Category Archives: center of gravity

What’s Up with Gravity? part 2

In part 1, I talked about fields and field gradients.  I want to expand on that just a little because I believe that it is key to action-at-a-distance and gravitational forces in particular, and I think I can make it a little clearer.

We know that Einstein’s General Theory of Relativity tells us that gravity is a result of space-time warping in the presence of a mass, often shown in figures as a membrane with a large body (such as the sun) in the middle, sitting in a depression in the membrane and a smaller body (such as the earth) circling around in a smaller depression in the same membrane.  I mentioned that we humans have a tough time getting our mind around that situation when it comes to our own bodies in the earth’s gravitational field.  When we are standing on firm ground, where is the membrane and what is being warped?

I also mentioned that a mass is surrounded by a field and we can draw a circle or sphere around that mass where the field strength (gravity) is the same at all points on the circle or sphere and additional circles around points further out for smaller and smaller strengths.   The result is a series of shells that stretch out to infinity, or at least as far as light has traveled since that mass was placed in that position.  This is different than the normal depiction of fields as being lines connecting two masses along the lines of force.  I’m convinced that my shell drawing of equal strength points will be easier to understand.

gravity figures 1a and 1b

The figure above illustrates two situations.  Figure 1a shows two masses that are different sizes and also far apart.   The field lines are drawn around each for some easily measurable strengths and the drawing shows only those fields that have sufficient strength to measure on our crude meter.  In fact the fields go on forever in ever-decreasing strength.  If we had a better meter, we could draw lines all the way between them and beyond.

The fields in figure 1a are essentially circles around each mass because the masses are positioned so far apart that we can’t discern any distortion in the circles.

The fields in figure 1b show a situation where the smaller mass has been placed closer to the larger one and overlap the outer two measurement circles of each.   The figure shows that the fields merge.   The outer rings of both masses were the same strength before and still are because we are measuring the field at equal strength at the minimum reading we can take with our poor meter.  

Notice that the outer ring and the one just inside of it have now combined for the two masses and as a result of the added strength moved out a little further, that is, bulged further out on the far side of the small mass.  In addition, the 3d ring of the bigger mass has also bulged a little due to the movement of the others.   It should be clear that the fields in the bulged areas are not stronger, but are the same strength as before, but now our measurements of that strength are further out.

The two masses are now part of one system  and the rings around them are distorted a little at all points as they now form equal fields around the center of gravity of the two masses.  That is not really apparent in my simplified drawings, but the system now acts as a larger mass to other masses (not shown) further out.

Our body is a system of masses that act like the system above but infinitely more complicated as the fields of every molecule of our body interacts with every other and with fields external.  However, we can now visualize our body as being the smaller mass and the earth a similar system of masses much bigger.   When we are on the earth, our mass interacts with and modifies the earth’s field ever so slightly (and the earth ours), but sufficient to feel the effects due to the enormous mass of the earth.

There is still a gradient across the two masses (the fields on each side of it are different sizes), and a tension across the gradient that tends to pull the masses together.  Actually, it is not clear if it is a pull or a push.  Is the larger mass pulling the smaller one or is the enhanced field that has now moved out behind the smaller one now giving it a slight push?  To be complete we have to say the small one is also pulling on the larger one or possibly the field behind the larger one is pushing it toward the smaller one.  Indeed the field behind the larger one has also moved out ever so slightly in the same manner as shown for the smaller one, but not discernable from the drawing.

From the drawing, I’m inclined to say they are being pushed together, in the same manner that a rubber band wrapped around two fingers pushes the fingers together.    

How did the fields get there in the first place?

There is no question that the fields are there.   But is the gravitational field moving at the speed of light outward from the mass?  The short answer to the last part is no.   The fields as I explain them are essentially static.  They are modulated by disturbances within the core of the mass (quarks, gluons flying around) but the field strength is essentially static except as modified by the fields of other masses elsewhere in the universe.  That modulation of the fields goes on constantly in ways we could never compute.   The modulation or changes in the field do move at the speed of light, but the lines drawn around our figure do not change except as other masses move and influence the fields.

The answer to the title question “How did the fields get there in the first place?” is this:  They have been there since the mass was created.   For the atomic scale, we are talking about when the quarks and gluons first condensed out of the big bang expansion and atoms and other particles were formed.   Each atom and each particle that has mass had a field established at that time and it has followed them around ever since.   On a larger scale, as atoms combined into molecules and dirt and other debris combined into lumps and moons, the systems of fields depicted in figure 1b began to grow as well.    Eventually a sun was formed, an earth was formed and we were born into it.  Our masses accumulate and become a smaller system of our own.

Thus we are composed of atoms from the creation and from the deaths of stars which may have flung our larger atoms and their attendant fields out into space to end up as us with enough intelligence to understand a few things about our world, including a little about gravity.

Where does mass come from?

If gravity is a function of mass, where does mass come from?   Actually there is no problem here:  if E = mc^2  then it can be restated as m = E/C^2.   Simply put, mass is a form of infinitely condensed energy.   Release the energy and you have an atomic bomb.   The components of an atom really have very little individual mass among them.  All of the mass is ultimately from the energy within.   The quarks and gluons and other stuff inside are moving about in a wildly speedy fashion, like a whirling dervish.   In effect, gravity is more of a function of energy than any real matter.  

The point of mentioning this is that I believe that the gravity fields that were established at the beginning, shortly after the big bang, are the left-over effects of energy being condensed into matter – huge amounts of energy being squeezed or formed out of the soup of creation during the bang and leaving lonely fields stretching out forever and following that condensed energy wherever it goes.  So what holds us down is essentially the debris of locked up energy condensed when our atoms were created, long before the earth was formed and eventually accumulated into the ground we walk on. 

Copyright 2007 by James A. Tabb

Marietta, Ga.