Many science fiction movies and TV shows have depicted using a nuclear weapon to destroy asteroids. What problem does Plait see with this plan?

This question may refer to the exelent TED talk of Phil Plait: How How to defend Earth from asteroids.

In it, he says that the problems may be timming: Because you should detonate the nuclear bomb in the exact time (with a tolerance of miliseconds) to move the asteroid, which is a really hard thing because the asteroids move really fast, and if you detonate the weapon a few seconds earlier or latter, you will miss the asteroid.

answer: i'm not sure which is which for i get confused on it all the time but i can tell you that the answer lies with the convex and concave devices. i hope this you. have a good day and best of luck to you!

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