# Thread: Gravity - Fluid Dynamics in Curved Time-space

1. Let's begin this thread with an excercise. If you think, that you're good at calculating things, I have an interesting problem to solve. I would like you, to use the basic rules of General Relativity - Einstein's field equations, combined with interior and exterior Schwarzschild solutions - to describe the gravitational field as an embedding diagram. Here is the basic knowledge, regarding the given problem:

https://en.wikipedia.org/wiki/Introd...on_to_geometry
https://en.wikipedia.org/wiki/Interi...zschild_metric

Here is an example, how to make such diagram for the Sun and Earth:
http://www.johnstonsarchive.net/relativity/stcurve.pdf

Try to use this knowledge, to define the gravitational field of an empty spherical shell with mass M (interior and exterior fields) - and compare the results with Newton's theorem...

Next step will be to change the interior of spherical shell and turn it into uniform distribution of matter - which can be treated as a liquid medium.
Now, you should include those two properties of liquids:

Hydrostatic pressure:
https://en.wikipedia.org/wiki/Hydrostaticsr

Surface tension:
https://en.wikipedia.org/wiki/Surface_tension

If you are rally good at calculating things, you should end up with a solution, which should be capable to properly explain those two scenarios:

If you will succeed, I will give you 40% of credit - so it's possible, that you can be quite famous :P

But in the meantime, I will keep explaining the subject of gravity and fluid dynamics, in my own way. My goal is to see, if the calculations will match my predictions...

3... 2... 1... Go!
Good luck!

2. Originally Posted by Astral traveler

But in the meantime, I will keep explaining the subject of gravity and fluid dynamics, in my own way. My goal is to see, if the calculations will match my predictions...
This is a mainstream science forum, not a place where you continue to push your fringe ideas.

3. This is a mainstream science forum, not a place where you continue to push your fringe ideas.
That's why I will use generally accepted scientific facts. If you will find in my explanation, something, what is contradicted by mainstream science, I hope, that you will let me know...

4. Originally Posted by Astral traveler
That's why I will use generally accepted scientific facts. If you will find in my explanation, something, what is contradicted by mainstream science, I hope, that you will let me know...
The correct calculations have nothing to do with "hydrostatic pressure" and "surface tension". Please cease and desist in pretending that you know what you are talking about.

5. The correct calculations have nothing to do with "hydrostatic pressure" and "surface tension". Please cease and desist in pretending that you know what you are talking about.
And can you explain, what allows you to make such statement?

https://ntrs.nasa.gov/archive/nasa/c...9980235567.pdf
https://www.ncbi.nlm.nih.gov/pubmed/23750547
General relationships between pressure, weight and mass of a hydrostatic fluid | Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences

"In curved geometries the hydrostatic pressure in a fluid does not equal the weight per unit area of the fluid above it. General weight–pressure and mass–pressure relationships for hydrostatic fluids in any geometry are derived. As an example of the mass–pressure relationship, we find a geometric reduction in surface pressure as large as 5 mbar on Earth and 39 mbar on Titan. We also present a thermodynamic interpretation of the geometric correction which, as a corollary, provides an independent proof of the hydrostatic relationship for general geometries."

Because from the scientific point of view, you just can't be more wrong... Or maybe you disagree with all the scientists, who are using those properties of matter, do describe planetary bodies?

6. "General relationships between pressure, weight and mass of a hydrostatic fluid"
https://arxiv.org/abs/1707.07675

"Spherical symmetry and hydrostatic equilibrium in theories of gravity"
http://discovery.ucl.ac.uk/1419850/2/THESIS_final.pdf

I love, when so-called scientists try to deny their own science. Last time I was called a pseudo-scientist, because I told, that the volume of an object has a direct influence on it's exterior gravitational field. 96% of physicists tell, that it's not true - because exterior Schwarzschild solution treats the source of gravity, as a point mass. This is true - but you seem to forget, that exterior solution has to be applied to the SURFACE of an object and surface defines it's volume. Changing the radius of a spherical body, will result in a different radius of it's exterior gravitational field.

Shortly - anyone, who tells you, that Sun can turn into a black hole and it won't have any effects on the orbits of planet, can't be called as a physicist. Such claim is in a direct opposition to the basic laws of General Relativity. You can't describe the gravity of an object, if you won't include the properties of it's interior... Most of you was simply misleaded by others...

7. Originally Posted by Astral traveler
"General relationships between pressure, weight and mass of a hydrostatic fluid"
https://arxiv.org/abs/1707.07675

"Spherical symmetry and hydrostatic equilibrium in theories of gravity"
http://discovery.ucl.ac.uk/1419850/2/THESIS_final.pdf
These papers have nothing to do with the naive rubbish you posted.

I love, when so-called scientists try to deny their own science.
Please stop posturing, you are not fooling anybody.

8. These papers have nothing to do with the naive rubbish you posted.
So hydrostatic pressure has nothing to do with fluid dynamics? Interesting... Can you explain why?
Not that I expect you to have any actual knowledge in this field... Probably, all what you can say, is that I'm wrong...
you are not fooling anybody.
Obviously, I don't have to

9. Originally Posted by Astral traveler
So hydrostatic pressure has nothing to do with fluid dynamics? Interesting... Can you explain why?
This is not what I said, you are trolling.