eli5 – Lighter than Air

302 viewsOtherPhysics

If one were able to create a “balloon” out of carbon nanotubes and evacuate the air inside, would it act like a helium balloon and be lighter-than-air? It is my understanding that the “lift” of a helium balloon is due to the gas inside creating more buoyancy than the weight of the balloon itself. So, if we could create a balloon out of a super-lightweight material that is structurally sound, but void of any gasses, it should create lift in our environment, correct?

In: Physics

3 Answers

Anonymous 0 Comments

Basically, yes, but that void inside it is going to be under some pretty intense pressure from the air outside pressing down on it, and nothing inside pressing out to balance that out. If it’s strong enough to withstand that, and big enough to displace more air than its own weight, then it will float.

I don’t know what carbon nanotubes are strong enough to withstand, but large surface areas basically have literal tonnes of weight on them on account of their size. It’s all about surface area – the more physical area exposed to air, the more place air can push down. If you can withstand that, sure you can float anyway.

You are viewing 1 out of 3 answers, click here to view all answers.