Lighter than air...

This was one of those beautiful spring like days.
About 72 F high. I turned the heat on about sundown as it was starting
to chill a bit.

Ok, I thought, here is a chance to observe and maybe learn how the lift
fairies work (feathers, we don' need no stinkin' feathers!)

My little floating friend got real excited. Actually went right up and
kissed one of the air vents in the ceiling! (Hey, I didn't know he was
THAT kind of blimp!)

Within a couple of minutes he settled down on the floor over in one
corner, and - went to sleep, I think. Hasn't moved an inch since then.

That first reaction was so strange though.
Temperature? Or was it pressure?
Or was it air flow past one side?

Air is sure strange stuff...

Richard

Richard Lamb wrote:

Air is sure strange stuff...

One of my favorite physics lesson is what happens when you have a
helium baloon floating in the back of your car.

Hit the gas, it flies forward.

Stomp the brakes, it flies to the back.

Or more accurately, the air in the car does the opposite.

Mark "light is relative" Hickey

Mark Hickey wrote:

Richard Lamb wrote:


Air is sure strange stuff...


One of my favorite physics lesson is what happens when you have a
helium baloon floating in the back of your car.

Hit the gas, it flies forward.

Stomp the brakes, it flies to the back.

Or more accurately, the air in the car does the opposite.

Mark "light is relative" Hickey

Neat!

I've been thinking about that pervious odd behavior of the blimp.

Try this on for size?

The air coming out of the vent hits the floor and spreads out.

Being warmer than the air around it, it starts to rise.

The stream blowing from the vent causes a lower pressure area
around it, causing the air rising from the floor to move back
in toward the stream.

That's a basic convection circulation system.
So the dumb blimp wanders over toward the down flow coming from above.

The lower pressure around the stream is what caused the blimp to stick
to the down flow. (it never did go completely into the stream.
Just stuck to the side of it.)

Now the air in the flow is warmer than the air in the room, and the
blimp's helium temperature is still at the lower room temp.

But the He warms quickly, expanding the bag a bit, and causing the
blimp to defy not only gravity - but the direction of the stream,
and rise up to the very attractive vent.

THEN, as the temperature in the room increased, and matched the temperature
of the blimp, the silly sated think sank back to the floor.


Anybody buy into that?
Or is this as demented as that TRUTH guy???

Richard

Naw, ya'll got it all wrong.

Feathers aren't magical - just pretty.
Well, MOST of them are.
Ostrich feathers aren't so cute though.

Which explains why they can't fly.
The Lift Fairies don't care much for ugly.
(read the NASA report more carefully!)

MY experiments show that Lift Fairies just love helium!
It's light and fluffy, and tickles their noses.

HeHeHe!

Richard

"Richard Lamb" wrote in message
news
MY experiments show that Lift Fairies just love helium!
It's light and fluffy, and tickles their noses.

HeHeHe!

Richard

Don't understand how feathers enter into the question of lift. I've seen
references to both
lift demons and lift fairies and neither have feathers. Demons wings are
leather sails like
those of pterasaurs or bats and fairy wings are like those of dragonflies.
That should lay to rest the obviously false theory of feathery antigravity
forces. Now helium dependent lift fairys, hmmmm, or even hydrogen generating
lift demons, well, that raises some intersting possubilities. No, no, I
don't think so, it totally confuses the lighter than air craft and the
heavier than air craft hierarchies. its just too confusing.(snG)

Harold
KD5SAK