Now, we know from scientific observation that your planet has discovered a rudimentary kind of atomic energy.
8 seconds sound clip from the The Day the Earth Stood Still (1954) classic radio play.
You can hear this line at 00:25:10 in the radio play.
Quote context
[...]
- Faith and, uh... Uh, curiosity.
- Do sit down. I have several thousand questions to ask you.
- I would like to explain my mission here.
- We also know that you're experimenting with rockets.
- What exactly is the nature of your mission?
- To warn you that your planet faces danger.
- What I have to say must be said to all concerned. I come to you as a last resort.
- Must I take drastic action in order to get a hearing?
- What sort of action do you mean?
- Perhaps leveling the island of Manhattan... or toppling the Rock of Gibraltar into the sea? Well?
[...]