How to graph Earth's path?

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Discussion Overview

The discussion centers on how to graph the Earth's movement in space, encompassing its various motions from the solar system level to the galactic scale. Participants explore the challenges of representing these movements visually, particularly in the context of an animation project by an artist.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that Earth's motion relative to the Sun and other planets can be considered independent from the solar system's motion relative to nearby stars.
  • Another participant notes the significant difference in scale between Earth's orbit and the galaxy, implying that Earth's movement may be indiscernible at a galactic level.
  • Some participants propose that all reference frames are valid, but emphasize the challenge of depicting movements due to the vast differences in scale.
  • Concerns are raised about whether it is possible to graph all these movements, particularly the motion of the galaxy relative to the local group and other galaxies.
  • Participants discuss the velocities involved, noting that the Earth orbits the Sun annually while the Sun orbits the galactic center over a much longer timescale (approximately 230 million years).
  • One participant mentions the Milky Way's movement towards Hydra and the local group's movement towards the Virgo Cluster, providing specific velocities.
  • Questions are raised about determining the distance our galaxy has traveled over time and whether exact vector values can be calculated, given the lack of absolute points in space.
  • It is mentioned that all motion is relative and that comoving coordinates can be used to describe Earth's motion relative to the expansion of space.

Areas of Agreement / Disagreement

Participants express a range of views on the feasibility of graphing Earth's movement in relation to other cosmic structures, with no consensus reached on the best approach or the possibility of accurately depicting these movements.

Contextual Notes

Limitations include the absence of absolute reference points in space, the dependence on chosen reference frames, and the unresolved nature of how to effectively visualize the vast differences in scale and velocity among the various movements discussed.

Annie_28
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Hi, is there a way to graph earths movement is space - I mean to combiane all the individual movements up to movements of our galaxy? I suspect the main problem would be a point of refrence but is there a way to just pick one?

Im an artist and in my project I want to include an animation of the mentioned path, but I dont want to stop only with the solar system orbiting the galaxy, I want to go as far as I can with it.


Thanks for your help.
 
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From a scientific point of view, the motion of Earth in our solar system, i.e. its motion or path if you like relative to the Sun and other planets, can for all practical purposes be considered independent from the motion of our solar system relative to the nearby stars. Depicting the actual path Earth has taken relative to, say, the center our galaxy with orientation fixed towards far away galaxies, would be like trying to depicting how one particular hair on your head moves when you walk around a ship sailing in the Atlantic relative to a point somewhere in the middle of the Pacific.

Perhaps you can elaborate what your animation is aiming to show or illustrate? Such animations often employ zooming in or out to illustrate the huge scale differences where the precise location of Earth relative to the Sun in indiscernible at the galaxy level, but perhaps you are looking for something else?
 
Annie_28 said:
Hi, is there a way to graph earths movement is space - I mean to combiane all the individual movements up to movements of our galaxy? I suspect the main problem would be a point of refrence but is there a way to just pick one?

Im an artist and in my project I want to include an animation of the mentioned path, but I dont want to stop only with the solar system orbiting the galaxy, I want to go as far as I can with it.


Thanks for your help.
All reference frames are equally valid. Note that the scale of the Earth's orbit round the Sun is extremely small compared to the scale of the galaxy. On a galactic scale, the Earth is at the same place as the Sun.
 
That's what I was thinking - the difference in scale is so big that the earths movement around the sun would simply disappear when showing the movement of our galaxy relative to other galaxies. But zooming in and out could solve this problem a little bit. Im just wondering if all of this movements are even possible to graph even on their own. For example the movement of our galaxy relative to local group? Do we know how this movement "looks"?

I know my questions may sound a bit stupid but bare in mind that l'm just an artist, trying my best to understand and I'm very thankful for any professional help.
 
The problem is the scale. The Earth is about 0.04 light seconds across. Its orbit is about 48 light seconds across and the galaxy is about 3 million million light seconds across. Any scale that shows one will show nothing of the rest.
 
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Ibix said:
The problem is the scale. The Earth is about 0.04 light seconds across. Its orbit is about 48 light seconds across and the galaxy is about 3 million million light seconds across. Any scale that shows one will show nothing of the rest.
Yes, but in animation in can be overcame with zooming in and out. The other thing I'm worried about is different velocities.
 
Annie_28 said:
Yes, but in animation in can be overcame with zooming in and out. The other thing I'm worried about is different velocities.
Yes, the Earth orbits the Sun every year, but the Sun orbits the galactic centre every x years. Where x is a lot!

PS 230 million years, apparently!
 
Next step up, the Milky way is traveling roughly in the direction of Hydra, at 361 km/sec relative to the Local group of galaxies as a whole, and then our local group is traveling at 600 km/sec towards the Virgo Cluster.
 
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Janus said:
Next step up, the Milky way is traveling roughly in the direction of Hydra, at 361 km/sec relative to the Local group of galaxies as a whole, and then our local group is traveling at 600 km/sec towards the Virgo Cluster.
How these movements are in relation to eachother? Is there a way to determine how far our galaxy is from where it's been for example 20 years ago? Do we know exact vector values or is it just not possible to calculate? (Point of refrence being Local Supercluster)
 
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Annie_28 said:
How these movements are in relation to eachother? Is there a way to determine how far our galaxy is from where it's been for example 20 years ago? Do we know exact vector values or is it just not possible to calculate? (Point of refrence being Local Supercluster)
There are no markers to identify absolute points in space. The points are defined by your arbitrary choice of reference frame. In the Earth's frame of reference it remains at the same point in space.

All motion in relative. There is no concept in physics of absolute position or absolute velocity.

That said, a lot of cosmogy uses comoving coordinates. That would give you the Earth's motion relative to the expansion of space itself. Even then, comoving coordinates are simply useful. The laws of physics hold in all reference frames.
 

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