Newton and the Standard Model

[modest]

QEdit: spinoff from thread elsewhere.

Originally Posted by CraigD

IMHO, a sign of a good model is that you don’t have to keep adding complexity to it to explain increasingly precise observations. I agree with Erasmus that the Standard Model exhibits this sign.

Agreed, but adding fictitious forces is also a bad sign. The end result may be between a complex truth or a fake simplicity. That's where we stand now, no?

-modest

[CraigD]

Originally Posted by modest

Agreed, but adding fictitious forces is also a bid sign. The end result may be between a complex truth or a fake simplicity. That's where we stand now, no?

I’m not sure which forces you mean, modest.

The Standard Model has only 5 fundamental bosons, two of which (the W and Z) are considered carriers of a single force (the weak nuclear), while 1 (the as yet unconfirmed Higgs) is not typically associated with a force, but rather with the common “opposing force” of inertia. A 6th boson, the graviton, is not an accepted Standard Model particle, for which reason the Standard Model does not explain gravity.

I must confess that, with my limited technical understanding of particle physics, I find the graviton attractive, and the Higgs unsatisfying and difficult to grasp – I don’t, on an intuitive level, “get” the flaws with the former, or the compelling virtues of the latter. I’ve been hoping for several years to gain an appreciation of the Higgs mechanism before it’s confirmed, or in time to be able to offer worthwhile commentary on its failure to be discovered with the expected energies and techniques.

[modest]

Originally Posted by CraigD

I’m not sure which forces you mean, modest.

The Standard Model has only 5 fundamental bosons, two of which (the W and Z) are considered carriers of a single force (the weak nuclear), while 1 (the as yet unconfirmed Higgs) is not typically associated with a force, but rather with the common “opposing force” of inertia. A 6th boson, the graviton, is not an accepted Standard Model particle, for which reason the Standard Model does not explain gravity.

huh?

The standard model does not have fictitious forces. A fictitious force is added to an inadequate law to make it applicable. Like adding the centrifugal force to Newtonian physics. I was saying that quantum mechanics may be complex, but at least it has this going for it.

[Qfwfq]

Originally Posted by modest

A fictitious force is added to an inadequate law to make it applicable. Like adding the centrifugal force to Newtonian physics.

The centrifugal force is just one example of what Newton called "inertial forces", I would scarcely say that it was "added to Newtonian physics". BTW it is more common to call inertial forces "apparent" than "fictitious".

[modest]

Originally Posted by Qfwfq

The centrifugal force is just one example of what Newton called "inertial forces", I would scarcely say that it was "added to Newtonian physics". BTW it is more common to call inertial forces "apparent" than "fictitious".

Yes,
Inertial force = fictitious force = apparent force = pseudo force

My point is that the standard model does not have these apparently fictitious forces. This is a very fundamental difference between the two that no one often mentions when comparing them. Otherwise we could use gravity in quantum mechanics as an apparent force without a foundation.

[Qfwfq]

Field theory is based on Lagrangian formulation, in which there is, in a sense, hardly a need for the notion of force. The word is still used in parlance as a term meaning interaction, pretty much a synonym, rather than to indicate a derivative of momentum.

The problem with gravity is in quantizing it, and when people say that the standard model "doesn't include" gravity, the meaning is not that the two can't be used together in describing phenomena in which both are relevant.

[CraigD]

Originally Posted by modest

The standard model does not have fictitious forces.
…
I was saying that quantum mechanics may be complex, but at least it has this going for it.

I agree. I was simply confused by your previous post, which I thought might be suggesting that the Standard Model does have such forces, and sought clarification. You’ve given it, thank you, clearing up my confusion.

Originally Posted by modest

A fictitious force is added to an inadequate law to make it applicable. Like adding the centrifugal force to Newtonian physics.

Classical mechanics’s use of pseudo-forces is, I think, fundamental, and stated explicitly in its third law of motion

For every force acting on an object, the object will exert an equal, yet opposite, force on its cause.

The real centripetal force : pseudo centrifugal force pair are just a special case of this for circular motion.

In the formalism of the gravity-less Standard Model (which I, for the most part, can only discuss, not actually formally do), the third law appears to be embedded in the rules governing the “exchange” of bosons by fermions. For example, two charged bodies/particles in circular motion about their barycenter (eg: an electron and positron) exchange a “swarm” of virtual photons of magnetic force, each photon carrying a vector quantity of energy to each fermion, resulting in an outcome agreeing (statistically) with classical mechanics. There is no “inertia particle of equal yet opposite force” in the model for this example, just a complicated, counterintuitive exchange of photons.

I find the Standard Model very satisfying. It has, to me, a “bookkeeping” quality, even if I’m not quite capable of keeping them, nor, for large, complicated interactions, is anybody. As the saying goes, the best reality simulator is reality.

[Qfwfq]

The third law is "embedded in" momentum conservation.

[modest]

Qfwfq,
CraigD,

I am absolutely in agreement with what you both are saying. I should have formed my thoughts more clearly to avoid this confusion.

People are frequently saying that QM governs the small and NM governs the large. I have no problem with this. There is also another major difference that is not frequently discussed. As it relates to this discussion here it is:

In a more classical physics gravity is a correction to be applied to Newton’s laws. It is not inherent or implicit to Newtonian physics. It is rather explicit. Gravity in Newtonian Mechanics is a fictitious force applied because it must be. There is no theory behind it or cause. I’m not saying this is wrong or bad - it is just lacking.

In the standard model gravity also has no understood cause. People see this as a weakness (well, some people who I’ve seen posting here). But, gravity is no more lacking in QM as in NM. The real difference lies where Newton’s system needs no explanation to add a fictitious force - the standard model absolutely does. This is a credit to the standard model that some people don’t see. Without the graviton or the Higgs boson (or some other similar mechanism) gravity and the electroweak aren’t going to work the way we know they should. This sets the standard model completely apart from the classical laws.

That's what I was thinking anyway.

-modest

[Qfwfq]

Aside from the fact that I disagree with:

Originally Posted by modest

In a more classical physics gravity is a correction to be applied to Newton’s laws. It is not inherent or implicit to Newtonian physics. It is rather explicit.

I also see that you are now shifting the meaning of fictitious force when you say:

Originally Posted by modest

Gravity in Newtonian Mechanics is a fictitious force applied because it must be. There is no theory behind it or cause. I’m not saying this is wrong or bad - it is just lacking.

This is more a matter of epistemology. However:

Originally Posted by modest

In the standard model gravity also has no understood cause.

I would simply say that the standard model doesn't describe gravity at all. In a like manner, QED doesn't describe strong interactions and QCD doesn't describe electromagnetic ones. Your point is therefore not even a substantial epistemological objection. It is a well known thing, once put in the appropriate terms.

Now, it also depends on what you mean by "understood cause" and what it would mean if said about the other interactions, and that has a lot do do with the matter of quantizing gravity.