A galaxy-sized problem
In recent decades, astronomers studying other galaxies noticed that the stars orbited the centre of their galaxies at a far faster speed than they should do, at least according to Newtonian motion or Relativity. The further out a star is from the centre of its galaxy, the slower it should move, in order to maintain a stable orbit, but according to the astronomers' measurements, the stars are actually going faster, the further away they are. According to the current laws of physics, those stars should have flown clear out of their galaxies long ago. The graph below from the M33 galaxy shows this strange phenomenon.
Physicists have worked hard to explain this effect and the current dominant theory amongst them is that an enormous amount of matter in present in the universe that we can't see. Not surprisingly, this is known as dark matter. It's interesting, from a psychological point of view, that the materialist physicists' solution is to make the universe more physical to explain the anomalous readings. Unfortunately for them, so far, no one at all has reliably detected dark matter, even though lots of money and many years have been spent looking for it.According to the rules of scientific investigation, dark matter should therefore be regarded as nothing more than an interesting idea, but as there is currently no popular theory to replace it, many physicists are pushing it as a fact, even without any direct, supporting evidence.
Interestingly, there is another possible way to approach this problem of 'speedy stars'. It involves a very important assumption.
Beliefs and Assumptions
Einstein's Theory of Relativity was a work of genius. His mathematics is elegant, inspired and with later refinements, flawless. His theory to explain the motion of bodies in the universe has stood the test of time with flying colours. Observations of the movement of physical bodies in our solar system match Einstein's predictions to an incredible degree.
But Einstein did make a very important assumption when it came to gravity. Einstein assumed that gravitational mass and inertial mass were the same. This is known as the Equivalence Principle. In other words, Einstein decided that the effort to push an object around is the same as the effort required for one object to be drawn to another by the force of gravity. Even now, no one has detected any measurable difference between these two phenomena, at least not here on Earth. It would therefore seem that Einstein was right to make this assumption.
But what if the Equivalence Principle was not true for all physical bodies? This possibility isn't completely crazy. In recent years, physicists have found evidence that the equivalence principle isn't true in all situations. Endre Kajari at the University of Ulm in Germany and his colleagues have shown theoretically that in a quantum situation, the gravitational mass and the inertial mass of a system can be very different.
It would seem that if the Equivalence Principle wasn't always true, physicists would have spotted this issue by now, but what if the Equivalence Principle fails when applied to physical bodies that possess high levels of electrical charge in a plasma state? It would be understandable that such a phenomena hadn't be spotted, since huge balls of highly electrified plasma under intense heat pressure aren't exactly a common occurrence on Earth, but if it was true, it could be the key to the anomalous rotation speed of stars.
It's interesting to note that if our star does have much less inertia because it is a huge ball of electrified, high-pressure plasma, how would we even tell? In our solar system, everything's moving through space except for our sun. Our sun rotates, but its movement through space is not easily apparent to us, since everything else is moving with it. As a result, we on Earth can observe the motions of ourselves, our moon, the other planets and our own satellites and rocket ships relative to each other with great precision, but it's much harder for us to work out how our sun moves with respect to other suns. Because of this, it's understandable that our sun might be hiding the fact that its inertial mass is not the same as its gravitational mass.
A quantum sea
Before continuing with the puzzle of 'speedy stars', it might be worth reading some new ideas about what causes mass and inertia. For example, one thought-provoking and innovative theory to answer this question is described on this CalPhysics Institute web page. The article states that what we call inertia and gravity can be explained as 'an interaction between the electromagnetic quantum vacuum and the fundamental charged particles (quarks and electrons) constituting matter.' In other words, what we think of as the physical universe isn't hanging out there in nothing. Instead, all the physical 'stuff' of our universe is floating on a quantum sea. As the fundamental constituents of matter moves across this quantum sea, their interaction with the quantum sea causes a resistance to motion that we call as inertia. The CalPhysics authors point out that their theory doesn't clash with Relativity, but instead explores another way of looking at the same behaviours. As the article goes on to say:
In this view, which we call the quantum vacuum inertia hypothesis, matter resists acceleration not because of some innate property of inertia, but rather because the electromagnetic quantum vacuum provides an acceleration-dependent drag force.
Note the words 'electromagnetic quantum vacuum'. If it is an electromagnetic field that is creating the drag, could it be possible that an object possessing a very high level of electromagnetic energy is more 'slippery' than one with a mundane level, like a planet or a cannonball or you or I? If this is true, then such a phenomena would transform the field of transportation and flight. If someone created a high-voltage, plasmic field around a vehicle, that vehicle might suddenly have much less inertia. Because the whole vehicle had now become 'super slippery' against the quantum 'sea' pervading reality, its pilots could move it through space at huge speeds with minimal effort. By strange coincidence, this possible ability has been mentioned as a form of technology being secretly developed by classified military teams working within our planet's major states, but as the information concerned is mostly hearsay, it's hard to be confident that it's solid fact.
But if it is true that the Equivalence Principle breaks down when applied to bodies possessing high levels of electrical charge under pressure, what would it tell us about the 'speedy star' problem of star orbiting the centre of their galaxies too quickly for Relativity?
The brakes are off
Solar systems begin as clouds of interstellar gas. Slowly, the molecules in the huge cloud of gas move towards each other due to the effects of gravity. As they draw together, the centre of the gas cloud becomes more and more dense. Eventually, as more material concentrates in the middle of the cloud, the matter in the centre becomes so dense that fusion reactions take place, where the hydrogen molecules of the gas fuse together to create helium and a pile of released energy. In a brilliant release of light, a star is born. The remaining matter in the cloud forms into planets that then orbit around this parent sun, thus creating a solar system. Galaxies form in just the same way, just with more stars and planets.
But if the idea described in the previous paragraphs is true, then at the moment when a cloud of gas becomes a star, that ball of matter will experience a large drop in its inertial mass. The ball of matter's gravitational mass may have stayed the same but its inertial mass has suddenly been much reduced. In a sense, the star has suddenly turned from something wading through treacle as it orbits its galactic centre to something that can skate on ice. Interestingly, if its gravitation mass has stayed the same but its inertial mass has dropped, then it has to move faster to maintain a stable orbit. If its momentum is conserved during its birth as a star, it will suddenly move much faster, which is exactly what it needs to do to stay in orbit. This would explain why the whole new-born galaxy wouldn't collapse on itself; the system of stars and gas are still orbitally stable, each star simply goes faster when it is born out of a ball of gas.
It would be great to do some maths to develop this idea. Unfortunately, I don't have the maths, but the observed speeds of galaxies do indicate the nature of the new gravitation/speed relationship.
If we study the orbiting speeds of stars around galaxies, it looks as if the gravitation attraction between stars is dependent on the inverse of the distance, rather than the inverse of the distance squared, as in normal Newtonian gravity. Here’s a rough graph to show the effect:
I’ve put in some reasonable values for the mass distribution of a galaxy as it heads out from its centre (shown by the blue spotted line). In other words, there’s a fat lump of stars in the middle of the galaxy and then a slow taper to nothing. I’ve also popped in reasonable values for the mass attraction acting on stars at increasing distances from the centre of the galaxy.
The green line shows how fast the orbiting stars should be going, in relation to their distance from the galaxy’s centre. I’ve calculated these values using Newton’s Equation of Gravity, which isn't exactly the same as Einstein's Law of Relativity, but it is pretty close.
The yellow line is the doozy. This line shows the speed of the orbiting stars if the gravitational attraction between stars is inverse-linear over distance, rather than inverse-squared. As you can seen, the stars have to move faster, the further away they are from the galaxy's centre, in order to maintain their orbits, rather than slower, which is how they're supposed to behave according to Einstein's Relativity and Newton's Law of Gravity.
If we compare that yellow line to the observed orbiting speeds of the stars in the M33 galaxy (as shown in the diagram earlier in this article), it's a pretty good match.
Why inverse-linear? I don't know. Interestingly, if suns do have an inertial mass much lower than their gravitational mass, then they would 'wobble' more than Relativity says they would, under the influence of their own planets. Checking for such stellar behaviour would be a good way to support or dismiss the idea in this article. Unfortunately, if it was true, it would make a mess of a lot of current exoplanet research, since many of those planets' existence have been deduced due to the wobble of their parent stars (unlike the 'dimming' method, which would be unaffected).
Overall thought, it's just a fun idea. I would put it in a box marked 'novel mental noodling'.