There is a big difference in flying and lifting. We have all gone off in the flapping our gu… er… arms direction. Evolutionary changes in muscle growth etc.
Seen the Jetwing dude pictures/video’s?
Fly in a high pressure dome at 1/6 G, piece of cake…
Missed the edit window: Also, we don’t need to be able to hover. I am envisioning birdlike flight–most birds can’t hover at all.
Make some assumptions.
Quote/use some physics/aerodynamics.
Make some calculations.
Show where I am terribly wrong.
Is it remotely possible? Perhaps, if you squint at the problem and cross your fingers.
Is it going to be where the average joe straps on something that looks like wings, casually flaps his wings every few seconds in near silence and soars like a bird?
Hell no IMO.
Yes. Look fun as hell ! And probably as noisy.
Are you aware the Jetdude has MANY times more power available to him than even the most fit human is capable of putting out ?
OK. Check out this site:
http://lavica.fesb.hr/~slap/pcurve/
If you plug in the numbers for a 12.5 kilogram bird with a 3 meter wingspan, and a velocity range of 1-10 m/s, you will see that it needs about 3 horsepower for very slow flight, and less than 1 horsepower to fly at human running speed. So I think I’m justified in dismissing your helicopter analogy.
Also, have a look at this information from the site ornithopter.com :
This was in the 1940s, by the way. I also found accounts of a supposedly successful (though short) human-powered ornithopter flight in 2006.
I call BS on this one.
The 40’s part, not the 06 part.
So, in 06 somebody (maybe) pedaled like hell and got airborn for a very short period of time. Still a FAR cry from flying anything like a bird.
Ben Bova’s book “Welcome to Moonbase” has his guests flying by muscle power in large pressurized spaces. I wonder if this could be an incentive for tourists going to the moon in the future. How much would someone pay for the reality of personal flight?
So 12 kilograms times 6 (lunar gravity advantage) equals 72 kilos, or about 160 pounds.
So, a fit person, and absolutely NO weight for the equipment. Lets say thats AOKAY anyway.
You are STILL talking 1 to 3 HP to fly on the moon.
I Repeat. Even very fit humans can NOT put out that amount of power for very long, if ever. For any extended period of time? Forget it.
And thats not even considering that to “fly like a bird”, you’d want your energy to come from flapping arms, not flailing/pedaling legs. Arms put out a fraction of the power legs do.
As someone noted above thread, the factor isnt EVEN 6 but square root of 6 (2.5 or so).
If you assume ALL the following:
Really dense atmosphere…
Really efficient flapping or whatever…which I aint believing
Very powerful human…
Equipment that weighs very little…
Some updrafts or large/tall structure to launch from…
You can just possibly maybe fly on the moon.
Note that, in The Moon is a Harsh Mistress, Mr. Heinlein also had Mannie (Manuel Garcia O’Kelly) say*:
“He even talked about the possibility of flying. Thought he had tripped his safeties.”
(Quote from memory, I don’t seem to have a copy on the shelf.)
- Mannie and the Prof are on Earth, attempting to convince groundhogs that living on the moon is a good thing. Prof does most of the talking.
So people could fly on the moon. Glad that’s settled.
Surely for lifting a given thing with 1/6th the force of gravity 1/6th the work is done. I can not see how a bird weighing 10,000 times as much as normal would need to do only do 100 times the work to fly.
Remember
To fly you are “throwing” air down in order to stay up.
Keep air density and other variables constant (besides gravity itself) and it does NOT surprise me that it is non-linear.
On what grounds? Physics hasn’t changed since the 40s.
Anyway, we’re almost agreed. I just don’t agree that flapping wings are necessarily a less efficient way to power flight than rotors or fixed wings. (I really have no idea how efficient they are, but I don’t see the reason to assume that they’re very inefficient.) I said above that I thought a very strong person might be able to do this with very well engineered wings, but not an average person.