Astronomy's Mass Confusion

The Plasma Blindspot

Astronomers have long grappled with a puzzling discrepancy; the universe's visible components--stars, gas, and dust--do not provide enough gravitational pull to explain observed motions, from individual galaxies to vast clusters. This "missing mass" problem, first quantified in the 1930s, led to the hypothesis of dark matter: invisible, non-luminous material inferred solely from its gravitational effects. To date, dark matter remains a mathematical construct, added to Newton's equations to match observations, with no direct detection despite decades of searches and billions of dollars worth of equipment constructed to detect it. Critics argue this approach piles hypothetical entities atop unproven assumptions, while alternatives like electromagnetic plasma dynamics offer a testable resolution without invoking unseen mass.

Early Hints: Jan Oort & the Milky Way (1930s)

Dutch astronomer, Jan Oort pioneered the issue while studying stars near the Sun. Using Doppler shifts in stellar spectra to measure velocities perpendicular to the galactic plane, he calculated the mass density needed to maintain their observed vertical oscillations. In other words, imagine the disk of the Milky Way is a trampoline. If you (a star) jump, the height of that jump depends on how stiff (heavy) the trampoline is. Oort measured "jump velocities" of the stars to be about 20 km/s. He used the "trampoline's thickness" (the thickness of the Milky Way's disk of about 300 light-years) in the equations. Solving he discovered the visible stars and gas only add up to about 50 solar masses per square parsec. 

Newton's gravity implied a central force sufficient to prevent the stars from escaping the disk (trampoline) of the Milky Way at the observed velocities, very much akin to the Sun holding the planets in its orbit. If the planets went too fast, they'd fly out of the Solar System. Yet Oort found the mass required to exert enough force to keep the stars in the Milky Way was at least twice the visible total observed. His conclusion? The disk of the Milky Way must contain twice as much mass as we can see.

This local "missing matter" in the Milky Way disk became known as the Oort Limit.

Fritz Zwicky & Galaxy Clusters (1933)

Independently, Fritz Zwicky applied what is called "the virial theorem" to the Coma Cluster of galaxies, measuring high relative velocities of its 1000+ galaxies via redshift.

The virial theorem was developed in 1870 by Rudolf Clausius. It is a simple but powerful idea in physics and astronomy. It says that for any group of things (like stars or gas) held together by gravity and not flying apart or collapsing, there's a balance between how fast everything is moving and how strong gravity is pulling. In other words, when a system is stable, the total kinetic energy (energy of motion) is equal to half the gravitational potential energy, but with the opposite sign. Basically, that means if gravity is pulling everything in very strongly, then the stars must be moving very fast to keep the system from collapsing. If the gravity is too weak, or the objects are too fast, then the system would fly apart.

Another way to imagine this is to think of a swarm of bees. If they're buzzing fast but not escaping the swarm, something strong holds them. That swarm is the Coma Cluster, and the individual bees are the galaxies.

So, Zwicky's data showed that the Coma Cluster of galaxies should have flown apart already unless bound by far more gravity than visible mass could account for. In fact, 400x more! He proposed "Dunkle Materie" (dark matter): unseen bodies too dim to detect but gravitationally potent. Using Newton's laws, astronomers could compute the required new "dark matter" distribution.

Vera Rubin & Kent Ford's Rotation Curves: A Decisive Anomaly (1960s-1970s)

Credit: Mario de Leo/Wikimedia Commons

Advances in spectroscopy allowed Vera Rubin (the person, not the new telescope) and Kent Ford to plot precise rotation curves for external galaxies, starting with the Andromeda Galaxy (M31). This graph shows orbital velocity on the y-axis, and radial distance from the galaxy's center on the x-axis. Newton's law predicts velocity of the objects orbiting the center of the galaxy should decline as distance increases away from the center of the galaxy. Just like the Solar System planets; Mercury zips around the Sun fast (47.9 km/s), while distant Neptune is much slower (5.4 km/s). But instead of finding this to work out, Rubin and Ford discovered the velocity curves were flat! In other words, the stars at the edge of the visible galaxy were moving at nearly the same speed as the stars near the center of the galaxy (about 200-300 km/s). Visibly, we see that the stars in a galaxy are much more sparse toward the edges of a galaxy, so how could the mass distribution of the galaxy's disc be the same at the edges as it was toward the center?!

This discrepancy demanded 5-10x more mass in extended invisible halos; either that, or a breakdown of Newtonian gravity at galactic scales!

Dark Matter: A Purely Mathematical Solution

Astronomers preserved Newton's laws by postulating "dark matter." This matter had to be non-baryonic (i.e. not made of normal atomic matter), electromagnetically inert particles or objects. Imaginary candidates multiplied:

• MACHOs (Massive Compact Halo Objects): brown dwarfs, neutron stars, black holes.
• WIMPs (Weakly Interacting Massive Particles): exotic particles.
• Variants: Hot (HDM, e.g., neutrinos), Cold (CDM), Warm (WDM), Self-Interacting (SIDM), etc.
• FAIRIE DUST (Fabricated Ad hoc Inventions Repeatedly Invoked in Efforts to Defend Untenable Scientific Theories).

OK, that last one is made up to exaggerate a point regarding the rest of the list. I got it from Dr. Donald E. Scott, an electrical engineer (BS, MA, PhD) who often comments on these kinds of things. But after nearly 60 years, searches yield no definitive proof. MACHOs account for <5% of the inferred mass. WIMPs remain undetected. Princeton cosmologist Jim Peebles called it an "embarrassment" that dominant matter forms are hypothetical. Big Bang cosmology, requiring flat geometry and structure formation, amplifies the issue: about 25% dark matter, 70% dark energy (even weirder), leaving ordinary atomic matter at about 5% of the entire universe! Fully 95% of the universe is said to be unseen and unmeasured--purely mathematical adjustments to gravity-only-based models.

Alternatives: Questioning the Assumptions

The reliance on invisible made-up entities has prompted scrutiny. MOND (Modified Newtonian Dynamics, proposed by Mordechai Milgrom in 1983) tweaks Newton's law at low acceleration, fitting rotation curves without dark matter. Though empirically successful for galaxies, it struggles with clusters and the rest of cosmology.

A deeper critique targets the gravity-only paradigm. We know the universe is about 99% plasma. Plasma is sometimes said to be the fourth state of matter (with the other three being solid, liquid, and gas). Plasma is not only responsive to electromagnetic forces, but generates them. And electromagnetic forces are 1000 trillion trillion trillion times (10^39; 1 followed by 39 zeros!) more powerful than gravity. It is vastly more powerful than gravity at cosmic scales. Even in the quantum world, electrostatic repulsion between protons exceeds gravitational attraction by 36 orders of magnitude. Magnetic fields in interstellar space store energy equivalent to centuries of solar output.

Plasma cosmology, drawing on James Clerk Maxwell's equations and the Lorenz force, can explain the flat galaxy rotation curves naturally. Charged particles in galactic plasmas follow helical paths around magnetic field lines generated by currents (e.g. Birkeland filaments). Unlike gravity's fall off at the inverse of distance squared, magnetic force from linear currents falls off only at the inverse of the distance, not the distance squared. In other words, it reaches further, sustaining constant velocities further outward. Simulations by Anthony Peratt reproduce spiral galaxy shapes and rotation profiles via electrodynamics alone--no missing mass required.

Neutrinos (with mass) were briefly touted as dark matter, but they ultimately failed. They distribute homogeneously, not in halos. Exotics like string theory's extra dimensions or "brane interactions" remain completely untestable.

Timeline of the Missing Mass Saga

Year	Astronomer/Development	Key Observation	Response
1930s	Jan Oort	Stellar motions in Milky Way require 2x visible mass	Local disk discrepancy
1933	Fritz Zwicky	Coma Cluster velocities demand 400x visible mass	"Dark matter" coined
1960s-1970s	Rotation curves (e.g., Rubin & Ford)	Flat velocities in spirals	Massive dark halos
1983	Mordechai Milgrom	Proposes MOND	Modify gravity
Ongoing	Plasma models (Peratt et al.)	Electromagnetic forces fit data	No dark matter needed

Conclusion: Nothing Is Missing

Dark matter began as a fix for Newtonian discrepancies and evolved into cosmology's dominant component--all without tangible evidence. It safeguards gravity's universality but at the cost of fabricating unobservable entities. Electromagnetic plasma dynamics, grounded in laboratory-tested physics, resolves galaxy rotation and structure formation straightforwardly. Newton's gravity works where applicable; in plasma-dominated space, however, Maxwell and Lorentz reign. The "case of the missing matter" closes not with invisible gnomes and fairy tales, but by recognizing the right forces at play. Just plasma doing what plasma does and modern-day astronomy blind to it.