system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek] Just what qualifies as a "life sign"?

On a planet with plenty of plant life, animals making quite a lot of noise, Data reports "No life signs." Just what is he looking for? "Signs of intelligent life" seems to be different and distinct.
gpt
Animal life still uses an electric current inside it. That's how your muscles move and heart beats. It is measurable, and most likely at a frequency specific enough to differentiate it as life.

It's like an EKG, but way more sensitive and powerful.