"Color interaction" in quarks gets stronger with distance

Yesterday, I posted an entry about George Pendle's article on the only time Einstein attended a seance. Einstein later said that one reason he did not believe in psi-forces was because the strength of their signal did not decrease with distance, unlike the other four known forces of nature.

Two scientists sent me email about this.

Dr. Paul J. Camp from the Department of Physics at Spelman College in Atlanta, GA emailed me with the following:

What Einstein could not have known at the time is that there is one interaction that does not decrease with distance. The color interaction, which holds quarks together inside particles such as protons and neutrons, vanishes as quark separation goes to zero and gets stronger the further apart the quarks are. This is called "asymptotic freedom" and its discovery won a Nobel prize last year for Frank Wilczek and Davids Gross and Politzer. The bulk of their work was done in the 1970's.

This is why you can't observe a free quark. As you push them further and further apart, trying to separate one out, you eventually add enough energy to create more quarks which immediately bind to each other. So instead of free quarks, you just get more hadrons. Leakage of the color interaction is what is responsible for the strong force, but Einstein could not have known that since he died in 1955. His stated reason was therefore partly wrong, but his conclusion is still valid. Psi forces only appear in poorly controlled experiments.

And Allen Knutson of UC Berkeley's math department wrote:

Actually the strong force increases with distance. That's why you can't pull protons apart into their constituent quarks. (If you dump in enough energy to pry one out, it'll go into creating a quark-antiquark pair with the new quark taking the place of the old one -- all you've done is create a meson.) Basically, the difference between it and electromagnetism in this respect is that electromagnetic waves (photons) are not charged, whereas "strong-force waves" (gluons) are indeed colored (the strong force version of charge).

Therefore, psi-forces are real, and denying them was Einstein's biggest blunder.