Orbital Mechanics: GR vs Newton's Laws

In summary, according to the Wikipedia article on orbital mechanics, general relativity is a more accurate theory than Newton's laws for calculating orbits, especially in high gravity situations. It can also predict the trajectories of solar objects, as it is a more precise version of Newton's laws. While there are some cases where the predictions of the two theories are similar, there have been enough differences detected to confirm that general relativity is more accurate. The formulas for calculating planetary distance, orbital period, and average velocity around the sun using general relativity can be found in textbooks on the subject.
  • #1
Peter Riedt
2
0
9/1/2016 Orbital mechanics Wikipedia, the free encyclopedia
This reference states:
"General relativity is a more exact theory than Newton's laws for calculating orbits, and is sometimes necessary for greater accuracy or in highgravity situations (such as orbits close to the Sun)".

Can GR predict/calculate the trajectories of solar objects?"
 
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  • #2
Yes, it can.
 
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Peter Riedt said:
Can GR predict/calculate the trajectories of solar objects?

Newton's laws are a weak field, low speed approximation to GR. So every scenario that you can predict with Newton's laws, you can predict with GR. In many applications in the solar system, the difference in the predictions between the two is too small for us to measure with our current technology. But there are enough cases where the difference is detectable for us to have confirmed with high confidence that GR is more accurate than Newton's laws wherever the two's predictions differ.
 
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What are the GR formulas to calculate a planetary distance to the sun or orbital period around the sun or average velocity around the sun?
 
  • #5
Peter Riedt said:
What are the GR formulas to calculate a planetary distance to the sun or orbital period around the sun or average velocity around the sun?

This is covered in most GR textbooks, including how Newtonian gravity is derived as a weak field, slow motion approximation to GR. It is much too general a topic to address in a PF thread. If you have specific questions about statements in a specific acceptable reference (textbook or peer reviewed paper), please start a separate thread. This thread is closed.
 

What is the difference between General Relativity and Newton's Laws in terms of orbital mechanics?

General Relativity (GR) and Newton's Laws are two theories that explain the behavior of objects in space. GR is a more advanced and accurate theory that takes into account the curvature of space and time, while Newton's Laws only consider objects moving in a flat, Euclidean space.

How does General Relativity affect our understanding of orbital mechanics?

General Relativity has significantly improved our understanding of orbital mechanics by providing a more accurate description of how objects move in space. It predicts the behavior of objects with high precision, especially in extreme conditions, such as around massive objects like black holes.

Can Newton's Laws still be used to calculate orbital trajectories?

Yes, Newton's Laws are still a valid and useful tool for calculating orbital trajectories. They are particularly useful for simpler and less extreme situations, where the effects of GR are negligible.

What are some real-world applications of understanding orbital mechanics using General Relativity?

Understanding orbital mechanics using General Relativity has many practical applications, such as improving the accuracy of satellite navigation systems, predicting the orbits of planets and moons, and aiding in space missions. It also helps in better understanding the motion of objects in the universe, such as galaxies and stars.

Are there any limitations to using General Relativity in orbital mechanics?

While General Relativity is a more accurate theory, it is also more complex and challenging to use compared to Newton's Laws. It requires advanced mathematical techniques and high computational power, making it less practical for everyday use. Additionally, it breaks down in extreme conditions, such as at the singularity of a black hole.

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