Liquid Helium II the superfluid (part 6 Second sound)

A 1963 film by Alfred Leitner demonstrating the remarkable properties of liquid helium when cooled below the lambda point (the superfluid state). Heat is conducted at 20 M/s in a way which is totally different to convention heat conduction.

Category:

Science & Technology

Tags:

• Superfluid
• helium
• entropy
• viscosity
• Leitner
• Physics
• statistical
• mechanics

[povilas84]

This is best educational video I have seen so far. Its quite detailed and yet very entertaining. Thanks a lot for putting it here.

[raachaell]

fantastic :D

[Zantorc]

@m9kuhn No even at a basic level that would violate quantum mechanics. As you localise the position of an electron to a smaller and smaller space you must increase its momentum (and therefore velocity), from the Heisenberg uncertainty principle.

[m9kuhn]

@Zantorc what i ment was at absolute zero do the electrons stop moving around the protons as if they were frozen as well, which would make a super solid

[Zantorc]

@m9kuhn Not sure I understand your question. The atoms in a superfluid or supersolid would all be in the ground state. But the ground state doesn't have zero energy. As you lower the temperature more atoms go into the ground state. Because they are in the same state it is impossible to distinguish them. We are not used to think about objects being in more than one place at the same time but that is literally what happens and it gives rise to all these phenomena.

[m9kuhn]

@Zantorc which would mean that the atoms themselves are not moving on the molecular and they have reached absolute zero right?

[bazanv12]

They found out over 50 years ago, and I found out just 20 minutes ago.. I wonder what other thigs I don't know...

[johny260]

how much heat can you put in it?

[KellerDude4]

Imagine sticking your tongue on that container. You'd be pretty sorry.

[kowalityjesus]

damnit this is what americans should be concerned with.

[TheCryptore]

@Zantorc WOW hey can I have ur contac such skype or msn I would really like to learn more about this! if u want!

[Zantorc]

@Zantorc Continued... When it comes to supersolids the jury is still out, but the evidence is mounting that they exist. In such a supersolid atoms in the superfluid state would lose individual identity. They would behave as a single entity. Each superfluid atom would be at the same position as every other superfluid atom.