MOD Gravity: Proven

[Dennis P Brown]

So, finally, someone has put a stake through the heart of the Dark Matter theory! This was done using the Gold Standard of direct experimental observation, which was overwhelming (meeting the famous 5 Sigma criteria requirement.) Modified Gravity's prediction's were tested in numerous binary star systems and shown to be the ONLY approch that exactly predicted the orbits observed - neither dark matter, Newtonian, nor Einstein GR* matched the systems orbits as closely (these theory's predictions did not supply the correct orbits and these results were well outside the experimental error bars.) The scientist examined many systems so the results are iron-clad and the five Sigma is well earned.

See: https://phys.org/news/2023-08-smoking-g ... -wide.html


*GR has Newtonian one over 'R' squared built in; so GR isn't disproven by this experiment but only needs to be adjusted for this fact

Aside: the fact that gravity has been shown to not follow a 1/r^2 law adds further weight to the fact gravity isn't either a 'force' nor is it carried by any massless particle (type of photon.)

Another aside: watch as 1) Most physicist/Astronomer's continue to ignore this fact 2) Continue to get millions $$$ to build 'Dark Matter' detector systems 3) Claim (by particle physicist) that gravity is carried by these nonexistent photons that the standard model does not in any manner or form predict.

[Richard Hull]

I still hold where there is no mass, there is no warped space. There is no chicken or the egg here. Mass and only mass warps space. There is no evidence of warped space or gravitational lensing without real matter and positive ponderable mass being present. Gravity and thereby, warped space, is a direct function of mass and mass alone. Warped space is a mere consequence or byproduct of ponderable mass, just as all electromagnetism (light) is a function of some form of accelerated or decelerated charge. Charge is found in all mass be it electronic or nuclear in origin. There is no light without charged mass in motion or mass being turned into pure energy. No mass, no EM, no light, no photons.... No mass, no warped space.

Richard Hull

[Frank Sanns]

While I agree that forces and gravitons are contrived concepts, I am not sure I understand all of the conditions of this.

How is the gravity environment at a great distance known?

Also, what of the inertial mass and gravitational mass equivalence principle? Can't the experiments not be done in the micro gravity of orbit?

[Richard Hull]

I can't imagine the inertial mass ( resistive, pondermotive mass) being different from the gravitational mass.
Otherwise, we would not be able to accurately work spacecraft in accurate acceleratory "slingshots" round other massive planets. I would think that due to truly minimal perturbations unknown to us around such bodies that small post slingshot corrections and minor steering thruster adjustments would certainly take place. Such corrections would have nothing to do with the mass of the craft, be it inertial or gravitational, but instead, Uneven anomalies in the mass distribution of the larger body having assumed an average smoothed mass of the larger orb.

Earth has its South-Atlantic anomaly which must be accounted for in critical positioning of the Hubble where precise positioning is critical for astronomical observations. I know a guy who does the nightmarish calculations for the Hubble's critical positioning for astronomer time slots in advance and he says the anomaly, while well understood now, must always be accounted for. The mass of the Hubble is fixed. The gravity of the Earth or the deformed space around it, take yer' choice is not perfectly uniform due to variable mass elements within the body.

Other planets' mass must be known to some degree of accuracy as an average to do "slingshot flybys". Any anomalies can be corrected by the steering jets on board, post flyby.

The closer you dare to approach such a slingshot event, the more acceleratory boost in speed you will get, but also the more an unseen anomaly might create a post encounter error in direction or trajectory.

Richard Hull

[Dennis P Brown]

I am no expert in this field by a long shot but know enough to not make any overt blunders; but I do agree with Richard that the entire concept of 'curved space' is related to the properties of matter (more or less - energy also comes into play but that is not relevant at this point.)

The idea of space being curved is how 'gravity' extends across space-time between objects (and time is the critical component here since that fundamental concept really is what gives gravity its 'force' relative to inertia mass or 'rest mass. Or so current interpretation is explained. It does not explain why this occurs but is suspected to be related to quantum entanglement.)

As for Mod gravity, it says nothing at all about why gravity is not an one over 'r' squared 'force'. The fact that this thing called gravity does not obey that property is a strong reason it is not 'carried' by photons. At least as we understand space being three dimensions (Time causing a non-spatial dimension) and how photons must distribute themselves in this space (if space has more than 3-D, then all bets are off.)

That there is no significant 'dark matter' within a solar system sized volume to account for the change in the binary star orbits (as carefully measured) this rules out that substance (unlike, say, a galaxy) as the cause of the measured orbit deviation from standard 1/r^2 orbit. Ditto this means that Newtonian gravity does not work in these systems either.

There are complexities - this was done for binary systems that have large separations (the mod effect is so small the distances must be large to see the true effect.) They did this measurement for many systems so the results are extremely strong (no outliers would dominate the results.) hence the high Sigma claim.

This is no minor result. This is on the same level as star light being 'bent' by the Sun for the 'proof' of relativity (in fact, better than those early crude measurements.) This completely invalidates dark matter (as being a physical particle - i.e. has gravitational effects) and makes gravitons far more unlikely.

The issue of inertial mass and gravitational mass is a subject that is beyond current theories but I do believe can be addressed. Hopefully - that is.

[Frank Sanns]

Gravity has many misunderstandings as it were. Scifi movies do not help and neither do news stories.

I remember being astonished that a horizontally fired projectile would hit the ground at the same time as an object dropped from the hand. I was in my early teens and was a rifle target shooter. To shoot with less drop, you increased the velocity of the projectile. Simple. However, it was not the velocity per se that changed when the bullet hit the ground. It was the TIME. If the bullet got there faster, it had less time to drop. Dahh! But until that moment, gravity, in my early mind, worked differently that reality.

Similarly, many people do not fully understand the gravitational sling shot. Gravity alone cannot sling shot anything. Gravity is a conservative force with zero curl so it is not path dependent. Throw a ball up in the air and the kinetic energy will be converted to gravitational potential energy. The ball will eventually stop its upward velocity then return to your hand with the same kinetic energy that it left with (ignoring air and all other non-elastic effects).

A gravitational velocity increasing slingshot cannot happen under simple conditions as KE and PE just trade off with each other. Momentum, a vector quantity on the other hand can change. An example is a simple orbit. Energy remains constant in a circular orbit but the moment is constantly changing direction. It is then possible to change the direction of a craft by using a massive body like a planet.

To have a velocity increasing gravitational slingshot, a planet has to be moving. It is the movement of the planet that can impart addition velocity to a spacecraft.

A simple way to understand this and the limit to which the velocity can be increased is to consider dropping a rock onto a magical moving platform. The rock could be moving straight down or at any angle to the moving platform. This magical platform does not arrest the original motion of the rock. All the platform does is give the rock a ride and brings it up to some percentage of velocity that the platform is already going. The rock can continue on its path at any time its trajectory has chosen, but when it leaves, it will also have some or all of the velocity of the platform added to it. This is how the slingshot works. It is really only velocity addition and opportunity to to change directions. Gravity only has to do with the string that holds the planet and object together while this is happening.

I think we have to be careful when we observe effects of gravity and consider that it is just the string in the experiment and not necessarily the CAUSE of what is being observed. Not saying it is not the cause, but it might not be either.

[Richard Hull]

In all slingshots, the planet orbital velocity is decreased and it orbit decays. This is a KE for KE exchange in the end. This would not be possible without the gravitational/curved space effect of the large orb. F=MA. The force here is the interaction between two kinetic inertial masses in motion. Thus, the resulting momentum exchange acceleration and vectored force.

Naturally, the orbital decrease and reduced velocity of something like Jupiter, say, is real, but imperceptible. Even a large asteroid of many thousands of tons in close pass by on Jupiter would be accelerated and suffer a direction alteration, with no real readily observed effect on the giant planet. Too close and tidal effects could shatter the asteroid and the smaller pieces would retain the accelerated velocity just prior to break up and have the individual momentum needed to orbit the planet. This is how planetary rings are formed. (conditions have to be perfect for this to occur.)

It is a good thing that we have the giant gas planets and even the sun to do what combustible fuels can't do for our robot probes. We trade travel time for increased momentum/KE and vectored directional change. Even an orbital item, like those that we have circling Mars are idealized captures at a critical slot computed to allow the momentum of the would be orbiter to be captured without tidal effects ripping it apart or having it slingshot off into space.

As the thing we call gravity is mutually attractive a dead stationary giant orb, (nearly impossible in space), would still be able to slingshot a small craft, the difference is the exchange would rob the small craft of velocity by again exchanging momenta with the 0 momenta giant body by increasing its momenta/velocity and changing its direction, even if marginally. All would remain the same, but both would have changed velocity and direction of travel. Flies in the ointment: always! Slowing or accelerating a craft via slingshot risks tidal destruction of a super velocity, flimsily constructed craft. Much data related to the strength of a craft, its approach velocity and desired boost in momentum must be considered and calculated.

Richard Hull

[Dennis P Brown]

Here is the link to the paper:

https://iopscience.iop.org/article/10.3 ... 357/ace101


Richard, I didn't know that about planetary ring formation.

[Frank Sanns]

No significant tidal forces for a close approach if a small celestial body like Jupiter. In fact, no felt forces in the acceleration if you were onboard. It is free fall. Unless there is atmospheric drag, you would not know you weren't traveling in a straight line.

Gravity acts on all atoms the same unlike an acceleration by thrust. With thrust, the first atoms push against the second row of atoms and so on. By the time they all pile up, there is great forces on them. No so with gravity UNLESS there is such curvature from being close to a super massive body that the distance from top to bottom feels more gravity because the radius from center of gravitational mass becomes very small.

[Dennis P Brown]

Frank, any time one's path is curved in space (of course, compared to the appropriate space-time metric), then an 'apparent force' (identical to a gravitational acceleration but generally, extremely small) occurs. So on Earth, we have three such 'forces' - the one due to the Earth's mass (the big one we feel) and the (far smaller) ones due to Earth's circular orbit as well as the one due to its axis rotation (both accelerating frames.) In fact, the rotation one causes 'frame dragging' of local space and that was recently measured using a special satellite built just for that purpose.

Aside: the orbital acceleration effect by a satellite going around the Earth occurs for GPS satellite's constantly. This time change (acceleration) must be accounted for to properly locate someone using the ground based receiver.