BTW, you can build your own Michelson interferometer (when it was first constructed, it was a technical marvel, involving a large hunk of metal floating on mercury, deep down in a building, and even then the experiment was affected by subtle vibrations): <a href="https:&#x2F;&#x2F;www.thorlabs.com&#x2F;newgrouppage9.cfm?objectgroup_id=6635" rel="nofollow">https:&#x2F;&#x2F;www.thorlabs.com&#x2F;newgrouppage9.cfm?objectgroup_id=66...</a>