7k views

### Are “broken” planets possible in the real world?

In the Star Wars universe, there are mentioned (or rather shown) two planets that had some kind of great explosion in their history. First is Peragus, with its exposed core, that partially exploded ...
319 views

### Why are stars spherical whereas (some) galaxies are disks?

I read here that galaxies become disks if there is a lot of gas in them, since their angular momentum is conserved while their energy decreases due to collisions of the gas particle. I have two ...
469 views

### Why are star systems flat but planets are spherical?

This video vaguely explains why the solar system (or other star systems and galaxies) are flat. So, does the same argument apply to planets? The general answer is that for a given volume, a sphere ...
1k views

### Is there a center of gravity in black hole?

I've come across this particular gif "http://i.imgur.com/AOCqg5j.gifv" If you can see the above gif, you can see the two perfectly spherical black holes merge together forming a single larger ...
711 views

### Is it possible to prove that planets should be approximately spherical using the calculus of variations?

Is it possible to use the Lagrangian formalism involving physical terms to answer the question of why all planets are approximately spherical? Let's assume that a planet is 'born' when lots of ...
789 views

### Why are many things in the universe round?

Take a walk outside and you'll realise many things are round. Wheels are round, a cup is round and even that home button on your iPhone is round. But that's all man made. In nature, there are many ...
483 views

### Why do planets have spherical shape? [duplicate]

Recently, I finished gravitation. I wonder why the shapes of planets or any body revolving around any star are not cubical or ellipsoidal. In our solar system all the planets are spherical in shape. ...
492 views

### Why is the Earth shaped like a sphere and not any other shape: cube, prism? [duplicate]

Why is the earth shaped like a sphere and not any other shape: cube, prism?