light travels in a straight line "through" space. However, if the space is curved, then an observer, who sees only a...lets call it projection of the path, will see a curved path.<br /><br />Light radiating from within the "dip" is redshifted.<br /><br />Light radiated from outside, but observed from inside a dip (on an objects surface) sees all incoming light blueshifted.<br /><br />Any light that passes through a dip, in one side, and out the other, has both happen. It's blueshifted on the way in (where if intercepted, is the second case above). On the way out, it's redshifted, but right back to it's original frequency (basically a conservation of energy effect). <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>