background top icon
background center wave icon
background filled rhombus icon
background two lines icon
background stroke rhombus icon
header logo icon

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

input logo icon
"videoThumbnail Why can't you put metal in a microwave? - Aaron Slepkov
Similar videos from our catalog
|

Similar videos from our catalog

Video tags
|

Video tags

microwaves
microwave oven
microwave metal
radar
radar technology
percy spencer
magnetron
light energy
frequency
gamma rays
x rays
radio waves
electric field
particles
charged particles
friction
frictional heat
water molecules
electrons
electromagnetic waves
radiation
microwave radiation
ionizing radiation
chemical bonds
chemistry
physics
education
animation
Aaron Slepkov
Yuriy Polyashko
Darvideo Animation Studio
TED
TED-Ed
TED Ed
Teded
Ted Education
Subtitles
|

Subtitles

subtitles menu arrow
  • ruRussian
Download
00:00:07
American engineer Percy Spencer developed World War II RADAR technology
00:00:12
that helped detect Nazi airplanes—
00:00:15
but it would soon have other surprising applications.
00:00:19
One day in 1945, Spencer was standing near a RADAR instrument
00:00:24
called a magnetron,
00:00:25
a device that produced high-intensity microwaves that could reflect off planes.
00:00:31
Suddenly, he noticed that the candy bar in his pocket had melted.
00:00:36
He exposed other things to the magnetron and, sure enough,
00:00:39
popcorn kernels popped,
00:00:41
and an egg—well— exploded onto a colleague.
00:00:45
Soon after, the first microwave oven became available,
00:00:48
operating using the very same technology.
00:00:52
So, how does it work?
00:00:54
All light energy travels in waves of oscillating electric and magnetic fields.
00:01:00
These oscillations span a range of frequencies
00:01:03
comprising the electromagnetic spectrum.
00:01:06
The higher the frequency, the more energetic.
00:01:09
Gamma rays and X-rays have the highest frequencies;
00:01:13
microwaves and radio waves, the lowest.
00:01:16
Generally, light’s oscillating electric field exerts forces on charged particles,
00:01:21
like the electrons in a molecule.
00:01:23
When light encounters polar molecules, like water,
00:01:27
it can make them rotate,
00:01:29
as their positive and negative regions are pushed and pulled in different directions.
00:01:34
The frequency the light is traveling at
00:01:36
also determines how it interacts with matter.
00:01:40
Microwaves interact strongly with the water molecules found in most foods.
00:01:44
Essentially, they make the molecules jostle against each other,
00:01:48
creating frictional heat.
00:01:51
Household microwave ovens are fitted with cavity magnetrons.
00:01:56
When you activate a microwave oven,
00:01:58
a heated element within the magnetron ejects electrons,
00:02:02
and a strong magnet forces them to spiral outwards.
00:02:06
As they pass over the magnetron’s metallic cavities,
00:02:09
the electrons induce an oscillating charge,
00:02:12
generating a continuous stream of electromagnetic microwaves.
00:02:17
A metal pipe directs the microwaves into the main food compartment,
00:02:21
where they bounce off the metal walls
00:02:23
and penetrate a few centimeters into the food inside.
00:02:28
When the microwaves encounter polar molecules in the food, like water,
00:02:32
they make them vibrate at high frequencies.
00:02:36
This can have interesting effects depending on the food's composition.
00:02:41
Oil and sugar absorb fewer microwaves than water,
00:02:45
so if you microwave them alone, not much happens.
00:02:49
But when microwaves encounter a marshmallow,
00:02:52
they heat the moisture trapped within its gelatin-sugar matrix,
00:02:56
making the hot air expand and the marshmallow puff.
00:03:00
Butter is essentially a suspension of water droplets in fat.
00:03:05
When microwaved, the water rapidly vaporizes,
00:03:08
making the butter melt quickly— and sometimes, a bit violently.
00:03:13
So microwaves heat food molecules mechanically, through friction—
00:03:17
but they don't alter them chemically.
00:03:20
Soup heated in the microwave is molecularly indistinguishable
00:03:23
from soup heated using a stove or oven.
00:03:26
The term “microwave radiation” can be alarming.
00:03:30
But in physics, radiation simply describes any transfer of energy across a gap.
00:03:36
High frequency, ionizing radiation may be harmful
00:03:40
because it can strip electrons from molecules, including DNA.
00:03:45
However, microwaves aren’t energetic enough to alter chemical bonds.
00:03:49
And microwave ovens are designed to prevent leakage—
00:03:53
for safety and efficiency’s sake.
00:03:56
Nonetheless, to totally limit exposure,
00:03:59
experts recommend simply standing a few feet away when a microwave oven is on.
00:04:05
Microwaving metal is dangerous, though, right?
00:04:09
Well, it depends.
00:04:11
Metals are conductors,
00:04:12
meaning their electrons are loosely bound to their atoms
00:04:16
and move freely in response to electric fields.
00:04:19
Instead of absorbing microwave radiation,
00:04:21
the metal’s electrons concentrate on the surface,
00:04:24
leading to high voltages at sharp edges, corners, and small gaps.
00:04:29
This includes areas between the creases on a sheet of aluminum foil,
00:04:33
the prongs of a fork,
00:04:35
or a metal object and the microwave oven’s metal walls.
00:04:39
Sometimes, voltages get high enough to strip electrons
00:04:42
from the surrounding air molecules.
00:04:44
This electrically charged gas, or plasma, may then form lightning-like sparks
00:04:50
and grow as it absorbs more microwaves.
00:04:53
Once the oven is turned off, the plasma dissipates.
00:04:57
But not all metal objects spark in the microwave—
00:05:01
though they might make things cook a little unevenly.
00:05:04
In fact, a lot of microwavable packaging takes advantage of this,
00:05:09
using a thin metal coating to crisp the food’s surface.
00:05:13
And overall, as long as it doesn't approach the oven's walls,
00:05:16
leaving a metal spoon in a microwaving bowl of soup
00:05:19
should be a pretty uneventful affair.
00:05:22
That’s just another neat benefit of cooking with RADAR.

Description:

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. Support Our Non-Profit Mission ---------------------------------------------- Support us on Patreon: https://www.patreon.com/teded Check out our merch: https://shop.ed.ted.com/ ---------------------------------------------- Connect With Us ---------------------------------------------- Sign up for our newsletter: https://ed.ted.com/newsletter Follow us on Facebook: https://www.facebook.com/unsupportedbrowser Find us on Twitter: http://bit.ly/TEDEdTwitter Peep us on Instagram: https://www.facebook.com/unsupportedbrowser ---------------------------------------------- Keep Learning ---------------------------------------------- View full lesson: https://ed.ted.com/lessons/why-can-t-you-put-metal-in-a-microwave-aaron-slepkov Dig deeper with additional resources: https://ed.ted.com/lessons/why-can-t-you-put-metal-in-a-microwave-aaron-slepkov/digdeeper Animator's website: https://darvideo.tv/ ---------------------------------------------- Thank you so much to our patrons for your support! Without you this video would not be possible! Nevin Spoljaric, Sid Chanpuriya, Anoop Varghese, David Yastremski, Noah Webb, Roberto Chena, Oliver Koo, Luke Pisano, Andrea Gordon, Aleksandar Donev, Nicole Klau Ibarra, Jesse Lira, Ezekiel Raui, Petr Vacek, Dennis, Olivia Fu, Kari Teffeau, Cindy Lai, Rajath Durgada Manjunath, Dan Nguyen, Chin Beng Tan, Tom Boman, Karen Warner, Iryna Panasiuk, Aaron Torres, Eric Braun, Sonja Worzewski, Michael Clement, Adam Berry, Ghaith Tarawneh, Nathan Milford, Tomas Beckett, Alice Ice, Eric Berman, Kurt Paolo Sevillano, Jennifer Heald, Megulo Abebe, isolwi, Kate Sem, Ujjwal Dasu, Angel Alberici, Minh Quan Dinh, Sylvain, Terran Gimpel, Talia Sari, Katie McDowell, Allen, Mahina Knuckles, Charmaine Hanson and Thawsitt.

Preparing download options

popular icon
Popular
hd icon
HD video
audio icon
Only sound
total icon
All
* — If the video is playing in a new tab, go to it, then right-click on the video and select "Save video as..."
** — Link intended for online playback in specialized players

Questions about downloading video

mobile menu iconHow can I download "Why can't you put metal in a microwave? - Aaron Slepkov" video?mobile menu icon

  • http://unidownloader.com/ website is the best way to download a video or a separate audio track if you want to do without installing programs and extensions.

  • The UDL Helper extension is a convenient button that is seamlessly integrated into YouTube, Instagram and OK.ru sites for fast content download.

  • UDL Client program (for Windows) is the most powerful solution that supports more than 900 websites, social networks and video hosting sites, as well as any video quality that is available in the source.

  • UDL Lite is a really convenient way to access a website from your mobile device. With its help, you can easily download videos directly to your smartphone.

mobile menu iconWhich format of "Why can't you put metal in a microwave? - Aaron Slepkov" video should I choose?mobile menu icon

  • The best quality formats are FullHD (1080p), 2K (1440p), 4K (2160p) and 8K (4320p). The higher the resolution of your screen, the higher the video quality should be. However, there are other factors to consider: download speed, amount of free space, and device performance during playback.

mobile menu iconWhy does my computer freeze when loading a "Why can't you put metal in a microwave? - Aaron Slepkov" video?mobile menu icon

  • The browser/computer should not freeze completely! If this happens, please report it with a link to the video. Sometimes videos cannot be downloaded directly in a suitable format, so we have added the ability to convert the file to the desired format. In some cases, this process may actively use computer resources.

mobile menu iconHow can I download "Why can't you put metal in a microwave? - Aaron Slepkov" video to my phone?mobile menu icon

  • You can download a video to your smartphone using the website or the PWA application UDL Lite. It is also possible to send a download link via QR code using the UDL Helper extension.

mobile menu iconHow can I download an audio track (music) to MP3 "Why can't you put metal in a microwave? - Aaron Slepkov"?mobile menu icon

  • The most convenient way is to use the UDL Client program, which supports converting video to MP3 format. In some cases, MP3 can also be downloaded through the UDL Helper extension.

mobile menu iconHow can I save a frame from a video "Why can't you put metal in a microwave? - Aaron Slepkov"?mobile menu icon

  • This feature is available in the UDL Helper extension. Make sure that "Show the video snapshot button" is checked in the settings. A camera icon should appear in the lower right corner of the player to the left of the "Settings" icon. When you click on it, the current frame from the video will be saved to your computer in JPEG format.

mobile menu iconWhat's the price of all this stuff?mobile menu icon

  • It costs nothing. Our services are absolutely free for all users. There are no PRO subscriptions, no restrictions on the number or maximum length of downloaded videos.