Data Suggests Early Universe was Superfluid

Ted writes "Experiments at the worlds largest nuclear collider, RHIC, at Brookhaven National Laboratory reveal striking new features of the state of the early Universe. With RHICs enormous collision energy, the researchers can create matter that is composed of the fundamental building blocks of nature, quarks and gluons, in a state with temperatures of more than 1000 billion degrees. The Universe is believed to have been in this state in the first microsecond after the Big Bang. Later the quarks and gluons were trapped in the nuclear particles that the visible universe is composed of today. Until recently, researchers have thought that the quarks and gluons formed a gas. The latest results from RHIC, however, indicate that under the extreme conditions just around the phase transition from quarks and gluons to ordinary matter, the quarks and gluons behaved as a liquid - in fact an almost perfect liquid."

Comments

That's one interpretation

[jd]

The scientists themselves suggest that the liquid state is one of a number of states that quark/gluon soups can take, but that the early Universe was still most likely a gas.

Of course, all their software is in CVS, so it shouldn't be too hard to check their calculations. :)

Re:That's one interpretation

[Raindance]

Right. To clarify,

Matter can be in a "superfluid" state when in solid, liquid, gas, and plasma form (this is a fairly new discovery).

The term "superfluid" has more to do with whether various properties obtain than being an actual fluid.

Re:That's one interpretation

[jericho4.0]

Superfluidity is the complete absence of viscosity, something kind of hard to visualize in a solid.

Liquids and Gasses are Fluids

[theblacksun]

The term fluid applies to both states of matter. I'm thinking the proper term for the universe would be superliquid.

This ain't superfluid, dammit.

[caffeinated_bunsen]

First the nanotube article, which made the mistake of thinking "really good conductor == superconductor" and now "really low-viscosity fluid == superfluid."

Superfluid means more than low viscosity. Specifically, it indicates that the fluid is a degenarate Bose system, which the quark-gluon whateverthefuckitis is not. But the article submitter probably reads science articles in Wired and the NYT, and thinks he can throw the cool-sounding jargon around without anybody noticing that it's bullshit.

Re:This ain't superfluid, dammit.

[bcrowell]

Specifically, it indicates that the fluid is a degenarate Bose system, which the quark-gluon whateverthefuckitis is not.
Some superfluids are degenerate Bose systems, e.g., helium-4. But some are fermionic, e.g., helium-3, or nuclear matter in its ordinary (cold) state.

Re:This ain't superfluid, dammit.

[Quantum Fizz]

The slashdot writeup uses the wrong terminology, but it's a similar concept. So whoever put the title as 'superfluid' was mistaken and should have written 'perfect fluid'.

A superfluid refers to a viscosity-less fluid. The most common being He4, which is easy to produce, just cool liquid helium down to about 2.2K. This has to do with the quantum interactions between the helium atoms, and is similar but different to a Bose-Einstein Condensate. The He4 atoms have an even number of fermions (two protons, two neutrons, 2 electrons) and act like Bosons. Ie, they aren't restricted to Pauli Exclusion principle, and can all be in the same state.

Another superfluid can come from He3, a rarer isotope of helium. The He3 atoms themselves, now having an odd number of fermions, act like fermions, and obey Pauli Exclusion. However, at cold enough temperatures (a few mK) they can pair together, thereby acting like a Boson, and can also form a superfluid. This is a process fairly similar to the Cooper pairing of two electrons in a superconductor (in the superconductor the normally repulsive electrons are paired through a phonon interchange mediated through the material's lattice).

Now regarding the quark-gluon soup, the physicists are talking about a perfect fluid. I just saw a physics colloquium by one of these researchers a few weeks ago, and unfortunately I don't remember the details. But basically if you take a ratio or some other mathematical function of the viscosity and another hydrodynamic parameter I can't remember, like surface tension or something, in a perfect fluid these approach some standard value such as unity or zero or some such. (this confuses me now because the ratio in question is either zero or infinity if a helium superfluid viscosity is exactly zero, so this is why i am hesitant to say anything definitively about which mathematical function or quantities are measured).

No such perfect fluid is known to exist, and of all known fluids the closest one can come to it is a cryogenic superfluid, which has a value like 4 or 4pi or something like that. All other known fluids have this value substantially larger.

Regarding the quark-plasma soup, I believe the speaker said this wouldn' necessarily display the same properties of a quantum superfluid, maybe not perfect viscosity, I really don't remember exactly. I was trying to talk to him a bit afterwards, but I didn't know enough about the physics of superfluidity to really get into the details.

We call it a Trillion

[Overzeetop]

Yes, thousands of Billions, because people are too stupid to know that the word Trillion exists?

Well, now I know why nobody is worried about the US national debt. 7 Trillion is, like, practially nothing. Let me know when we get to 7000 Billion and I'll start getting worried. And don't tell me that millions of millions crap - it just gets confusing. Besides, a million isn't as much as it used to be. Inflation, you know.

Hint: after Trillion, the next is Quadrillion, and then (hold you breath) Quintillion. Gosh it's, like, a pattern!

Re:We call it a Trillion

[sbryant]

10^9: Millard (not commonly used)

Not in English so much, but very common in German. A billion in Germany is always 10^12, and never 10^9.

Damn those 17th century Frenchies for changing the 200 year old long scale to the short scale, I say! Well, the Germans may not be known for their humour, but they are very good engineers, and they don't like their mathematical standards being changed. Actually, the Americans only changed because they were on better terms with the French than the British after their revolution.

I wasn't aware that the official scale in the UK and Oz had been changed, but when I did physics and maths at school, we never used "million" or "billion" as terms - we always had to specify large numbers like this: 1.234 * 10^12.

Here's a link with more info on the subject.

-- Steve

Supersolids

[Anonymous Coward]

However, it may well be possible for solids to exhibit superfluid flow. How? Imagine the flow of a liquid, except that all the atoms in the liquid have a crystal structure, and that entire structure is flowing in lockstep while maintaining a rigid crystalline structure. When Bose-Einstein condensation comes into play, you can have macroscopic coherence of atoms across the entire bulk of material.

Kim and Chan at Penn State claim to have created a supersolid state of matter in helium (and now, hydrogen). It's arguably the biggest experimental result in condensed matter physics right now; if confirmed, it will probably mean the Nobel Prize. However, theoretical studies have so far failed to unambiguously predict the existence of such as state of matter; there are arguments for and against, and the dust hasn't settled. If other experimental groups can replicate these results, we'll know for sure, regardless of whether theory has caught up with nature.

Re:Not much of a surprise

[bcrowell]

You don't know what you're talking about. The material in your post was all known several years ago. The fact that nuclear matter at high temperatures can be a superfluid (not just a normal fluid) is entirely new and unsuspected, and has nothing to do with what you're talking about in your post.

For anyone who wants to know something about this, from a source that actually knows something, you might want to start with the wikipedia article on the liquid drop model of the nucleus, and then this one on superfluids in ordinary matter (as opposed to nuclear matter). Nuclear matter in its normal cold state (as found in the nuclei in your body) is a fluid (known since ca. 1930), and is also a superfluid. The mechanism that causes superfluidity in the atomic nucleus is in some ways analogous to the mechanism that causes superfluidity in some types of ordinary (very cold) matter. It's also been known for a long time that if you heated nuclear matter up to high temperatures (on the order of MeV's per nucleon), the superfluidity would vanish. This is exactly analogous to what happens if you heat a superfluid like helium-3 beyond a certain point: it undergoes a phase transition and is no longer a superfluid.

This new discovery is completely unexpected: if you heat nuclear matter even hotter (to on the order of GeV's per nucleon) it may somehow become a superfluid again (maybe depending on other variables, like pressure). This is the regime where everything is moving at relativistic speeds, and the quarks may actually be free to move around the whole fluid, rather than being bound in sets of three within individual nucleons.

Mod parent down - incorrect.

[dr. loser]

The parent comment is a non-sequitor.

The CMB results have very little to do with the Brookhaven RHIC results. The CMB uniformity tells you nothing about the hydrodynamic properties of the quark-gluon plasma. The CMB does tell you about the electron-nucleon plasma that happened later.

And yes, I am a physicist.

1 trillion

[doppe1]

From trillion

We are all agreed that 1 million = 1x10^6.

In the world (Britain, France, and Germany) where 1 billion = 1 million million (1x10^12), then 1 trillion = 1 million billion (1x10^18) or another way 1 trillion = 1 million million million (tri-million), or million cubed, to the power of three, as in tri.

In the parts of the wolrd (US & Canada) where 1 billion = 1000 million (1x10^9), then 1 trillion = 1 million million (1x10^12) so 1 trillion = 1000 billion.

As it is an American lab, it will be 1x10^12.
Personally, i feel the Americans just like their numbers sounding bigger.