# Field due to moving masses

1. Apr 21, 2012

### Alpharup

It is known Magnetic fields are set due to moving electric charges. Since electric and gravitational fields are proportional to 1/r^2 where r is the distance from the charge and body respectively. Also both these fields obey Gauss law. So they are identical in certain aspects
I was sitting in my balcony drinking a cup of tea and suddenly a thought came to my mind. Is there a new field set up due to moving masses, the same way magnetic field is set up due to moving charges?
For example when an electric current(I=dq/dt) passes through a wire, magnetic field is set up in concentric circles. now the same analogy can be extended to this situation. let us take a tube and let water flow through it. let the rate of flow of mass be constant, the same way the rate of flow of charge is constant in given wire ie.. dm/dt is constant.Now by analogy, will a new field be set up in concentric circles around the tube the same way magnetic field is set up around the wire ?

2. Apr 21, 2012

### andrien

well you should see that if this flowing will affect as it affect in the case of current carrying wire to anything out, also electromagnetism and gravitation are different otherwise maxwell might have given a theory of gravitation also.

3. Apr 21, 2012

### Staff: Mentor

In general relativity, yes, in a way. It's not really a "new" field in that it's simply an aspect of the gravitational field (space-time curvature) that comes out of solving the Einstein field equations of GR, under certain conditions.

http://en.wikipedia.org/wiki/Gravitomagnetism

4. Apr 21, 2012