Back to Home

Blackholes Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Blackholes I | Post

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
The Radial Velocity...

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Bruce on January 19, 2002 23:16:28 UTC

of light with respect to the GR bookkeeper (far away observer at rest in flat spacetime) is

dr/dt = 1-2M/r so as r -> 2M then dr/dt -> 0.

Because of the equivalence principle we do all the local physics using SR and it can be shown that the local coordinate speed of light is always measured at c.

The local radial velocity of light.

drshell/dtshell = + or - 1

The equations of motion for radial and tangential motion of light are a little more complicated because there is another term, b = impact paramenter, accounted for. But when b = 0 the equations are equivalent to the two I mentioned.

The gravitational redshift is due to a loss of energy as the light 'climbs out' of the gravitational field.

Follow Ups:

Login to Post
Additional Information
About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
Unless otherwise specified, web site content Copyright 1994-2023 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins