Looks to me like the right place to ask :-)

I've never seen your question before so my answer is a guess based on what I do know.

Gravitational bending does change the direction light travels. How much depends on both the mass of the body and how close it passes.

Gravity decreases with the square of the distance - but it never disappears compeletely. It's called the inverse square law, F=G((m1*m2)/r). Since light has no mass, we can use F=G(m1/r) or the force of gravity (F) is equal the mass of the planet or star divided by the distance from the star. G is the gravitational constant, it never changes. I'll call it 1 for simplicity.

What that means is if a planet has a gravity of 16 - the "F" - and light pasees 1 distance away from the planet, gravity curves light by the power of 16.

If light passes by the same planet at a distance of 2, the light is curved only by a power of 8.

As you know, the universe is a huge place. Most of the time light passes objects so far away there is insignificant gravity to cause a measuerable curving.

For the times light does pass close enough to something to suffer curveature, it's fair to assume that in the millions of years it travels, it also passes soemthing on the other side that causes an equal and opposite direction.

So over the millions of years light travels, it still appears as coming from approximately the place it really did start.

Does that help?

thanks Fromz,

you certainly know more about it than I do. yes the universe is big. it would be good if the forces balance out like you say, imagine the computing power it would take if we had to make corrections for every object light passes by on it's way to us!

I don't really know that much, not in comparison to what an astrophycist or astronomer would know.

But I've been in discussions with a few of those people and been lucky enough to find they're willing to explain at a level I can understand.

I've also spent more time wandering around sites like BadAstronomy.com than I probably should have.

Just to throw a kink in here, you know we really don't see any star where it is, right?

We see the sun where it was about 8 minutes ago. The furthest visible objects, we see where they were 15 Billion years ago. It's the time light takes to get here from there.

If this question passes by my brain one more time IT will be bent beyond recognition! But everything I've come across on this idea supports what Fromz had to say. As usual, ok ok quit gloating over there Fromz.

I have stumbled across the topic in Nature a couple of times recently and don't recall anything that would disagree with you.

Fromz, thank you, very informing.

So what is the current projected time when we will be able to see "The Big Bang?"

Couldn't you ask an easier question? :)

OK, the basic answer is "When we can see gravity."

For the first few hundred thousand years after the BB, the universe was 5000 degrees fahrenheit and hotter. Matter was opaque to anything we use to see with.

Gravity is believed to be like light, something that is both an energy wave and a particle. For light the particle is a photon. Gravity is a graviton.

The theoretical gravity wave could be used to see back to the instant of the bang.

But almost everythign about gravity is still theory. There may be no wave or graviton to see.

The other trick is the big bang created the universe. Some very heavy math tells us it didn't happen in the universe, it created space and time.

Here's Ask the Astronomoer on the subject: http://www.astronomycafe.net/qadir/q1164.html

Your answer helps to explains the great increase in work to understand gravity.

Followed the link. Brought back a lot of old memories about research, studies, and theories. Thanks again, Fromz