ADVANCED PHYSICS CONCEPTS
FROM SPRING 2017
Watch the lecture sequence here.
"...the chance is high that the truth lies in the fashionable direction. But, on the off-chance that it is in another direction - a direction obvious from an unfashionable view of field theory - who will find it? Only someone who has sacrificed by learning quantum electrodynamics from a peculiar and unusual point of view; one that they may have to invent..."
-Feynman
-Feynman
The cutting edge of modern physics little resembles the work of Isaac Newton. While the realm of classical physics remains fundamental to understanding the natural world, the most cited physics paper of all time is Juan Maldacena's 1997 work connecting quantum physics to gravity. To solve today's problems, the next generation of physicists need a sense of such important works. In fact, they may need new approaches that haven't been invented yet. This lecture series will help interested science students survey the landscape of modern physics.
Week 1: April 18 & April 20
SPACETIME
In Newton’s vision of the universe, space is just the background against which things move; time ticks away invariably. Einstein’s theory of special relativity, formulated in 1905, demonstrates that space and time affect one another dynamically. Moving observers disagree about measurements. Einstein spent the years 1905-1915 working on the general theory of relativity, which incorporates gravity. In Einstein’s model, mass & energy warp the geometry of spacetime and we experience the distortion as gravity.
April 18 - Technical difficulties, no footage available! Sorry! Here is a slideshow from Mike about the special theory of relativity.
April 20 - Lecture footage here. Still issues with live stream. Notes here.
Week 2: April 25 & April 27
PARTICLES & FIELDS
Since the late 19th century, scientists have made tremendous progress refining our model of the building blocks of matter. The discovery of atoms, atomic nuclei, electrons, and other subatomic particles has coincided with the development of quantum physics theories based on discrete states and probabilities. Today’s “Standard Model” of matter is a quantum field theory, with particles modeled as excitations of underlying fields.
April 25 - Lecture footage / Notes.
April 27 - Lecture footage / Notes.
Week 3: May 2 & May 4
ΛCDM COSMOLOGY
Hubble’s 1929 work with redshift established that distant galaxies are moving away from us, suggesting a universe that was once more compact. In the 1960s, discovery of the cosmic microwave background further solidified the view that the universe began in a dense hot state 13.7 billion years ago. Measurements from the 1960s to 1990s spurred the introduction of “dark matter” to explain the clumping of galaxies and “dark energy” to explain accelerating expansion of the universe.
May 2 - Lecture footage / Notes
May 4 - Lecture footage / Notes
Week 4: May 9 & May 11
BLACK HOLES
The warping of spacetime near an extremely dense body can get so extreme that nothing can escape, not even light. Astronomical observations show such massive entities, called “black holes,” do exist. Matter and energy crossing over the perimeter of the black hole can never return, and their fate remains somewhat mysterious. Hawking showed in the 1970’s that black holes do emit radiation and eventually decay. Arguments continue about the prevalence of black holes in the universe.
May 9 - Lecture footage / Notes
May 11 - Lecture footage / Notes
Week 5: May 16 & May 18
STRING THEORY
Quantum field theory has achieved great success in high energy particle collisions but fails to describe gravity. General relativity describes gravity but not microscopic quantum phenomena. Developing a quantum theory of gravity is a major challenge for modern physics. Since the 1970s, one promising candidate has been string theory, which models subatomic particles as “strings” that vibrate in higher dimensional space. String theory is heavily based on the mathematics of symmetry and symmetric groups.
May 16/18 - Notes
Week 6: May 23 & May 25
EMERGENT GRAVITY
The Large Hadron Collider has failed to discover evidence of the “supersymmetry” which string theory requires. Simultaneously, the puzzles of dark matter and dark energy indicate major shortcomings in our understanding of the universe. Verlinde’s work since 2011 uses holographic techniques to model gravity as a thermodynamic (i.e. statistical) phenomena that emerges at large scales from quantum systems. This hotly debated model could explain both dark energy and dark matter as quantum effects.
May 23/25 - Notes
SPACETIME
In Newton’s vision of the universe, space is just the background against which things move; time ticks away invariably. Einstein’s theory of special relativity, formulated in 1905, demonstrates that space and time affect one another dynamically. Moving observers disagree about measurements. Einstein spent the years 1905-1915 working on the general theory of relativity, which incorporates gravity. In Einstein’s model, mass & energy warp the geometry of spacetime and we experience the distortion as gravity.
April 18 - Technical difficulties, no footage available! Sorry! Here is a slideshow from Mike about the special theory of relativity.
April 20 - Lecture footage here. Still issues with live stream. Notes here.
Week 2: April 25 & April 27
PARTICLES & FIELDS
Since the late 19th century, scientists have made tremendous progress refining our model of the building blocks of matter. The discovery of atoms, atomic nuclei, electrons, and other subatomic particles has coincided with the development of quantum physics theories based on discrete states and probabilities. Today’s “Standard Model” of matter is a quantum field theory, with particles modeled as excitations of underlying fields.
April 25 - Lecture footage / Notes.
April 27 - Lecture footage / Notes.
Week 3: May 2 & May 4
ΛCDM COSMOLOGY
Hubble’s 1929 work with redshift established that distant galaxies are moving away from us, suggesting a universe that was once more compact. In the 1960s, discovery of the cosmic microwave background further solidified the view that the universe began in a dense hot state 13.7 billion years ago. Measurements from the 1960s to 1990s spurred the introduction of “dark matter” to explain the clumping of galaxies and “dark energy” to explain accelerating expansion of the universe.
May 2 - Lecture footage / Notes
May 4 - Lecture footage / Notes
Week 4: May 9 & May 11
BLACK HOLES
The warping of spacetime near an extremely dense body can get so extreme that nothing can escape, not even light. Astronomical observations show such massive entities, called “black holes,” do exist. Matter and energy crossing over the perimeter of the black hole can never return, and their fate remains somewhat mysterious. Hawking showed in the 1970’s that black holes do emit radiation and eventually decay. Arguments continue about the prevalence of black holes in the universe.
May 9 - Lecture footage / Notes
May 11 - Lecture footage / Notes
Week 5: May 16 & May 18
STRING THEORY
Quantum field theory has achieved great success in high energy particle collisions but fails to describe gravity. General relativity describes gravity but not microscopic quantum phenomena. Developing a quantum theory of gravity is a major challenge for modern physics. Since the 1970s, one promising candidate has been string theory, which models subatomic particles as “strings” that vibrate in higher dimensional space. String theory is heavily based on the mathematics of symmetry and symmetric groups.
May 16/18 - Notes
Week 6: May 23 & May 25
EMERGENT GRAVITY
The Large Hadron Collider has failed to discover evidence of the “supersymmetry” which string theory requires. Simultaneously, the puzzles of dark matter and dark energy indicate major shortcomings in our understanding of the universe. Verlinde’s work since 2011 uses holographic techniques to model gravity as a thermodynamic (i.e. statistical) phenomena that emerges at large scales from quantum systems. This hotly debated model could explain both dark energy and dark matter as quantum effects.
May 23/25 - Notes