Pendulum Gravity

a reply to: Bedlam

A balloon rises because the hot air in it is less dense than the air surrounding it. How does a hypothetical force that has never been proven and is said to pull matter down to the center of the Earth, have anything to do with this.

Buoyancy and density are proven concepts and are all that is needed. Your "gravity" only serves one purpose.

originally posted by: BakedCrusader
a reply to: Bedlam
How does a hypothetical force that has never been proven and is said to pull matter down to the center of the Earth, have anything to do with this

Because no gravity, no buoyancy. The only reason you get a buoyant force is acceleration, and for most buoyant force problems, that acceleration is due to gravity.

a reply to: Bedlam

Because no gravity, no buoyancy.

Gravity is a hypothetical, unproven concept. Bouyancy and density are proven concepts.

The only reason you get a buoyant force is acceleration

Acceleration?

and for most buoyant force problems, that acceleration is due to gravity.

What buoyant force problems, what acceleration, what gravity?

a reply to: Bedlam

No, but the air isn't the same pressure at the bottom of the balloon as at the top, because gravity creates a pressure gradient in a working fluid.

Air pressure has nothing to do with it because it is the same in all directions, there is as much pressure pushing down as pushing up causing a net effect of zero. If I would release a helium balloon the air pressure pushing down on the balloon would be the same as the pressure pushing up, and despite the hypothetical gravity pulling it down, it goes up.

The only reason it goes up is because the Law of Gravity does not exist in reality, only a law that says that high density matter goes down and low density matter goes up.

Now Qiang and Tie have created a metamaterial that distorts space so severely that light entering it (in this case microwaves) cannot escape.

www.technologyreview.com...

a reply to: Bedlam

Would there be gravity on a space elevator?

a reply to: D8Tee


At some point it would be like living on the ISS.




This one is just really cool...

originally posted by: D8Tee
a reply to: Bedlam

Would there be gravity on a space elevator?

There is gravity everywhere.

originally posted by: Phage

originally posted by: D8Tee
a reply to: Bedlam

Would there be gravity on a space elevator?

There is gravity everywhere.

I'm aware.

What G force would you feel in that hypothetical space elevator.

a reply to: D8Tee

That would depend upon your position on the "beanstalk." At the bottom, at Earth's surface, you would experience 1 g (lower case, upper case is something different). At its geostationary position you would be in freefall. Below, and above that, it would vary, being the resultant vector of acceleration due to gravity (the mass induced thing) and angular acceleration (aka centrifugal "force").

Going up you would weigh less and less until you reached the critical point. After that, you would weigh more and more, but upside down.

a reply to: Phage

Well explained, thank you.

originally posted by: BakedCrusader
a reply to: Bedlam

No, but the air isn't the same pressure at the bottom of the balloon as at the top, because gravity creates a pressure gradient in a working fluid.

Air pressure has nothing to do with it because it is the same in all directions, there is as much pressure pushing down as pushing up causing a net effect of zero. If I would release a helium balloon the air pressure pushing down on the balloon would be the same as the pressure pushing up, and despite the hypothetical gravity pulling it down, it goes up.

The only reason it goes up is because the Law of Gravity does not exist in reality, only a law that says that high density matter goes down and low density matter goes up.

So you understand neither gravity nor buoyancy. A sad example of a failing education.

Here's a fun thought problem in buoyant force. You're on a passenger jet. Sitting on the runway, you release a helium balloon. The jet gets clearance and hauls down the runway.

The balloon:

1) does nothing different
2) shoots forward
3) shoots to the rear

a reply to: Bedlam

None of the above. Unless you clarify #1.

originally posted by: Phage
a reply to: Bedlam

None of the above. Unless you clarify #1.

It's dramatic but unintuitive. Buoyant force problems I tend to get backwards

a reply to: Bedlam

In a passenger jet? The forward acceleration is probably too low to create a noticeable horizontal pressure gradient.
www.youtube.com...

Better use a car.
www.youtube.com...

a reply to: moebius

The time I saw it this guy's kid let the balloon go just as the plane floored it. That balloon went for the cockpit like the killer bunny on Holy Grail.

originally posted by: moebius

originally posted by: BakedCrusader
a reply to: Bedlam

No, but the air isn't the same pressure at the bottom of the balloon as at the top, because gravity creates a pressure gradient in a working fluid.

Air pressure has nothing to do with it because it is the same in all directions, there is as much pressure pushing down as pushing up causing a net effect of zero. If I would release a helium balloon the air pressure pushing down on the balloon would be the same as the pressure pushing up, and despite the hypothetical gravity pulling it down, it goes up.

The only reason it goes up is because the Law of Gravity does not exist in reality, only a law that says that high density matter goes down and low density matter goes up.

So you understand neither gravity nor buoyancy. A sad example of a failing education.

What is gravity? Your "educational" institutes can't even explain or prove it.

Gravity is strong enough to keep the atmosphere from being sucked up into the vacuum of space, even though it gets weaker by the distance, yet a vacuum sucks up air and can be strong enough to lift heavy solid objects, overcoming the force of gravity, just above the surface, where gravity is supposed to be the strongest.

The hypothetical force of gravity pulls every object no matter what the mass or density (neglecting air resistance) toward the Earth with enough force to have it accelerate 9.81 m/s2

All matter is being pulled down by gravity with the same RELATIVE force regardless of its density.

So what's the difference between a balloon filled with air and a balloon filled with helium, of the same volume?

Why doesn't the pressure gradiant cause a buoyant force to make the balloon filled with air go up, when it does so for the helium balloon?

Gravity doesn't care, it is supposed to be pulling down on both with the same net force.