Fields & Energy

Fields & Energy explores electromagnetism and quantum mechanics, examining historical and philosophical perspectives alongside technical concepts. It aims to bridge the gap between theoretical physics and practical engineering, questioning established scientific norms and proposing a new understanding of fields and energy in physics.

Electromagnetism Quantum Mechanics Scientific History Scientific Philosophy Physics Education Scientific Theories Transmission Lines

The hottest Substack posts of Fields & Energy

And their main takeaways

4.5 An Introduction to Electromagnetic Models

279 implied HN points • 28 Aug 24
🔬 Science Physics Energy Electromagnetism Models Theory
  1. Electromagnetic energy can flow along wires due to charge imbalances. This creates electric and magnetic fields that help guide the energy.
  2. There are different viewpoints on what influences electromagnetic behavior the most: charges and currents, fields, or energy itself. Each aspect plays a role in how energy moves.
  3. Understanding these concepts can lead to better insights into electromagnetic models, but it can be complex since many elements are connected and affect each other.

4.4.2 The Catt Question

319 implied HN points • 21 Aug 24
🔬 Science Electromagnetism Electricity Physics Energy Engineering
  1. When a voltage is applied to a transmission line, it creates a net positive charge in the top wire and a net negative charge in the bottom wire. This happens as electrons move under the influence of the electric field set by the voltage.
  2. While it seems like charge must move quickly with the wavefront, it is actually the density of charges that changes. The actual movement of electrons is slow compared to the speed of light.
  3. Understanding how charges interact with electric fields helps explain electrical conductivity and related effects. Electromagnetic phenomena involve more than just moving charges; the interaction of fields and energy is also crucial.

4.4.1 How Do Transmission Lines Work?

319 implied HN points • 14 Aug 24
🔬 Science Physics Electromagnetism Engineering Technology Mathematics
  1. Transmission lines work by sending electrical signals through wires, where one wire gets a negative charge and the other gets a positive charge. This creates electric fields that help move energy along the line.
  2. To avoid signal loss and distortion, it's important to balance the electric and magnetic energies in transmission lines. If they are not balanced, the signal can get messed up over long distances.
  3. Oliver Heaviside developed key equations that describe how signals travel through transmission lines. His work highlighted the importance of using both electric and magnetic energies to achieve clear signal propagation.

An Introduction to Quantum Entanglement

279 implied HN points • 18 Aug 24
🔬 Science Physics Quantum Technology Communication Innovation
  1. Quantum entanglement happens when two particles are linked, so changing one changes the other right away, no matter how far apart they are. It's a strange and fascinating concept that Einstein called 'spooky action at a distance.'
  2. This effect has practical uses like Quantum Key Distribution (QKD) for super secure communication. But there are challenges, such as keeping the entanglement stable and dealing with issues that disrupt it over long distances.
  3. Even though quantum tech is still complex and expensive, it might inspire new ideas for amateur radio operators. Staying informed about these advancements could lead to innovative practices in their field.

The Story of the Telegrapher's Equations

259 implied HN points • 16 Aug 24
🔬 Science Physics Mathematics History Technology Engineering
  1. Oliver Heaviside was a young scientist who created the Telegrapher's Equations in 1876. His work helped connect theories of electromagnetism to practical applications in telecommunication.
  2. Before Heaviside, the diffusion model was the main idea for how signals traveled. Heaviside improved this by showing that signals could travel as waves instead of just spreading out slowly.
  3. The development of these equations was influenced by earlier mathematicians like Fourier and scientists like Lord Kelvin. Heaviside's contribution built on their ideas and advanced the understanding of signal transmission over long distances.
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4.4 Signals Along a Transmission Line

319 implied HN points • 07 Aug 24
🕹 Technology Signal Processing Telecommunications Innovations
  1. Long telegraph cables can cause delays and signal blurring, which was a problem when laying the first transatlantic cable.
  2. Using too much voltage to fix signal issues can break the cable, leading to more problems rather than solutions.
  3. The first successful transatlantic cable started working in 1866, just after an important theory on electromagnetism was published.

The Birth of Transmission Line Theory

279 implied HN points • 09 Aug 24
🔬 Science Physics History Mathematics Electromagnetism Engineering
  1. The first Transatlantic Telegraph Cable in 1858 was crucial for developing transmission line theory. It helped researchers understand how to send messages over long distances.
  2. Lord Kelvin created an early model for long cables, focusing on how to evenly spread resistance and capacitance. This helped explain why the first cable failed.
  3. Oliver Heaviside later added the concept of inductance to the equations, which improved the understanding of transmission lines even further.

4.3.3 Cross Coupling

259 implied HN points • 31 Jul 24
🕹 Technology Electronics Telecommunications Music technology Signal Processing History
  1. Thaddeus Cahill invented an early electronic music system called the Telharmonium in 1897, aiming to broadcast music through telephone lines. However, his venture failed because the music interrupted phone calls, causing complaints from users.
  2. Cahill's difficulties were largely due to a problem called cross coupling, where signals from one line affect nearby lines. This was common back in the day when many phone lines ran close together.
  3. The situation shows that electrical signals can spread beyond their wires, not just following what we'd think of as direct paths. This understanding is important in telecommunications and electrical engineering.

4.3.2 Inductive Telegraphy at a Distance

299 implied HN points • 24 Jul 24
🕹 Technology
  1. Inductive telegraphy was one of the first ways to send signals wirelessly over distances. Scientists like Joseph Henry made early experiments that showed electricity could work at a distance.
  2. Wireless technology progressed with experiments by inventors like William Preece, who managed to send signals over several miles. These early developments paved the way for later communication technologies.
  3. Although some early wireless systems were practical, they often faced challenges in business. Ideas like train telegraphs were innovative, but people weren’t ready for constant communication as we see today.

Near-Field Technology - An Emerging RF Discipline

259 implied HN points • 29 Jul 24
🕹 Technology Wireless Technology Communications Sensors
  1. Near-field technology focuses on short-range wireless communication, which is useful for applications like NFC and RFID. This tech works well because lower frequencies can pass through obstacles and provide reliable connections.
  2. The near-field zone, where signals are stronger and behave differently than in far-field, is often overlooked. Understanding this area can improve antenna design and application.
  3. There is a growing demand for near-field applications in everyday uses like contactless payments and real-time location tracking. This presents new opportunities for innovation and development in the tech industry.

4.3.1 Skin Depth & Litz Wire

299 implied HN points • 17 Jul 24
🕹 Technology Electronics Engineering Physics Energy
  1. Skin depth refers to how electric current mainly flows close to the surface of a wire, especially at high frequencies. This means most of the current doesn't penetrate deep into the conductor.
  2. Litz wire is made up of many fine strands that help reduce resistance by allowing current to flow through a larger area. This is especially useful at high frequencies where skin depth is very small.
  3. Using litz wire not only reduces energy loss due to resistance but also makes wires more flexible and less likely to fail mechanically compared to solid wires.

4.3 Actions at a Distance: Fluids or Fields?

259 implied HN points • 10 Jul 24
🔬 Science Physics Electricity Technology Engineering Energy
  1. Electricity can't really be thought of as a fluid. It has unique properties that can't be explained by the fluid model, especially in AC systems.
  2. Capacitors and inductors operate using electric and magnetic fields rather than fluids. This makes it easier to understand how they work.
  3. Transformers also rely on these fields. Their functionality shows that electric effects can occur at a distance, which a fluid model fails to explain.

4.2.1 Ancient Views

319 implied HN points • 26 Jun 24
🔬 Science Physics History Electricity Magnetism
  1. Ancient civilizations had early insights about magnets and electricity. For example, Thales discovered static electricity from amber and believed magnets had a 'soul' because they moved metal.
  2. The compass became crucial for navigation by the sixteenth century. Mariners relied on it heavily, and misdirecting a ship was seriously punished, reflecting the compass's importance.
  3. William Gilbert made significant contributions to the understanding of magnetism and electricity. He proposed that the Earth is like a giant magnet and identified various materials that produce electric effects.

4.2.2 Fluid Theories of Electricity

259 implied HN points • 03 Jul 24
🔬 Science Electricity Physics History Technology Chemistry
  1. Electricity was thought to behave like a fluid that could flow through conductors, which helped scientists understand how it could be transmitted over distances.
  2. Benjamin Franklin proposed a one-fluid theory of electricity, categorizing electricity into 'positive' and 'negative' charges, which laid the groundwork for future electrical theories.
  3. Alessandro Volta created the first battery, making it possible to study electricity as a continuous flow, leading to advancements in electrical science and technology.

I Know That I Know Nothing

339 implied HN points • 17 Jun 24
🔬 Science Physics Philosophy Research Education
  1. Admitting you don't know something is important for growth. It helps you start fresh and build better understanding.
  2. Real science often challenges the current beliefs. Great discoveries come when people realize the accepted ideas might be wrong.
  3. Being open to being wrong can lead to better learning. It's key for scientists to question what they think they know.

The Right-Hand Rule for Radiation

499 implied HN points • 29 Apr 24
🔬 Science Physics Electromagnetism Energy Radiation Research
  1. The right-hand rule for radiation helps us understand how electromagnetic energy behaves. It's a simple concept that suggests the direction of radiation can be figured out using your right hand.
  2. Radiation doesn't just come from single charges; it comes from interactions between charges. If a charge is isolated, it doesn't radiate any energy on its own.
  3. Understanding the difference between fields and energy in electromagnetism is important. They work together but behave differently, and grasping this can help us solve complex problems in physics.

"Oliver Heaviside. An Appreciation : The Personal Equation : The Work of a Genius Elucidated"

279 implied HN points • 10 Jun 24
🔬 Science Physics Engineering Mathematics History Biography
  1. Oliver Heaviside was a genius who contributed greatly to electrical science but was often misunderstood and neglected during his life. His work wasn't acknowledged until long after he had passed away.
  2. Heaviside developed important theories on cable signaling and electromagnetic waves, introducing many key terms that are still used today. His insights helped improve how signals could be transmitted over long distances, which was crucial for communication.
  3. Despite his brilliance, Heaviside lived a reclusive life and struggled financially. He preferred to work alone and only began to receive recognition later in life, which made him a complex figure in the world of science.

4.1 Heaviside, Poynting, & Energy Flow

239 implied HN points • 12 Jun 24
🔬 Science Physics Energy Electromagnetism Theories Mathematics
  1. Poynting and Heaviside explained how energy moves through space, not just through wires. They believed that energy travels through the surrounding medium as it shifts from one spot to another.
  2. They challenged the traditional 'fluid' model of electricity, saying that while current flows through wires, the energy actually flows outside of them. This highlights the importance of electric and magnetic fields in energy transfer.
  3. The debate between the fluid model and the electromagnetic theory showed that although the latter was complex, it provided a more accurate understanding of how energy moves in electrical systems.

4.0 Electromagnetism Comes of Age

259 implied HN points • 05 Jun 24
🔬 Science Physics Electromagnetism Innovation Technology History
  1. Oliver Heaviside improved upon Maxwell's ideas about electromagnetism. He made complex concepts simpler and more useful, opening doors for new technologies.
  2. Heaviside's work helped solve many technical issues with telegraphy, making long-distance communication possible. His innovations changed how electrical signals were sent across wires.
  3. Heaviside created important terms used in electronics today and developed a simplified way to describe energy flow in electromagnetic fields. His contributions are still fundamental in understanding electromagnetism.

3.4.1 Ohm's Law

519 implied HN points • 03 Apr 24
🔬 Science Physics Education History Engineering Mathematics
  1. Ohm's Law shows that voltage is equal to current times resistance, which is key to understanding how electrical circuits work.
  2. Georg Simon Ohm faced a lot of criticism during his time for his ideas, but later scientists recognized his important contributions to physics.
  3. Henry Cavendish had discovered concepts similar to Ohm's Law before Ohm, but much of Cavendish's work went unnoticed because he rarely published his findings.

3.5 Summary and Conclusions

259 implied HN points • 29 May 24
🔬 Science Physics Electromagnetism
  1. Maxwell built on the work of earlier scientists to develop his laws of electromagnetism. He connected electricity and magnetism, proving they are linked like never before.
  2. Maxwell emphasized the importance of careful experimentation and having a clear understanding of facts rather than jumping to theories. This approach helped in developing the scientific understanding of electromagnetism.
  3. Innovative ideas often face skepticism, especially from those already established in the field. Acknowledging our limitations and being open to new ideas are crucial for advancements in knowledge.

3.4.7 What is “Free Space?”

299 implied HN points • 15 May 24
🔬 Science Physics Electromagnetism Energy Theories History
  1. Free space is a place where electromagnetic waves can travel without any barriers. It has properties that support these waves, even if it seems empty.
  2. In history, scientists debated whether something could exist in a vacuum. They realized that the vacuum still has physical qualities, leading to the idea of the 'æther' as a medium for wave propagation.
  3. Modern physics shows that even a vacuum is rich in properties, meaning it's not truly empty. We should recognize that there's always something there, supporting energy and wave movement.

4.2 Early Models of Electricity

179 implied HN points • 19 Jun 24
🔬 Science Physics Electricity Electromagnetism Models History
  1. Electricity can be understood in two ways: as a fluid traveling through wires or as fields in the space around electric charges. This is still a big question in physics.
  2. Different cultures have unique approaches to explaining scientific concepts. For example, English physicists use hands-on models, while French scientists prefer abstract theories.
  3. Benjamin Franklin was key in shaping the idea that electricity is a single fluid. This foundational concept helps us still today in understanding electricity and electronics.

3.4.6 Permittivity & Permeability

279 implied HN points • 08 May 24
🔬 Science Physics Electromagnetism Materials Energy Theory
  1. Permittivity describes how a material can allow electric displacement, showing the relationship between electric field and displacement. It helps us understand how electric forces behave in different materials.
  2. Permeability relates to how materials respond to magnetic fields, defining the strength of magnetic interactions. It helps in understanding the magnetic forces within various materials.
  3. Both permittivity and permeability are key concepts that link electrical physics and mechanical physics. They provide important information about how electric and magnetic fields interact with materials.

Reading List for Chapter 3

199 implied HN points • 31 May 24
🔬 Science Physics Education History Literature Technology
  1. To understand electricity and magnetism, start with accessible introductory books. These give a good overview but aren't deeply technical.
  2. For more in-depth study, look into undergraduate textbooks. They cover more complex topics and are aimed at those ready to dig deeper into the science.
  3. Supplementary texts and guides can be very useful. They often explain difficult concepts clearly and may include helpful resources like online solutions and podcasts.

3.4.8 Maxwell's Methods and Views

219 implied HN points • 22 May 24
🔬 Science Physics Mathematics History Theories Research
  1. Maxwell used physical analogies and models to understand complex electrical and magnetic behaviors. This helped him discover important concepts like the displacement current.
  2. He believed that energy is linked to electromagnetic fields, not just to electric charges. This was a key part of his theory of electromagnetism.
  3. Despite his great contributions, some of Maxwell's ideas were not recognized during his time. His work on gases faced rejection, showing how science can overlook important discoveries.

3.4.2 Maxwell’s Original Equations

339 implied HN points • 10 Apr 24
🔬 Science Physics Mathematics Electromagnetism Equations History
  1. Maxwell's equations describe how electric and magnetic fields interact. They show the principles of electromagnetism in a clear way.
  2. Heaviside simplified Maxwell's original equations, reducing them from twenty to four. This makes them easier to understand and use today.
  3. The concepts of electric displacement and charge continuity are central to these equations. They help us understand how electricity flows and behaves in various situations.

3.4 James Clerk Maxwell & His Equations

359 implied HN points • 27 Mar 24
🔬 Science Physics Mathematics Electromagnetism History Mechanics
  1. James Clerk Maxwell was a key figure in understanding electricity and magnetism. He linked these topics together, showing how they relate to light.
  2. Maxwell created a set of equations that describe how electric and magnetic fields behave. These are known today as Maxwell's equations.
  3. Maxwell built on the ideas of earlier scientists, like Gauss and Faraday, and later, Heaviside simplified his work into the four equations used today.

"On Action At a Distance"

219 implied HN points • 03 May 24
🔬 Science Physics Research Mathematics Electricity Magnetism
  1. There are debates about how forces act over distances. Some people think there's a hidden connection, while others believe that objects can directly affect each other without any medium.
  2. Here’s a fun example: when you ring a bell using a wire, the movement happens gradually, showing that actions often involve a series of connections, not just instant forces.
  3. Scientists like Faraday introduced the idea of 'lines of force' to visualize these actions. Instead of just thinking about pushes and pulls, we can now understand force as stretching and pressing through a medium.

3.4.3 Gauss’s Laws

259 implied HN points • 17 Apr 24
🔬 Science Physics Mathematics Electromagnetism History
  1. Johann Carl Friedrich Gauss was a brilliant mathematician known for his early talent, like solving a tricky addition problem in second grade. He made significant contributions to math and physics, including the development of formulas to calculate important dates, like Easter.
  2. Gauss's Law describes how electric fields and charges relate to each other. For instance, electric field lines begin at positive charges and end at negative ones, while magnetic field lines always form loops.
  3. Gauss and Wilhelm Weber worked together to measure the Earth's magnetic field. They created detailed maps of magnetic intensity that are still referenced today, showing the long-lasting impact of Gauss's work in science.

3.4.4 Ampère’s Law

239 implied HN points • 24 Apr 24
🔬 Science Physics Electromagnetism Mathematics Research Theory
  1. Ampère’s Law explains how electric currents create magnetic fields. You can use the right-hand rule to find the direction of the magnetic field around a current.
  2. We visualize magnetic fields using 'dot-x' notation. A 'dot' shows current coming toward you, while an 'x' shows it going away, helping to understand how fields form around currents.
  3. Maxwell introduced the idea of displacement current, which means a changing electric field can create a magnetic field. This is important for understanding how electromagnetic waves travel.

3.2 Michael Faraday

359 implied HN points • 12 Mar 24
🔬 Science Physics Electromagnetism History Innovation Experimentation
  1. Michael Faraday discovered that moving magnets can create electricity, a process called induction. This was a major breakthrough in understanding how electricity and magnetism work together.
  2. Faraday also introduced the idea of 'lines of force' to visualize magnetic fields. This concept helps us understand the direction and strength of magnetic effects.
  3. He believed scientific discoveries should come from direct observations of nature, not just complicated math. Faraday's practical experiments made him one of the great experimental physicists.

3.4.5 Faraday’s Law & Electromagnetic Waves

219 implied HN points • 01 May 24
🔬 Science Physics Electromagnetism Light Energy
  1. Faraday's Law shows that a changing magnetic field can create an electric field. This means electricity and magnetism are like partners that can influence each other.
  2. When electric and magnetic fields change together, they can create electromagnetic waves, which is how light travels. It's like a dance between the two fields that lets energy move through space.
  3. In history, scientists like Faraday and Maxwell noticed that light might be connected to electromagnetism. They found evidence that light behaves like an electromagnetic wave, leading to important discoveries about how we understand light and energy.

3.3 Potentials, Energy, & Fields

239 implied HN points • 20 Mar 24
🔬 Science Physics Mathematics Theory Electricity Energy
  1. There's a debate in science about how we understand forces, like whether they act at a distance or through fields in space. Two main theories exist: one says forces happen instantly, while the other suggests they spread out gradually.
  2. George Green, a self-taught baker turned mathematician, made important contributions to the math behind electromagnetism. His work, which included ideas about electric potential and field theory, changed how we study these forces.
  3. Fields and potentials are two simple ways to describe how electricity and magnetism work. They help us understand how energy moves and behaves in different situations, like around charges or between capacitor plates.

3.0 The Birth of Electromagnetism

279 implied HN points • 28 Feb 24
🔬 Science Physics Electromagnetism History Measurement Innovation
  1. Coulomb created the torsion balance, a tool that helped him measure tiny forces between electrically charged objects. This was a big step in understanding electricity and magnetism.
  2. His findings showed that electric forces follow a similar pattern to gravitational forces, which Newton discovered. This means both types of forces can be explained using related mathematical laws.
  3. Coulomb's work laid the foundation for modern electromagnetism, even though he faced challenges during the French Revolution. His contributions are still recognized today, as the unit of electric charge is named after him.

2.6.3 The Misinterpretation of Newton

299 implied HN points • 14 Feb 24
🔬 Science Physics Mathematics History Philosophy Theories
  1. Newton did not explain why gravity exists. He focused on describing what gravity does instead of offering guesses about its cause.
  2. Many scientists after Newton misinterpreted his ideas, leading to a belief that gravity was an essential quality of matter, even though Newton disagreed with such views.
  3. Over time, Newton's concepts became viewed as abstract ideas rather than being connected to real evidence from the physical world.

3.1 The Discovery of Electromagnetism

239 implied HN points • 06 Mar 24
🔬 Science Physics Mathematics Electromagnetism History Experimentation
  1. Hans Christian Örsted proved that electricity and magnetism are connected by running a current near a compass, making them part of the same field called electromagnetism.
  2. André-Marie Ampère built on Örsted's work, showing that moving electric currents can attract or repel each other just like magnets do.
  3. Many scientists assumed forces acted at a distance, but Michael Faraday later suggested that closer particles must interact to create these forces.

2.6.1 Newton’s Methods

299 implied HN points • 31 Jan 24
🔬 Science Physics Philosophy Mathematics History Methodology
  1. Newton believed that geometry should be connected to real-world observations, rather than just logical deductions from axioms. He saw math as a tool to understand the physical world.
  2. He emphasized that we should always seek the simplest explanation for natural phenomena, following the principle of parsimony. If a simpler explanation fits the facts, it should be preferred.
  3. Newton argued that conclusions drawn from experiments should be regarded as generally true, even if new evidence could change our understanding later on. This highlights the importance of adapting our views as we gather more information.

Fields & Energy

459 implied HN points • 29 Oct 23
🔬 Science Physics Electromagnetism Quantum Mechanics Philosophy History
  1. The author is working on a book called 'Fields & Energy' that explores electromagnetism and quantum mechanics. He plans to share sections of the book weekly over about two years.
  2. The book argues that electromagnetism involves two different phenomena: fields and energy, which could help explain various puzzles in physics. It also ties these concepts to historical and philosophical insights.
  3. The author aims to make the book accessible to both professionals and non-specialists, blending technical details with general concepts to engage a wider audience.

1.0 On Generation & Corruption

459 implied HN points • 25 Oct 23
🔬 Science Physics Mathematics Technology Philosophy History
  1. In physics, our understanding has greatly improved over time, but some concepts can still feel confusing or counterintuitive. We often have to rely on complex math that works well, even if it doesn't make total sense at first.
  2. Michael Faraday challenged the common ideas of his time by introducing the concept of 'fields' instead of just focusing on point particles. This helped explain how forces work in a way that made more sense to him.
  3. Today, we still face similar questions about our understanding of reality in physics. As we develop new mathematical tools, we should ask if we need to rethink our basic ideas about how things work, just like Faraday did.