3 ms·

I'll have a go at sketching a simple explanation (feel free to correct): Light has some intrinsic properties, one of those is a repeating quantity called phas

I'll have a go at sketching a simple explanation (feel free to correct): Light has some intrinsic properties, one of those is a repeating quantity called phase. Simply, think of a number going 012301230123... By sending two identical beams of light out at source A, and reading at sink B then the phase should be identical at B. Since the phase has changed the same number of times for both. But if one of those beams has travelled further, it will be out of phase, eg., A1 = 01230123012, A2 = 012301230123 Imagine taking a difference of that last reading: 3 - 2. That difference is then a measure of how further A2 travelled than A1. By keeping all conditions equal along the paths of these beams except for one, you can measure the impact of the difference of that one condition. Eg., with gravity, we take such differences to be a kind of "mapping of space", since it is gravity which causes one to have travelled further, and gravity is really more-or-less just another name for "the geometry of space as determined by mass".

IIAOPSW 4y ago
The original experimentalist (Michelson) gave perhaps the best lay mans description in terms of an analogy with a swimmer crossing a fast moving river. Long story short, an interferometer detects the difference between two swimmers in their apparent distance swam (number of strokes they had to make), even though the physical distance traversed was the same for both. In this analogy the swimmers are individual photons of light and the "number of strokes" actually means the peaks / troughs of a given wave of light. Basically, a beam of light is split and then meets up again. If the length of the two paths are different, the peaks and troughs of the light wave will have drifted out of sync when they meet back up, and that will cause the interference pattern of the light wave interfering with itself to shift in proportion to the amount of drift. "Phase" is just the word scientists have settled on to describe this offset effect. Amplitude, wavelength and phase together give a complete description of any wave (light or otherwise). Hope that takes the mystery out of this "intrinsic physical property". Everything you wrote was accurate. I am merely expanding on the gaps.
- hammock 4y ago
  Two people walking side by side, in synchronized step, come upon a hill. The left side of the hill is flatter than the right side. By the time them have crossed the hill, the two people are out of step due to the difference in distance walked between them

IIAOPSW 4y ago

The original experimentalist (Michelson) gave perhaps the best lay mans description in terms of an analogy with a swimmer crossing a fast moving river. Long story short, an interferometer detects the difference between two swimmers in their apparent distance swam (number of strokes they had to make), even though the physical distance traversed was the same for both. In this analogy the swimmers are individual photons of light and the "number of strokes" actually means the peaks / troughs of a given wave of light. Basically, a beam of light is split and then meets up again. If the length of the two paths are different, the peaks and troughs of the light wave will have drifted out of sync when they meet back up, and that will cause the interference pattern of the light wave interfering with itself to shift in proportion to the amount of drift. "Phase" is just the word scientists have settled on to describe this offset effect. Amplitude, wavelength and phase together give a complete description of any wave (light or otherwise). Hope that takes the mystery out of this "intrinsic physical property". Everything you wrote was accurate. I am merely expanding on the gaps.

hammock 4y ago
Two people walking side by side, in synchronized step, come upon a hill. The left side of the hill is flatter than the right side. By the time them have crossed the hill, the two people are out of step due to the difference in distance walked between them