I need to hear more about this: Early Universe was 'liquid-like'

[JoeP]

Early Universe was 'liquid-like' (http://news.bbc.co.uk/1/hi/sci/tech/4462209.stm)

They found the quark-gluon plasma! What does it all mean?

[Dragoon]

It means that the price of potatoes in Poland is about to go up.

It means that your whole world is about to turn upside down and everything you ever learned in Science Class will become bunk.

Stay tuned for later developments, film at 11. :popcorn:

:yawn:

[livius drusus]

That Relativistic Heavy Ion Collider is way cool. Paging Dragar and The Lone Ranger for more what does it all mean info.

[Ensign Steve]

It means we can use a quantum singularity to create an aperture into fluidic space. It means we can finally assimilate species 8472.

:rif:

[Dragar]

They found the quark-gluon plasma! What does it all mean?

It's actually quite interesting.

You guys have all heard of protons and neutrons, right? They belong to a family called 'hadrons' (I believe it means 'heavy ones' but I could be wrong). This is in contrast to particles like electrons, which are part of a family called 'leptons' ('light ones' - but again, I might just be making this part up - anyway, the meanings aren't important).

"What's the difference?", I hear you cry!

I'll tell you.

Leptons (like electrons) are considered 'fundemental'. You can't smash and electron up into bits. It's not made of any other particles.

Hadrons, however, are made of other particles. The evidence for this comes from scattering experiments - we can explain why electrons and photons (light) bounce off protons and neutrons by positing that they are composed of a number of these smaller particles, which are called quarks.

For protons and neutrons (and some others), they are made of three quarks each. For other, more unusual particles, they are composed of two quarks.

Normally, these quarks are so amazingly tightly bound to each other, they cannot be detected individually. But these cool guys at CERN have smashed stuff together so hard that they've actually got quarks on their own - or at least, they're inferred to be acting on their own. By the time they're detected, they've hooked up with some of their quark buddies again.

Quarks come in six 'flavours', and in three 'colours'. These are just whimsical names given to the properties these little guys have. You can think of them as just another property - like charge or mass. But we have no macroscopic analog.

The 'flavours' are: up, down, top, bottom, strange and charm. You'll hear all sorts of interesting phrases from particle physics, like 'charm is conserved', but don't let that scare you. The name is just bit of whimsical fun.

The colours are typically called 'red', 'green' and 'blue' - but again, these are just names.

Now, what about these 'gluons'?

You may have heard about the nuclear forces inside atoms. These forces are what holds protons and neutrons together. How does this force come about?

Well, you may or may not know that electromagnetic forces (how charges attract one another) is a result of an exchange of a particular particle. In this case, it is the photon. Two particles interacting via the electromagnetic force is a result of them throwing photons back and forth to each other!

So maybe you'd guess from knowing this that the same (or something similar) is true for the nuclear force?

You'd be right! Only this time, it's not photons - but a particle called a 'gluon'. These little guys are what holds the nucleus of an atom together.

This was a very hasty description, because I've got to go run and watch Law and Order: Criminal Intent. But I hope that gave you the flavour (pun intended!) of what's going on. :)

[viscousmemories]

Thanks Dragar!

Minor typo correction: The "heavy ones" are called hardons. :wink:

[JoeP]

Thanks Dragar!

Now, after you've met your other needs, how about tackling the "fluid" bit? If gluons are what sticks quarks together, what sticks gluons together? The way I read it, they've found this condition that behave like a liquid. Surely this means a bit more than density - does it imply they resist expansion more than a gas-like state?

[Dragar]

Now, after you've met your other needs, how about tackling the "fluid" bit? If gluons are what sticks quarks together, what sticks gluons together?

I'd hesitantly suggest 'quarks'.

The way I read it, they've found this condition that behave like a liquid. Surely this means a bit more than density - does it imply they resist expansion more than a gas-like state?

It does seem to imply that, and it does suggest so in the article - but we're pretty much out of my depth now. It will take someone who has studied for a little longer than me to go into any further detail. Ask me this time next year, after I've actually had a particle physics and a cosmology course. ;)

The key point I think, though, is that they'd assumed the quark-gluon mix would be like a gas, where all the particles wander about without really any concern to where the other bits are. A liquid, on the other hand, clumps together. Or, if you prefer, they swim together like a school of fish, as the author of another of those pieces so elegantly puts it

[Dragar]

Thanks Dragar!

Minor typo correction: The "heavy ones" are called hardons. :wink:

:doh:

[Shake]

Particles (http://hyperphysics.phy-astr.gsu.edu/hbase/particles/parcon.html), a subsection of Hyper-Physics (http://hyperphysics.phy-astr.gsu.edu/hbase/hph.html#hph). The 'particles' section is under 'Quantum mechanics'. I found this site once while looking for some electronics information. Lots of good, basic information there.

[JoeP]

Linking to it now.

[Dragar]

Ah, you've found hyperphysics!

That's one of my favourite sites online. It's got an incredibly broad and yet accurate amount of information available. Nice catch Shake! I should have thought to link to that earlier!