What is the electromagnetic spectrum? - Invisible Labs with Craig Beals

00:04:23
https://www.youtube.com/watch?v=PVPwGsaHups

Ringkasan

TLDRCraig Beals, a science teacher, explains the fascinating aspects of light and its place in the electromagnetic spectrum, which is a broad range encompassing various types of light waves, from gamma rays with short wavelengths to radio waves with long ones. Visible light, which includes all the colors we see, is just a small part of this spectrum. Infrared technology, a recent advancement, allows us to explore heat energy beyond what is visible to the naked eye. The presentation provides insights into how we perceive different parts of this spectrum in everyday life, such as in microwaves and radio signals, while emphasizing the unseen marvels beyond visible light.

Takeaways

  • 🌈 Light is only a small part of the electromagnetic spectrum.
  • 📡 Radio waves have the longest wavelength we can perceive.
  • 👀 We can only see visible light, but other types exist around us.
  • ⚡ Gamma rays have the shortest wavelengths and are very dangerous.
  • 🔦 Ultraviolet light is just beyond visible light and can cause sunburns.
  • 🎨 Rainbows are visible light bent by water droplets.
  • 🔥 Infrared light reveals heat energy we can't see with our eyes.
  • 🛠️ Microwaves cook food using longer wavelengths of light.
  • 🎙️ Tuning into a radio station is receiving a light signal.
  • 🕶️ Infrared technology lets us see thermal energy.

Garis waktu

  • 00:00:00 - 00:04:23

    Craig Beals, a science teacher, explains the fascinating aspects of light within the electromagnetic spectrum. Light is only a small part of this spectrum, which ranges from gamma rays to radio waves, each with different wavelengths. Starting with gamma rays, which are dangerous, it includes X-rays used in medical imaging. Ultraviolet light, familiar from sunburns, is on the edge of visible light—what our eyes can see. Each element, like the visible colors in a rainbow, occurs because light bends when interacting with elements like water droplets. Beyond visible light, longer wavelengths include infrared, used in special equipment to see heat. Microwaves, common in cooking, are similar to light but longer. Radio waves used in broadcasting also belong to this spectrum. The technology now allows us to see infrared, revealing thermal energy our eyes can't see, demonstrating the unseen aspects of the electromagnetic world.

Peta Pikiran

Video Tanya Jawab

  • What is the electromagnetic spectrum?

    The electromagnetic spectrum encompasses all types of light, including those we can't see, like gamma rays, X-rays, ultraviolet, infrared, microwaves, and radio waves.

  • Why can't we see all types of light?

    Our eyes are only sensitive to visible light, which is a small portion of the electromagnetic spectrum.

  • What are gamma rays?

    Gamma rays have the shortest wavelength in the electromagnetic spectrum and are highly dangerous.

  • What is infrared technology used for?

    Infrared technology allows us to see heat energy that is not visible to the naked eye.

  • How do microwaves cook food?

    Microwaves use electromagnetic radiation with longer wavelengths to heat and cook food.

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Teks
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Gulir Otomatis:
  • 00:00:00
    I'm Craig Beals and as a science
  • 00:00:05
    teacher, I obviously love science, but
  • 00:00:07
    what I really like about science is when
  • 00:00:09
    it explains things that we can't always
  • 00:00:12
    see. And one of those things is light! Now,
  • 00:00:15
    of course, we can't see without light. But,
  • 00:00:18
    there's so much more to light that most
  • 00:00:20
    of us don't really understand. Light, like
  • 00:00:23
    we think of it, is just one small part of
  • 00:00:25
    something much bigger called the,
  • 00:00:27
    'Electromagnetic Spectrum.' And, the
  • 00:00:30
    wavelength changes from very short
  • 00:00:32
    wavelengths on one end, to very long
  • 00:00:34
    wavelengths on the other, and what we see
  • 00:00:37
    is just right in the middle. So right on
  • 00:00:38
    this very short end is something called,
  • 00:00:40
    'Gamma Rays.' I didn't bring any today,
  • 00:00:42
    because we would all die if I had gamma
  • 00:00:43
    rays here, but as we move our way to a
  • 00:00:45
    little bit longer wavelength, those are
  • 00:00:47
    'X-Rays,' so when you have to go in, and
  • 00:00:50
    they shoot x-rays in through your skin it
  • 00:00:52
    interacts with your bone and it takes a
  • 00:00:54
    picture. So that's light, even though our
  • 00:00:56
    eyes can't see it. We get to a little bit
  • 00:00:59
    longer wavelength and we get up to
  • 00:01:01
    something called 'UV,' or 'Ultraviolet.' So,
  • 00:01:04
    I've got something that's right on the
  • 00:01:05
    edge of ultraviolet, which many people
  • 00:01:07
    are familiar with, this is just a black
  • 00:01:09
    light so not perfectly ultraviolet
  • 00:01:11
    otherwise I'd be getting a tan right now.
  • 00:01:13
    But, if you've ever been in a tanning
  • 00:01:15
    booth or you've ever been outside and
  • 00:01:16
    gotten a sunburn, you're familiar with
  • 00:01:18
    ultraviolet light. And It's the exact same
  • 00:01:20
    stuff as the light we see around us, just
  • 00:01:24
    a little bit different wavelength.
  • 00:01:26
    Then we get into that 'Visible,' the
  • 00:01:29
    visible little tiny chunk of what we can see.
  • 00:01:34
    All the colors of the rainbow are inside
  • 00:01:37
    visible light. I'm just using a CD here,
  • 00:01:39
    because it bends the light. So when you
  • 00:01:42
    look out and you see a rainbow you're
  • 00:01:44
    just seeing the sun's rays passing
  • 00:01:46
    through droplets of water. Think of each
  • 00:01:48
    one of those droplets of water like a
  • 00:01:50
    prism, okay? Prisms falling out of the sky
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    sun's rays are hitting it and it's
  • 00:01:55
    bending that light into the colors of
  • 00:01:57
    the rainbow. We get to a little bit
  • 00:01:58
    longer wavelength, we get to something
  • 00:02:00
    called 'Infrared,' and that's one of my
  • 00:02:02
    favorites, but I'm gonna come back to
  • 00:02:04
    that one, because we've got some special
  • 00:02:06
    equipment to see infrared. And we get a
  • 00:02:09
    little bit longer than that, we get all
  • 00:02:10
    the way up to, right here,
  • 00:02:14
    America's favorite cooking utensil, the microwave.
  • 00:02:18
    Nobody can survive college without one
  • 00:02:21
    of these, but this thing cooks your food
  • 00:02:23
    using electromagnetic radiation. It uses
  • 00:02:27
    micro-waves, and microwaves are almost
  • 00:02:29
    the exact same thing as the light we see
  • 00:02:31
    with our eyes, it's just a little bit
  • 00:02:33
    longer wavelength. And then we get all
  • 00:02:35
    the way up to 'Radio' waves. When you go, and
  • 00:02:40
    you tune your radio into your favorite station,
  • 00:02:44
    you're really listening to a light
  • 00:02:45
    signal, because radio waves are just like
  • 00:02:48
    visible light, but a really long
  • 00:02:50
    wavelength, and it's passing through the
  • 00:02:51
    air, and we can tune-in to just one small
  • 00:02:54
    portion of that frequency and you can
  • 00:02:56
    listen to your favorite radio station.
  • 00:02:57
    And here's the thing I like to talk
  • 00:02:59
    about with radio waves, when you tune-in
  • 00:03:02
    to your favorite station, it doesn't mean
  • 00:03:04
    that all the other stations went away,
  • 00:03:07
    they're still there. It's just like our
  • 00:03:09
    eyes, our eyes are tuned-in to one small
  • 00:03:11
    piece of the spectrum, but it doesn't
  • 00:03:13
    mean the other ones aren't there. They
  • 00:03:16
    exist and they're all around us, all the
  • 00:03:17
    time. And now, we've got new technology
  • 00:03:20
    that allows our eyes to see infrared, a
  • 00:03:24
    world that we couldn't even experience
  • 00:03:27
    not that long ago. Safety glasses, ready?
  • 00:03:30
    Yeah! So look, obviously this flame is
  • 00:03:35
    giving off visible light,
  • 00:03:37
    otherwise we wouldn't be able to see it,
  • 00:03:38
    but it's actually giving off so much
  • 00:03:40
    more. In fact, the visible light stops
  • 00:03:42
    right about there. But there's heat
  • 00:03:44
    energy rising all the way up off of
  • 00:03:46
    the top of this flame. Now, obviously, our
  • 00:03:50
    eyes can't see it, but it doesn't mean it
  • 00:03:52
    isn't there.
  • 00:03:53
    There's a whole world out there that we
  • 00:03:56
    can only experience with this new
  • 00:03:59
    infrared technology.
  • 00:04:00
    I mean, imagine going out into your world,
  • 00:04:03
    and exploring thermal energy, exploring
  • 00:04:06
    the electromagnetic spectrum in a way
  • 00:04:08
    you never imagined.
Tags
  • science
  • light
  • electromagnetic spectrum
  • gamma rays
  • x-rays
  • ultraviolet
  • visible light
  • infrared
  • microwaves
  • radio waves
  • infrared technology