The Electromagnetic Spectrum

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Measuring the electromagnetic spectrum

You actually know more about it than you may think! The electromagnetic (EM) spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group. Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of electromagnetic radiation.

Other examples of EM radiation are microwaves, infrared and ultraviolet light, X-rays and gamma-rays. Hotter, more energetic objects and events create higher energy radiation than cool objects. Only extremely hot objects or particles moving at very high velocities can create high-energy radiation like X-rays and gamma-rays.

The different types of radiation in the EM spectrum, in order from lowest energy to highest:

Radio: Yes, this is the same kind of energy that radio stations emit into the air for your boom box to capture and turn into your favorite Mozart, Madonna, or Justin Timberlake tunes. But radio waves are also emitted by other things ... such as stars and gases in space. You may not be able to dance to what these objects emit, but you can use it to learn what they are made of.

Microwaves: They will cook your popcorn in just a few minutes! Microwaves in space are used by astronomers to learn about the structure of nearby galaxies, and our own Milky Way!

Infrared: Our skin emits infrared light, which is why we can be seen in the dark by someone using night vision goggles. In space, IR light maps the dust between stars.

Visible: Yes, this is the part that our eyes see. Visible radiation is emitted by everything from fireflies to light bulbs to stars ... also by fast-moving particles hitting other particles.

Ultraviolet: We know that the Sun is a source of ultraviolet (or UV) radiation, because it is the UV rays that cause our skin to burn! Stars and other "hot" objects in space emit UV radiation.

X-rays: Your doctor uses them to look at your bones and your dentist to look at your teeth. Hot gases in the Universe also emit X-rays .

Gamma-rays: Radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma-rays. Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma-rays. But the biggest gamma-ray generator of all is the Universe! It makes gamma radiation in all kinds of ways.

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[spl]

I like these vids, I watch them and for a few minutes after it i feel smart, then i forget everything i just listened to not long after. =]

[roberhor]

This video reminds me of when I was in college and my professor asked me, do you know why the sky is blue? And I said, I don't know... It turns out that, the light rays from the sun that fall within the blue region of our color spectrum are more strongly scattered by molecules of air and particles of dust within the earths atmosphere.

[BoooDave]

What kind of person watches a video called "The Electromagnetic Spectrum", which starts off with the title "an introduction to the electromagnetic spectrum" and then voted it down? What could possibly have not lived up to the description, in this clear and neatly explained description of the electromagnetic spectrum on an introductory level?

Madness! Madness, I tell you!!

[acheofficial]

"There are Rays in your room right now"
Me looking around the room: 👁️👄👁️

[Incepter.]

The Electromagnetic Spectrum really is a fascinating force to see, it is so mysterious yet so intriguing

[Lee_yourboylee]

Fantastic explanation. If i'd had this sort of thing available to me when i was a schoolboy i might've studied physics at degree level rather than finding it too scarily abstract and impossible to comprehend and visualise the concepts.  Love stuff like this, it really helps make sense of the world, technology and scientific concepts that i previously found innacessible.

[leonela]

I’m just looking at these comments from ten years ago wondering what these ppl r doing now

[lykaaliyab.talamayan]

I'm here because my teacher wants me to explain electromagnetic spectrum through video. This video helps me a lot TY.

[amrzedan]

الي جاي من عند مستر محمد عبد المعبود ☝♥️

[JohnnyAnderson]

WOW!!! thanks for the invite to you station!! LOVE IT!!! good job!

[NoirpoolSea]

A very good introduction to the subject of the electromagnetic spectrum by NASA. So I was very surprised that there is an error in this otherwise fantastic video. At minute 2:47 the narrator says "..and GPS units in the cars driving by". GPS signals are emitted ONLY from the satellites in space. All they do is continuously broadcast a radio signal saying what time it is. The GPS unit in your car (or phone) reads the time signals from four or more satellites and compares their discrepancies. As radio (or light) travels approximately one foot each nano-second, the time  readings from the further satellite will read an older time by the GPS unit. Distance from that broadcast can then determined and along with the distance to the other 3 or more satellites overhead, using simple geometry, one can then determine the receivers location on (or above) the earth. The GPS unit in your phone emits nothing by itself. Of course your phone (or car) will then likely send your information to whatever computer the map (or other) application is connected to over your phones data radio, and THAT DOES emits electromagnetic radiation. But by itself. GPS does NOT broadcast your position. (So any conspiracy folks out there can relax a tiny bit now about that particular meme.)

[Nada-vsfn]

دكاتره مستر محمد عبد المعبود ❤❤
حد فاهم حاجه😂😂

[tensleeplake]

An excellent explanation for my middle school science classes. Thanks. I talk and they tune out. I put on a video and the listen.

[CRISNCHIPS]

Why do people feel the need to say "first" in their comments? It's not like you get some sort of recognition or award for seeing a video first.

Other than that, another great video "Best0fScience"

[tenshi]

Great video!

As an electrical engineering student, I can say that this 5 minutes video helped me understand waves better than the university classes I have had on the subject. It talks a lot more than equations and numbers.

[deeliciousplum]

what a wonderful beginner to intermediate talk on the electromagnetic spectrum. Quite a few questions were answered with this vid and that quite a few news ones were given birth to.

[kamam]

1:11 -- "text message" and shows a calculator

[camelotsecho]

This video is by far the best I've seen. I feel much more comfortable with these materials now. Thank you, BestOfScience!

[TheSamarakitten]

thank you for helping me understand physics better :) great vid!

[dadasajad]

Here because tomorrow I am having presentation on EMS. Thanks very much for fine stuff. Much appreciated. I wish I could have learnt Physics in this way.