Emotions can be detected via brain scans. When certain emotions arise certain parts of the brain are activated.<quoted text>
Tell me, bubba, have they developed any instruments that can detect love? What about compassion? How about mercy? Courage? Justice?
According to your logic that means that since things like love, compassion, mercy, etc, are 100% undetectable by any instruments they are therefore nonexistent and should be dismissed as just idiotic ideas.
As for the rest, they are abstract concepts and exist as nothing more than thoughts in people's heads. You can no more detect 'justice' than you can detect 'adventure'.