i want to know how an animal could have a vacuum inside itself (in an organ), survive, and also for it to be stable, what materials could be used to contain it, and how could it be implemented without changing much of the shape of an animal, and any other data you want to give etc.

thank you very much, this is also in an earth-like enviroment

edit:the purpose is to reduce weight, and yes, the vacuum grows with the animal, which is a flying lizard

edit:the creature is born without an actual vacuum, but it has the chamber, it just needs to make it a vacuum

  • $\begingroup$ Any idea of a specific animal type? Aquatic, land based? Mammal, insect...? There are a lot of possibilities, so the question is a bit broad to give the answer you want to read about :). $\endgroup$ Dec 30, 2020 at 13:39
  • 5
    $\begingroup$ When you inspire air into your lungs what you do is use the intercostal and abdominal muscles to expand the thoracic cavity; this create a partial vacuum in the lungs, and the exterior atmospheric pressure pushes air in. If you block your nose, close your mouth and try to inspire, what you get is a partial vacuum in the lungs. The point being that humans (and most land animals) already have "vacuum chambers" inside their bodies.... I take it that this is not what you wanted? $\endgroup$
    – AlexP
    Dec 30, 2020 at 13:40
  • 3
    $\begingroup$ You need to be a bit more precise. What do you mean by vacuum inside? Is the entire animal "empty", is it an organ? how big is that organ. What is the environment? "Earth-like" can mean a variety of environment - is it a land animal, an airborne animal or an aquatic one? $\endgroup$
    – JANXOL
    Dec 30, 2020 at 13:42
  • $\begingroup$ A permanent stable vacuum inside the creature’s body. How big does the chamber need to be? How big is the creature? It’s a good question, but it needs details before being answered. $\endgroup$
    – SRM
    Dec 30, 2020 at 14:28
  • 1
    $\begingroup$ Not likely. Even if you have a vacuum inside a dense bone structure, the surrounding tissue will outgass into the vacuum, slowly making it non-so-vacuum. $\endgroup$
    – PcMan
    Dec 30, 2020 at 14:47

1 Answer 1


A rigid swim bladder would do the trick

Fish already have an organ that allows them to control their floatation called a swim bladder. In fish, it's basically a ballon, but if the bladder covered bone with only a small opening, it would likely be able to hold a low-pressure region relative to the outside.

Mythbusters tested if you could cause a container train car to implode with a vacuum and succeeded with a damaged one, so if you wanted larger forces in play you'd have to go with something stronger than bone.

  • $\begingroup$ thank you very much $\endgroup$
    – Dexyan
    Dec 31, 2020 at 12:45

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .