HowardRoark:
>So if this field is strong enough to bend light, why doesn't it affect the cigar smoke?
If the passenger blew smoke into the gravitational field then the only smoke we see is the smoke that the light is passing through. Anyway, who say's
it's not
>And wouldn't it also bend the light rays that are being back scattered by the smoke before they get back to the car?
You're probably right. If that is the case then the beam, in reality, is only bending in an arc equal to half of what we actually see. I haven't got
a gravity field modifier handy so I can only go on theory here
>In other words, the beam of light is being bent as it leaves the car, but when the light rays are backscattered by the smoke particles, why do they
travel a straight path back to the car?
They aren't. What you are seeing is a "modified" light beam (see above).
>(they have to be traveling a straight path back, that is what shows the beam as bieng bent.)
Not necessarily so.
Think about this: If you stand at the edge of a pool and look at the bottom on the other side of the pool, can you see the bottom? Of course you can -
the image that our eye detects is from the surface and this is slightly bent due to refraction.
If what you say is true then we wouldn't be able to see the bottom of a pool...or through a lens...or through a prism

All these things modify
light in some way.
Cheers
JS