/sci/ - Science & Math

>>8833811
helium balloons float because the balloon, when inflated, displaces a volume of air which weighs more than the balloon+the gas in the balloon

if you wanted to "fill" a balloon with vacuum the balloon would still need to be inflated to the point where it displaced more air than the weight of the balloon.

The reason a balloon inflates is because the pressure exerted on the interior of the balloon by the fluid that fills it is greater than the pressure exerted on the exterior of the balloon by the atmosphere. Vacuum does not exert pressure on the inside of the balloon. Therefore the balloon will not inflate.

If your balloon is not already buoyant in the atmosphere it won't be buoyant when you fill it with literal nothing.