Well it most certainly was legit. What you are all talking about was the addition that Physicist freepmailed me for a post I was making. (If you note: I added this caveat in front of that paragraph with this statement: " An addition by Physicist")
It was a paragraph he added to my description of the Standard Model for a post I made a while back. I had originally only included the (Pion and others) as an exchange force and he made the addition that the “others” needed to be a bit clearer. I should have added my two cents to this to make that paragraph more understandable from the beginning.
My apologies for not doing this from the beginning. So here goes:
BTW This is all mine, so any mistakes are mine as well:
First, lets take a look at Van der Waals Forces:
(I am attempting this without a complete lecture on chemical bonding so please be kind) Atom and molecules are attracted to each other by two classes of bonds. The Intramolecular bond and the Intermolecular bond.
The Intermolecular bond is divided into these categories; Van der Waals Forces, Hydrogen Bonds, and molecule-ion attractions.
The Intramolecular bond (which are much stronger than the Intermolecular bond) is divided into these categories; Ionic bonding, covalent bonding, and metallic bonds.
We will only concentrate on the Van der Waals Forces.
Van der Waals Forces arise from the interaction of the electrons and nuclei of electrically neutral atoms and molecules. How is this possible if these are considered electrically neutral I hear you ask. What is going on here is that the electrons and nuclei of atoms and molecules (for this description: from here out called particles) are not at rest, but are in a constant motion. Since this is the case, there arises an electrical imbalance (called an instantaneous dipole [another term is a temporary polarity]) in this electrically neutral particle. Two “particles” in this dipole state will attract. Also this dipole action in one particle can cause a dipole in an adjoining (nearby) particle. So the dipole-dipole attraction is what is known as Van der Waals Forces. If these “particles” kinetic energies are low enough (anc close enough together), the repeated actions of the instantaneous dipoles will keep them attracted together.
One of the interesting things about this that the more electrons are in play the greater the Van der Waals Force. This is why the noble gas Krypton liquefies at a higher temperature than the noble gas Neon.
Whewwwwww!!!!!! Half done!:
Back to the Standard Model.
Again trying to keep this at an understandable level I may mess this up So if I did not explain this quite right, please correct me!.
A brief background: How does a nucleus stay together when it is packed with positively charged protons? Since “like” charges repel, you would think that the nucleus would fly apart. The force that keeps this from happening is the Strong Force. One of the things that was discovered is that the mass of any nucleus is always less than the sum of the individual particles (called nucleons) that make it up. The difference (residual) is due to the “Binding Energy” of the nucleus. This binding energy is directly related to the strength of the strong force. Note: This is why there is a release of energy when an atom is split. (nuclear fission).
So just what is this Strong Force anyway? The Strong force has an effect on quarks, anti quarks and gluons. Oh my, another term, QUARKS! After much research, it was discovered that the protons and neutrons in the nucleus were made up of smaller particles called quarks. It turned out that two types of quarks were needed to “produce” a proton or a neutron. However, there are six types of quarks in normal matter. The strong force binds these quarks together to form a family of particles called hadrons which include both protons and neutrons. (SORRY IF THIS IS GETTING COMPLEX) To simplify this discussion, quarks have a “color charge” (red, green, and blue). BTW, this was a convenient way of describing the charge, it is not referring to color as we commonly use it). Like colors repel and unlike colors attract. There are also antiquarks. The attraction between the quark and antiquark is stronger than between just quarks. If it is a quark/antiquark (same color) it is called a meson. If its between quarks it is called a baryon (protons and neutrons fall in this category). Here is the rub, baryonic particles can exist if their total color is neutral; i.e. have a red green and blue charge altogether.
Without getting into too much more detail, quarks can interact, changing color, etc. so long as the total charge is conserved.
The quark interactions are cause by exchanging particles called gluons. There are eight kinds of gluons each having a specific “color” charge.
So back to the original paragraph. Neutral (all three colors) hadrons (which include protons and neutrons) can interact with the strong force similarly to the way atoms an molecules react via the Van der Waals forces.
Physicist? Anything you want to add or change if I "stuffed it up" so to speak?
"Binding energy" is a negative energy. If the mass of a nucleus were always less than any sum of its potential components, then it would always take energy to split a nucleus. This is true for any nucleus below iron. For nuclei above iron, the binding energy becomes less and less; the strong nuclear force creates stable minima in which very heavy nuclei can exist, but these are but local minima sitting high on the electromagnetic hill. A uranium nucleus is heavier than thorium plus helium.
Doc Smith, in the classic novel Triplanetary, made the error of taking binding energy to be a positive, exploitable energy. Accordingly, the aliens used iron as fuel for their starships, iron having the maximum binding energy...sucking it, if necessary, out of the hemoglobin of human beings! In reality, iron is the one nucleus that can't be used for fuel, but I'm glad I didn't know that as a 12-year-old just the same.
I believe the attraction between them is the same, as they have the same strength of charge.
If it is a quark/antiquark (same color) it is called a meson. If its between quarks it is called a baryon (protons and neutrons fall in this category). Here is the rub, baryonic particles can exist if their total color is neutral; i.e. have a red green and blue charge altogether.
Both mesons and baryons are "colorless" with respect to the outside world. In baryons, as you say, red + blue + green = colorless. In mesons, for example, red + anti-red (or, if you like, red - red) = colorless.
[Deep-Fried, Insufferable Geek Alert: there are three color charges, each with a corresponding anti-color. Every gluon carries both a color and an anti-color charge. Shouldn't there be nine kinds of gluon? Why are there only eight?
The combination red-antired + green-antigreen + blue-antiblue is colorless. Therefore, if I assign three gluons that are red-antired, blue-antiblue, and green-antigreen, I'm doing something redundant, because blue-antiblue (for example) is just 0 - red-antired - green-antigreen, and so forth. I'm using three vectors to span a two-dimensional space.
So what we do is choose two of the three color-anticolor pairs, and use them to compose two orthonormal basis vectors (such as g1=(red-antired + blue-antiblue)/sqrt(2), g2=(red-antired - blue-antiblue)/sqrt(2)), with the other gluons being g3=red-antigreen; g4=red-antiblue; g5=green-antiblue; g6=green-antired; g7=blue-antired; g8=blue-antigreen.]
[Atomic Wedgie Geek Alert: The symmetry group of Quantum Chromodynamics is SU(3). In the minimal representation of SU(3), there are three generators...the color charges. In the non-minimal representation, there are 3²-1 generators...the eight gluons! This was spookily mirrored by Murray Gell-Mann's original (1964) quark theory, which also exploited the SU(3) symmetry. Only this time, the minimal representation was the three light quark flavors (up, down, strange), and the non-minimal representation was Gell-Mann's famous Eightfold Way, which correctly(!) predicted the properties of all the light hadrons, including some that had not yet been discovered.]
Trivia Of The Day: Because their foot pads end in literally billions of microscopic filaments, geckos use Van Der Waals forces to allow them to stick to just about any surface and climb up walls and across ceilings. They do this so efficiently that the average gecko is "glued" to the wall with about 200 pounds of force.
