yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Electromagnetism 101 | National Geographic


2m read
·Nov 11, 2024

  • [Instructor] Electromagnetism or the electromagnetic force is one of the four fundamental forces of nature. It generates light and energy and holds atoms, matter, and the world as we know it together.

Electromagnetism is a branch of physics that studies the interactions between electric and magnetic fields. All matter has an electric charge which can be positive, negative, or zero. Opposite charges attract while like charges repel. These electric forces bring and hold atoms together.

And when atoms gain a positive or negative charge through the transfer of electrons, a measurable electric field will form. If those electrically charged particles start to move, the field will become a flowing electric current and form a magnetic field around it. Under the right circumstances, interacting electric and magnetic fields can continuously produce and sustain one another.

This generates an electromagnetic field that transmits waves of electromagnetic energy, or radiation, into space. The intensity of this radiation is determined by its frequency. These frequencies make up what's known as the electromagnetic spectrum. Near the middle of the spectrum is visible light such as light emitted by stars, fireflies, and computer screens.

On either side are invisible electromagnetic waves. On one end are long, low-frequency radio waves that broadcast television and radio signals, microwaves that carry telephone signals and cook food, and infrared waves emitted by fires. On the other are short, high-frequency wavelengths: ultraviolet, X, and gamma radiation.

Unlike low-frequency waves, these waves can pass through the human body making them useful for medical applications. While electromagnetism has daily applications, it's also the engine that drives the planet as a whole. Thousands of miles below the Earth's surface, a layer of liquid metals churn and flow.

This generates electric currents that then produce magnetic fields that all together encompass the entire planet. Called a geodynamo, this process causes Earth's poles to attain positive and negative charges turning the planet into a giant electromagnet.

This phenomenon also creates a protective layer around the planet that shields us from the most harmful radiation in space leaving us to enjoy a world held together by the strange and fundamental force of electromagnetism.

More Articles

View All
Great Schism or East-West Schism part 1 | World History | Khan Academy
In previous videos, we talked about the dramatic turnaround in the 4th century in terms of how Christianity was treated in the Roman Empire. As you enter into the 4th century, it’s persecuted by Diocletian, but then Constantine takes power. He’s sympathet…
Food Too "Ugly" to Sell Becomes a Feast for 5,000 People | National Geographic
Feeding the 5,000 is a celebration of the solutions to food waste, where we feed 5,000 people a delicious meal made entirely out of food that would otherwise have gone to waste. America is a country which has a massive problem of food waste. Forty percent…
How To Build Wealth With $0 - The Easy Way
What’s up, Graham? It’s guys here. Now, here’s the thing: if you’re already wealthy, it’s easy to find new ways to make money. But if you have nothing to fall back on, it’s not exactly looking so good. It was recently found that just 30% of the poorest A…
Discover Ancient Wonders on the Coast of Newfoundland and Labrador | National Geographic
[Music] Mistaken Point around us, missed underfoot, petrified. Deep time rises, and Wealth’s to prod our souls here and there, breaking into sudden vow relief. 88% of Earth’s history is called the Precambrian age. Mistaken Point is the only World Heritage…
Representing alloys using particulate models | AP Chemistry | Khan Academy
In many videos, we have already talked about metals and metallic bonds. In this video, we’re going to dig a little bit deeper, and in particular, we’re going to talk about alloys, which are mixtures of elements but still have metallic properties. So firs…
Why most New Year's Resolutions fail
[Applause] As autumn settles in, leaves fall from the trees, and another growing season ends with the harvest. This might not have been a great year for crops, but winter will destroy the evidence of last year’s efforts and present a new opportunity for g…