Originally posted by CrazyLilTing
Thanks to all posters!
Xantos, sorry... My mother tongue is spanish. And I an a very bad typist btw...
Thanks sonhouse for your post. It is very interesting.
But a caveat about my original post: it is only a mathematical formulation, not a physical one... so how it enters here the physics, asuming there is is a super mass that curves the space? Su ...[text shortened]... eel fre to correct my english and spelling. It will be welcome. If you have the time, of course!
The "super mass" that curves space is nothing less than the entire
mass of the universe. Thats the overall geodesic. Theory goes, if
you aim a beam of light away from you into open space, billions of
years later, that beam will hit the back of your head, come at you
from the opposite direction. Thats because the whole universe curves
in on itself. At least thats the theory. In a three dimensional analogy,
if you draw a line on the surface of a sphere, a globe of the earth
for instance, keep on drawing a straight line, it will come back to itself.
Thats the geodesic for the sphere in 3D. The universe is like that
but in a higher dimensional version where if you draw a straight line,
it will come back to itself even though you think you are going in
a straight line, you are actually curving but you don't see it. Just like
drawing a line on the surface of our planet earth, you keep drawing
a straight line but you don't notice the small curvature which will
eventually bring you right back to the same place.
BTW in my post on gravitational lensing, I said the curve was
1/117,000th part of a circle. Actually its more like 1/750,000 th part of
a circle. The 117,000 number is the equivalent of the F stop number
on a camera lens. Like F8 means the focal distance is 8 times the
diameter of the lens. So the "F stop" of the solar lens is
F117,000. If you divide the focal distance of the sun, about 52 billion
miles to first focus by 117,000 you get the radius of the sun, about
440,000 miles. So that is actually twice the F stop number, the
real Fstop of the sun is half that, or about F 58,000.
Been a while since I examined those numbers.