Inspired by this Kongregate game:
The TL;DR of the plot of the game is this: All life on Earth is dead, so shoot potatoes into the sun to make it a black hole, then orbit really close to the edge of the black hole, use time dilation to experience the end of the universe. Then use a misunderstanding of Stephen Hawking's "A Brief History of Time" to hit the end of the universe, travel back in time then save Earth.
Ignoring relativity in all aspects and time travel, the bit about potatoes got me thinking: if a comet crashes into The Sun it will clearly burn up, but if trillions upon trillions of comets crash into the sun, its mass could substantially increase.
If I fire enough potatoes into the sun for its mass to double, what will happen to the nuclear fusion? will it be slowed down, or continue as normal?
Also, is it even possible for me to fire enough potatoes into the sun to make it become a black hole? or is a potato not dense enough/
Handwaving limit: Just ignore where this many potatoes are coming from and also the mechanism by which they are fired into the sun