How Does Frame Dragging Affect Light Speed Observations?

[narrator]

From http://en.wikipedia.org/wiki/Frame-dragging" :

"Under the Lense–Thirring effect, the frame of reference in which a clock ticks the fastest is one which is rotating around the object as viewed by a distant observer. This also means that light traveling in the direction of rotation of the object will move around the object faster than light moving against the rotation as seen by a distant observer."

Is this a speed change to light wrt itself? Is the observation of the "distant observer" different to an observer sitting on the object?

Side question: Is the location of the object, the observer and the traveling light what is meant when people talk about a "coordinate chart"?

 

[Drakkith]

The change is due to space itself bing dragged around the rotating object. This drag would affect the time it takes for light to travel past the object because space itself is being altered. Locally the speed of light is the same.

 

[bcrowell]

Is this a speed change to light wrt itself?

Not sure what you mean by "wrt itself." The velocity of a physical object with respect to itself is always zero. You can't have a frame of reference moving with a beam of light, so the velocity of light with respect to itself isn't zero, it's just undefined.

Side question: Is the location of the object, the observer and the traveling light what is meant when people talk about a "coordinate chart"?

No, GR doesn't have global frames of reference like that. A coordinate chart means a set of coordinates that label every event in a certain region of spacetime.

 

[narrator]

Thanks folks.. understandable and makes sense :)