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Author Topic: What would it be like to sail on a sea of liquid helium?  (Read 1889 times)

Offline Atomic-S

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I got to thinking that somewhere out in the universe there could be a planet having a lot of helium and a very low temperature, and could have oceans of superfluid helium. And I got to wondering how that might be unusual, and what would happen if a vessel set sail upon such an ocean. If it is superfluid, and there is a storm, when the storm is over, does the sea ever calm down?  If not, the ocean must be extraordinarily wild. Would propellers and rudders work normally?
« Last Edit: 01/11/2013 22:18:39 by chris »


 

Offline CliffordK

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Re: Sailing in liquid helium
« Reply #1 on: 01/11/2013 10:02:54 »
Just about the only solid (not hollow) that would float on it would be solid hydrogen.  The atmosphere would have to be mostly helium, at near the boiling point of helium. 

One of the interesting things is that liquid helium may have a tendency to coat just about everything. 

Am I missing something?  I would think the waves would be controlled by wind and gravity.  I don't see why it would be any different.

What happens when you shake up a beaker full of liquid helium?  Doesn't it settle down (other than boiling if in a warmer environment)?
 

Offline SimpleEngineer

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Re: Sailing in liquid helium
« Reply #2 on: 01/11/2013 10:27:46 »
I would love to get my hands on some of that superfluid.. (raises some ideas on a perpetual motion machine .. haha)

Although I always considered the rollin film a form of the capillary action in the boundary layer, however as to never ending storms.. surface tension may be enough to return the agitated waters back to steady state.
 

Offline evan_au

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Re: Sailing in liquid helium
« Reply #3 on: 01/11/2013 10:50:46 »
Storms occur because temperature differences cause evaporation and pressure differences.

In our atmosphere, evaporation and condensation of water carries immense amounts of heat between different parts of the atmosphere. However, Helium does not carry that much energy between liquid & gaseous states.

In contrast, superfluid helium conducts heat better than almost any other material, so temperature differences would be minimal, and any differences would be quickly eliminated by conduction through the liquid/superfluid phases.

So perhaps helium storms would be quite different from storms on Earth?
 

Offline Atomic-S

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Re: What would it be like to sail on a sea of liquid helium?
« Reply #4 on: 13/11/2013 08:10:36 »
In view of that, helium storms may not even be possible.
 

Offline CliffordK

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Re: What would it be like to sail on a sea of liquid helium?
« Reply #5 on: 13/11/2013 12:09:15 »
Presumably one could still have a Helium Tsunami. 
 

Offline AndroidNeox

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Re: What would it be like to sail on a sea of liquid helium?
« Reply #6 on: 13/11/2013 21:28:49 »
You couldn't have a typical boat, open at the top, because the superfluid would just flow up the sides and fill it to a height equal the level of the fluid outside the boat. It would have to be a sealed container.

"superfluid helium conducts heat better than almost any other material"... actually, superfluids cannot have any measurable differences from point to point. The temperature at every point will be the same. Superfluids, like superconductiors, are perfect conductors of heat.

Regarding perpetual motion... you can do that with superfluids. If you set a pool of superfluid spinning, it will continue to spin indefinitely. If one or more vortices are set to spinning within a pool of superfluid, they will continue spinning frictionlessly until something intervenes.

The properties of superfluids seem less weird if you consider that they don't behave like accumulations of helium atoms, or whatever, but like a single quantum entity. When spin (or temperature) changes, it changes for the entire blob of fluid simultaneously and in quantized increments. Literally, there is not enough free energy to describe the individual molecules and the mass, as a whole, sort of collapses into a state where the component molecules lose identity within the whole.

You could sail a sea of superfluid in a sealed boat, being pushed by a wind. In fact, if you neglect friction from the atmosphere above the superfluid, you don't need continuous propulsion... just push the boat in the right direction from one shore and it would float frictionlessly to the other shore. A propeller in the superfluid would do nothing for propulsion. You might be able to generate regions of spinning fluid but you wouldn't get any propulsion.
 

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Re: What would it be like to sail on a sea of liquid helium?
« Reply #6 on: 13/11/2013 21:28:49 »

 

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