Re: How would be life on earth without sun? And if there was no night?

In short DARK!  Along with light comes heat. So very cold as well. Most 
of the activity and life on earth are due to the energy from the Sun. 
Without light, photosynthesis will not take place. Most plants cannot 
grow. Every other living thing would be without food. Almost nothing 
would survive if light were removed. 

No Sun would mean not heat or any other radiated energy sufficient to 
creat the movement of air and water as we know it. The Earth would be 
frozen and likely not to have an atmosphere. 

Without the Sun, the Earth would have not gravitational pull to a central 
star... so would be in a totally different motion and relationship to the 
rest of the universe. 

Life on Earth without the sun would not exist.