Modern examples of examples of example of the Michelson-Morley experiment

Starting with concrete examples of the Michelson–Morley experiment

Before getting lost in theory, let’s talk about actual setups. When people ask for examples of examples of example of the Michelson-Morley experiment, they usually mean: How is this thing really done in practice today? That can mean a historical reconstruction, a teaching lab, or a high‑precision modern variant.

Instead of a single “canonical” procedure, physicists now use a family of related interferometer experiments. These range from simple Michelson interferometers in college labs to ultra‑stable optical cavities that push the limits of special relativity.

Below, we’ll walk through several real examples, from low-tech to high-tech, and show how each one plays the same basic game Michelson and Morley played in 1887: compare the speed of light along different directions and look for tiny differences.

Classic tabletop lab: a teaching example of the Michelson–Morley idea

A first example of the Michelson–Morley experiment that most physics students see is the standard undergraduate optics lab. The equipment is modest: a laser, a beam splitter, two mirrors, and a screen.

Here’s how that modern teaching version works in practice:

You start with a small, stable laser (often a red He–Ne or a diode laser). The beam hits a beam splitter that sends light down two perpendicular arms. Each arm ends with a mirror that reflects the light back to the splitter, where the beams recombine and create an interference pattern of bright and dark fringes.

This is a direct example of the original Michelson interferometer. Students rotate the entire apparatus on an air table or a rotating platform. If the speed of light depended on direction relative to some “ether wind,” the fringe pattern would shift as the device turns. In reality, within the sensitivity of the lab setup, students see no systematic shift.

That simple null result is one of the best examples of how the Michelson–Morley logic survives in modern education. It’s not just history; it’s a live demonstration of isotropy of the speed of light.

Historical reconstructions: real examples that mirror 1887

Another category in any list of examples of examples of example of the Michelson-Morley experiment is the full‑scale historical reconstruction. Museums and some advanced labs rebuild (or closely mimic) the 1887 apparatus:

• A large stone or metal platform floating in a pool of mercury to allow smooth rotation.
• Long optical paths (tens of feet) folded back and forth with mirrors to amplify any time‑of‑flight difference.
• Careful temperature control to keep the interference fringes stable.

These reconstructions are real examples that show just how demanding the original measurements were. Visitors and students can see the fringes, watch the slow rotation, and understand why Michelson and Morley were confident that their null result was not just an equipment glitch.

A nice historical overview and context can be found in the materials around special relativity from MIT OpenCourseWare and other university physics departments, for example the relativity notes at MIT Physics. These sources often use the experiment as the canonical example of a null result that changed theory.

High‑stability optical cavities: 21st‑century Michelson–Morley analogs

If you want the best examples of modern precision tests that carry the Michelson–Morley DNA, you look at experiments using ultra‑stable optical cavities and lasers. These aren’t cosmetically similar to the 1887 setup, but conceptually they’re very close.

Here’s how a typical 2020s version works:

Researchers lock a laser to an optical cavity — essentially a pair of highly reflective mirrors facing each other. The resonance frequency of the cavity depends on the speed of light along the cavity’s axis. If the speed of light were direction‑dependent, a cavity oriented north–south would resonate at a slightly different frequency than one oriented east–west.

Now put two such cavities at right angles, stabilize them in temperature‑controlled vacuum chambers, and compare their resonance frequencies over time as the Earth rotates. This is a modern example of the Michelson–Morley idea: different directions, same physics question.

Teams around the world have used this approach to test Lorentz invariance — the idea that the laws of physics, including the speed of light, are the same in all inertial frames. Results published through collaborations with institutes like the Max Planck Society and U.S. universities show no detectable anisotropy, tightening bounds on any deviation from special relativity by many orders of magnitude compared to 1887.

For background on Lorentz invariance and modern tests, the relativity resources from Stanford University and the American Physical Society provide reliable context and citations.

GPS and satellite timing: indirect but powerful examples

Not every example of the Michelson–Morley concept uses mirrors and beam splitters on a bench. Some of the most interesting real examples live in orbit.

The Global Positioning System (GPS) relies on extremely accurate timing signals from satellites. Those signals must account for both special and general relativity: the satellites’ motion and the weaker gravity at their altitude change the rate at which their onboard clocks tick compared with clocks on Earth.

If the speed of light depended on direction in some ether‑like way, GPS calculations would drift in a direction‑dependent pattern. Engineers and physicists have checked for exactly that kind of behavior. The fact that GPS works to meter‑level precision over long timescales is a strong, ongoing, real‑world example of the Michelson–Morley principle in action: light’s speed is isotropic to extremely high accuracy.

Organizations like NASA and the U.S. National Institute of Standards and Technology (NIST) publish accessible explanations of how relativity enters GPS and precision timing. These are some of the best examples of how a 19th‑century null result shapes 21st‑century infrastructure.

Fiber‑optic interferometers: telecom‑era examples of Michelson–Morley logic

In the telecom and sensing world, fiber‑optic interferometers provide another family of examples of examples of example of the Michelson-Morley experiment.

Instead of free‑space beams, light travels through long coils of optical fiber. A fiber‑based Michelson interferometer splits light into two paths, sends it through separate fiber coils, and recombines it. Engineers use these devices for sensing strain, temperature, and rotation.

When researchers use fiber interferometers to look for anisotropy in the speed of light or direction‑dependent propagation effects, they are effectively running a modern, practical example of the Michelson–Morley experiment. The geometry is different, but the question is the same: do different directions or paths through space (or through moving fiber) change the effective speed of light in a way that violates relativity?

Results so far line up with special relativity. These experiments double as both engineering tools and subtle tests of fundamental physics.

Rotating cryogenic setups: pushing sensitivity to the edge

Some of the best examples of cutting‑edge Michelson–Morley‑style experiments use rotating platforms and cryogenic temperatures. The basic idea is: if you cool everything down, reduce vibrations, and rotate cavities or interferometers slowly, you can detect unbelievably tiny frequency or phase shifts.

A typical 2020s research‑grade setup might include:

• Optical or microwave cavities cooled to cryogenic temperatures to minimize thermal noise.
• A slowly rotating turntable that changes the orientation of the cavities with respect to the stars.
• Ultra‑stable lasers or oscillators locked to those cavities.

By monitoring frequency differences as the apparatus rotates and as Earth orbits the Sun, researchers look for periodic patterns that would be signatures of Lorentz violation. These ultra‑sensitive tests are some of the sharpest real examples of the Michelson–Morley mindset applied with modern technology.

Again, the bottom line: no convincing deviation from relativity has been seen. But each new experiment tightens the bounds, and the methodology is a direct descendant of Michelson and Morley’s original work.

Classroom simulations: digital examples for teaching relativity

Not every student can access a high‑end optics lab, so digital simulations have become popular examples of the Michelson–Morley experiment in teaching.

Physics education platforms and open‑source tools let students:

• Adjust arm lengths and rotation speed of a virtual Michelson interferometer.
• Add a hypothetical ether wind and watch the predicted fringe shifts.
• Then switch to Einstein’s postulate of constant light speed and see the fringe shifts vanish.

These simulations are lighter‑weight examples of examples of example of the Michelson-Morley experiment, but they do something important: they let students compare “pre‑Einstein” and “post‑Einstein” expectations side by side. That contrast makes the historical null result feel less abstract and more like a real decision point in physics.

Many university physics departments, including major U.S. schools, host such simulations or link to them from their course pages. They have become standard teaching tools by 2024–2025.

Why these examples still matter in 2024–2025

So, where does this leave us? Across all these examples of examples of example of the Michelson-Morley experiment — from tabletop lasers to GPS satellites — a consistent picture emerges:

• The speed of light in vacuum is isotropic to within extremely tight experimental bounds.
• No experiment has found the directional dependence that an ether theory would predict.
• Modern tests probe Lorentz invariance far beyond Michelson and Morley’s original sensitivity.

In 2024–2025, the frontier isn’t about “proving Einstein right” in a broad sense; it’s about looking for tiny cracks where new physics might appear. High‑precision interferometry and cavity experiments are part of that search, whether the goal is testing quantum gravity ideas, probing dark sector models, or cross‑checking standard relativity.

The fact that so many different real examples — optical cavities, satellite timing, fiber interferometers, cryogenic setups, and classroom labs — all point in the same direction is exactly why the Michelson–Morley experiment remains a staple of physics education.

FAQ: common questions about examples of the Michelson–Morley experiment

What are some accessible examples of the Michelson–Morley experiment for students?

Accessible examples of the Michelson–Morley experiment include simple Michelson interferometers in undergraduate optics labs, where a laser is split into two perpendicular arms and recombined to form interference fringes. Rotating the apparatus and seeing no systematic fringe shift is a direct, hands‑on example of the original experiment’s null result. Digital simulations hosted by university physics departments are another student‑friendly option.

What is a modern high‑precision example of the Michelson–Morley idea?

A leading modern example of the Michelson–Morley idea uses ultra‑stable optical cavities and lasers in vacuum. By comparing the resonance frequencies of cavities oriented in different directions as Earth rotates, researchers test for any direction‑dependence in the speed of light. These experiments, often done in collaboration with national labs and universities, are among the best examples of high‑precision relativity tests.

Are GPS systems really related to Michelson–Morley‑style experiments?

Indirectly, yes. GPS relies on the constancy and isotropy of the speed of light to compute positions accurately. If there were a detectable ether wind or direction‑dependent light speed, GPS timing and positioning would show systematic errors tied to direction and time of day. The fact that GPS works so well is a powerful real‑world example of the same principle Michelson and Morley tested.

How many different examples of examples of example of the Michelson-Morley experiment exist today?

There isn’t a fixed number, but you can group many examples of examples of example of the Michelson-Morley experiment into a few broad categories: classic tabletop interferometers, historical reconstructions, optical‑cavity experiments, satellite‑based timing tests, fiber‑optic interferometers, and digital classroom simulations. All of them, in one way or another, compare light propagation along different directions and look for differences that would contradict special relativity.

Where can I read more about modern relativity tests?

For reliable, technical information, check relativity and precision measurement resources from major institutions such as NIST, NASA, and university physics departments like MIT Physics. These sites regularly discuss timekeeping, GPS, and optical frequency standards, which are some of the best examples of how the Michelson–Morley legacy lives on in modern science and technology.