cuddihy wrote:Only a post-modern physicist could say this with a straight face and mean it.
Not at all. A description of the universe which excludes the use of the idea of forces is entirely consistent* - more so than with that idea. We, as humans, have an experience of reality that is 'macroscopic' and is the accumulation of underlying phenomena. We experience what we have come to term as 'force', but it is just an idea in much the same way it is only an idea that physics will behave in exactly the same way tomorrow, and that things are consistent and not subject to chance. So, our experience excludes us from properly understanding quantum physics, for example, in an intuitive way.
*[I'm not suggesting don't use forces in calculations, it would be far too complex to calculate only with 'energy', but recognise they are derivative of other 'real' physical quantities.]
When you go to work, what is happening is that the system-state is changing; you go from being not-at-work to being-at-work. A system-state change requires energy. Force, without dimensional displacement, isn't energy so you can't get to work using forces. You get to work by using energy, and as you use energy with respect to displacement so we, as macroscopic humans, call that 'force'.
Dropping the notion of 'force' immediately provides, for example, a complete description of gravity. We live in an expanding universe and so the space in which our planet and us reside is expanding. But the dimensional relationship we have with our planet doesn't change because matter doesn't expand along with the space it occupies. However, as there is a 'system-state change' [that we have gone, from one second to the next, from occupying a different fraction of space] so we experience that change of state as 'the force of gravity'. If you can drop the notion of 'force' and instead embrace my idea that force is fully explicable simply by looking at the of change of energy with respect to distance (in gravity's case; with respect to spatial expansion) so the origin of inertia and gravity becomes self-evident.
Just consider where you might disagree with me in the following sequence of axiomatic/ logical statements, and if you don't [and remain oper-minded] then you should get to the end of this and say "oh! I see...";
1) force is the derivative of the amount of energy converted with respect to distance
2) a change of state requires a change of energy
3) an expanding universe means that from one moment to the next, the universe has changed its state (else there wouldn't have been 'expansion'). So, by (2), there has been a change of energy in the unverse from one moment to the next
4) the change of energy experienced by the universe, as refered to in (3), is measured as a change of dimension and as there is a change of energy with respect to distance, so, according to (1), there must be some 'force' manifest somewhere.....
what do you think that force is... if it ain't gravity?....