Engaging the Youth:
Carver Mead begins by expressing his desire to connect with young people just starting their careers, emphasizing their importance in the continuation and progression of scientific thought.

Feynman’s Insight:
Mead references a quote from his colleague, Richard Feynman, highlighting that the beauty of science lies in discovering ways of thinking that make the fundamental laws of the universe evident.

Three Key Theories:
Mead mentions three significant theories of physics: electromagnetism (via Maxwell’s equations), general relativity (which covers gravitation), and quantum mechanics (exploring the smallest scales of matter). Notably, all these theories are over a century old.

Essence of Quantum:
In celebrating the centenary of Louis de Broglie’s insight, Mead emphasizes that at the quantum level, matter is not composed of solid particles but waves. This wave nature challenges traditional views of matter being like “grains of sand.”

Understanding Waves:
A wave’s characteristics include its frequency (how fast it wiggles) and wavelength (distance between peaks). These attributes correspond to energy and momentum, respectively, in the context of matter waves.

Two Slit Experiment:
Highlighting the famous “two slit experiment,” Mead explains the concept of interference patterns. When waves pass through two slits, they can interfere with each other, leading to a pattern of maxima and minima. This interference is crucial for understanding quantum mechanics and the behavior of particles at a micro scale.

Wave Frequency vs. Angle:
Mead illustrates that waves with different frequencies (and therefore energies) interfere at different angles. A low-frequency wave will create an interference pattern at a larger angle compared to a high-frequency wave.

Real-world Application:
Mead concludes by referencing a 1927 experiment at Bell Labs. This experiment validated de Broglie’s theory by observing electron beams behaving as waves when passing through a crystal, further cementing the wave nature of matter.

These insights emphasize the importance of understanding matter’s wave nature and the profound implications it has for our understanding of the universe at the smallest scales.

Historical Context:
Carver Mead highlights experiments from the 60s and 70s that provided insights into wave behaviors, noting that the theorists of past generations did not have access to these findings.

Neutron Wave Experiment:
In an experiment from the mid-70s, a single crystal silicon was modified to have three fins. Neutrons passing through this setup demonstrated wave-like behaviors, taking multiple paths. Although it’s a single neutron, it behaves like a wave, taking multiple paths simultaneously, proving that it isn’t just a simple particle.

Wave Interference:
Two primary paths were identified: A, C, D and A, B, D. These paths converge at point D. Depending on how they combine, they can either enhance each other (in-phase) or cancel each other out (out-of-phase). The pattern of interference (in-phase or out-of-phase) can be detected and counted.

Gravitational Influence:
The setup is designed to be rotated in Earth’s gravitational field. By doing so, the height of the paths relative to the gravitational field changes. This causes the neutron waves to experience changes in gravitational potential, which affects their kinetic energy and therefore their wavelength. As the setup is rotated, the neutron waves shift between in-phase and out-of-phase due to these gravitational effects, showcasing the direct influence of gravitational potential on neutron waves.

Vector Effects:
Apart from gravitational effects, Mead suggests another possible influence on neutron waves. If the entire setup is rotated, the distance the neutron has to cover for each path changes. This creates a phase delay, which Mead refers to as a “vector effect”. The discussion is left open-ended, prompting the audience to consider what might be the origin or consequence of this vector effect.

Universe’s Influence on Neutrons:
Carver Mead highlights the intriguing idea that when considering the frame of reference of a neutron, the majority of matter influencing our experiments is located far out in the universe. This matter’s effect on potential increases as its distance grows, emphasizing the vast interconnectedness of the universe.

Experiment Setup:
To understand the effects of rotation on the wave nature of neutrons, a challenging experiment was conducted. It was imperative to neutralize the significant gravitational influence of the Earth. To do this, the experiment was set on a post, allowing the Earth itself to provide a steady rotation. If the perpendicular plane was aligned with the Earth’s rotation vector, it resulted in a phase shift, and its opposite alignment caused an opposite phase.

Neutron’s Message:
Intriguingly, the findings from the experiment revealed that the vector part of the neutron wave, which is directional, is somehow aware of the universe’s position. Mead describes this as a “direct message from the neutrons” which showcases the wave nature of matter in relation to the vastness of the universe.

Limitations of Modern Labs:
Such experiments, however, are intricate and expensive. While most educational institutions, even those at higher levels, can’t afford neutron sources or the elaborate setups, Mead suggests that simpler experiments can equally elucidate the wave nature of matter.

Revisiting Electrical Concepts:
Mead critiques traditional teachings about electricity, where voltage from a battery is used to drive current through a resistor, which offers resistance to electron flow. This teaching implies that an electric field pushes electrons linearly. Mead likens this to outdated mechanics, where force was believed to be necessary to maintain motion. He points to Galileo’s revelations about kinetic and potential energy as more insightful. In the context of electricity, Mead believes the conventional setup disrupts the natural wave nature of electrons, which would otherwise propagate harmoniously.

Traditional Understanding Challenged:
Carver Mead starts by addressing the conventional understanding of electrons. The teaching is that an electron’s velocity is determined by the electrical field. However, Mead insists it should be the electron’s acceleration that depends on this field, a realization that comes when electrons are in an environment that doesn’t disrupt their natural behavior.

Revolutionary Experiment in Leiden:
In 1911, in the town of Leiden, Karmerlingh Onnes, while trying to measure Ohm’s law using a mercury wire, made a groundbreaking observation. When cooled using liquefied helium (which he was the first to produce), the resistance of the mercury wire unexpectedly disappeared, only to reappear as the temperature increased. This piqued his interest as a potential physical phenomenon.

Ring Experiment and Superconductivity:
To understand this zero-resistance state, Onnes formed the mercury into a continuous ring. He theorized that if a current could be initiated in this ring, it would create a detectable magnetic field. And he was right; not only did a magnetic field form, but the current remained persistently, even overnight. This phenomenon, which was perpetual motion of current in the absence of resistance, was unlike anything seen before.

Understanding the Phenomenon:
This experiment gave the first evidence of what’s now known as superconductivity. Decades later, the London brothers provided an explanation, positing that the behavior could only be a result of a coherent quantum system. This system, in the form of a wave, would circle the mercury ring and align in phase with itself. Given the vast number of electrons involved, minor temperature changes would have no effect. It was an unprecedented, macroscopic wave of matter.

Significance of the Discovery:
Superconductivity stands as a monumental discovery in the field of physics. It provides a unique, in-depth understanding of matter waves in a way no other phenomenon does, revolutionizing our perception of the quantum world.

Missed Experimental Opportunity:
Carver Mead starts by noting an astonishing 50-year delay in a key experiment following Onnes’ work on superconductivity. The experiment, which could have been conducted by Onnes but wasn’t, was eventually carried out independently by a German group and another from Stanford in 1961, both publishing their findings in the same journal issue.

Refined Experiment with Lead:
These groups experimented with a ring made of lead, another superconductor. They managed to trap a current within the ring when it became superconducting. Instead of using a physical compass, as Onnes did, they hung the superconducting ring (which had the current) on a spider web, allowing it to rotate with minimal force. By subjecting the ring to a weak external magnetic field, they essentially turned the sample itself into the “needle” of a compass.

Understanding Magnetic Moment:
How the ring rotates in response to the magnetic field provides insights into its magnetic moment. This magnetic moment essentially indicates how the wave of superconducting electrons wraps around the ring and aligns in phase with itself. It can be in phase with no change, one cycle of change, two cycles, and so on. These variations are essentially quantized fluxes and magnetic moments.

Quantization in Phase:
The quantized phase of the superconducting wave reflects its necessity to remain coherent or in phase with itself. This quantization is the very essence of where the term “quantum” comes from. Mead draws parallels with an electron in an atom, explaining that its energy levels come from the wave’s need to align in phase with itself. An electron’s state can’t be zero due to its complex property called spin, which is still not entirely understood. Therefore, all quantum energy levels arise because matter behaves as waves and these waves must align in phase with themselves.

Experimental Simplicity:
In conclusion, Mead points out that despite the profound implications of the described experiment, it’s simple enough to be carried out in an introductory physics laboratory.

The London’s Prediction:
Carver Mead presents an experimental setup that can be conducted in a beginner’s physics lab based on a prediction made by the London brothers. According to their theory, if you spun a superconducting ring, it would generate a magnetic field. This assertion prompts Mead to explore its underlying mechanism.

Composition of the Ring:
The ring consists of positive charges from the atoms and ‘free’ electrons that form a unique condensate. This electron condensate is frictionless, implying that it has a unique behavior in the superconducting state. Even when the ring is spun, leading to the movement of positive charges, the negative electrons don’t exactly align with the positive charges. As a result, a current is generated due to this misalignment.

Behavior of the Electron Condensate:
In a perfect superconducting state, the electron condensate has a consistent phase throughout its structure. When the ring rotates, it introduces a change. Although this electron condensate is frictionless, it still experiences a ‘lag’ or delay. It doesn’t perfectly align with the positive charges, leading to a relative acceleration.

Understanding the Magnetic Effect:
This lag can be thought of as the superconductor trying to align with the universe’s frame of reference. When the ring isn’t moving, the electrons perfectly align with the positive charges, resulting in no magnetic flux. However, once the ring is set in motion, the electron condensate, despite its perfection, doesn’t align completely with the positive charges. This misalignment, driven by both its charge and mass, induces a magnetic effect.

Role of Vector Coupling:
The behavior can be attributed to the vector coupling between the moving positive charges (termed magnetism) and the electron condensate’s relative movement against the universe (causing what is referred to as inertia). It’s a demonstration where the absence of friction accentuates the effects of magnetism and inertia.

Conclusion:
These experiments, which can be conducted in elementary physics labs, make the complex interplay between magnetism, superconductivity, and inertia evident.

Light and Matter Waves:
Carver Mead proposes an interesting perspective on light, suggesting that it behaves like a matter wave – one that interacts between charged entities. He hints at the possibility of light coupling with gravitation.

Einstein’s Theory Evolution:
Mead recounts Einstein’s evolution of thought on gravitation. In 1911, Einstein’s theory suggested that the speed of light changed based on gravitational potential. However, by 1915, with the introduction of general relativity, the understanding of light’s speed became more complex. This theory involves an equation for gravitational potential and an assumption about the function of light speed relative to gravitational potential. Einstein’s eventual choice that light speed is independent of gravitational potential led to the prevailing use of the concept of curved spacetime.

Shapiro’s Experiment:
Mead shares an experiment from the late 1960s by Irwin Shapiro using the haystack observatory. The experiment demonstrated a delay in the radar signal when it passed close to the sun, aligning with the idea that light’s speed is proportional to the gravitational potential. The results indicated that gravitation has a scalar effect on light.

Fiber Optic Gyroscopes:
Mead explains how modern inertial navigation has transitioned from mechanical gyroscopes to fiber optic gyroscopes. These devices utilize light in a manner similar to the way neutrons work, producing interference patterns during rotation. The observed patterns suggest a vector coupling with the distant universe.

Preferred Frame of Reference:
Contrary to popular belief, Mead argues that there is a preferred frame of reference in our universe, which is dictated by distant cosmic masses. Einstein’s special relativity, according to Mead, asserts that as long as one is moving in a straight line without rotation or acceleration, there’s equivalence in local experimental results regardless of velocity or direction.

Expanding Universe & Special Relativity:
Diving deeper into cosmic understanding, Mead speaks about the expanding universe and Hubble’s 1922 discovery – things that are farther away move faster from us. This introduces the idea of a cosmic horizon beyond which we cannot see or interact because objects move away at the speed of light. If one moves towards such a horizon, it retreats. This dynamic equilibrium, where the universe appears to move with an observer, explains why special relativity functions as it does, making it not just a mathematical concept but a physical reality rooted in the vastness of the universe.

Concluding Thoughts:
Mead emphasizes the interconnectedness of light, gravitation, and our understanding of the universe. He presents a holistic perspective, suggesting that the behavior of light and its interaction with gravitational fields can be comprehended more intuitively by considering the broader cosmic context.

Universe Expansion and Gravity: Carver Mead begins by providing a visualization of the universe’s expansion, likening the gravitational potential between matter to the stretching of rubber bands. As the universe expands, these metaphorical rubber bands stretch, representing the gravitational attraction between all matter.

Einstein’s Energy Relation: Mead references Einstein’s E=mc^2 to emphasize the profound connection between energy and matter. He makes the bold assertion that 100% of the rest energy of matter is due to gravitational potential. Furthermore, he points out that the entirety of matter’s inertia, its resistance to acceleration, can be attributed to a gravitational vector coupling.

Call for a New Perspective: Addressing his audience, Mead urges them to see past traditional, complex theories and approaches. He emphasizes that the universe’s fundamental laws are evident and can be understood with basic mathematical principles like trigonometry and calculus. This simplified perspective not only opens the door to a new way of thinking but also enables fresh theories and predictions.

Limitations of Traditional Theories: Mead asserts that the current dominant theories have been so thoroughly explored over the past century by brilliant minds that little remains to be discovered within their confines. He encourages his listeners to challenge these norms, noting that there are many questions yet to be asked and answered, questions that aren’t even permitted within the framework of traditional theories.

Challenging Quantum Mechanics: As an example of these limitations, Mead recalls being told as an undergraduate that he couldn’t question the mechanism behind the wave function collapse in quantum mechanics. He uses this anecdote to stress the importance of curiosity and the right to question established notions.

Empowerment to Explore: Concluding his talk, Mead inspires his audience to take leadership in exploring the universe’s mysteries through fresh eyes and innovative experiments. He emphasizes that these experiments have the power to reveal the evident laws of the universe, and he encourages his audience to boldly venture into this realm of discovery.