This page covers the relativity section of the course.

The key to understanding the Michelson–Morley experiment (Topic 3.1) is realising that turning the apparatus through 90º alters the relationship between the beam paths and the Earth’s motion – no matter which way the Earth is moving. The null result disproves the ether theory.

Inertial frames of reference can be explained as places where the observer is considered to be at rest compared to the measuring equipment they are using. Since the value of the speed of light is always the same, then the observer’s measuring equipment (their ruler or their clock) must adapt to conform with any relative motion. Thus at high relative velocities their ruler would shrink and their clock would slow so as to indicate the correct readings.

Did you know that everything is moving? Even you, as you're sitting perfectly still, because the earth is moving, and the sun, and the galaxy, and so forth. For this ...reason, it only makes sense to talk about the motion of some object relative to some other object, just as Galileo told us. Watch this and see what I mean!

Did you know that everything is moving? Even you, as you're sitting perfectly still, because the earth is moving, and the sun, and the galaxy, and so forth. For this ...reason, it only makes sense to talk about the motion of some object relative to some other object, just as Galileo told us. Watch this and see what I mean!

This physics video tutorial provides a basic introduction into relative velocity problems in one dimension. It explains the concept of the frame of reference and how it's used to ...determine the relative velocity of an object with another regardless if the two items are traveling in the same direction or in the opposite direction. This video contains a few examples of car and train problems traveling in the same direction and in the opposite direction toward each other. It provides all of the formulas and equations needed to calculate the relative velocity.

The experiment which tried to prove the existence of a mysterious medium for light called ether but failed at it. It instead proved that light ...does not need a medium to travel.

Background Music: Interstellar Sitar [http://freemusicarchive.org/music/Dana_Boule/We_All_Need_To_Calm_Down/Interstellar_Sitar_1847][+] Show More

active

Einstein's twin paradox explained - Amber Stuver

Follow two astronauts into outer space to explore time dilation and Einstein’s theory of relativity through the Twin Paradox thought experiment.

--

On their 20th birthday, identical twin astronauts volunteer for ...an experiment. Terra will remain on Earth, while Stella will board a spaceship. Stella’s ship will travel to visit a star that is 10 light-years away, then return to Earth. As they prepare to part ways, the twins wonder what will happen when they’re reunited. Who will be older? Amber Stuver investigates the “Twin Paradox.”

Lesson by Amber Stuver, directed by Aim Creative Studios.

Thank you so much to our patrons for your support! Without you this video would not be possible! Rare Media, Rayo, Faizan, Elizabeth Gu, Nazmul Idris, Po Foon Kwong, Siobhan O'Connor Gwozdz, NinjaBoffin, Jesse Jurman, Josue Perez Miranda, Jan-Erik, Scott Markley, Kaitlyn holland, Elija Peterson, Michele Lynn Rose, Jai Prasanth, Vack91, David Lucsanyi, Xavier dupont, Marisa Miller, Boytsov Ilya, Steven Razey, Javier Aldavaz, Nathan Giusti, Mada Arslan, Joichiro Yamada, Ritul Raghavan, Aline de Paula Zillig, Yambu Ganesh Shaw, Abeer Rajbeen, John Hong, Minh Tran, Helen Lee, Anthony Benedict, Turine Tran, Mathew Samuel, Karthik Balsubramanian, Lee, Livia-Alexandra Sarban, Annastasshia Ames, João Henrique Rodrigues, Sebastiaan Hols, Aries SW, SANG HAN, Amy Lopez, ReuniteKorea, Vinh-Thuy Nguyen, Liz Candee, Clovis Norroy and Danielle Downs.[+] Show More

active

Relativistic Mass and Energy

Does Relativistic Mass actually exist?

active

Time Dilation - Einstein's Theory Of Relativity Explained!

Time dilation and Einstein’s theory of relativity go hand in hand. Albert Einstein is the most popular physicist, as he formulated the theory of relativity, which gave the Energy mass ...equivalence formula and is directly related to time dilation. But what is time dilation? Time dilation and space time are interrelated. Einstein made one of the most important contributions to physics and had the concept of space time explained. A simple explanation of space time is that it is a mathematical model that fuses the three dimensions of space and the one dimension of time into a single four-dimensional continuum. But it is very important to understand that the general theory of relativity and the special theory of relativity are different. In this short animated video, we give a simple explanation of time dilation and Einstein’s theory of relativity and also explain how time slows down in a moving vehicle!

Thanks to Brilliant.org for supporting MinutePhysics! The first 200 people who go to http://www.brilliant.org/minutephysics will get 20% off a Premium Subscription to Brilliant.

This video is about how terrestrial muons ...are part of our experimental proof of time dilation, length contraction, and special relativity in general.