But the bottle was empty!?! ⤵ Yes, but no… the only thing inside was air! And when we placed it in hot and cold water to see what would happen, that air reacted differently to the different temperatures. When the bottle goes into hot water, the heat makes the air molecules inside move faster and spread out (called thermal expansion) and it blows up the ghost balloon! 👻 When it’s moved to cold water, the air slows down and takes up less space (thermal contraction) which makes the balloon deflate

This 360-degree footage of a hot air balloon ride is breathtaking 🎈🤩 | In The Know Travel