In special relativity, the action of a particle has a nice geometric interpretation: it is the length of the world line that the particle traces as it moves through space-time. Get the notes for free here: https://courses.physicswithelliot.com/notes-sign-up

Get all the links here: https://www.physicswithelliot.com/special-relativity-action-mini

This video is part two of a series on the principle of least action. The first video concerned a particle in Newtonian mechanics. The third concerns a particle in general relativity and the fourth concerns a string in string theory.

Part 1 Introduction to the principle of least action: https://youtu.be/sUk9y23FPHk

Part 3 Action in general relativity: https://youtu.be/h2SEK6Jjv3Y

Part 4 Action for string theory: https://youtu.be/KpIaWiWvuRs

Tutoring requests: https://www.physicswithelliot.com/tutoring

If you find the content I create useful and want to help me continue to share more, please consider supporting me! You can make a recurring contribution at https://www.Patreon.com/PhysicsWithElliot, or make a one-time contribution at https://www.physicswithelliot.com/support-me. Thank you so much!

About mini physics lessons:
In these intermediate physics courses, I will try to give you a self-guided introduction to fascinating physics topics. If you're just starting your physics journey, you may not understand every detail in each video – that's okay! What I really hope is that you will be inspired to continue learning on your own.

On me:
I'm Dr. Elliot Schneider. I love physics and I also want to help others learn (and love) physics. Whether you are a beginner just starting out in your study of physics, a more advanced student, or a lifelong learner, I hope you find resources here that will deepen your understanding of the laws of nature. For more interesting physics stuff, visit me at https://www.physicswithelliot.com.

Please take the opportunity to connect and share this video with your friends and family if you find it useful.