Helps on the upstroke, but they need to exert that much more energy on the downstroke. The gas also adds mass to the wings; the wings are more buoyant, but the extra mass takes more energy to move. I don’t think the net effect is in your favor.
Really debatable. Maybe you could design a more efficient brain, but there was clearly a very strong selective pressure in the past to give us the brain we have today in spite of its drawbacks. We would not have heads this large if we did not need them.
Remember also that intelligence is not the only thing that correlates with brain size. Large bodies have more sensory input to process and more muscles to control, which also means larger brains. (It’s not linear, though – 2x large creatures might not need 2x large brain)
In regards to the floating mantas specifically, also remember that it isn’t just the brain you need to lift off the ground, it’s muscle, guts, blood and bone (or equivalent) too.
wait, what is actual definition for plantoid??? Wiki says it is robotic or synthetic plant, in sci fi movies / games plantoids are also walking plants eventually humanoid.
I was thinking that the muscles would be specialized for pulling the wings down and the hydrogen could help pull them back up, also forgot to mention that it’d be much less stable if they were in the middle. And in regards to the brain being not all the mass, I know, I was just using that to show that it wouldn’t need way too much hydrogen, and the creature doesn’t use blood, it uses water to spread sugar through its body, and oxygen comes through the lungs and fills its whole inside.
I don’t know, I guess i was just assuming something that was photosynthetic was a plantoid.
EDIT: It’s been a while since I got any feedback, does that mean that plant civs are possible?
You asked for a response to this in the other thread, so fine. Here we go.
The flying green manta ray is not a plant. It’s an animal that happens to be capable of photosynthesis, which as far as I can tell, was never out of the question as a possibility.
This is like the people who said that underwater civs are possible, because you can just be amphibious… You can, but that wasn’t the assignment.
The extraneous details about it flying around using hydrogen and how it discovers fire are irrelevant, and only serve to distract from the actual point.
Said point has to do with this next part:
You say that this thing gets “most” of its energy from photosynthesis, yet you provide literally nothing to back it up, nor prove that it’s possible.
This is a problem, because the inability of photosynthesis to provide enough energy to sustain an advanced nervous system is literally the one thing standing in the way of plantoid civs. Much like fire usage is holding back Atlantis from being in thrive, energy efficiency is the one thing true plantoids must overcome, without falling for the cop out of becoming a less efficient animal.
If you actually want to prove that you can support an advanced nervous system as an actual plant, what you will need is not a nice sounding story, but a calculator, the appropriate equations, and a whole lotta math.
Then you get to have fun running the numbers on calories, sunlight conversion, surface area, and whatever else needs to apply.
Ok, so according to hyrylainens calculations, to power a human body it would take five square meters, the image is 3.5x 3 .5 meters, so 12.25 square meters is more than enough, and it can hold itself together because the hydrogen bladders on the wings, and according to Jimbo_Jambo (and common sense) the larger the bladders, the more efficient they are, because they need less membrane.
I actually can’t think of anything preventing these creature from existing that I haven’t solved, because hydrogen bladders completely negate the need to figure out structural integrity.
EDIT: I hope people haven’t forgotten about this thread, I want to see if someone can prove me wrong, but if nobody can it will be fun making plants that dominate the galaxy (once thrive is done, which will take a long time).
i feel like this would evolve on Jupiter or a similar gas giant, that it would have tendons for structural integrity and that it would have the muscles produce excess chloroplasts that are modified to contain oxygen or Sulphur bearing proteins
edit: sorry for the necropost
If you scroll up for a bit, someone had linked some posts, and in those posts they also explained why it would be almost exactly as, maybe less, efficient in a gas giant rather than on a terrestrial planet.
Maybe im not understanding you, but what im saying is gas giants are always made up of lighter elements, and even with higher air pressure it will still be just as hard to float as it is on earth.
So your saying just a planet with a lot of water vapor? How would that work? Wouldn’t it have to be too hot for liquid water to exist on the surface? I can think of a few major issues.
a said or a similar gas giant as well also there are plenty of fires on Jupiter which indicate presence of oxygen and produce water in the case of a hydrogen giant, there could be carbon on similar gas giants and same for salt
I think that would be far from similar, but i guess it could possibly exist, I just don’t see the point, a creature could float on a normal planet using hydrogen, and making it be too hot for normal water just adds extra steps.