h is for hertz

automatic captions, checked for structure and key terms; corrections welcome.

0:08[unclear opening audio]

0:36Huh, so the internet comes in through here

0:41and then moves wirelessly to the laptop.

0:47But if it's not using wires, what does it use?

0:52Electromagnetic energy.

0:53Oh, hello. Who are you?

0:57My name is Heinrich Hertz.

0:59Oh, I know about Hertz. Hertz is how many times something happens per second.

1:05Yes, Hertz is a unit of measure that was named after me.

1:09But my true passion is inquiring into the nature of electromagnetic energy.

1:15And that's what the internet uses to get to my laptop?

1:18Ja, natürlich! Wi-Fi sends data over radio waves, which are in fact

1:23electromagnetic energy.

1:25Radio waves? Like my little FM radio?

1:28Yes, but electromagnetic waves aren't just used to transmit sound.

1:33They do so many other things, you know. They're all around us every day.

1:39Imagine if we could see all of them?

1:42Well, it might look something like this.

2:02Waves with different frequencies are used for different things.

2:08What kind of different things?

2:11Well, you see, waves of electromagnetic energy that change somewhat slowly are known as radio waves.

2:23We use radio waves to send sound and data without wires.

2:30Waves that change at a faster rate are called infrared.

2:35We use these to control our televisions and so many other different things.

2:43And waves that move faster than infrared are known as visible light.

2:49Why?

2:50Yeah, it's true. The light we see with our eyes is made of electromagnetic energy.

2:56So we see electromagnetic energy all the time. Very cool.

3:02Yeah, electromagnetic energy at any frequency is an astonishing thing.

3:13Wow, so when something is wireless, it uses electromagnetic energy instead

3:19of wires.

3:20I guess that answers my question. Thanks for your help Mr. Hertz.

3:24Oh, Mr. Hertz, where'd he go?