The Big Misconception About Electricity
Veritasium・2 minutes read
A giant circuit with a battery, switch, and light bulb spanning 300,000-kilometer wires questions how quickly light illuminates after the switch is closed, showcasing energy transmission through electric and magnetic fields, not electron movement. The Poynting vector formula demonstrates energy flowing from the battery to the bulb almost instantly, emphasizing the significance of understanding energy flow through fields in circuits.
Insights
- Energy in circuits flows through electric and magnetic fields, not the physical movement of electrons, as described by Maxwell's equations and the Poynting vector formula.
- The light bulb in the giant circuit scenario would light up almost immediately, in approximately 1/C seconds, showcasing the rapid propagation of electric and magnetic fields through space.
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Recent questions
How does electricity flow in circuits?
Electricity in circuits flows through electric and magnetic fields, not the movement of electrons. Energy is transmitted via these fields, as described by Maxwell's equations and the Poynting vector formula for energy flux.
What is the Poynting vector formula used for?
The Poynting vector formula is used to show the flow of energy in circuits, from the battery to the light bulb, even in alternating current circuits. It describes the transmission of energy through electric and magnetic fields, rather than the movement of electrons.
What is the significance of understanding energy flow through fields?
Understanding energy flow through electric and magnetic fields is crucial, as highlighted by issues faced by undersea telegraph cables due to signal distortions. Energy transmission through fields, not electron movement, plays a key role in efficient energy transfer in circuits.
How quickly does a light bulb light up in a circuit?
In a circuit with a battery and light bulb, the light bulb would light up almost instantaneously, in roughly 1/C seconds. This rapid lighting is due to the propagation of electric and magnetic fields through space, rather than the physical movement of electrons.
Where can I find more information about Caseda's smart switch?
More information about Caseda's smart switch can be found at lutron.com/veritasium. This smart switch can be connected with assistance available through a simple click or call, providing convenient and efficient control over lighting systems.
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