The hottest Electromagnetism Substack posts right now

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What's the deal with magnetic fields?

lcamtuf’s thing • 4897 implied HN points • 04 Feb 25
🔬 Science Physics Electromagnetism Electricity Materials
  1. Electric fields are easy to understand because they involve the forces between charged particles, like how magnets attract or repel each other. This basic concept helps explain how electricity works in circuits.
  2. Magnetic fields can be confusing because they seem separate from electric fields, but they are connected through the concept of relativity. When things move, their distances and timings can change, affecting how we see electric and magnetic effects.
  3. Understanding that moving charges create magnetic fields helps simplify the whole idea. It's all about how motion changes our perspective on distance and forces between charges.

4.5 An Introduction to Electromagnetic Models

Fields & Energy • 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

Fields & Energy • 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?

Fields & Energy • 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.

The Birth of Transmission Line Theory

Fields & Energy • 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.
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The Right-Hand Rule for Radiation

Fields & Energy • 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.

4.1 Heaviside, Poynting, & Energy Flow

Fields & Energy • 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

Fields & Energy • 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.

3.5 Summary and Conclusions

Fields & Energy • 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?”

Fields & Energy • 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

Fields & Energy • 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

Fields & Energy • 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.

3.4.2 Maxwell’s Original Equations

Fields & Energy • 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

Fields & Energy • 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.

3.4.3 Gauss’s Laws

Fields & Energy • 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

Fields & Energy • 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

Fields & Energy • 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

Fields & Energy • 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.

3.0 The Birth of Electromagnetism

Fields & Energy • 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.

3.1 The Discovery of Electromagnetism

Fields & Energy • 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.

Fields & Energy

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.

1.2 A New Understanding

Fields & Energy • 319 implied HN points • 08 Nov 23
🔬 Science Physics Quantum Electromagnetism
  1. Reality is made up of two separate things: fields and particles. They work together to create the world we see.
  2. Electromagnetism is guided by fields that act like waves, while energy behaves like particles at the quantum level.
  3. This new approach shows that instead of thinking of light as just photons, we should view it as energy guided by fields.

O-Day - Evening

Remote View • 275 implied HN points • 02 Apr 23
🔬 Science Physics Geometry Electromagnetism
  1. The O-Day - Evening post discusses the electromagnetic properties of the Great Pyramid.
  2. The post delves into the connections between alchemy, sacred geometry, and the 'Great Work'.
  3. There are references to scientific articles and historical figures within the context of the post.

1.4 What’s the Benefit of This New Model?

Fields & Energy • 199 implied HN points • 22 Nov 23
🔬 Science Physics Quantum Mechanics Electromagnetism Mathematics
  1. This new model helps us understand how antennas and electromagnetic radiation work better. It shows how waves and fields can create visible effects, like standing waves, which we see in everyday life.
  2. The theory offers answers to old physics puzzles like wave-particle duality. Instead of seeing particles and waves as opposites, they work together as two different things.
  3. It provides solutions to tricky problems in electromagnetism, like radiation reaction and vacuum energy. The model suggests that radiation comes from the applied fields, not just from accelerating charges.

1.3 Wait... That's All There Is To It?

Fields & Energy • 179 implied HN points • 15 Nov 23
🔬 Science Physics Electromagnetism Quantum Mechanics Astrophysics Chemistry
  1. To understand how fields guide energy, you need to think deeply about concepts like light and electromagnetic waves. This involves understanding how energy balances between electric and magnetic forms.
  2. There's a new way to look at electromagnetism that contradicts a lot of what we've assumed for over a century. This new view can help explain some confusing aspects of quantum mechanics.
  3. Even though electromagnetism seems fully understood, there’s still room for fresh ideas that could change our understanding. Just like a miner finding new gems in a familiar mine, new insights might be waiting to be discovered.

1.6 The Plan & Purpose of this Book

Fields & Energy • 159 implied HN points • 06 Dec 23
🔬 Science Physics Energy Electromagnetism
  1. The book discusses two big ideas in physics: particles versus waves and two different ways of understanding nature. This involves looking at how scientists have debated these ideas over time.
  2. It introduces a new way of thinking about electromagnetism, saying that fields and energy are separate but related. Fields behave like waves, while energy can act like particles.
  3. Finally, the book explores how this fresh perspective can change our view of quantum mechanics, suggesting that light and energy might interact in ways we don't typically understand.