If a white dwarf acquires more mass than the Chandrasekhar limit, then a _______ occurs?

Assuming there even is intelligent life out there advanced enough to make the long trip to Earth, it's very likely they would have already visited other civilizations throughout the cosmos before coming here. Perhaps they've learned from previous mistakes that making contact with a civilization that is very primitive by comparison is just a bad thing to do.

Because no aliens live within a huge distance of us. We have detected about 4000 planets of other stars so far. None of them appear to be suitable for life forms to exist on.

The closer stars have been examined, making the distance to an inhabited planet grow. So the problem appears to be the vast distance that an alien would have to travel. More than 50 light years.

We don't have any space craft that could travel such a distance and still be in working order. And presumably, that would be a problem for aliens to visit us. We do assume that travel at the speed of light is impossible.

So even a speed of 1% of light speed implies a travel time for 50 light years of 5,000 years. That is why aliens are not visiting us.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.