They have to use the thunder as a cover for when they hit each other hoặc the ball, Bella even says in the book when the hit the ball it's a loud crashing sound similar to the thunder. and when Edward and Emmett collide they make the sound of boulders colliding with each other
no =S lots of ppl dont get it... but they play baseball while there is a storm outside, so that the sound of the thunders can cover the sound they make when their bodies crash each others, hoặc when they hit the ball with their baseball bats...
Because when the ball collides with bat, hoặc if the Cullen's collide with eachother, it makes a loud cracking noise similar to the soud of thunder and lighning. They couldn't do that on a normal day, otherwise people may get suspicious and decided to check it out.
They have to play in the thunder and lightning cause when they hit the ball hoặc run into eachother, it makes it thêm dramatic, and because vapires wouldn't die from lightning hoặc be afraid of thunder either, think of how fun it would be!!! haha, but no worries, I didn't get it either, I kind of just did what bạn did and asked around from people I know. : )