<p>Suppose we approach a neutron star or a stellar black hole close enough, is the gravitational lens around it 3-dimensional (like a tunnel) or is it 2-dimensional? It's 3-dimensional as if you entered a spacetime tunnel, isn't it? If you entered the tunnel, sidewards you'd see the firmament distorted too, right?</p>

CC BY-SA 4.0
2020-12-02T18:20:44.277Z
You'll get distortions in the shape of the field if the body is not spherical, or has asymmetric internal density variations.
Wayfaring Stranger
CC BY-SA 4.0
2020-12-03T06:49:24.903Z
@WayfaringStranger What do you mean by 'not spherical'? White dwarves, neutron stars and quark stars _are_ spherical. Do you mean black holes / singularities?
Greenhorn
CC BY-SA 4.0
2020-12-03T17:15:19.593Z
I'm thinking asteroids, moons, planets and the like. Doesn't really fit into your stellar question, but does put limits on when you can expect a spherical field. Come to think of it, rotating neutron stars do frame dragging, which would affect the symmetry of the gravitational field: https://duckduckgo.com/?t=ffsb&q=neutron+star+frame+dragging+gravitational+field&ia=web
Wayfaring Stranger
<general-relativity><gravitational-lensing>
Does a gravitational lens around a body look 3-dimensional?
Greenhorn
# Does a gravitational lens around a body look 3-dimensional?

(Asked by: username_0 on 2020-12-02)

Suppose we approach a neutron star or a stellar black hole close enough, is the gravitational lens around it 3-dimensional (like a tunnel) or is it 2-dimensional? It's 3-dimensional as if you entered a spacetime tunnel, isn't it? If you entered the tunnel, sidewards you'd see the firmament distorted too, right?

**Tags:** general-relativity, gravitational-lensing

> **Comments:**
> **username_1**: You'll get distortions in the shape of the field if the body is not spherical, or has asymmetric internal density variations.  
> **username_0**: @username_1 What do you mean by 'not spherical'? White dwarves, neutron stars and quark stars _are_ spherical. Do you mean black holes / singularities?  
> **username_1**: I'm thinking asteroids, moons, planets and the like. Doesn't really fit into your stellar question, but does put limits on when you can expect a spherical field. Come to think of it, rotating neutron stars do frame dragging, which would affect the symmetry of the gravitational field: https://duckduckgo.com/?t=ffsb&q=neutron+star+frame+dragging+gravitational+field&ia=web  

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