Hydrogen balloon experiment -- How high can it rise?

[Entropix]

If we launch a hydrogen balloon from the Earth surface (let's say it has a 2 meter radius) and assuming it's strong enough so it doesn't pop/disintegrate (it's made out of carbon nano-tubes). Where this balloon will stop? I'm more interested in the exact altitude it reaches or if it will keep going further away into the outer space.

Also would be interesting what acceleration does our hydrogen balloon have?

 

[russ_watters]

It won't go into space. It will rise until its density equals the air's. You can easily enough find its final altitude based on its density...though I'm not sure your description is sufficient to find that.

 

[Baluncore]

Where this balloon will stop? I'm more interested in the exact altitude it reaches or if it will keep going further away into the outer space.

It will stop somewhere, and cannot rise above the thin atmosphere, into space.

The balloon will start to rise when it is partly filled.

As it continues to rise, the hydrogen will expand until the envelope is full. At that point the density of the balloon is fixed by the volume of the full envelope, the mass of hydrogen, and the weight of the envelope.

Your balloon will still continue to rise, but only until the density of the atmosphere is the same as the density of the full balloon.

A weather balloon is designed to burst and fall back down before that point, but your balloon is made from stronger stuff.

It will become stable, floating at that level, while the hydrogen lifting gas gradually leaks from the envelope that is still under pressure, and it creeps up very slowly as the mass of hydrogen is reduced by envelope leakage, the density becomes lower, and it rises slightly, following the atmosphere with neutral buoyancy.

That is the highest it will get.

There will come a time, when the envelope is no longer tight. The balloon will begin to sink as its volume gradually falls, as it follows down the atmospheric hydrostatic density profile. This will take a long time as the envelope membrane is not under internal pressure, so hydrogen escapes at a lower rate.

Once it falls to about 50,000 feet, it will become a hazard to aircraft navigation, and you will wish it had burst earlier.

In the end it will be blown into a mountain, or fall into the sea.

 

[Entropix]

I would predict that our balloon will go indefinitely into the outer space till the force exerted by the hydrogen will get so powerful it can no longer be contained even by those tough carbon nano tubes. Once the balloon eventually disintegrate, hydrogen within will be scattered around and will be no traces of hydrogen pretty quick more than what's usually there.

 

[Baluncore]

You are dreaming.

How can it both "go indefinitely into the outer space", and "eventually disintegrate" ?

 

[Entropix]

You are dreaming.

How can it both "go indefinitely into the outer space", and "eventually disintegrate" ?

Cos the further outer space it gets hydrogen exerts higher and higher pressure. But assuming thru absurd the balloon never disintegrates nor leak what will happen then?

 

[Baluncore]

The balloon has a density greater than space, so it will stay in the atmosphere. How much does the envelope material weigh?

Cos the further outer space it gets hydrogen exerts higher and higher pressure.

The hydrogen pressure in the balloon cannot be high, because then it will be too dense, so will not rise through the air.

 

[phinds]

I would predict that our balloon will go indefinitely into the outer space

You should study some physics before you make posts on a science forum.

You were told twice that it will NOT go into outer space yet you continue to insist on it.

 

[Vanadium 50]

You should study some physics before you make posts on a science forum.

The problem isn't the posting. The problem is telling the people who have learned some physics that they surely must be wrong,

 

[Entropix]

So you guys say the balloon will simply remain somewhere on the edge of the atmosphere? Ok I'm not insisting that the balloon goes indefinitely in the outer space but why scientists didn't make this kind of experiment?

The only experiment I've heard of was about an astronaut jumping from a balloon from 100 km or so reaching speed of sound in its fall.

For the folx that think they know everything namely @Vanadium 50 & @phinds one of the initial questions was at what altitude the balloon in question will stop? Or you guys like to respond only what's easy while turning a blind eye to the hard part?

Enlighten me and everyone who might have this curiosity and show us your calculations.

 

[Vanadium 50]

I never said that I know everything. I do, however, know more than you.

 

[Baluncore]

This is a case of the Dunning-Kruger effect, where the universe is limited to what has been taught, and nothing more. A little knowledge is dangerous, as a beginner thinks they know-it-all.

The expert questions everything, and expects complexity.

The only experiment I've heard of was about an astronaut jumping from a balloon from 100 km or so reaching speed of sound in its fall.

There are balloons going over 60,000 feet every couple of days.
Here is a high altitude balloon that was launched an hour ago and is still rising to where it will use light winds to navigate;
https://flightaware.com/live/flight/HBAL651

 

[Entropix]

I never said that I know everything. I do, however, know more than you.

Good luck with that..

 

[Entropix]

This is a case of the Dunning-Kruger effect, where the universe is limited to what has been taught, and nothing more. A little knowledge is dangerous, as a beginner thinks they know-it-all.

The expert questions everything, and expects complexity.There are balloons going over 60,000 feet every couple of days.
Here is a high altitude balloon that was launched an hour ago and is still rising to where it will use light winds to navigate;
https://flightaware.com/live/flight/HBAL651

Above 60000 feet (~18 km) those balloons can't reach or those are meteorological balloons? What's the maximum height those balloons can reach?

 

[phinds]

Above 60000 feet (~18 km) those balloons can't reach or those are meteorological balloons? What's the maximum height those balloons can reach?

You should learn how to use Google. It will be helpful to you with the easy questions

There will ALWAYS be some point where the balloon density becomes greater than the atmospheres's density and the balloon can't go any higher that that. It will always have a density greater than that of the space outside the atmosphere

 

[Entropix]

The hydrogen pressure in the balloon cannot be high, because then it will be too dense, so will not rise through the air.

It's not high but just outside of it density is very low once it reaches the outermost atmosphere.

You should learn how to use Google. It will be helpful to you with the easy questions
View attachment 330329

I trust more PF than google ;) but even from your search we can see 173900 is huge vs 137000. So you see more likely those balloons can't make it very far even taking 173900 as reference. So we can't really know what really happens but just assume thru our current knowledge that balloons stops somewhere upon their fabric, weight and laws of physics that govern there.

 

[Baluncore]

They do not need to go higher than 60k ft because there are very few aircraft above 50k ft, and they can hold their position there in the light and variable winds. Their altitude is regulated by using a second internal slightly higher pressure balloon. They usually carry large instrument packages for experimental purposes, solar panels, and communications equipment.

 

[Baluncore]

So we can't really know what really happens but just assume thru our current knowledge balloons stops somewhere.

We know exactly what is happening.

The mass of the balloon envelope and the density of the upper atmosphere are known.

Research that is too high for balloons is done with rockets.

 

[russ_watters]

...but why scientists didn't make this kind of experiment?

Why would they bother? This is something for kids in a junior high school level class to calculate, not an issue for real scientists to investigate. You really need to start putting forth at least a junior high school level of effort. Pick some properties and calculate how much your balloon weighs and what its volume is when it is high in the atmosphere. Then google for the density of the atmosphere vs altitude. You should be able to figure out easily how high a specified balloon can go.

I trust more PF than google ;)

We are not a live version of google. Our rules say that you owe us more courtesy than that. You need to better/try harder here.

 

[Entropix]

We know exactly what is happening.

The mass of the balloon envelope and the density of the upper atmosphere are known.

Research that is too high for balloons is done with rockets.

Does any astronaut had the curiosity to inflate a hydrogen balloon on orbit? Inside space station and outside.

 

[russ_watters]

Does any astronaut had the curiosity to inflate a hydrogen balloon on orbit? Inside space station and outside.

No. It is not worth the effort/would be pointless.

 

[Entropix]

No. It is not worth the effort/would be pointless.

Your opinion mate.

 

[russ_watters]

Your opinion mate.

You asked "does any astronaut...." It's not an opinion, it's a fact that this hasn't been done and my explanation is the real reason why.

I can see you're not interested in serious discussion/learning how to do this easy calculation yourself, so I'm going to go ahead and lock the thread. You need to do better than this here.