Hi there! I’m Tess Winlock, a software engineer at Google. Have you ever wondered how a picture, text message, or email gets from one place to another? It’s not magic—it’s the Internet! The Internet is a real, physical system that moves information around, kind of like a postal service. But instead of sending boxes and envelopes, it sends information in the form of binary code.
Information on the Internet is made up of bits. A bit is like a tiny piece of information that can be either “on” or “off,” “yes” or “no.” We usually use a 1 to mean “on” and a 0 to mean “off.” Since there are two possible states, this is called binary code. When you put eight bits together, you get a byte. A thousand bytes make a kilobyte, and a thousand kilobytes make a megabyte. For example, a song might be about three to four megabytes. Whether it’s a picture, video, or song, everything on the Internet is sent as bits!
We don’t actually send ones and zeros physically. So, how do we send information? Imagine using a light to send a signal: light on for a 1 and light off for a 0. This method works but is slow and can have mistakes. That’s why we use machines to help us.
Over time, we’ve created systems to send binary information using electricity, light, and radio waves. For example, if you connect two light bulbs with a copper wire, turning on the electricity lights up the bulb. If both people agree that light on means 1 and light off means 0, they can send bits of information.
To send information faster, we need to increase bandwidth, which is the maximum amount of data that can be sent in a certain amount of time. Bandwidth is measured by bit rate, or how many bits are sent per second. Another important measure is latency, which is how long it takes for a bit to travel from one place to another.
Imagine you want to download a 3-megabyte song in three seconds. Since there are 8 million bits in a megabyte, you need a bit rate of about 8 million bits per second. Machines can handle this speed easily, even though humans can’t.
What kind of cable should we use to send these messages? Ethernet cables are common in homes and offices, but they lose signal strength over long distances. For global Internet connections, we use fiber optic cables. These cables send bits as light beams through glass threads. Light travels fast and keeps the signal strong over long distances, which is why fiber optic cables are used to connect continents across oceans.
In 2008, a fiber optic cable was cut near Alexandria, Egypt, disrupting Internet service for much of the Middle East and India. This shows how important and delicate the Internet’s physical system is. While fiber optics are great, they are expensive and tricky to work with, so copper cables are still widely used.
How do we send information without wires? Wireless devices use radio signals to send bits. These devices change binary data into radio waves, and the receiving devices change it back into binary. Wireless technology makes the Internet mobile, but radio signals can get distorted over long distances, which is why you can’t listen to a Los Angeles radio station in Chicago.
Even with wireless technology, wired connections are still important. For example, when you use Wi-Fi at a coffee shop, the bits travel wirelessly to a router and then through physical wires for long-distance travel.
The ways we send bits might change in the future, like using lasers between satellites or radio waves from drones. However, the basic idea of using binary code and protocols to send and receive information stays the same. Everything on the Internet—whether it’s words, emails, images, or videos—comes down to these ones and zeros being sent by electronic pulses, light beams, radio waves, and a lot of hard work!
Create a piece of art using binary code! Choose a simple image or pattern and convert it into binary code using 1s and 0s. Use graph paper to color in squares for 1s and leave squares blank for 0s. This will help you understand how images are represented digitally.
With a partner, build a simple circuit using a battery, a light bulb, and copper wire. Practice sending messages using light signals: light on for 1 and light off for 0. This activity will demonstrate how binary information can be sent using electricity.
Participate in a classroom race to simulate bandwidth and latency. Form teams and use different methods (walking, running, skipping) to pass a “data packet” (a small object) from one end of the room to the other. Discuss which method was fastest and why, relating it to bandwidth and latency concepts.
Watch a demonstration of how fiber optic cables work. Use a flashlight and a clear plastic tube to simulate how light travels through fiber optics. Discuss why fiber optics are used for long-distance communication and how they differ from copper cables.
Conduct an experiment using walkie-talkies to understand wireless communication. Try sending messages from different distances and note any changes in clarity. Discuss how wireless signals can be affected by distance and obstacles, and relate this to Wi-Fi and radio signals.
My name is Tess Winlock, and I’m a software engineer at Google. Here’s a question: how does a picture, text message, or email get sent from one place to another? It isn’t magic; it’s the Internet, a tangible physical system designed to move information. The Internet is similar to the postal service, but instead of boxes and envelopes, it ships binary information.
Information is made of bits, which can be described as any pair of opposites—”on” or “off,” “yes” or “no.” We typically use a one to mean “on” and a zero to mean “off.” Because a bit has two possible states, we call it binary code. Eight bits strung together make one byte, and 1,000 bytes make a kilobyte. One thousand kilobytes is a megabyte. For example, a song is typically encoded using about three to four megabytes. It doesn’t matter if it’s a picture, a video, or a song; everything on the Internet is represented and sent around as bits—these are the atoms of information!
However, we’re not physically sending ones and zeros from one place to another. So, what is the physical stuff that actually gets sent over wires and airwaves? Let’s look at a small example of how humans can physically communicate to send a single bit of information. Imagine we could turn on a light for a 1 or off for a 0, or use beeps like Morse code. These methods work, but they’re slow and error-prone, totally dependent on humans. What we really need is a machine.
Throughout history, we’ve built many systems that can send binary information through different types of physical mediums. Today, we physically send bits using electricity, light, and radio waves. For example, to send a bit via electricity, imagine two light bulbs connected by a copper wire. If one operator turns on the electricity, the light bulb lights up. If the operators agree that light on means one and light off means zero, we have a system for sending bits of information.
However, if we want to send five zeros in a row, we need a way for either person to count the number of zeros. The solution is to introduce a clock or timer. The operators can agree that the sender will send one bit per second, and the receiver will record every second to see what’s on the line. To send five zeros, the sender turns off the light and waits five seconds, while the receiver writes down all five seconds as zero zero zero zero zero. For ones, the sender turns on the light.
Of course, we want to send things faster than one bit per second, so we need to increase our bandwidth, which is the maximum transmission capacity of a device. Bandwidth is measured by bit rate, the number of bits sent over a given period, usually measured in seconds. Another measure of speed is latency, the time it takes for one bit to travel from one place to another.
Let’s say you want to download a 3 megabyte song in three seconds. At 8 million bits per megabyte, that means a bit rate of about 8 million bits per second. While humans can’t send or receive that many bits per second, machines can do it easily.
Now, what sort of cable should we use to send these messages, and how far can the signals go? With Ethernet wire, commonly found in homes or offices, there’s measurable signal loss over just a few hundred feet. To make the Internet work globally, we need a different way to send information over long distances—like across an ocean.
What moves faster than electricity through a wire? Light! We can send bits as light beams using fiber optic cables, which are threads of glass engineered to reflect light. When a beam of light travels down the cable, it bounces along the length until it reaches the other end. Depending on the bounce angle, we can send multiple bits simultaneously, all traveling at the speed of light. Fiber optic cables are fast and maintain signal quality over long distances, which is why they are used across oceans to connect continents.
In 2008, a cable was cut near Alexandria, Egypt, interrupting Internet service for much of the Middle East and India. We often take the Internet for granted, but it’s a fragile physical system. While fiber is excellent, it’s also expensive and challenging to work with, so copper cables are more common.
How do we send information wirelessly? Wireless devices typically use radio signals to transmit bits. These machines translate the binary data into radio waves of different frequencies, and the receiving machines convert it back into binary. While wireless technology has made the Internet mobile, radio signals don’t travel far without distortion, which is why you can’t pick up a Los Angeles radio station in Chicago.
As great as wireless is, it still relies on wired connections. For example, when you’re in a coffee shop using Wi-Fi, the bits are sent through a wireless router and then transferred via physical wires for long-distance travel.
The methods for sending bits may evolve in the future, whether through lasers between satellites or radio waves from drones. However, the underlying binary representation of information and the protocols for sending and receiving that information have remained consistent. Everything on the Internet—whether it’s words, emails, images, or videos—comes down to these ones and zeros being delivered by electronic pulses, light beams, radio waves, and a lot of dedication.
Internet – A global network of computers that allows people to share information and communicate with each other. – Example sentence: “I used the internet to research information for my science project.”
Bits – The smallest unit of data in a computer, represented as a 0 or 1 in binary code. – Example sentence: “Computers process data in bits to perform calculations and store information.”
Bytes – A group of 8 bits, used as a unit to measure data size in computers. – Example sentence: “A simple text file might only be a few kilobytes in size.”
Binary – A number system that uses only two digits, 0 and 1, to represent data in computers. – Example sentence: “Computers use binary code to execute instructions and perform tasks.”
Bandwidth – The maximum amount of data that can be transmitted over an internet connection in a given amount of time. – Example sentence: “Streaming videos requires a high bandwidth to avoid buffering.”
Latency – The delay before a transfer of data begins following an instruction for its transfer. – Example sentence: “High latency can cause delays in online gaming and video calls.”
Cable – A physical medium used to connect computers and other devices to the internet or a network. – Example sentence: “I connected my computer to the router using an Ethernet cable.”
Ethernet – A system for connecting computers within a local area network (LAN) using wired connections. – Example sentence: “The school’s computer lab uses Ethernet for fast and reliable internet access.”
Wireless – A method of connecting devices to a network without the use of physical cables. – Example sentence: “Most smartphones connect to the internet using wireless technology.”
Signals – Electrical or electromagnetic waves used to transmit data between devices in a network. – Example sentence: “Wi-Fi signals allow laptops and tablets to connect to the internet without wires.”
