computerized telescope aiming question

Amateur/hobbyist telescopes have computerized aiming gadgets on them. You align the mount axis to parallel the earth's axis and punch in what you want to look at. My friend has one, I have seen this done. Punch in the moon, it points at the moon, it does that somehow, I have seen it.

Consider that at any moment at different places on earth, the moon is at a different angle, and it appears to move across the sky. The freely purchaseable telescope from multiple different manufacturers can be purchased to verify this. Just punch it in and moters whir, and you are looking at it.

So a programmer at a telescope company wrote a program to do that.

Since we know it works, if the earth is flat, how does it work?

Programmers in on it, or they have been fooled?

The Native South Americans wrote formulas to predict where to see heavenly objects and when too. Sure, it adds another order of complexity for anywhere on the earth, but that does not necessitate that the truth of the matter is that it is round. Its a matter of tabulation and extrapolation - no model required or necessitated.

The Mayans wrote formulas to predict where to see heavenly objects and when too. Sure, it adds another order of complexity for anywhere on the earth, but that does not necessitate that the truth of the matter is that it is round. Its a matter of tabulation and extrapolation - no model required or necessitated.

I wrote a formula, too, that tells where and when the location of the Sun is.

(1) During the day, the Sun is in the sky.
(2) During the night, the Sun is not in the sky.

Sure, it adds another level of complexity to refine the time and the azimuth/elevation, but my formula is just as valid as those clever Mayans. And them programmers.

So you think that telescope controller programs are just tabulation and extrapolation, huh? That's interesting.

The Native South Americans wrote formulas to predict where to see heavenly objects and when too. Sure, it adds another order of complexity for anywhere on the earth, but that does not necessitate that the truth of the matter is that it is round. Its a matter of tabulation and extrapolation - no model required or necessitated.

Except that planetry orbits are not close enough to being periodic for a simple set of formulas like that to predict the ephemerides of the planets to the required accuracy.

Ephemerides data is now calculated from the equations of motion and gravitation, which are based on not only the Globe but on the Heliocentric Solar System.

And "computerized telescope aiming" would, I imagine, use data from JPL and/or the Almanac.

Have a look at

CHAPTER 8: Orbital Ephemerides of the Sun, Moon, and Planets[[/i][/url]
Fundamental Ephemerides
The fundamental planetary and lunar ephemerides of The Astronomical Almanac, starting in the year 2003, are DE405/LE405 of Caltech’s Jet Propulsion Laboratory (JPL).
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
These fundamental ephemerides are the bases for computing the planetary and lunar positions and other related phenomena that are .
For the final (integration) phase of the ephemeris creation process, there are three main ingredients, each of
which constitutes a major phase itself:

• the equations of motion describing the gravitational physics which govern the dynamical motions of the
  bodies,
  
  
• a method for integrating the equations of motion , and
  
  
• the initial conditions and dynamical constants; i.e., the starting positions and velocities of the bodies at
  some initial epoch along with the values for various constants which affect the motion (e.g., planetary
  masses).

It is mainly the accuracy of the third component, the initial conditions and dynamical constants, which determines the accuracy of modern-day ephemerides, since the other two components (the physics and the integration method) are both believed to be sufficiently complete and accurate.
. . . . . .

DE405 is based on perturbations like all other of astronomical predicting tools.

http://www.eclipsewise.com/help/jpl-de.html

"DE102 was the first numerically integrated so-called Long Ephemeris, covering much of history for which useful astronomical observations were available: 1141 BC to AD 3001. DE200, a version of DE118 rotated to the J2000.0 reference frame, was adopted as the fundamental ephemeris for the new almanacs starting in 1984. The JPL ephemerides have remained the basis of the Astronomical Almanac to the present; the current Almanac is derived from DE405. Each such ephemeris was produced by numerical integration of the equations of motion, starting from a set of initial conditions"

Perturbations = Epicycles.

See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

DE405 is based on perturbations like all other of astronomical predicting tools.

http://www.eclipsewise.com/help/jpl-de.html

"DE102 was the first numerically integrated so-called Long Ephemeris, covering much of history for which useful astronomical observations were available: 1141 BC to AD 3001. DE200, a version of DE118 rotated to the J2000.0 reference frame, was adopted as the fundamental ephemeris for the new almanacs starting in 1984. The JPL ephemerides have remained the basis of the Astronomical Almanac to the present; the current Almanac is derived from DE405. Each such ephemeris was produced by numerical integration of the equations of motion, starting from a set of initial conditions"

Perturbations = Epicycles.

See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

From your own link:

"The physics modeled include the mutual Newtonian gravitational accelerations and their relativistic corrections, the accelerations caused by the tidal distortion of the Earth, the accelerations caused by the figure of the Earth and Moon, and a model of the lunar librations."

How are you so bad at this?

Also Perturbations =/= Epicycles.

Read the second link for a description of perturbations. Newtonian gravity and the inverse squared law is used as a variable in the perturbation computations as the ideal.

Perturbations = Epicycles.

Read the second link for a description of perturbations. Newtonian gravity and the inverse squared law is used as a variable in the perturbation computations as the ideal.

Perturbations = Epicycles.

Do you mean the description of perturbations in your link  from a book published in 1922? How is that even relevant?

Quote from: Tom Bishop on August 15, 2019, 09:09:24 PM

Read the second link for a description of perturbations. Newtonian gravity and the inverse squared law is used as a variable in the perturbation computations as the ideal.

Perturbations = Epicycles.

Do you mean the description of perturbations in your link  from a book published in 1922? How is that even relevant?

There are multiple sources linked. The meaning has not changed.

Read the second link for a description of perturbations. Newtonian gravity and the inverse squared law is used as a variable in the perturbation computations as the ideal.

Perturbations = Epicycles.

No. 

Perturbations are gravitational interactions between the planets. 
https://en.wikipedia.org/wiki/Perturbation_(astronomy)

Epicycles explain planetary retrograde motion.
https://en.wikipedia.org/wiki/Deferent_and_epicycle

DE405 is based on perturbations like all other of astronomical predicting tools.

http://www.eclipsewise.com/help/jpl-de.html

"DE102 was the first numerically integrated so-called Long Ephemeris, covering much of history for which useful astronomical observations were available: 1141 BC to AD 3001. DE200, a version of DE118 rotated to the J2000.0 reference frame, was adopted as the fundamental ephemeris for the new almanacs starting in 1984. The JPL ephemerides have remained the basis of the Astronomical Almanac to the present; the current Almanac is derived from DE405. Each such ephemeris was produced by numerical integration of the equations of motion, starting from a set of initial conditions"

Perturbations = Epicycles.

See https://wiki.tfes.org/Astronomical_Prediction_Based_on_Patterns

Does not answer the question of how the locations of celestial bodies in the International Celestial Reference Frame are converted to local coordinates when local coordinates are entered in the telescope; a key part of the OP's question.

https://stellarium.org/

Here you can get the source and join the developer community.

https://www.instructables.com/id/Control-Your-Telescope-Using-Stellarium-Arduino/

Instructions to do as many have done:






Just the first 4, many more have done this on youtube, undoubtedly many more did it but no youtube.

I would read the code and verify that the code uses RE calculations. FE will not believe me, waste of time.

I would honestly be greatly amused to read a FExplanation.

The math for the telescope to figure out is all heliocentric calculus, and a lot of 3D math.
It has orbital elements of all the planets, including us, and all the moons too.
Some allow you plug in the orbit of a new comet and it will point to it.
I have old book from the 80's how to apply it, with just a scientific calculator.