The universe is literally screaming at us in gamma rays, X-rays, infrared, radio waves, and a whole electromagnetic circus we can't even see - but humans insist on only believing the tiny sliver of visible light our pathetic eyeballs evolved to detect. It's like refusing to believe in elephants because you can only see their toenails. Next time someone demands visible proof of something, just point to this spectrum chart and whisper "The universe is laughing at your 400-700 nanometer worldview, Karen."