Interesting talk (commercial) on the force [not] of gravity.

@KellyJay
The balloon goes to the lesser pressure which would be in front, assuming the car is accelerating forwards, not backwards🙂
It will follow the direction of the acceleration. The reason helium balloons rise is going from a higher pressure to lower pressure and the same thing happens in the car, there is a pressure differential due to the acceleration, so the air in the back of the car is slightly denser than the air in the front so the balloon follows the line from most pressure to least pressure so it goes straight forward and hits the inside of the windshield.
I wonder if that effect could be used to measure acceleration?
Not with balloons but with a very sensitive pressure sensor in the back and another pressure sensor in the front, both have to be able to see very small changes in pressures and if they can then reading the two pressures and a bit of math you could come up with how much acceleration you are undergoing.

@sonhouse said
@KellyJay
The balloon goes to the lesser pressure which would be in front, assuming the car is accelerating forwards, not backwards🙂
It will follow the direction of the acceleration. The reason helium balloons rise is going from a higher pressure to lower pressure and the same thing happens in the car, there is a pressure differential due to the acceleration, so the air i ...[text shortened]... the two pressures and a bit of math you could come up with how much acceleration you are undergoing.

@KellyJay
I used to use helium balloons at home to show how they can be made to hover in place, neither going up or down.

I reasoned if I took one of those little store bought balloons on a string and added exactly the right weight to the string it would hover in place, you can try that anytime, it is a fun exercise and works every time.

Whatever the vertical thrust lifting it is, you add just enough counterweights to the string to keep it in place, say 5 feet up and staying at 5 feet up.
One thing I found out, when you do get the counterweight right, the balloon becomes hyper sensitive to air motions, like if you have an AC in the next room, the flowing air will push the balloon around and such.

I also found I could modulate how it floated by heating it with a IR light, holding the IR light a few feet from the balloon would heat it up and therefore slightly expand the gas inside and then start rising and would go up till it started cooling off and would come back down to the same pressure gradient holding it in place.
It was instructional for my kids and I learned as much as they did with that little bit of fun technology.

@sonhouse said
@KellyJay
I used to use helium balloons at home to show how they can be made to hover in place, neither going up or down.

I reasoned if I took one of those little store bought balloons on a string and added exactly the right weight to the string it would hover in place, you can try that anytime, it is a fun exercise and works every time.

Whatever the vertical thrust l ...[text shortened]... instructional for my kids and I learned as much as they did with that little bit of fun technology.

@KellyJay
I bought one, a cheapo, I needed something to get my ham antenna's over the house and the trees in our yard but it was so unstable it basically could not be controlled.
I did have a remote controlled wire dropper, where if the drone had worked would run a thin fishing line over the trees and that attached to the antenna where I could pull it up over the branches but that was doomed. Then made a potato gun run by compressed air, I have one of those small tire pumps running off the cigarette lighter plug and got the thing pumped up to about 70 PSI and that would shoot a projectile over the trees and got it partially done that way.
When I checked the resonant frequencies of the dipole however, (using a Ukrainian made RG analyser, the Rig Expert 600) it showed my 40 meter part of the dipole was not resonant on 7 megs but 9 megahertz so I have to take it down and extend the length to get it into the 40 meter band. I thought I did the numbers right but no joy there🙂
Still want a drone controllable enough to sling a fishing line over the other trees on my property, they are about 60 feet high and our house is about 40 feet high by itself and that causes problems getting any kind of wire antenna up.

@sonhouse said
@KellyJay
I bought one, a cheapo, I needed something to get my ham antenna's over the house and the trees in our yard but it was so unstable it basically could not be controlled.
I did have a remote controlled wire dropper, where if the drone had worked would run a thin fishing line over the trees and that attached to the antenna where I could pull it up over the branches ...[text shortened]... house is about 40 feet high by itself and that causes problems getting any kind of wire antenna up.

@KellyJay
Yeah, I need one more stable, able to go where I want to get the fishing line over the trees to huff antenna wire over those trees.

@moonbus said
If, as she maintains, I am being accelerated upward while standing still on the surface of the Earth, why am I not launched into outer space? Don’t say because the air is holding me down. The air too must be being accelerated upwards, so what is keeping the air from being accelerated into outer space?

@AThousandYoung
There is this pesky problem with the flat Earth:
So on OUR Earth, you have say a GPS and aircraft with an extraordinary amount of fuel. So you want to fly directly over the equator.
So you get to the equator and using coordinates from GPS you fly directly over said equator.
You can fly as long as you want without turning. Flying in an apparent straight line.
Of course you are constantly turning going around the planet but your course direction doesn't change.

Now suppose we were a flat Earth, the maps still shows the equator.
Ok, so we do the same flight, GPS guides us on the equator.
The problem is, you cannot fly over the equator in a straight line, you have to continually be turning left or right depending on which direction you are going, keep turning to maintain that line over the equator.

Since we in fact can fly over OUR equator staying on course in a straight line without turning either left or right, proves we are flying on a sphereish globe.