Someday in the near future, only rich kids will know what it is to play with a helium filled balloon. While there is some controversy over exactly when we will run out of helium on Earth, one thing is for sure, we will run out of it since it cannot be produced, only extracted. Apparently, helium should be 20 times the cost it currently is to be sustainable, which means no balloons for the children of the world. Helium has a much higher calling since the liquid form is used to cool super magnets in medical diagnostic devices like MRI machines. And no, you cannot produce helium mixing vinegar and baking soda. The problem is that there is only one other gas that is lighter than air: hydrogen. Not a good idea to use hydrogen (see Hindenburg disaster). Perhaps we could use warm air like in a hot air balloon, though that may not be practical on the small scale since the balloon would have to be insulated, making it heavier, requiring more warm air, leading to a vicious cycle the likes of we will never recover from!!!