# What were the intention/conclusions for Michelson-Morley experiment?

Which of the following were the intentions of M&M?

1. to disprove the existence of aether.
2. to show that the aether has no effect on matter and energy and therefore is as good as non-existent.

Feel free to insert more reasons/intentions.

Which of the following were the corollaries/conclusions?

1. Aether indeed does not exist
2. M&M does not prove or disprove the existence of aether.
3. M&M was a pointless experiment.

Feel free to add more corollaries/conclusions.

• I'm not sure we need that tag, but anyway... I'm wondering, why do you have a given list of answers to choose from? This reads like a multiple-choice homework question; is it actually from a homework or self-study assignment, or something similar like a practice test? If not, what is the context? Such questions are strongly discouraged around here if you don't put some effort into them yourself. – David Z Aug 22 '12 at 5:00
• Did you check Wikipedia before asking? – Qmechanic Aug 22 '12 at 8:59
• This whole question is based on a oddly distorted, hindsight-driven view of how things were. It was the 1880's version of the Higgs search: a very hard, cutting edge, painfully technological, expensive, time consuming, delicate measurement of a fairly subtle effect predicted by the best theory going. – dmckee --- ex-moderator kitten Aug 22 '12 at 15:43

The purpose of the Morley-Michelson experiment was to detect the motion of the lab relatively to the inertial system of the luminiferous aether, i.e. the "aether wind". The theory that the electromagnetic waves were waves of a composite medium – analogously to sound's being made of waves in the air – predicted that the speed of light should change to $c-v$ and $c+v$ if we move relatively to the preferred frame by the speed $v$ (in the direction of light or against it, respectively).
So none of your entries 1,2 in the first list describe the situation correctly. The intent was exactly the opposite (not that it matters too much). The conclusion is 1 in the second list of yours, aether indeed doesn't exist (or doesn't pick a preferred frame) and the electromagnetic waves are waves that don't require any medium and that violate the rules for the additional of velocities (the speed of light is always $c$, not $c\pm v$, regardless of the speed of the source or the detector), except that you should erase "indeed" because no one had expected that result, not even Einstein who was 8 at that time in 1887.