Lighter-than-air

denverpilot

denverpilot

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DenverPilot
Does anyone else find the use of this phrase, really stupid?

Had you ever thought about it before I asked? :)
 
Many things are lighter than air.
 
I suppose it's technically "less dense than air." Lighter than what quantity of air? Air doesn't have a defined weight unless you know how much you have...o_O

But a "less-dense-than-air" craft sounds kinda stupid on its face.
 
chemgeek said:
I suppose it's technically "less dense than air." Lighter than what quantity of air? Air doesn't have a defined weight unless you know how much you have...o_O

But a "less-dense-than-air" craft sounds kinda stupid on its face.
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Even that’s not accurate. The craft is significantly more dense than air, or you’d fall out of it. :)
 
Comparing volume for volume, it makes sense. A LTA balloon is lighter than the volume of air it displaces. Makes sense to me.
 
If a lighter than air craft isn't less dense (overall) than the air it displaces, it don't go up. Or more pedantically, the displaced air don't go down.

Any gas with a molar mass less than 29 will be less dense than air. That includes hydrogen, helium, and (barely) nitrogen.
 
chemgeek said:
If a lighter than air craft isn't less dense (overall) than the air it displaces, it don't go up. Or more pedantically, the displaced air don't go down.

Any gas with a molar mass less than 29 will be less dense than air. That includes hydrogen, helium, and (barely) nitrogen.
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Aren’t most dirigibles and blooms designed to be as close to neutrally bouyant as possible and then use thrust to move about the airmass?

Kinda off topic but just thinking about it. They’re not really lighter. Just equal. :)
 
The term refers to the method used to create the lift. Lift is created by a volume of gas that is lighter than air.
 
Salty said:
The term refers to the method used to create the lift. Lift is created by a volume of gas that is lighter than air.
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Hahaha I’m just having fun with this.

So when we heat air we get air that’s lighter than air? :)

And no, I don’t have a better term in mind for what to call floating contraptions in the sky. I just think the name is goofy. :)
 
denverpilot said:
Hahaha I’m just having fun with this.

So when we heat air we get air that’s lighter than air? :)

And no, I don’t have a better term in mind for what to call floating contraptions in the sky. I just think the name is goofy. :)
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Flying around in a balloon you have nearly no control over is what’s goofy. I kinda like goofy.
 
Salty said:
Flying around in a balloon you have nearly no control over is what’s goofy. I kinda like goofy.
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Yep, like when a Griffis Approach trainee gave a balloon in the vicinity a vector for traffic. Now THAT was goofy, and resulted in a lot of open mics on freq going "ffffff ffffff ffffff". :p
 
Alright Nate. We are all looking forward to the day you get back to flying heavier than air stuff. Soon!

So you spend more time on that...and less time thinking about stuff like this. :p
 
chemgeek said:
If a lighter than air craft isn't less dense (overall) than the air it displaces, it don't go up. Or more pedantically, the displaced air don't go down.

Any gas with a molar mass less than 29 will be less dense than air. That includes hydrogen, helium, and (barely) nitrogen.
Click to expand...

Or, increasing the temperature of the contained parcel of air relative to the surrounding air, the density is reduced resulting in buoyancy in the (relatively) cooler surrounding air. The atmosphere is about 29g per mole (@ STP; 22.414 l, assuming "ideal gas" behavior), but raising the temperature decreases the density of the contained parcel relative to the density of the surrounding (cooler) atmosphere. Thus, positive buoyancy.
 
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And here I was hoping for something useful. We’re heading to the Albuquerque balloon fiesta tomorrow, and thinking about getting our LTA ratings.
 
Zeldman said:
My wife gets annoyed with me when I release something ''lighter than air'' in Walmart....
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Sure, Z:
And soon we'll be hearing about "silent but deadly" attacks at Walmarts.
 
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Hot-air balloons are "lighter than air" in the same way that feathers are "lighter than lead." What's the issue?
 
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