Wi-Fiの歴史！

現代の生活に欠かすことのできなくなったWi-Fiですが、その仕組みはご存知ですか？

今回はどのようにしてWi-Fiが作られたか、その仕組みについて見てみましょう！

ここで動画の内容について確認クイズです。(世界ふしぎ発見みたいｗ)

動画中に答えがありますので、探しながら聞いてみましょう～！

Q1.Wi-Fi何の略でしょう？

　①Wirelee fiber

　②Wide fiber

　③特に何の略でもない

Q2.Wi-Fiの身体への影響は？

　①長時間浴び続けると危険

　②特に害はない

　③むしろ健康に良い

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Hey, remember back in the day when your internet was connected through the phone line? Ugh,

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the sound of dial-up still haunts me in my sleep… Well, we’ve come a long way since

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then, and chances are that you’re watching this video through Wi-Fi right now. So how

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did we get here anyway? Just hop into my time machine, and I’ll show ya!

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The roots of Wi-Fi go way back to the 1940. That’s when a popular Hollywood actress

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and inventor by the name of Hedy Lamarr came up with a way to prevent radio signals from

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being tampered with. That was a pretty important goal, since back then, radio-controlled torpedoes

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could easily be intercepted and change their course, which meant a huge fail for the Navy

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submarines. So, she came up with the brilliant idea of frequency-hopping signals, where people

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who controlled them could jump from one frequency to the other and make those torpedoes practically

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immune to radio interference.

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Now grab your double-knit blazer and let’s fast forward to the 1980s. This is when personal

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computers had begun to enter our lives for good. But at that time, computers were connected

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to the internet through the infamous Ethernet cables. Seems to me like scientists were getting

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tired of tripping over all those cables since they decided they wanted to start sending

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data using radio signals. However, those early attempts were unsuccessful since it all bounced

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back on walls, furniture, and pretty much anything that stood in a computer’s way.

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What scientists didn’t know at the time was that the problem had been solved a decade

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before PCs were even invented!

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It all started back in the 1970s, with electrical engineer Dr. John O’Sullivan, a.k.a. “the

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father of Wi-Fi.” At the time, he and his team were trying to detect radio signals from

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distant black holes in space, and they came up with complex equations called Fast Fourier

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transforms. Unfortunately, they couldn’t detect those black holes, and they put all

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their equipment back on the shelves to sit and collect dust.

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Surprisingly, twenty years later, Dr. O’Sullivan and his co-workers decided to give wireless

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networking a chance, and those forgotten complex equations would play a key role in the invention

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of Wi-Fi. After a lot of experimentation, they took their fancy Fast Fourier transforms,

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added them in the mixture with the data equations they’d previously tried to send over radio,

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and thus they formed the basis for the Wi-Fi we all know and love today!

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But, again, that was just the basis. Later in 1996, they further developed their original

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key patent, and by 1997 they finally cracked the code and came up with the first version

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of the 802.11 protocol. (Now is where you go, “Oooh! Ahhh!”) Oh, well, maybe you

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didn’t catch what I was saying among all that numeric mumbo jumbo.

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Ok, so let’s talk about the name you’re more familiar with: Wi-Fi. What does it mean

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anyway? I always thought it was some sort of acronym or abbreviation for two technical

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terms or something. But truth be told, --and that’s what we do here on Bright Side --it

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doesn’t stand for anything! Here’s how the naming situation went down. Since their

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first protocol, the Wi-Fi Alliance wanted to come up with a catchier name than 802.11

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(good idea!), so they hired some market-savvy people to help them with that. And ta-da:

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“Wi-Fi” was born! Wi-fi is a pun for the word Hi-Fi, which means “high fidelity”

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– a technical term used for high-quality audio technology. Now imagine walking into

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a café and asking the staff for the password to the “IEEE 802.11”!

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Anywho, now that we’ve covered all these decades and how we got where we are today,

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let’s take a look at how Wi-Fi really works. You already know that wireless internet helps

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you send and receive files, pictures, messages, and whatnot, but did you know that this is

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all via radio waves? (Hey, don’t forget about Hedy Lamarr and Dr. O’Sullivan – I

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told you all that stuff for a reason!) Yes, Wi-Fi uses radio waves to transmit data between

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your router (which is your Wi-Fi source) and your device (or the “receiver). These frequencies

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are measured in Gigahertz. To put all the sciencey stuff behind that in laymen’s terms,

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imagine this:

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You’re sitting on the beach enjoying the sun and watching the waves crash into the

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shore. If you were to calculate the time between each wave-crash, you’d be calculating the

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frequency of the wave. Let’s assume that the time it takes for each wave to hit the

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shore is one second: that second is calculated by hertz. In other words, 1 Hertz = 1 second.

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Now, 1 Gigahertz equals 1 BILLION waves per second. If you could see that many ocean waves

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moving so fast, then you might wanna scoot outta there and head for the hills!

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So, the frequencies Wi-Fi routers use are 2.4 or 5 Gigahertz per second, which is why

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data gets transferred so quickly to your phone. When it comes to speed, the 5 Gigahertz frequency

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sends information faster over shorter distances, whereas the 2.4 Gigahertz router covers farther

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distances but goes slower.

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You also have to keep in mind the interference from other devices in our homes that also

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use the 2.4 Gigahertz radio frequencies. For example, if you have baby monitors, garage

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doors, microwaves, cordless phones, and wireless cameras, they can interfere with your Wi-Fi.

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And this kind of interference can reduce the speed, or you might lose your internet connection

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altogether! Uh-oh! Hold off before you microwave some popcorn while binging on some Bright

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Side videos! Although, the latter 5 Gigahertz wireless frequency has 23 channels available

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to send all your information. Therefore, it doesn’t let any of those home devices cause

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connectivity issues.

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When you turn your phone or computer on and get on the internet, all the information you’d

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like to access is broken down into binary code. You’ve probably heard of this computer

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language made up of 0s and 1s. And when you access something through Wi-Fi, then that

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binary code is transformed into wave frequencies.

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If you’re trying to visualize how this process works exactly, think of it this way. Imagine

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you’re trying to send an embarrassing picture you took on your birthday to your best friend

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for a laugh. When you hit “send,” the photo is broken down into smaller pixels or

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packets and travels around different routers until it reaches your friend. Then, these

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packets are quickly reassembled like a puzzle, and your friend can finally see the photo

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(and giggle accordingly). All that happens with pretty much anything you try to send,

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be it videos, recordings, even my voice and the animation you’re seeing right now! Whoaaa,

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mindblown…

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Do you ever wonder what it’d be like if we could see all these radio frequencies swirling

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around the room? I picture myself sitting comfortably on the couch watching cat videos

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– I mean, getting some work done, of course! – and suddenly all these waves become visible

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and I can see everything. I see the little packets of data going from my router to my

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phone, all those pixels and colorful frequencies drifting through the air. Everything would

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be traveling around me like a long exposure photo in slow motion, kinda like a little

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rainbow storm right in my living room!

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Now, I know what you’re thinking. (Ok, maybe I don’t, but I can take a guess.) If we’re

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truly surrounded by all these radio waves, what does it do to our health? Is Wi-Fi dangerous?

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Well, the short answer is no. Wi-Fi works at extremely low voltages. Even at short distances,

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Wi-Fi is just part of the household "smog" that’s generated by TV and radio signals.

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Wi-Fi uses non-iodizing wavelengths of radiation that are harmless to the human body. The sun,

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on the other hand, uses iodizing radiation wavelengths (or ultraviolet rays) that aren’t

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so good for you. In fact, it’s more dangerous for your body to go outside than it is if

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you just sit next to your Wi-Fi router. Great! Think I’ll keep myself planted on the couch

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then! And to put your mind at ease a bit more, according to the World Health Organization,

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there is no scientific evidence to confirm that exposure to low levels of electromagnetic

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fields has any negative effects on our health.

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Ok, now that we’ve all calmed down and taken off our aluminum foil hats, let’s talk about

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why your Wi-Fi signal drops in certain places around your house. Wi-Fi works just like light

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and sound. The further you are away from the router, the less energy you get. A typical

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router works at about 100 feet in every direction. As for what can block it, that’s pretty

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much anything that conducts electricity, like metal, water, mirrors, and even our bodies

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since they mainly consist of water. For example, if you stand between your router and your

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device, you might notice a signal drop. Sometimes, even thick brick walls and concrete can hinder

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the signal – you just probably won’t notice the difference since it’s teeny-tiny, another

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highly technical scientific measurement. Just smaller than a “tad”.

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And there ya have it, folks! Now that you know a little more about the Wi-Fi you spend

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hours and hours on each day, perhaps you’ll appreciate it that much more! …Especially

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if you were around during the dark days of dial-up – I still thank my lucky stars each

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time I hop online within a fraction of a second!

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So, are you as addicted to Wi-Fi as I am? Let me know down in the comments! If you learned

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something new today, then give this video a like and share it with a friend.

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But don’t go anywhere just yet! We have over 2,000 cool videos for you to check out.

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All you have to do is pick the left or right video, click on it, and enjoy! Stay on the

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Bright Side of life!