Michelson–Morley Experiment introduction | Special relativity | Physics | Khan Academy | Summary and Q&A

TL;DR

The Michelson-Morley Experiment proved that there is no luminiferous ether, challenging the idea that light travels through a medium.

Key Insights

• 🌊 Many waves in nature, such as water waves and sound waves, are disturbances traveling through a medium.
• 🙂 Scientists in the 19th century believed the luminiferous ether to be the hypothetical medium through which light traveled.
• 🙂 The Michelson-Morley Experiment demonstrated that the interference pattern of light did not change, challenging the concept of the luminiferous ether.

Transcript

• [Voiceover] We've seen in several videos so far that most of the waves that humans have encountered in nature--waves in the water, sound waves, or just waves traveling along a rope-- they were disturbances traveling through a medium. And so when light displays or has wave-like properties a very natural assumption was, well, light must also be a d... Read More

Questions & Answers

Q: What is the luminiferous ether?

The luminiferous ether is a hypothetical medium assumed to exist in the 19th century, through which scientists believed light waves traveled.

Q: How did the Michelson-Morley Experiment challenge the concept of the luminiferous ether?

The experiment demonstrated that the interference pattern of light did not change, regardless of the orientation of the apparatus, suggesting that there is no luminiferous ether affecting the velocity of light.

Q: Why was the Michelson-Morley Experiment considered a failed experiment?

The experiment failed in detecting the expected slowdown or speedup of light due to the hypothetical ether. However, it successfully challenged the belief in the existence of the luminiferous ether.

Q: What impact did the Michelson-Morley Experiment have on our understanding of light?

The experiment led to the realization that light can travel through a vacuum without the need for a medium like the luminiferous ether, revolutionizing our understanding of light and its properties.

Summary & Key Takeaways

• Most waves humans encounter travel through a medium, leading to the assumption that light also travels through a medium called the luminiferous ether.

• Physicists in the 19th century attempted to prove the existence of the ether and determine our relative velocity to it.

• The Michelson-Morley Experiment demonstrated that the interference pattern of light did not change, suggesting that there is no luminiferous ether affecting the velocity of light.