Hud wrote:I have to eliminate this from my thinking. It's not the Earth's Crust is it?
Hud wrote:I have to eliminate this from my thinking. It's not the Earth's Crust is it?
ronk wrote:Does this balloon carry human passengers?
udosuk wrote:Or the Earth's Atmosphere/Ozone Layer etc?
udosuk wrote:But if it's about Earth then it's more Geography...
udosuk wrote:I think JPF has got the correct answer...
Wikipedia wrote:On stratified planets, such as Earth, the lithosphere is floating on fluid interior layers.
The University Corporation for Atmospheric Research (UCAR) wrote:This picture shows how the rigid outer layer of the Earth, called the lithosphere, is made of plates which fit together like a jigsaw puzzle
Hud wrote:Now I'm forgetting the clues in which case it has to be a "balloon" shaped thing.
tarek wrote:"...By the way there is this remote possibility...... that the first sentence in the riddle is not connected to the second sentence, a nice goose chase this would be "
MCC wrote:As a general rule, balloons float.
You would think this one doesn't, but it does.
MCC wrote:As a general rule, balloons float.
You would think this one doesn't, but it does.
A small bear-cloud wrote: "When you go after honey with a balloon, the great thing is not to let the bees know you're coming. Now, if you have a green balloon, they might think you were only part of the tree, and not notice you, and if you have a blue balloon, they might think you were only part of the sky, and not notice you, and the question is: Which is most likely?"
Hud wrote:Speaking of balloons, have you heard that a helium filled balloon in a moving vehicle, goes forward when the vehicle is accellerating? I believe it's because the air is denser toward the rear of the vehicle then. Let me know if I have that wrong since it's been awhile since I heard that and could recall it incorrectly.
the Department of Physics, University of Virginia wrote:After a party at work, a friend tied a helium balloon to his car's gearshift lever and drove off. As he started driving forward, the balloon first went forward and then backward. That's not what happens to everything else. Why does it happen for the helium balloon? -- S
The helium balloon is the least dense thing in the car and is responding to forces exerted on it by the air in the car. To understand this, consider what happens to you, the air, and finally the helium balloon as the car first starts to accelerate forward.
When the car starts forward, inertia tries to keep all of the objects in the car from moving forward. An object at rest tends to remain at rest. So the car must push you forward in order to accelerate you forward and keep you moving with the car. As the car seat pushes forward on you, you push back on the car seat (Newton's third law) and dent its surface. Your perception is that you are moving backward, but you're not really. You're actually moving forward; just not quite as quickly as the car itself.
The air in the car undergoes the same forward acceleration process. Its inertia tends to keep it in place, so the car must push forward on it to make it accelerate forward. Air near the front of the car has nothing to push it forward except the air near the back of the car, so the air in the front of the car tends to "dent" the air in the back of the car. In effect, the air shifts slightly toward the rear of the car. Again, you might think that this air is going backward, but it's not. It's actually moving forward; just not quite as quickly as the car itself.
Now we're ready for the helium balloon. Since helium is so light, the helium balloon is almost a hollow, weightless shell that displaces the surrounding air. As the car accelerates forward, the air in the car tends to pile up near the rear of the car because of its inertia. If the air can push something out of its way to get more room near the rear of the car, it will. The helium balloon is that something. As inertia causes the air to drift toward the rear of the accelerating car, the nearly massless and inertialess helium balloon is squirted toward the front of the car to make more room for the air. There is actually a horizontal pressure gradient in the car's air during forward acceleration, with a higher pressure at the rear of the car than at the front of the car. This pressure gradient is ultimately what accelerates the air forward with the car and it's also what propels the helium balloon to the front of the car.
Finally, when the car is up to speed and stops accelerating forward, the pressure gradient vanishes and the air returns to its normal distribution. The helium balloon is no longer squeezed toward the front of the car and it floats once again directly above the gear shift.
One last note: OGT from Lystrup, Denmark points out that when you accelerate a glass of beer, the rising bubbles behave in the same manner. They move toward the front of the glass as you accelerate it forward and toward the back of the glass as you bring it to rest.
Or could be that planet earth is floating in space.........
A.A.Milne wrote:How sweet to be a Cloud
Floating in the Blue!
Every little cloud
Always sings aloud,
"How sweet to be a Cloud
Floating in the Blue!"
It makes him very proud
To be a little cloud.
JPF wrote:...One last note: OGT from Lystrup, Denmark points out that when you accelerate a glass of beer, the rising bubbles behave in the same manner. They move toward the front of the glass as you accelerate it forward and toward the back of the glass as you bring it to rest.
Long year by en