• agamemnonymous@sh.itjust.works
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      6 hours ago

      To be pedantic, they’re pretty different. Fish are neutrally buoyant, they stay “aloft” due to a similar density to the medium they travel in and swimming is merely a means of propulsion. Birds are more dense than the medium they travel in, and only stay aloft by active interaction with their medium. If a bird stops flying, it plummets; if a fish stops swimming, it continues to float mid-medium.

      • just2look@lemmy.zip
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        6 hours ago

        I didn’t say fish fly like birds, but airships and hot air balloons fly by matching density with the air. Hot air balloons then use air currents to move similar to things like jellyfish use water currents. And blimps and other airships use propulsion that would be analogous to fish using their fins to propel them. Still flight.

        There is a reason fluid dynamics encompasses hydrodynamics and aerodynamics. The differences in medium to impact things, but the basic principles are the same. You can use the same principles to create lift in water, and you can change buoyancy to float in air.

        • agamemnonymous@sh.itjust.works
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          5 hours ago

          Technically maybe, but this seemed more like an animal-centric topic. Yes, technically, fluid dynamics are the same. But animals overall have a density much closer to water than air, so in this case the principles of remaining “aloft” are heavily influenced by that difference in medium. LTAVs more float than fly, and jellyfish more float than swim . When we say an animal flies, we are referring to heavier-than-air organisms using lift, not floating.

          The general principle of generating lift is very different from the general principle of floating and propelling oneself through a similarly dense medium. I’ll concede bivalves as “flying” in water, since they do sink when not actively propelling themselves. But fish, the subject here, do not interact with their fluid the same way birds fly.

          • just2look@lemmy.zip
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            1 hour ago

            So guess it all depends on how you define flight haha. I don’t really see any reason tk argue over a silly comment on a silly meme.