Percy Spencer's accidental discovery of microwave technology and its surprising applications.

The Birth of the Microwave Oven

An explanation of how microwaves interact with matter and the technology behind microwave ovens.

How Microwaves Work

The effects of microwaves on different food compositions and the science behind it.

Effects of Microwaves on Food

Addressing safety concerns and misconceptions about microwave radiation and metal in microwaves.

Safety and Misconceptions

Exploring the benefits and practical applications of microwave technology in cooking and packaging.

Benefits and Practical Applications

**The Surprising Origins of Microwave Technology**

**How It All Started**

American engineer Percy Spencer developed World War II radar technology that helped detect Nazi airplanes, but it would soon have other surprising applications. One day in 1945, Spencer was standing near a radar instrument called a magnetron, a device that produced high-intensity microwaves that could reflect off planes. Suddenly, he noticed that the candy bar in his pocket had melted. He exposed other things to the magnetron and sure enough, popcorn kernels popped and an egg, well, exploded onto a colleague. Soon after, the first microwave oven became available, operating using the very same technology.

**Understanding the Science Behind Microwaves**

- All light energy travels in waves of oscillating electric and magnetic fields.
- The oscillations span a range of frequencies comprising the electromagnetic spectrum.
- Microwaves interact strongly with the water molecules found in most foods, making them jostle against each other and creating frictional heat.

**How Microwave Ovens Work**

- Household microwave ovens are fitted with cavity magnetrons.
- When activated, a heated element within the magnetron ejects electrons, and a strong magnet forces them to spiral outwards.
- The microwaves are directed into the main food compartment where they bounce off the metal walls and penetrate a few centimeters into the food inside.

**Safety Concerns and Myths**

- Microwave radiation is not harmful as it does not alter chemical bonds and microwave ovens are designed to prevent leakage.
- Standing a few feet away when a microwave oven is on is recommended to limit exposure.
- Microwaving metal can be dangerous as it can lead to high voltages and potentially form lightning-like sparks.

**The Benefits of Cooking with Radar**

- Microwavable packaging takes advantage of metal coatings to crisp the food's surface.
- Cooking with radar technology can lead to some unexpected and interesting results.

**In Conclusion**

Microwave technology has come a long way from its accidental discovery during World War II. Understanding the science behind microwaves and the safety concerns associated with their use can help us make informed decisions when using this convenient kitchen appliance.

"Unlocking the Power of Microwave Technology: From Accidental Discovery to Modern Convenience"

His candy bar had melted near a radar instrument

The radar instrument produced high-intensity microwaves

The radar instrument could reflect off planes

The candy bar in his pocket had disappeared

It can make them rotate due to forces exerted by the oscillating electric field

It can make them vibrate at low frequencies

- American engineer Percy Spencer developed radar technology during World War II
- He accidentally discovered the heating properties of microwaves when a candy bar in his pocket melted near a radar instrument
- Microwaves work by making water molecules vibrate at high frequencies, creating frictional heat
- Microwave ovens use cavity magnetrons to generate electromagnetic microwaves that heat food
- Microwaves heat food molecules mechanically through friction, but do not alter them chemically
- Microwaves are not harmful as they do not alter chemical bonds, and microwave ovens are designed to prevent leakage
- Metals can spark in the microwave due to high voltages at sharp edges, corners, and small gaps
- Some microwavable packaging uses a thin metal coating to crisp the food's surface
- Cooking with radar technology has many benefits, including the convenience of microwave ovens

Dig into the science of how microwave ovens use electromagnetic waves to heat your food, and what you should avoid cooking in them.

--

In 1945, engineer Percy Spencer was standing near a RADAR device that produced high-intensity microwaves and noticed that his candy bar had melted. He then exposed popcorn kernels to the magnetron device, and sure enough, they popped. Soon after, the first microwave oven became available, using the very same technology. So, how does it work? Aaron Slepkov explores the science of microwave ovens.

Lesson by Aaron Slepkov, directed by Yuriy Polyashko, Darvideo Animation Studio.

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American engineer Percy Spencer developed World War II radar technology that helped detect Nazi airplanes, but it would soon have other surprising applications.

1 day in 1945, Spencer was standing near a radar instrument called a magnetron, a device that produced high-intensity microwaves that could reflect off planes.

Suddenly, he noticed that the candy bar in his pocket had melted.

He exposed other things to the magnetron and sure enough, popcorn kernels popped and an egg, well, exploded onto a colleague.

Soon after, the first microwave oven became available, operating using the very same technology.

All light energy travels in waves of oscillating electric and magnetic fields.

These oscillations span a range of frequencies comprising the electromagnetic spectrum.

The higher the frequency, the more energetic.

Gamma rays and X-rays have the highest frequencies, microwaves and radio waves the lowest.

Generally, light's oscillating electric field exerts forces on charged particles, like the electrons in a molecule.

When light encounters polar molecules, like water, it can make them rotate, as their positive and negative regions are pushed and pulled in different directions.

The frequency the light is traveling at also determines how it interacts with matter.

Microwaves interact strongly with the water molecules found in most foods.

Essentially, they make the molecules jostle against each other, creating frictional heat.

Household microwave ovens are fitted with cavity magnetrons.

When you activate a microwave oven, a heated element within The magnetron ejects electrons, and a strong magnet forces them to spiral outwards.

As they pass over the magnetron's metallic cavities, the electrons induce an oscillating charge, generating a continuous stream of electromagnetic microwaves.

A metal pipe directs the microwaves into the main food compartment where they bounce off the metal walls and penetrate a few centimeters into the food inside.

When the microwaves encounter polar molecules in the food, like water, they make them vibrate at high frequencies.

This can have interesting effects, depending on the food's composition.

Oil and sugar absorb fewer microwaves than water, So if you microwave them alone, not much happens.

But when microwaves encounter a marshmallow, they heat the moisture trapped within its gelatin sugar matrix, making the hot air expand and the marshmallow puff.

Butter is essentially a suspension of water droplets in fat.

When microwaved, the water rapidly vaporizes, making the butter melt quickly.

So microwaves heat food molecules mechanically through friction, but they don't alter them chemically.

Soup heated in the microwave is molecularly indistinguishable from soup heated using a stove or oven.

The term microwave radiation can be alarming, but in physics, radiation simply describes any transfer of energy across a gap.

High frequency, ionizing radiation may be harmful because it can strip electrons from molecules, including DNA.

However, microwaves aren't energetic enough to alter chemical bonds, and microwave ovens are designed to prevent leakage for safety and efficiencies' sake.

Nonetheless, to totally limit exposure, Experts recommend simply standing a few feet away when a microwave oven is on.

Microwaving metal is dangerous though, right?

Metals are conductors, meaning their electrons are loosely bound to their atoms and move freely in response to electric fields.

Instead of absorbing microwave radiation, the metal's electrons concentrate on the surface, leading to high voltages at sharp edges, corners, and small gaps.

This includes areas between the creases on a sheet of aluminium foil, the prongs of a fork or a metal object and the microwave oven's metal walls.

Sometimes voltages get high enough to strip electrons from the surrounding air molecules.

This electrically charged gas, or plasma, may then form lightning-like sparks and grow as it absorbs more microwaves.

Once the oven is turned off, the plasma dissipates.

But not all metal objects spark in the microwave, though they might make things cook a little unevenly.

In fact, a lot of microwavable packaging takes advantage of this, using a thin metal coating to crisp the food's surface.

And overall, as long as it doesn't approach the oven's walls, leaving a metal spoon in a microwaving bowl of soup should be a pretty uneventful affair.

That's just another neat benefit of cooking with radar.

Learn how another accidental discovery led to X-ray technology and why it makes you see through with this video, or tap into how touchscreens work and why they hate your gloves with this 1.


Speaker 0: American engineer Percy Spencer developed World War II radar technology that helped detect Nazi airplanes, but it would soon have other surprising applications. 1 day in 1945, Spencer was standing near a radar instrument called a magnetron, a device that produced high-intensity microwaves that could reflect off planes. Suddenly, he noticed that the candy bar in his pocket had melted. He exposed other things to the magnetron and sure enough, popcorn kernels popped and an egg, well, exploded onto a colleague. Soon after, the first microwave oven became available, operating using the very same technology.

So, how does it work? All light energy travels in waves of oscillating electric and magnetic fields. These oscillations span a range of frequencies comprising the electromagnetic spectrum. The higher the frequency, the more energetic. Gamma rays and X-rays have the highest frequencies, microwaves and radio waves the lowest.

Generally, light's oscillating electric field exerts forces on charged particles, like the electrons in a molecule. When light encounters polar molecules, like water, it can make them rotate, as their positive and negative regions are pushed and pulled in different directions. The frequency the light is traveling at also determines how it interacts with matter. Microwaves interact strongly with the water molecules found in most foods. Essentially, they make the molecules jostle against each other, creating frictional heat.

Household microwave ovens are fitted with cavity magnetrons. When you activate a microwave oven, a heated element within The magnetron ejects electrons, and a strong magnet forces them to spiral outwards. As they pass over the magnetron's metallic cavities, the electrons induce an oscillating charge, generating a continuous stream of electromagnetic microwaves. A metal pipe directs the microwaves into the main food compartment where they bounce off the metal walls and penetrate a few centimeters into the food inside. When the microwaves encounter polar molecules in the food, like water, they make them vibrate at high frequencies.

This can have interesting effects, depending on the food's composition. Oil and sugar absorb fewer microwaves than water, So if you microwave them alone, not much happens. But when microwaves encounter a marshmallow, they heat the moisture trapped within its gelatin sugar matrix, making the hot air expand and the marshmallow puff. Butter is essentially a suspension of water droplets in fat. When microwaved, the water rapidly vaporizes, making the butter melt quickly.

And sometimes, a bit violently. So microwaves heat food molecules mechanically through friction, but they don't alter them chemically. Soup heated in the microwave is molecularly indistinguishable from soup heated using a stove or oven. The term microwave radiation can be alarming, but in physics, radiation simply describes any transfer of energy across a gap. High frequency, ionizing radiation may be harmful because it can strip electrons from molecules, including DNA.

However, microwaves aren't energetic enough to alter chemical bonds, and microwave ovens are designed to prevent leakage for safety and efficiencies' sake. Nonetheless, to totally limit exposure, Experts recommend simply standing a few feet away when a microwave oven is on. Microwaving metal is dangerous though, right? Well, it depends. Metals are conductors, meaning their electrons are loosely bound to their atoms and move freely in response to electric fields.

Instead of absorbing microwave radiation, the metal's electrons concentrate on the surface, leading to high voltages at sharp edges, corners, and small gaps. This includes areas between the creases on a sheet of aluminium foil, the prongs of a fork or a metal object and the microwave oven's metal walls. Sometimes voltages get high enough to strip electrons from the surrounding air molecules. This electrically charged gas, or plasma, may then form lightning-like sparks and grow as it absorbs more microwaves. Once the oven is turned off, the plasma dissipates.

But not all metal objects spark in the microwave, though they might make things cook a little unevenly. In fact, a lot of microwavable packaging takes advantage of this, using a thin metal coating to crisp the food's surface. And overall, as long as it doesn't approach the oven's walls, leaving a metal spoon in a microwaving bowl of soup should be a pretty uneventful affair. That's just another neat benefit of cooking with radar. Learn how another accidental discovery led to X-ray technology and why it makes you see through with this video, or tap into how touchscreens work and why they hate your gloves with this 1.

Thanks for watching!

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Why can't you put metal in a microwave? - Aaron Slepkov