1926 · Proceedings of the National Academy of Sciences
A Refinement of the Michelson-Morley Experiment
Verdict
MIXED
The study follows the scientific method, but the paradigm it assumes splits the tests. The worse layer decides. The verdict is mixed.
1·Study methodology · inside the paradigm
SCIENTIFIC
Follows the scientific method within Luminiferous Ether.
2·Paradigm · Luminiferous Ether
MIXED
Splits the tests. The worse layer decides.
How the verdict is decided
The verdict grades both layers: the paradigm this study assumes, and how the study was carried out inside it. Both must be scientific for the whole thing to be scientific. A clean method inside an unscientific paradigm is unscientific. An unscientific method inside a better paradigm is unscientific. A split on either layer is mixed. The worse layer decides.
1·Study methodology
Did this study test its claim with methods that are independent, falsifiable, and non-circular?
SCIENTIFIC
This paper claims that a refined Michelson-Morley experiment using a compact helium-filled interferometer found no shift in the interference pattern, failing to confirm Miller's reported ether drift. All three tests pass.
Independently Verifiable
Pass
The fringes are visible through a telescope, and their failure to move when the apparatus rotates is something anyone can witness.
Falsifiable
Pass
If the fringes had shifted by even a quarter of what Miller predicted, Kennedy's null claim would have been dead.
Non-Circular
Pass
The interferometer tests a prediction of the ether theory without building the conclusion into its design.
Why
Kennedy built a small interferometer with 4-meter light paths sealed in a helium-filled case to eliminate the temperature and air density problems that plagued Miller's 65-meter instrument. He looked through a telescope at interference fringes and rotated the apparatus. The fringes did not move. A shift as small as one-quarter of what Miller predicted would have been visible, and that shift would have killed Kennedy's claim. The observation is a pattern of light and dark bands that stays put when you turn the device. Anyone can see that. The interferometer is a physical instrument that produces visible fringes regardless of whether the ether theory is correct. The theory predicts a shift. The experiment tests that prediction. The null result is not assumed by the instrument.
2·Paradigm · Luminiferous Ether
Does the framework this study assumes pass the three tests?
MIXED
Independently Verifiable
Fail
The ether is not something you can see, touch, or feel. It exists only as the theory's explanation of how light travels.
Falsifiable
Pass
The ether theory predicted a detectable fringe shift, and when no shift appeared, the field eventually accepted that the ether was dead.
Non-Circular
Fail
The ether was named by the same theory that told you what the interferometer should detect.
Why
The luminiferous ether is a medium nobody has ever directly observed. The theory says light travels through it, and if the apparatus moves through it, interference fringes should shift. Kennedy's interferometer tested that prediction. The prediction failed, and over time the field accepted the failure as the death of the ether. That is real falsifiability, and it is why this paradigm is dead rather than degenerating. But the ether itself was defined by the same theory that designed the instrument to detect it. The theory named the medium, predicted what it would do to light, built a device to catch the effect, and then interpreted the device's output as evidence about the medium. The entity never existed outside that loop. The fringes are real. The ether is not.
From the paper
The result was perfectly definite. There was no sign of a shift depending on the orientation.
a shift as small as one-fourth that corresponding to Miller's would be perceived
Because of its small size the apparatus could be effectively insulated, and circulation and variations in density of the gas in the light paths nearly eliminated.