system
Given the following post, respond as if you're commenting on Reddit:
human
[The Culture] What does gridfire look like?
gpt
Blinding white light. 

Gridfire is just energy manifested in this universe. Its the "fabric" that separates dimensions and that fabric is pure energy. We smash the atom to release the energy in the bonds holding it together resulting in a very large explosion. This is the same principal just removing the atom smashing part. Just opens a door to the explosion dimension. 

Gridfire simply opens a hole in that fabric, that hole can be pretty much any size and at any location. 

You can*t defend against it, all you can do is avoid it.