Solution help for the Geodesic Equation

In summary, the conversation discusses the path of an asteroid entering earth's atmosphere and how to solve for it using initial conditions. It mentions the 4-velocity and momentum at 0+, as well as the Riemann Geometry and its components such as the metric, affinity, curvature, and Ricci tensor. The question is about formulating x^{i} to solve for the path using the geodesic equation.
  • #1
Jack3145
14
0
Let’s say an asteroid is about to enter earth’s atmosphere(it will burn up of course). The initially sitting is at:

[tex]point = [x_{0},y_{0},z_{0},t_{0}] = [r_{0},\\theta_{0},\\phi_{0},t_{0}][/tex]

With a 4-velocity:

[tex]V = [v_{1},v_{2},v_{3},v_{4}][/tex]

The momentum at 0+

[tex]p_{0+} = mass*V = mass*[v_{1},v_{2},v_{3},v_{4}][/tex]

The Riemann Geometry is Riemann Space with Torsion = 0. The metric is the Schwarzschild metric. Affinity is the Christoffel Symbol. Curvature is non-zero. And, the Ricci tensor is null.

My question is how do you formulate [tex]x^{i}[/tex] to attempt solve for the path, "s" in the second-order geodesic differential equation from the given initial 4-velocity vector and starting point?
 
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  • #2
I am looking for how to solve the geodesic path, I. Something like this except taking into account initial conditions:

[tex]I = \int[(1-2m/r)^{-1} + r^{2}(d\theta/dr)^{2} + r^{2}(sin\theta)^{2}(d\phi/dr)^{2} - (1-2m/r)(dt/dr)^{2}]^{1/2} dr[/tex]
 
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  • #3
The geodesic is a graph of many curves. You have to go piece-meal or one part at a time. Use the Geodesic equation to lesson the amount of unknowns:
 
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1. What is the Geodesic Equation?

The Geodesic Equation is a mathematical equation used to describe the shortest path between two points on a curved surface, such as the surface of the Earth. It takes into account the curvature of the surface and the acceleration of an object moving along that path.

2. Why is the Geodesic Equation important?

The Geodesic Equation is important because it allows us to calculate the most efficient path between two points on a curved surface. This is useful in many fields, including physics, engineering, and navigation.

3. How is the Geodesic Equation derived?

The Geodesic Equation is derived from the laws of motion and the concept of a geodesic, which is the shortest path between two points on a curved surface. It involves using calculus and differential equations to find the path that minimizes the distance between two points.

4. What are some real-world applications of the Geodesic Equation?

The Geodesic Equation has many real-world applications, including in satellite navigation systems, aircraft flight paths, and even in the design of roller coasters. It is also used in general relativity to describe the motion of objects in space-time.

5. Are there any limitations to the Geodesic Equation?

While the Geodesic Equation is a useful tool for calculating paths on curved surfaces, it does have limitations. For example, it assumes a constant curvature and does not take into account external forces acting on the object. In some cases, more complex equations may be needed to accurately describe the motion of an object.

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