Can we make a vacuum balloon?

I mean, can we with current technologies & materials make a container with little enough air in it that it will float, or are the materials you need to keep the container rigid too heavy?

Well, there is graphene, which is impermeable to gases and estimated to be about 200 times stronger than steel. However, a square inch of it would cost several million dollars to produce, so you’d still be limited to a very, very small balloon.

I did a quick search on the boards, and found these two prior threads:
Can we make a floating metal ball?
Vacuum balloon?

It looks like the board consensus is that withstanding the one-way forces (with nothing inside to counteract the external air pressure) requires either pretty exotic materials or a very large balloon.

Thanks for the links

We can make aerogels that are sturdy and impervious enough to maintain a partial vacuum inside while still being light enough that the net effect is to be buoyant in air. They are fragile and the vacuum doesn’t last, but for a short while at least, this is a sort of vacuum balloon - or perhaps as close to it as one could get.

I used to vacuum bag kayak parts.

The vacuum system (at 25 inches) involved mason jars attached to the mold that were modified to accept hose barbs in the lid to distribute vacuum and receive excess resin via gravity . So I can tell you the a mason jar can hold a vaccum easily.

oh wait. Are you talking about floating in air ?