Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
A discussion of how to synchronize clocks that are separated in space, and how this leads to the relativity of simultaneity.
• Understanding that clock synchronization is a physical process, and exploring various methods of synchronization using spacetime diagrams.
• How to measure distance with a clock: the concept of radar ranging distance.
• A profound realization about the nature of spacetime: Events that are simultaneous for one observer might not be simultaneous for another.
Highlighting the essential difference between the classical and quantum worlds.
• A recap of what we’ve learned so far.
• Understanding that in the classical world we have either “particle moving to the right” OR “particle moving to the left.”
• Understanding that, in the quantum world, OR can be replaced with AND: “particle moving to the right” AND “particle moving to the left.”
A discussion of the Heisenberg Uncertainty Principle as another way to understand quantum weirdness.
• Some deeper insights into what a particle probability pattern means.
• The Heisenberg Uncertainty Principle gives a limit to the precision with which we can simultaneously know both the position and the momentum of a particle.
• Deriving the Heisenberg Uncertainty Principle from the de Broglie relation.
A more in depth discussion of what the Heisenberg Uncertainty Principle is trying to tell us about the nature of reality.
• Understanding the strong interpretation of the HUP: “Particles cannot simultaneously possess a definite position and a definite momentum.”
• Why the classical question: “Given a particle’s initial position and momentum, what is its position and momentum as some later time t?” makes no sense in the quantum world.
• Richard Feynman’s remarkable sum over paths interpretation of quantum mechanics.
Repeating the experiment from SR-3 using light rather than sound, and understanding what Einstein assumed regarding the speed of light.
• How to draw a spacetime diagram that represents the sending and receiving of a light signal.
• Understanding that Einstein's Speed of Light Principle: "For an observer at rest, the speed of light is c, independent of the motion of the source" is natural and easy to believe.
Einstein"s Relativity Principle applies to both mechanical and electromagnetic phenomena.
Deriving the Doppler shift for light, from which all of special relativity follows.
• Return to the thought experiment in SR-3. By replacing Newton’s assumption of Universal Time with Einstein’s Relativity Principle we arrive at the Doppler shift for light.
• How the Doppler shift for light provides us with important clues about the nature of time as experienced by moving observers.
• Understanding relativistic time dilation in terms of the geometry of spacetime.
A demonstration of electron superposition using an electron diffraction apparatus, plus an introduction to quantum entanglement.
• Concrete demonstration related to the surprising 360/720 degree prediction discussed in QM-15.
• Understanding how an electron diffraction apparatus works, and how its surprising experimental results are explained by electron superposition, i.e. the electron behaving as if it can exist in multiple paths simultaneously.