For some time I’ve been toying with the idea of buying *lots* of Helium and balloons. I was not really planning to fly (as this would be far to dangerous) but rather just to reduce my effective weight by, say, 50-60kg so that I could easily jump to a height of 2-3 meters. The balloons would be attached with strings to a climbing harnest.

Now I just did the math. Please double-check it. Hopefully, I made a mistake.

The density of air is roughly 1.2kg/m³ which is (check!) 1.2g/liter. Now if Helium had no weight at all, then I would need to displace about 50kg/(1.2g/liter) = 42,000 liters = 42m³

This is about the volume of my whole office and would take tens of thousands of regular-sized latex balloons to hold. Price-wise it would probably boil down to about 10,000 Euros just for the Helium (… though I could probably get a considerable discount when buying that amount). Of course, filling tens of thousands of balloons is non-trivial in itself.

What a shame.

Of course, there are lots of other options (parachute jumping, paragliding, …) to “fly” a bit, but I wanted to have a more ground-based method just to lift me up a bit in a safe but yet fairly unconstrained manner.