# What’s the Physics Behind Texting?

You probably send a bunch of texts everyday.
But when you hit send, what happens? How does your message make its way across the room
or to the other side of the world, to someone else’s phone? I’m Greg, and What The Physics?! To send a message out of your phone, electricity
from your battery jiggles electrons in the antenna of your phone, giving off a kind of
light. Not visible light like the filament of a lightbulb gives off, but longer wavelengths,
radio waves, which can be thought of as invisible light. So, how does that invisible light encoded
your message? Well, How would you do it with a flashlight? Maybe you’d shine it on and
off with some sort of code, like Morse code. Dots and dashes. Or ones and zeros, binary.
When your phone and sends the letter U it turns it into a 01010101. Or the message “Why
don’t we text in binary?” is this. Then the antenna in your phone sends out the ones
and zeros in short jiggle stop jiggle stop jiggle stop jiggle stop. Where does the light encoding your message
go? Straight to your friends phone? To a satellite? Nope, the antenna in your phone is too tiny,
and can only send the message a few miles, so to where? You may have never noticed them before, but
if you keep your eyes open you might spot some of these strange fake trees. Have you
ever wondered why it’s called a cell phone? Well antenna towers at like these are every
few miles, or closer, even in what appears to be the middle of nowhere. Every antenna
tower presides over an area of land around it called a cell. These cells divide our land.
And when you send a text from inside a cell, A sphere of invisible light emanates outward
from your phone to an antenna tower jiggling its electrons and transferring the message. But you aren’t the only one sending out invisible
light. How does the tower know that your message didn’t come from somebody else? Like all light,
visible and invisible, for radio waves come in different frequencies, for visible light
that’s different colors. Imagine you have a bunch of people shining
a flashlight Morse code at you, But you can’t tell them apart. If you tell one person, “only
shine in the red,” and another person, “only shine in green,” then you can distinguish
them. That’s kind of what happens with phones. The tower tells my phone, “only text in
these particular frequencies,” and tell your phone, “text in these different frequencies.”
It’s like I am texting in green, and you’re texting in red. And all across cities and towns, spheres of
different frequencies are emanating outward from phones. Now your cell tower knows your message came
from you and it needs to send it to your friend. But how does it know where your friend is?
Well, you might as well call it a brain cell, because it’s connected to all the other cells
through a network of computers that knows all. It watches an tracks your friend, you
and everyone you know. When ever your phone’s on, wherever you go, the big computer brain
of your cellular network knows… your friend is in this cell. And to relay the message to them, the big
computer brain sends the message through cables to their cell ,where now, everything happens
in reverse. That cell tower send out a particular frequency to your friend’s phone, those
radio waves jiggle their antenna, that becomes zeros and ones, which are translated into
the message. And that’s what happens when you send a text.

## 42 thoughts on “What’s the Physics Behind Texting?”

• ### Joe Scott Post author

Nice! I like the comparison of different frequencies to colors. Well done. 🙂

• ### Ruven Pinkhasov Post author

Great video. I wonder, how sensitive are the towers to changes in frequency?
The density of some areas in the world is ridiculously high so I assume it is very sensitive based on the fact that everyone gets a different frequency.
Some numbers would help me to put things into perspective. Thanks!

• ### TMP Chem Post author

Love the series thus far. Excited to continue seeing new episodes. Saw some things I already knew explained in a fun cool way. Learned some new things as well. Already one of my favorite science based channels on YouTube. Great work.

• ### Mr Wasteed Post author

OMG awesome video but the music and style makes it an X-Files episode

• ### Swyggles Johnson Post author

doin God's work, son

• ### Luis Post author

that's why I don't trust on the government

• ### Timmate Post author

Awesome videos you got in your channel! You deserve more likes and subscribers actually. I'm expecting more videos from you in the future! Keep it up man!

• ### lolfisheatpoo Post author

How do the signals tell the cell towers to whom the text is for, and which cell tower to relate it to? Sorry if it was in the video and I missed it, but I've replayed it a few times and haven't caught that.

• ### Lirim Sopaj Post author

+WhatThePhysics. How the message is transfered in the other side of sea? As I known,there aren't any towers in the sea to transfer the message in the other side,are there?. Thank you for ur lovely videos!They are really great!

• ### Belling Personal Post author

Great video–love the graphics. Just one thing you might consider fixing: It looks like you have different radio frequencies traveling at different speeds at 2:27 in the video

• ### Patrick Glogovčan Post author

You are awesome you deserve more subs

• ### jferry ! Post author

this was amazing but what if your friend or you changed cells?

• ### gamerdude456x Post author

Really loving these jokes! That "Stop texting me" text is genius! lmao

• ### NumberSixteen BusShelter Post author

what if you created a device that could select a random frequency, or match a specific frequency of another target and monitor the messages?

• ### TonyAnd Kevin Post author

So is this how the CIA or someone could track where you are? using these cells?

• ### Saumav Kapoor Post author

+WhatThePhysics?! When a cell phone sends a message, the waves reflect from various surfaces causing possible change in order in which the tower receives the message. In case of binary it will totally ruin the message. So how do we deal with this?

• ### Viacheslav B Post author

A brain? Really?

TIL

• ### Dennis Roberts Post author

Great video! I hope you add more soon.

• ### gotkot Post author

Hello 🙂
Now i Know what happens while i'm texting. But… What happens while i call sombody? 😀

• ### Hugo Lolein Post author

dude i hope u get more subs, your content is great!

• ### Gene Dela Rosa Post author

It's actually way way more complicated than that.

• ### Rachel Gill Post author

In the UK we don't call them 'cell phones' we call them 'mobile phones' but now, for me, 'cell phone' makes so much more sense!

• ### niko luke Post author

Good video but its really not the full truth. There are many things that are mentioned in the Video that do not apply to the reality. Nevertheless the Video does give a good model of how text are sent

• ### Kyrakia Post author

I always thought cell phones were named so because they had cells (batteries), well, the more you know…

• ### Vidhan Jain Post author

how does video gets its 1 0 number

• ### KUDFURY272 Post author

Then how do they send a vid

Just, wow!

• ### Athira KP Post author

Really informative

• ### cool company4545 Post author

What if i send a video or picture?

• ### Coolslaw 11;1 Post author

1101010101101000111001100111000011111000101010010111000111100001110000100101000011111010010101010101011011001010110

• ### Radwa Omran Post author

I have a question though .
u said every radio wave has a particular shap/color . so does that mean radio waves have unlimited shapes?

• ### Random Derpy Family Post author

I'm texting right now!

• ### Lunatic Programmer Post author

Interesting, after watching this video, I know for a fact I can make a system like this. Pretty easily might I add. It wouldnt be very secure though

• ### Ashli Martin Post author

So how is the actual phone number involved in this process?

• ### Sandile Nyanda Post author

My question is, is it possible for someone who is a stranger to send a text that has the same frequency as you? There can only be so many different frequencies. Now what would happen then

Mind- blow

Wowwww