I was reading "Ringworld" by Larry Niven. I'll spare you most of the details of the story, and say that one of the parts of the plot is that the center of the Milky Galaxy blows up, because all of the stars in the galactic center are all so close that when one goes supernova, it causes the remaining stars to go supernova which results in an explosion that will annihilate Earth when the explosion reaches it in about 20,000 years. I'll let the book explain:
"The stars are too close together," said Louis. "An average of half a light year apart, all through the core of any galaxy. Near the center, they're packed even tighter. In a galactic core, stars are so close to each other that they can heat each other up...
"Then one star went nova. It let loose a lot of heat and a blast of gamma rays. The few stars around it got that much hotter... So a couple of neighboring stars blew.
"...The combined heat set off a few more. It was a chain reaction"
So, my questions are:
- Is it possible this could happen in our galaxy?
- Is it theoretically possible this could happen to some galaxy?
- If it is possible, how close would stars have to be, and how big would the resultant explosion be (for example would it be able to annihilate a planet 20,000 lightyears away)? *I understand that the jets emanating from supermassive black holes can travel over 100,000 lightyears, but I am specifically talking about the resultant supernova explosion. (If there is no difference between the two, educate me about that.)
My initial guess is that there is just too much space for something like this to happen, but I have zero qualifications to judge the plausibility of this.