OT: Gravity, Dark Energy, Universal expansion

[capnq]

Randallw said: in fact since matter can not be created

Given enough energy, matter & antimatter can be created by pair production.

[Randallw]

I see. of course I should have said energy cannot be created or destroyed. my mistake.

[Gozra]

Just Finished scanning this topic. Gravity is nothing, black holes are mathematical expressions of Newtonian physics. The reality is we have an electric universe that easily explains what we are seeing. The next time you see that Scientist are "surprised" at what they find in outer space please question in your mind if our current theory is correct why are they surprised? The electric universe easily explains what we are seeing and how things work.Try to think past Newton and realize that Gravity is really weak.

http://www.thesurfaceofthesun.com/

http://www.mikamar.biz/book-info/tes-a.htm

[MasterChiToes]

Gozra said:
Just Finished scanning this topic. Gravity is nothing, black holes are mathematical expressions of Newtonian physics. The reality is we have an electric universe that easily explains what we are seeing. The next time you see that Scientist are "surprised" at what they find in outer space please question in your mind if our current theory is correct why are they surprised? The electric universe easily explains what we are seeing and how things work.Try to think past Newton and realize that Gravity is really weak.

http://www.thesurfaceofthesun.com/

http://www.mikamar.biz/book-info/tes-a.htm

I haven't read these, but generally the problem with an EM structure is propagation speed of EM forces being c, creating a lag that doesn't correspond to observation.

[Raapys]

I thought they'd just about concluded that even gravity was limited to c?

[MasterChiToes]

Unless a lot of old observations were way off... objects appear attracted to about where the mass is, not where it was d/c ago.

[Suicide Junkie]

Raapys said:
I thought they'd just about concluded that even gravity was limited to c?

There are a number of observations that do indicate that:
http://en.wikipedia.org/wiki/Speed_o...measurement.3F


As MCT mentioned, however, the earth accelerates towards where the sun *is*, not where it was 8 minutes ago.
Otherwise the earth's orbit would be quite unstable, and we'd all go spinning off into space.

So, there seems to be a relativistic effect that mostly cancels out the lag for slowly moving things.

[Raapys]

Hmm, I don't get it. Why would the earth's orbit be unstable? I mean, the sun travels at a constant speed, doesn't it? And the gravitational pull is continous, even if there is 'lag'. So the worst thing I can picture is that the earth will be travelling a tiny bit closer to the sun on one side and a little further behind on the other.

[douglas]

That falls under the "no such inertial reference frame exists" clause, and the speed of gravity does matter for such systems. Technically the Sun is accelerating so no inertial reference frame has it perfectly at rest either, but the difference is small enough on the scale of the solar system that it hardly matters.

[douglas]

One of the most basic assumptions of relativity is that all inertial reference frames are equally valid. Simply choose your inertial reference frame to be one where the sun is motionless, and you can trivially show that the speed of gravity makes virtually no difference to the influence of the sun on any of its planets. Working out how this is compensated for in other reference frames is a bit more work, but the conclusion is guaranteed unless relativity is wrong.

For the speed of gravity to have a significant effect on gravitational interactions, both masses must be large enough to have significant effects on each other so that both have significant acceleration and no inertial reference frame exists where either body is reasonably close to at rest.