We've all been there — you get a bunch of helium balloons for a party, and the next day, they're half-deflated and drooping sadly in the corner. So, how long do helium balloons last?
First, it's important to understand that helium leaks out of balloons. Helium is a very small atom, and latex is pretty porous at the scale of a helium atom (if you ever go looking to buy balloons, you will see that there are "helium-grade" balloons, which are typically thicker and less porous).
The weight balance that keeps a balloon afloat does not leave a lot of room for leakage, so once a little leaks out, the balloon falls. But there are a few factors to consider beyond that. Let's dive deeper into the world of balloons and helium.