Posted on 03/28/2006 12:09:01 PM PST by orionblamblam
Echo of the obvious.
"The coordinate system used in this tutorial has its origin at the center of Earth. In this coordinate system the Sun goes around the earth, contrary to what you may have heard. There is actually no harm in this viewpoint, since the origin of coordinates can always be whatever is convenient. It is true that Earth would be an awkward origin if we were interested in the motion of other planets (since they have complicated orbits in Earth-centered coordinates), but the planets do not sensibly affect Earth satellites, the subject of interest here, so the center at Earth will do fine."
The coordinates are for the orbiting satellite, not for the rotating earth.
> The coordinates are for the orbiting satellite, not for the rotating earth.
Sigh. Well, if you want to continue bleating out your dishonesty *and* staggering lack of understanding of basic launch dynamics, go ahead. I'll sit back and watch. I'll be particularly interested in how you go about determining launch elements *without* incorporating the Earth's rotation.
Go ahead, work it out.
I'll wait.
Note post 282. A constant moving of the goalposts, just as we've seen with the IDers.
Ah, well, there's always the entertainment value of their self-parody. So, now some of the Creationists have backed up the barge back to geocentrism. I can't wait until they decide the Earth *really* *is* flat, and that the sun sinks in the mud every night.
Here's another one.
http://www.du.edu/~jcalvert/phys/orbits.htm
Clearly, 'surface-to-space' intercept are calculated from a fixed-earth center point.
The deception comes from switching from an initial position where you argue that the earth orbits the sun to a position where you argue that the relative rotation of the universe and the earth (which are interchangeable as a point of reference) is your point.
So, we can assume that you acknowledge that 'surface-to-space' intercepts are *not* calculated using a heliocentric model, but rather use the fixed-earth center as the reference point. There is really no reason to add the earth-sun orbital calculations to the problem.
As for whether the calculations propose a rotating earth or a fixed earth with a rotating universe, one only need reference my post on Foucalt pendulums to see the illogic in that position. In either case, the calculations are the same. You merely add or subtract the relative rotation from your point of origin or your destination point depending on your perspective. There is no real difference in those calculations.
If that is your claim to 'difference' from a geocentric model, then there is none. You have merely shifted your argument to one that is consistent with geocentricity without anyone else noticing.
Yup, moving the goal posts. Your dishonesty is again noted.
I'd be interested to see what the big boys have to say.
(no offense intended to any other posters here, the people at BA have almost infinite patience and love to debate this stuff)
I am not the one who moved the goalposts, you are. And you did so very disingeniously, I must admit. I didn't even realize it the first few interations of this discussion, but I do now so the point will continue to be made.
You then, must make a positive statement that 'surface-to-orbit' intercepts are calculated using a heliocentric model in contrast to the links I posted showing that the orbital position of the sun is not part of those calculations.
Otherwise, my position that orbital calculations are made using a geocentric assumption stands, regardless of the relative motion red-herring that you insist on introducing to the discussion.
Your next move is also obvious to me. Please proceed, if you know.
I already perused that forum and noted that 'surface-to-orbit' calculations have been admitted as being 'earth-based' only. The orbital position of the sun is irrelevant to these calculations, as I said.
Link to this statement please?
"The equations & physics used by NASA to launch satellites & interplanetary probes are identical to the equations derived from a geocentric universe. All are planned & executed on the basis of a FIXED EARTH! They do not use the Copernican System! You can confirm this with them & the National Oceanic & Atmospheric Administration in Washington DC!"
"True, but that doesn't make geocentric coordinate systems more valid than heliocentric, or even joviocentric coordinate systems. It's just more convenient, in much the same way it's convenient to think of the night sky as Earth-centered to simplify stargazing."
http://www.bautforum.com/archive/index.php/t-2529.html
The first paragraph is correct about satellites but not always correct wrt interplanetary probes. Even so, it is often correct and the only point of difference is which 'coordinate system' is chosen, not the calculations themselves. We were discussing earth orbits, not interplanetary probes, so the statement is correct for our purposes.
Don't know if you can understand that, but there it is.
> You then, must make a positive statement that 'surface-to-orbit' intercepts are calculated using a heliocentric model
Hogwash. neither I nor reality must accept your flawed notions.
However: with your sufficiently vague statement, I *can* make this positive statement: "Earth surface-to-Mars-orbit intercepts are calculated using a heliocentric model."
> Otherwise, my position that orbital calculations are made using a geocentric assumption stands, regardless of the relative motion red-herring that you insist on introducing to the discussion.
Hold up, son. Do you or do you not recognize that the Earth's rotation is require for surface-to-space intercepts?
* If you do not accept it: you're just dead wrong.
* If you do accept it: then you accept that the geocentric model completely collapses, as geocentrism has *nothing* going for it except for the illusion that "everything goes around the Earth." If it's demonstrated that that doesn't happen... geocentrism goes away.
So: which is it: are you wrong, or are you wrong? Or do you drop this silliness and recognize that the motion of the Earth - ALL the motion of the Earth - is required for basic orbital dynamics?
> relative motion red-herring
As anyone with any knowledge of practical launch vehicle prediction and trajectory optimization woudl point out to you (and then proabbly walk away shaking their heads, mumbling about the tragic state of the educational system), this "relative motion" that you try to ignore is not a "red herring," but an integral part of the equation.
So: where will you rest the goalposts to *this* time?
> Perhaps you would like to post your theory at the Bad Astronomy forum.
Perhaps we should direct him to Crank.net instead. He'd find links to many friends there...
If the universe is rotating about a fixed earth, wouldn't it have to be moving awfully fast?
If you just take the nearesr star, which is about 4.3 light years away, it would have to travel over 72 trillion miles* in 24 hours.
*I used 6 trillion for a light year, and multiplied pi times the diameter (2 x 4.3 light years)
I already perused that forum and noted that 'surface-to-orbit' calculations have been admitted as being 'earth-based' only.
You then post the response from ONE geocentrist as proof that the forum admits something.
I guess it is easy to ignore the posters who disagreed with him.
The first paragraph is correct about satellites but not always correct wrt interplanetary probes.
Gee, and why would that be?
Quite a difference.
Not to mention the silliness in believing that such a massive object as the sun would rotate about a minute object such as earth.
Every orbital system we observe has less massive object orbiting more massive ones. Why would this one be different?
"However: with your sufficiently vague statement, I *can* make this positive statement: "Earth surface-to-Mars-orbit intercepts are calculated using a heliocentric model.""
It's perfectly clear by now that you are the one who moved the goalposts when you said 'surface-to-space' intercepts are calculated from a heliocentric model.
If you move from the earth's 'surface' to 'space', then that intercept clearly ends when you first reach 'space' and those are clearly calculated using a fixed point within the earth.
Now you change the terms to 'surface-to-interplanetary' which is a different thing in terms of where you set your coordinate system, not which calculations you perform.
But you are safe. Most people can't tell the difference, but I can.
You are confused here. There is no way to tell absolutely which is rotating, the earth or the universe. I explained that previously with my foucalt pendulum example.
Therefore, any opinion as to whether the earth or the universe is doing the rotation is just than, an opinion and only the relative rotation goes into the calculations, not some absolute earth-based rotation.
Wouldn't what have to be moving awfully fast?
The star is not moving that fast, so no problem w/ 'c' there and 'c' does not apply to the universe itself. Only to objects in the universe.
Is that what you mean?
It wasn't a geocentrist who agreed with the geocentrist.
You also have to be able to understand what those who appear to disagree are really saying and exactly where they are disagreeing, in totality or in just a narrow way.
You missed it.
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