Whats the name of this book?

Question

Its about these guys who make a time machine and they decide to cash in on the idea and let people go into the past to see the dinosoars but they have this one rule where you cant leave this platform and this one guy drops his hat and it falls outside the platform and he decides to pick it up and when they go back into the present, everything is written in a diffrent language, and when the guy looks at the bottom of his shoe, he realizes he stepped on a butterfly.

Answer 1

I'm not sure but it might be Bill and Ted's Excellent Adventure

Answer 2

Sounds like a fun book!

I googled stepping on a butterfly and a book called A Sound of Thunder

matches your description =) I hope its the book!