Motion of light in a gravitational field

In summary, the conversation discusses the path of light in a gravitational field and the principle of least time. The correct path for a massive object with zero initial velocity is the brachistochrone, which is a cycloidal curve. However, light already has an initial velocity and its path is dependent on its initial direction.
  • #1
khil_phys
93
0
Would it be correct to say that light follows a cycloidal path in the presence of a gravitaitonal field, in accordance with the principle of least time?
 
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  • #2
Hi Khil_phys
Why cycloidal ? don't you mean brachistochronic ?
 
  • #3
I did mean brachistochronic. What will be that brachistochrone?
 
  • #5
khil_phys said:
Would it be correct to say that light follows a cycloidal path in the presence of a gravitaitonal field, in accordance with the principle of least time?
No. The brachistochrone is quickest path in gravity for a massive object with zero initial velocity. But light already has an initial velocity, and the path is dependent on its initial direction.
 
  • #6
Thank you :)
 
  • #7
oli4 said:
http://en.wikipedia.org/wiki/Brachis...is_the_cycloid[/QUOTE]

Thank you A.T. :)
 
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FAQ: Motion of light in a gravitational field

What is the theory of "Motion of light in a gravitational field"?

The theory of "Motion of light in a gravitational field" is a fundamental concept in physics that explains how light behaves in the presence of a gravitational field, such as that of a massive object like a planet or a star. This theory is described by Einstein's theory of general relativity, which states that light is affected by the curvature of spacetime created by a massive object.

How does the motion of light change in a gravitational field?

In a gravitational field, light bends or curves towards the center of the mass due to the curvature of spacetime. This means that the path of light is no longer a straight line, but rather a curved path. This effect is known as gravitational lensing and has been observed in the bending of light from distant galaxies around massive objects like galaxy clusters.

What is the difference between the motion of light and other objects in a gravitational field?

Unlike other objects, light always travels at the speed of light, regardless of the gravitational field it is in. However, the path it takes will be affected by the curvature of spacetime, leading to the bending of light. This is because light has no mass, so it is not affected by the force of gravity in the same way as massive objects.

Can light escape from a black hole's gravitational field?

Light cannot escape from a black hole's gravitational field because the gravitational pull of a black hole is so strong that it bends the path of light to the point where it cannot escape. At the event horizon, the point of no return, the escape velocity is equal to the speed of light, making it impossible for anything, including light, to escape.

Are there any real-world applications of the theory of "Motion of light in a gravitational field"?

Yes, the theory of "Motion of light in a gravitational field" has many real-world applications, including the use of gravitational lensing to study distant galaxies and map dark matter. It also plays a crucial role in the functioning of GPS satellites, which use precise measurements of light's travel time between satellites and receivers on Earth to determine location and time.

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