satellite has a different orientation after six months because the satellite reverses orientation twice every stellar day, and you have pictured the satellite after 182.5 stellar days so it will obviously have the opposite orientation then.

The satellite reverses orientation once every stellar day, and the satellite reverses orientation once every six months. The satellite orientation change every six months due to the earth's orbit around the sun means the satellite must twist in space. The extra twist will be accounted for by using an extra barycenter at the center of the sun. But then again, the sun barycenter is ignored in the geosychronous satellite orbit design. The lack of using the sun barycenter in the satellite design means the satellite orbit must require an extra force acting to cause the torque in the satellite that rotates the satellite 180 degrees in space every six months.

JM

[JohnMartin]

So you just completely ignored what I said about Earth's rotational period, then. I'll just chalk that up to your cognitive dissonance.

Add Time of Day to the cluelessness list.

You said -

The Earth's rotational period is not exactly 24 hours. It's 23 hours, 56 minutes and 4.1 seconds. (We have the same time facing the Sun each day because the Earth is moving around the Sun as it's rotating.) By the time the Earth gets to the exact opposite side of the Sun, there's a difference of 12 hours, facing the observer away from the Sun.

The time difference is only a time marker that implies the satellite must rotate in space 180 degrees every six months. So where is the force that does this rotation to the satellite? Gravity doesn't do it, because gravity is focussed on the satellite center of mass, and the force causing the rotation must be offset from the center of mass. Each day the difference in solar and sideral days indicates the satellite must rotate on its own axis about 1 degree in space, for the satellite face to remain directed towards the earth, yet there is no force acting within the satellite to cause the daily twist, which accumulates to the satellite twisting 180 degrees on its own axis over 6 months.

JM

[JohnMartin]

Ah, yes.

Makes sense.

Sorry, JohnMartin - let's not overdo the problems for them.

Unless you meant : what makes the satellite turn twice every stellar day?

No, what makes the satellite turn on its own axis about 1 degree per day, which accumulates to about 180 degrees over six months? The satellite must twist in space as the earth orbits the sun, otherwise the satellite will not have the same satellite face directed towards the earth at the same solar time every day. This is especially important for geosychronous satellites, that remain over the same point on the earth all through the year.

JM

[Sparko]

No, what makes the satellite turn on its own axis about 1 degree per day, which accumulates to about 180 degrees over six months? The satellite must twist in space as the earth orbits the sun, otherwise the satellite will not have the same satellite face directed towards the earth at the same solar time every day. This is especially important for geosychronous satellites, that remain over the same point on the earth all through the year.

JM

The only "twisting" is throughout the actual 24 hour day, the satellite has to keep the same face pointed toward the earth so that it can align with the ground station. That means the satellite rotates once every day (the same way the moon rotates once every orbit keeping the same face towards the earth) - and as the satellite does this once per day rotation, it does always keep the same face towards the same spot on the earth. No matter where the earth is in the yearly orbit. No other "twisting" is needed. Or the satellites can have a moving antenna that will rotate to align with the earth as needed. either way, your idea is preposterous.

[Roy]

Emphasis mine:

I've thought about it, and concluded that you are a blithering idiot who has forgotten that the Earth rotates the satellite has a different orientation after six months because the satellite reverses orientation twice every stellar day, and you have pictured the satellite after 182.5 stellar days so it will obviously have the opposite orientation then.

The satellite reverses orientation once every stellar day,...

Stupidity personified.

The extra twist will be accounted for by using an extra barycenter at the center of the sun.

I've never before encountered anyone who invents straw-man arguments that they don't understand themselves.

[JohnMartin]

JM demonstrates yet again his ignorance of gravity.

How so?

JM

[JohnMartin]

The only "twisting" is throughout the actual 24 hour day, the satellite has to keep the same face pointed toward the earth so that it can align with the ground station. That means the satellite rotates once every day (the same way the moon rotates once every orbit keeping the same face towards the earth) - and as the satellite does this once per day rotation, it does always keep the same face towards the same spot on the earth. No matter where the earth is in the yearly orbit. No other "twisting" is needed. Or the satellites can have a moving antenna that will rotate to align with the earth as needed. either way, your idea is preposterous.

You say - it does always keep the same face towards the same spot on the earth. Consequently when the earth moves around the sun for 6 months the satellite on one side of the orbit faces stars on a line X-Y, then on the other faces stars on a line Y-X, whilst always facing the earth. Hence the satellite must have twisted in space. The satellite twists in space is like that of the moons change in orientation in space. The change in direction of the orange shaded face of the moon indicates the moon is twisting in space.

mt1.jpg


mt2.jpg

The top picture has the moon face right, and the bottom picture has the moon face left. Hence the moon has rotated on its axis by 180 degrees over a period of about 15 days. Similarly the satellite will also rotate on it axis by 180 degrees over a period of about 6 months.

JM

[JohnMartin]

Emphasis mine:Stupidity personified.I've never before encountered anyone who invents straw-man arguments that they don't understand themselves.

The dwarf speaks again.

JM

[oxmixmudd]

You said -



The time difference is only a time marker that implies the satellite must rotate in space 180 degrees every six months. So where is the force that does this rotation to the satellite? Gravity doesn't do it, because gravity is focussed on the satellite center of mass, and the force causing the rotation must be offset from the center of mass. Each day the difference in solar and sideral days indicates the satellite must rotate on its own axis about 1 degree in space, for the satellite face to remain directed towards the earth, yet there is no force acting within the satellite to cause the daily twist, which accumulates to the satellite twisting 180 degrees on its own axis over 6 months.

JM

I already answered this. Satellites have a wide range of possible attitude adjustment technologies available to them. The exist because they are necessary. They are necessary because the satellites are in orbits around a rotating Earth which orbits the Sun - among other reasons.

Jim

[hansgeorg]

I already answered this. Satellites have a wide range of possible attitude adjustment technologies available to them. The exist because they are necessary. They are necessary because the satellites are in orbits around a rotating Earth which orbits the Sun - among other reasons.

And how many of these adjustment technologies exist for non-man-made objects like the Moon or Eris?

[Yttrium]

No, what makes the satellite turn on its own axis about 1 degree per day, which accumulates to about 180 degrees over six months?

You don't need to keep applying a force to maintain a rotation in space (outside of minor corrections once in a while). The satellites are set to a specific rotation. The moon is rotating.

[oxmixmudd]

And how many of these adjustment technologies exist for non-man-made objects like the Moon or Eris?

The moon is tidally locked. This same tidal force, accessed by extending a weighted boom from a satellite, is in fact one of the methods used to, as with the moon, keep the satellite pointed at the earth throughout its orbit and over the course of the Earth's orbit around the Sun.

Jim

[Sparko]

You say - it does always keep the same face towards the same spot on the earth. Consequently when the earth moves around the sun for 6 months the satellite on one side of the orbit faces stars on a line X-Y, then on the other faces stars on a line Y-X, whilst always facing the earth. Hence the satellite must have twisted in space. The satellite twists in space is like that of the moons change in orientation in space. The change in direction of the orange shaded face of the moon indicates the moon is twisting in space.

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[ATTACH=CONFIG]19977[/ATTACH]

The top picture has the moon face right, and the bottom picture has the moon face left. Hence the moon has rotated on its axis by 180 degrees over a period of about 15 days. Similarly the satellite will also rotate on it axis by 180 degrees over a period of about 6 months.

JM

a geosynchronous satellite rotates on it's axis over a period of ONE DAY, John. It orbits with the Earth's 24 hour rotation.