Title text:
When Galileo dropped two weights from the Leaning Tower of Pisa, they put him in the history books. But when I do it, I get ‘detained by security’ for ‘injuring several tourists.’
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3154/
That’s good, it means you’re on the right track.