Force that becomes stronger with increasing distance?

[mooka]

I was reading this news story:

http://news.bbc.co.uk/1/hi/sci/tech/2987195.stm

And they casually mention in it that the force that binds quarks together becomes stronger with distance. I carried on reading, then suddenly thought WTF?! I assumed all forces declined with distance? I’ve never heard of anything like that! Hows does that work? What is this force called? Anyone know?

[Enola_Straight]

Tis true.

The Strong Nuclear Force does indeed increase in strength the farther two particles are pulled away from each other…this is why we can never see a lone quark all by itself.

[Achernar]

Any more information? Is it linear with distance, or what? All I can find is that it has a range of about 2 fm.

[Shark]

*Originally posted by mooka *
**Force that becomes stronger with increasing distance? **

I believe that fondness also increases with distance. Hence the saying “absence makes the heart grow fonder.”

Shark

[Desmostylus]

*Originally posted by mooka *
** I assumed all forces declined with distance? I’ve never heard of anything like that! **

You certainly have heard of and experienced forces like that. Take a spring and stretch it. Does the force between the ends of the spring increase or decrease as you stretch it?

[Satchmo]

First thing I thought of was an avalanche! Though they do peter out again eventually.

[jonpluc]

Gossip.

[pravnik]

*Originally posted by Shark *
**I believe that fondness also increases with distance. Hence the saying “absence makes the heart grow fonder.”

Shark **

Damn you Shark! I opened this thread to make that joke!

[jonpluc]

*Originally posted by Shark *
**I believe that fondness also increases with distance. Hence the saying “absence makes the heart grow fonder.”

Shark **

Hmm but does it change with an increase of distance? Does the heart grow even fonder if the hearts move to say Asia as compared to just a few thousand miles?

[rsa]

I don’t know this stuff off the top of my head, but I can give you a few clues on the strong force from Leon Lederman’s book The God Particle. It might help you Google for more details.

[Leon]
[Discussing experimental results] “Whatever the force was, the electron scatttering indicated that it was surprising weak when the quarks were close together.”

“Gauge theories could predict the counterintuitive idea that the strong force gets very weak at close approach and stronger as the quarks move apart. The process,… carried [the] name… asymptotic freedom. Asymptotic roughly means “getting closer and closer, without ever touching.” Quarks have asymptotic freedom. …What this means, paradoxically, is that when quarks are close together they behave almost as if they are free. …Short distances imply high energy, so the strong force gets weaker at high energies.”
[/Leon]

Also, the messenger particle for the strong force is called a gluon. Get it? The gluon is the “glue” that holds quarks together.

[netscape_6]

assuming the spring analogy, what is ‘coiled piece of metel’ for quarks?

[netscape_6]

never mind. by the time i got and replied someone answered.

[Q.E.D]

One thing to remember about the nuclear strong force, is that although it may seem to increase with increasing distance, it’s effect is over a limited distance which is roughly in the neighborhood of the atomic radius. If quarks can be pulled apart farther than that, they’ll break free

[Ring]

“If quarks can be pulled apart farther than that, they’ll break free”

No they won’t. The energy gets so high that another bound quark is created. We’ll never observe a free quark.

[rsa]

*Originally posted by Achernar *
Any more information? Is it linear with distance, or what? All I can find is that it has a range of about 2 fm.

I found these links which give a lot of additional information.

How strong is the strong force?

Simple formula for the strong and weak interactions?

As for the relationship of the strength of the strong (or any force) with distance there apparently is not an easy answer at the sub-atomic scale.

from second link above
Conclusion: Whether some formulae are nice and simple, depends on the typical scale you are talking about. On our everyday life scales, the electromagnetism, gravity, weak and strong formulae are nice and simple. On much smaller scales, like the radius of a nucleus, the formulae are very complicated and not simple and nice at all for neither of the 4 mentioned forces.

[Ring]

*Originally posted by Ring *
**No they won’t. The energy gets so high that another bound quark is created. We’ll never observe a free quark. **

Let me correct and expand a little. I should have said a quark antiquark pair is created. Second, the top quark has been observed and to some extent it’s free, it decays so quickly that it doesn’t have time to pair up with another quark.

However, no assembly of bound quarks can be severed to create a free quark.

[Jonathan_Chance]

*Originally posted by Shark *
**I believe that fondness also increases with distance. Hence the saying “absence makes the heart grow fonder.”

Shark **

You guys have obviously never hung out with ad reps on the road.

Heck, it’s LIBIDO for those guys that gets stronger the farther they are from their wives.

Hence the phrase. “blow jobs and on the road don’t count.”

[Chronos]

Second, the top quark has been observed and to some extent it’s free, it decays so quickly that it doesn’t have time to pair up with another quark.

Not quite. If there’s not another quark (strictly speaking, an antiquark or two other quarks) there to pair up with, then you can’t form the t to begin with. Most likely, you’ll form some sort of antiquark at the same time as the t quark, so what you’re actually observing is a meson which contains a t quark, not the quark itself.

As a nitpick, by the way, it’s not the strong nuclear force we’re talking about here, it’s the color force. Even though the strong force is orders of magnitude stronger than the electromagnetic force, the strong force itself is just a sort of leftover residue of the stronger yet color force.

And as an aside, I know that the terms are a bit outdated, but I personally prefer the names “Truth” and “Beauty” for the t and b quarks, rather than “Top” and “Bottom”.

[Q.E.D]

*Originally posted by Ring *
**No they won’t. The energy gets so high that another bound quark is created. We’ll never observe a free quark. **

Never say never:

Quark deconfinement should arise when the energy of the colliding nuclei is high enough and their size is big enough. What is enough? When plans were made to collide heavy nuclei using the particle-physics accelerators that were available almost 20 years ago, nobody knew for sure if even the largest nuclei would be large enough to make a quark-gluon plasma, or if the collision energy possible with the existing technology would be high enough. There was also the possibility that the deposition of energy from the collision into the fireball would be more effective if the collision conditions were not too extreme. With this in mind, it seemed appropriate to first study and explore the “moderate” collision energies that were available at the time.

From this article.

Bolding mine.

[scr4]

*Originally posted by jonpluc *
**Hmm but does it change with an increase of distance? Does the heart grow even fonder if the hearts move to say Asia as compared to just a few thousand miles? **

In my experience, yes. You really feel the increased distance thanks to the increased cost of phone calls and travels, time zone differences, phone time lag, different TV and movies playing, etc.

(Sorry for the hijack)