Today in #PHY131 #QuantumForEveryone: The midterm exam, which covers established quantum technologies involving quantization of light, quantization of energy in atoms, particle-wave duality, quantization of energy in solids, tunneling, and quantization of angular momentum.
November 3, 2026 at 8:52 PM
Today in #PHY131 #QuantumForEveryone: The midterm exam, which covers established quantum technologies involving quantization of light, quantization of energy in atoms, particle-wave duality, quantization of energy in solids, tunneling, and quantization of angular momentum.
Today in #PHY131 #QuantumForEveryone: An orbiting electron has orbital and intrinsic angular momentum. Both are quantized. Intrinsic/spin creates a magnetic field used in hyperfine levels of atomic clocks, observations that our galaxy is spiral, magnetic sensing, and MRI imaging.
October 29, 2026 at 6:14 PM
Today in #PHY131 #QuantumForEveryone: An orbiting electron has orbital and intrinsic angular momentum. Both are quantized. Intrinsic/spin creates a magnetic field used in hyperfine levels of atomic clocks, observations that our galaxy is spiral, magnetic sensing, and MRI imaging.
Today in #PHY131 #QuantumForEveryone: A quantum particle can "tunnel" through a barrier, even if it lacks the energy to overcome it. A scanning tunneling microscope finds atoms by measuring where electrons from the atoms tunnel to the probe. Video from toutestquantique.fr/en/scanning-....
October 27, 2026 at 7:53 PM
Today in #PHY131 #QuantumForEveryone: A quantum particle can "tunnel" through a barrier, even if it lacks the energy to overcome it. A scanning tunneling microscope finds atoms by measuring where electrons from the atoms tunnel to the probe. Video from toutestquantique.fr/en/scanning-....
Today in #PHY131 #QuantumForEveryone: Computers use binary digits (bits) to store information. Computation is done using logic gates, like NOT, OR, and AND. Logic gates can be made using switches. Nowadays, the switches are transistors, which are made from p-n junctions.
October 23, 2026 at 2:47 AM
Today in #PHY131 #QuantumForEveryone: Computers use binary digits (bits) to store information. Computation is done using logic gates, like NOT, OR, and AND. Logic gates can be made using switches. Nowadays, the switches are transistors, which are made from p-n junctions.
Today in #PHY131 #QuantumForEveryone: A light emitting diode (LED) emits visible light when forward biased. A photodiode is reverse biased and pushes mobile electrons created via the internal photoelectric effect. They're used in smoke alarms, pulse oximeters, & digital cameras.
October 21, 2026 at 2:20 AM
Today in #PHY131 #QuantumForEveryone: A light emitting diode (LED) emits visible light when forward biased. A photodiode is reverse biased and pushes mobile electrons created via the internal photoelectric effect. They're used in smoke alarms, pulse oximeters, & digital cameras.
This past Tuesday in #PHY131 #QuantumForEveryone: In the internal photoelectric effect, light excites a bonded electron, making it mobile and decreasing the semiconductor's resistance. The semiconductor is a photoresistor, which a night light uses to detect when it's dark.
October 9, 2026 at 4:47 AM
This past Tuesday in #PHY131 #QuantumForEveryone: In the internal photoelectric effect, light excites a bonded electron, making it mobile and decreasing the semiconductor's resistance. The semiconductor is a photoresistor, which a night light uses to detect when it's dark.
Today in #PHY131 #QuantumForEveryone: A semiconductor's conductance can be modified by adding atoms with less or more of valence electrons, called p- and n-type doping. Putting both types together creates a p-n junction, which is used for solar panels and is also a diode.
October 9, 2026 at 4:51 AM
Today in #PHY131 #QuantumForEveryone: A semiconductor's conductance can be modified by adding atoms with less or more of valence electrons, called p- and n-type doping. Putting both types together creates a p-n junction, which is used for solar panels and is also a diode.
Today in #PHY131 #QuantumForEveryone: When atoms are near, their orbitals overlap, interfere constructively or destructively, and yield molecular orbitals and energy levels. With many atoms, the levels form bands. The bandgap yields conductors, insulators, and semiconductors.
October 1, 2026 at 9:40 PM
Today in #PHY131 #QuantumForEveryone: When atoms are near, their orbitals overlap, interfere constructively or destructively, and yield molecular orbitals and energy levels. With many atoms, the levels form bands. The bandgap yields conductors, insulators, and semiconductors.
Today in #PHY131 #QuantumForEveryone: A trapped wave has stable ways it can wiggle. A wave on a string or electron in a box has standing waves. An electron trapped by a nucleus (i.e., an atom) has orbitals. Molecular bonding is explained by the interference of orbitals.
September 29, 2026 at 5:14 PM
Today in #PHY131 #QuantumForEveryone: A trapped wave has stable ways it can wiggle. A wave on a string or electron in a box has standing waves. An electron trapped by a nucleus (i.e., an atom) has orbitals. Molecular bonding is explained by the interference of orbitals.
Today in #PHY131 #QuantumForEveryone: Wave-particle duality isn't just a curiosity, it's useful! Microscopes with smaller wavelengths have higher resolution, and microscopes using electrons can have resolutions five orders of magnitude greater than visible light. toutestquantique.fr/en/transmiss...
September 25, 2026 at 1:43 AM
Today in #PHY131 #QuantumForEveryone: Wave-particle duality isn't just a curiosity, it's useful! Microscopes with smaller wavelengths have higher resolution, and microscopes using electrons can have resolutions five orders of magnitude greater than visible light. toutestquantique.fr/en/transmiss...
Yesterday in #PHY131 #QuantumForEveryone: Precision timekeeping via atomic clocks enabled the first picture of a black hole by synchronizing radio telescopes across the earth. It also makes GPS possible using the time between GPS signals being sent and received.
September 23, 2026 at 4:34 PM
Yesterday in #PHY131 #QuantumForEveryone: Precision timekeeping via atomic clocks enabled the first picture of a black hole by synchronizing radio telescopes across the earth. It also makes GPS possible using the time between GPS signals being sent and received.
Today in #PHY131 #QuantumForEveryone: The second used to be defined by the earth's motion. Now it's the time for 9,192,631,770 cycles of a microwave light that excites cesium atoms. Such atomic clocks also define the meter and enable the internet, stock trading, & power grid.
September 17, 2026 at 6:09 PM
Today in #PHY131 #QuantumForEveryone: The second used to be defined by the earth's motion. Now it's the time for 9,192,631,770 cycles of a microwave light that excites cesium atoms. Such atomic clocks also define the meter and enable the internet, stock trading, & power grid.
Yesterday in #PHY131 #QuantumForEveryone: Lasers are one of the most important inventions of the 20th century. It uses stimulated emission to create more and more coherent photons that are released as a collimated monochromatic beam.
September 16, 2026 at 9:58 PM
Yesterday in #PHY131 #QuantumForEveryone: Lasers are one of the most important inventions of the 20th century. It uses stimulated emission to create more and more coherent photons that are released as a collimated monochromatic beam.
Yesterday in #PHY131 #QuantumForEveryone: Each atom's spectra is like a barcode or fingerprint that uniquely identifies the element. They are why neon signs and fireworks are different colors. In spectroscopy, an object's spectrum determines what it is made of and how it moves.
September 11, 2026 at 7:00 PM
Yesterday in #PHY131 #QuantumForEveryone: Each atom's spectra is like a barcode or fingerprint that uniquely identifies the element. They are why neon signs and fireworks are different colors. In spectroscopy, an object's spectrum determines what it is made of and how it moves.
Today in #PHY131 #QuantumForEveryone: We made spectrometers and saw that only certain colors are emitted from each element. The Bohr model of the atom explains this by restricting electrons to discrete shells. Electrons absorb and emit photons to jump up and fall down.
September 9, 2026 at 3:40 AM
Today in #PHY131 #QuantumForEveryone: We made spectrometers and saw that only certain colors are emitted from each element. The Bohr model of the atom explains this by restricting electrons to discrete shells. Electrons absorb and emit photons to jump up and fall down.
Today in #PHY131 #QuantumForEveryone: Einstein explained the photoelectric effect, where light ejects electrons from a metal, by proposing that Planck's quantized energies correspond to particles, now called photons. The effect is the basis for image intensification night vision.
September 3, 2026 at 9:51 PM
Today in #PHY131 #QuantumForEveryone: Einstein explained the photoelectric effect, where light ejects electrons from a metal, by proposing that Planck's quantized energies correspond to particles, now called photons. The effect is the basis for image intensification night vision.
Today in #PHY131 #QuantumForEveryone: Planck explained blackbody radiation by proposing a quantum of energy = hf.
Applications:
(1) Blackbody radiation explains why people emit infrared light, which thermal imaging picks up.
(2) Planck's constant defines the kilogram.
Applications:
(1) Blackbody radiation explains why people emit infrared light, which thermal imaging picks up.
(2) Planck's constant defines the kilogram.
September 1, 2026 at 5:00 PM
Today in #PHY131 #QuantumForEveryone: Planck explained blackbody radiation by proposing a quantum of energy = hf.
Applications:
(1) Blackbody radiation explains why people emit infrared light, which thermal imaging picks up.
(2) Planck's constant defines the kilogram.
Applications:
(1) Blackbody radiation explains why people emit infrared light, which thermal imaging picks up.
(2) Planck's constant defines the kilogram.
Today in #PHY131 #QuantumForEveryone: Students shined lasers through two slits and saw bright and dark fringes, corresponding to constructive and destructive interference, so light is a wave. It's an electromagnetic wave, and different wavelengths have different names and uses.
August 27, 2026 at 7:45 PM
Today in #PHY131 #QuantumForEveryone: Students shined lasers through two slits and saw bright and dark fringes, corresponding to constructive and destructive interference, so light is a wave. It's an electromagnetic wave, and different wavelengths have different names and uses.
Today in #PHY131 #QuantumForEveryone: National quantum initiatives and strategies, and the 2025 International Year of Quantum Science and Technology, signify a strong commitment to the field by governments. Only ~half of jobs at quantum companies necessitate technical expertise.
August 25, 2026 at 8:14 PM
Today in #PHY131 #QuantumForEveryone: National quantum initiatives and strategies, and the 2025 International Year of Quantum Science and Technology, signify a strong commitment to the field by governments. Only ~half of jobs at quantum companies necessitate technical expertise.
Today in #PHY131 #QuantumForEveryone: Quantum science has enabled countless everyday technologies, such as semiconductor electronics, which the founders of quantum did not anticipate. Quantum information science is likely transformational, but exactly how and when are uncertain.
August 21, 2026 at 3:06 AM
Today in #PHY131 #QuantumForEveryone: Quantum science has enabled countless everyday technologies, such as semiconductor electronics, which the founders of quantum did not anticipate. Quantum information science is likely transformational, but exactly how and when are uncertain.
Happy New (School) Year! This semester, I'm teaching:
1. Quantum Physics and Technology for Everyone #PHY131 #QuantumForEveryone
2. General Physics for the Life Sciences 1 #PHY201 #GenPhys1
3. Quantum Mechanics #PHY531 #QuantumMechanics
1. Quantum Physics and Technology for Everyone #PHY131 #QuantumForEveryone
2. General Physics for the Life Sciences 1 #PHY201 #GenPhys1
3. Quantum Mechanics #PHY531 #QuantumMechanics
August 18, 2026 at 7:02 PM
Happy New (School) Year! This semester, I'm teaching:
1. Quantum Physics and Technology for Everyone #PHY131 #QuantumForEveryone
2. General Physics for the Life Sciences 1 #PHY201 #GenPhys1
3. Quantum Mechanics #PHY531 #QuantumMechanics
1. Quantum Physics and Technology for Everyone #PHY131 #QuantumForEveryone
2. General Physics for the Life Sciences 1 #PHY201 #GenPhys1
3. Quantum Mechanics #PHY531 #QuantumMechanics
Today in #PHY131 #QuantumForEveryone: 100% of my students had heard of "quantum" before, mostly from movies. A quantum is the smallest amount of something, so a sugar grain is a quantum of granulated sugar, and a water molecule is a quantum of water. Nearly everything has a quantum when you zoom in.
August 18, 2026 at 7:16 PM
Today in #PHY131 #QuantumForEveryone: 100% of my students had heard of "quantum" before, mostly from movies. A quantum is the smallest amount of something, so a sugar grain is a quantum of granulated sugar, and a water molecule is a quantum of water. Nearly everything has a quantum when you zoom in.