and when we left off last time we were talking about all the different kinds of light from the smallest wavelength to the longest wavelength okay and we covered visible light infrared light and microwave light and remember let me kind of zoom in here we're increasing in wavelength as we go to the right on this page alright so there's one longer category than the ones we talked about last time and it's the catch-all for anything longer than 10 centimeters anything longer than 10 centimeters is called radio and you probably have heard of radio okay you probably have heard of radio in the radio so here's my question about it is radio a type of Soundwave yes or no is radio a type of Soundwave yes or no so again and even split here so no it's not okay because remember what are we listing here appear we're listing types of what what are all of these things they're all types of what yeah these are all types of light there are all types of light waves okay so visible light is a type of light infrared is a type of light microwave is a type of light so radio is also a type of light okay so technically because everybody is familiar with radio in the radio a lot of people will associate radio with the sound that comes out of the radio but that sound that comes out has nothing to do with actual radio light right do you many of you guys know where the radio light is involved in the radio where where is the radio light coming into this what's what's why do we call radio radio if the sounds not radio it's the signal right it's the signal so if if you want to pick up something with your radio okay like let's say this is your radio right here it's like a boombox or something you have an antenna on it and somewhere else there's a radio tower right at a station or something and what they're doing is they have something they want to send you like a song or some news or or some other kind of audio recording and so what they do is they send out radio waves in all directions that are coming out in in sort of a coded pattern okay just just like you can encode words in Morse code where you know by a pattern of beeps you can have someone who understands Morse code decode that into word kind of similar to that they're sending out a pattern of word or sorry a pattern of radio that corresponds to whatever they're trying to send you right and if your radio is nearby when some of that radio light hits it it will decode that signal into whatever they were trying to send okay so the radio light that's traveling through the air from the antenna over here to your antenna that's that's the actual radio part of radio okay the sound that comes out of the radio is just what they encoded on the beam of light not the actual radio okay yeah so a technically somebody's asking is this a fancy decoder essentially yes the thing you're listening to is a decoder in fact it's it it's actually called a radio receiver that's like the full name for it just nobody really calls it that anymore but if you look back you know like in old timey movies from like the 50's sometimes you'll hear somebody say radio receiver but yeah so it's a it's a decoder okay now um so this is not the only thing that uses that to communicate what's something else that also uses radio light to to send signals what's something else other than like a radio receiver here's a hint okay a walkie talkie a walkie talkie could use radio yes TVs do and walkie talkie is kind of close to what I was hoping somebody would mention satellites satellites can use a combination of radio and microwave as their communication signals yeah what are we typically using what are you using like everyday to communicate with those satellites phones right cell phones right so all of those things use a combination of radio and microwaves communicate Wi-Fi Wi-Fi is actually I think it I think Wi-Fi I don't quote me on this but I think Wi-Fi is usually in the microwave range not full-on in the radio range but it's somewhere in there oh and don't worry a lot of times when people hear that their cell phones use partially microwaves to communicate they're really afraid that it's gonna cook their head okay but remember most microwaves are not dangerous because they're low energy right are the cellphone companies going to pick that one wavelength in the microwave range that cooks water to be the one that they communicate to you with is that the one they're gonna pick I'm not even gonna you don't even have to answer that no they're not gonna pick that one wavelength that cooks water because then they would be cooking there I mean you don't want they don't want to cook their customers or anything right so they're they're not gonna pick the one that cooks food remember the rest of microwave is not super dangerous because it's such low energy right yeah they need your money right now with that in mind radio is radio light dangerous is radio light dangerous yes or no in general is radio light dangerous no and why not why would radio in general be low danger why would this be a low danger kind of light over here what about it makes it low danger low energy that's correct always remember you're three L's long wavelengths mean low frequencies and low energies so if the energy of radio was enough to be dangerous then all of these would be way more dangerous right visible light would be the most dangerous out of all these in equal amounts right so yeah and also that's a really good thing because radio towers are everywhere right satellites are everywhere you're spending your entire life being bathed in radio light right anywhere that you can turn on a cellphone and it works or or a radio and it works your you've got radio like going through you already basically so it's a good thing that it's not dangerous because we have your entire life has been in radio