Re: Sulfur hexaflouride
Yup it's real, it works in the same but opposite way as helium. It's 6 times denser then air, so sound waves travel through it 6 times slower. While in helium, sound travels through faster.
THe invisible water one, is not water, its the gas, SF6. It's a gas, but it's denser then air, so air floats on it, so the boat floats. The aluminum is denser, but not when it's fille with air. Same way a boat floats on water. It's as real as it gets.
“Adults are just obsolete children and the hell with them.” - Dr. Suess