Off Topic — HabitableZone

Off Topic » in reply to re: The magic of force

not sure where this is leading, but anyway here goes

thanks, no I'm not a Physics professor and doubt I ever will be. I'm a mature-age Phd student-shitekicker, and happened to be on a roll over the weekend. Probably the pros like RL and others are simply too busy or tired to be able to devote time to this sort of stuff. The same probably applies to those with family responsibilities.

All I can do at this stage is reply to a few of your points -

I used the words "potential energy" to try and impress on the idea that the stationary object or mass does not have any kinetic form of energy, even though it may conceal a large amount of latent or "potential" for kinetic energy.

Well that seems to agree with the standard concepts of potential vs. kinetic energy ..

In other words the word energy when used by itself has the meaning of the word kinetic integrated with it.

I'd be careful here; energy as a term can refer to thermal energy as well, for instance. On the other hand thermal energy does include the concept of kinetic energy of individual particles. The hotter the fluid or gas, the faster these particles move, and hence the greater their kinetic energy.

Perhaps a better way of indicating that concept would be to say that the Einstein's formula tells us that mass can be converted into kinetic energy. If the mass is stationary in relation to its surroundings, then there may be a stress or a force or a pressure difference between it and its surroundings but one can not call that stress or force by the word energy if the above definition is accepted.

Don't forget the idea of EQUILIBRIUM, in which a object could be stationary because all the various forces acting on it are perfectly balanced in size and in direction. This is a common concept used all the time in science and engineering.

The physics word force as described by my encyclopedia is a: "vector quantity that tends to produce an acceleration of a body in the direction of its application."

For such a force to initiate the falling of a rock down, after I have thrown it up, the force would need to be exerted from the top.

Not necessarily: gravity is exerted from below, causing the rock to fall. You exerted the upwards force in the first place - and the rock would keep moving in a straight line with the same velocity if not for the downwards gravitational force. Gravity causes the upwards-moving rock to slow down to an eventual stop, and then pulls it increasingly faster back down to the ground.

In both ideas the unwanted word force creeps into the equation.
Well in this context, force is not an unwanted word, it's actually very useful in describing the situation. Forces are very useful descriptors in everyday Newtonian mechanics. It's just when we get to deeper and greater explanations, that we try and 'write them out of the picture' in favor of more basic quantities like energy and the geometry of space.


I do not know if Mr. Bernoulli intended his formulas to be used for the explanation of the fundamentals of kinetic and potential (latent) energies. However, the formulas that he came up with are very good explanation of the behavior of mass in motion.


That's a fair question; the answer is no. Bernoulli's theorem deals only with the BULK properties of fluids and gasses, not with their individual molecular components. It is extremely useful in all fields of aeronautical and naval engineering for instance. It says nothing about the fundamentals of space and time however, so you'd be wrong to extrapolate that into those areas IMO.

His principle states that the total energy in a steadily flowing fluid system is a constant along the flow path. An increase in the fluid's speed must therefore be matched by a decrease in its pressure.
There is a "flow" of photons in space, we already know that the speed of this flow is constant, if we consider space as the fluid that we are examining, then the speed of light becomes the constant that we can plug into Bernoulli's equations and by that method examine fields such as gravity, magnetism and electricity.


Yes 'photonic flux' is indeed an accepted concept - I don't know much about it though. Thing is, by considering SPACE as the fluid to be examined, you've got it upside-down. A 'flow of photons' implies that it's the PHOTONS, or the LIGHT ITSELF, which you should regard as the 'fluid' in question.

And keep in mind also, that Bernoulli can't be simply transplanted into this context - he knew nothing about electromagnetism or about quantum mechanics, which are the foundations of our knowledge of light. These were developments which came later in the 19th century and early in the 20th.

(BTW, Space DOES interact with light, insofar as the speed of light was shown by Maxwell (in the late 19th century) to depend on the permittivity and the permeability of pure vacuum (called 'free space'). These things describe how easily (or otherwise) a vacuum 'allows' the passage of an electric field (permittivity), and how 'well' it gets magnetized in response to an existing magnetic field. Pretty abstract concepts to be sure, but they apply to any materials at all (not just 'free space') and so are standard usage in physics, engineering and geology.

The main thing to extract from this last paragraph is that the permittivity and permeability of free space are both constants - unchangeable numbers ; and that the speed of light depends ONLY on these two quantities. This is one pointer to the question of why lightspeed is an absolute constant. )

I may not be able to respond to any reply for a few days (maybe not even till the weekend), but do keep checking ...

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