The Internet: Wires, Cables & Wifi

Summary

Tess Winlock, a software engineer at Google, demystifies the Internet by comparing it to the postal service but for binary information. She explains how bits, the fundamental units of data, are transmitted through various physical mediums like electricity, light, and radio waves, highlighting the importance of bandwidth and latency. The video script delves into the technical aspects of how information travels across the globe, using fiber optics for long distances and wireless for mobility, while emphasizing the Internet's underlying fragility and the enduring protocols that govern data exchange.

Takeaways

• 💡 The Internet is a tangible, physical system designed to move information, similar to how the postal service moves packages.
• 🔢 All information on the Internet is represented as binary code, consisting of bits (1s and 0s).
• 📏 Eight bits form a byte, and data is typically measured in bytes, kilobytes, megabytes, etc.
• ⚡ Bits are transmitted through different physical mediums like electricity, light (fiber optics), and radio waves.
• ⏱ Bandwidth refers to the bit rate, or the number of bits transmitted per second, while latency is the time it takes for a bit to travel from source to destination.
• 🔌 Ethernet cables are common for short distances, but fiber optic cables are used for long-distance communication due to their speed and minimal signal degradation.
• 🌍 Fiber optic cables are laid across ocean floors to connect continents, highlighting the global nature of the Internet.
• 📡 Wireless communication uses radio signals to transmit data, but it still depends on wired infrastructure for long-distance transmission.
• 🚀 Future technologies may involve lasers, satellites, or other methods to send data, but the basic principles of binary information and transmission protocols remain constant.
• 💻 Despite its complexity and reliance on physical systems, the Internet enables the seamless transmission of all types of data, from emails to videos, through a combination of electronic pulses, light beams, and radio waves.

Q & A

What is the Internet often compared to in the script, and why?

The Internet is compared to the postal service because both systems move information from one place to another. However, instead of sending physical items like boxes and envelopes, the Internet transmits binary information.

What is a bit, and why is it considered the 'atom of information' on the Internet?

A bit is the basic unit of binary information, represented by a '1' or '0'. It is considered the 'atom of information' because all data on the Internet, whether text, images, or videos, is ultimately broken down into bits for transmission.

How do humans physically send a single bit of information using a light bulb in the script's example?

In the example, humans send a bit by turning a light bulb on to represent '1' and off to represent '0'. Both operators agree on this method and use a clock to time each bit, allowing them to send information like a sequence of zeros.

What is bandwidth, and how is it measured?

Bandwidth is the maximum transmission capacity of a device, measured by bit rate. Bit rate refers to the number of bits that can be sent over a given period of time, usually in seconds.

Why is fiber optic cable preferred for transmitting data over long distances?

Fiber optic cable is preferred because it transmits data as light beams, which can travel at the speed of light with minimal signal degradation over long distances. This makes it ideal for connecting continents, such as through undersea cables.

What physical methods are used to send bits of information over the Internet?

Bits are sent over the Internet using three main methods: electricity (through copper wires), light (through fiber optic cables), and radio waves (for wireless transmission). Each method has its own advantages and limitations.

How does wireless transmission of data work, according to the script?

Wireless transmission uses radio signals to send bits of information. Devices translate the binary data into radio waves of different frequencies, and receiving machines reverse the process to convert it back into binary data.

Why can't you pick up a Los Angeles radio station in Chicago, and how does this relate to wireless Internet?

Radio signals, including those used for wireless Internet, don't travel far before they become distorted or lost. This is why you can't pick up a Los Angeles radio station in Chicago. Wireless Internet relies on physical wires to transmit data over long distances.

What event in 2008 demonstrated the fragility of the Internet's physical infrastructure?

In 2008, a fiber optic cable was cut near Alexandria, Egypt, disrupting Internet service for much of the Middle East and India. This incident highlighted the Internet's reliance on a fragile physical infrastructure.

How might the physical methods for sending bits of information change in the future?

In the future, we might use lasers between satellites or radio waves from balloons or drones to send bits of information. However, the fundamental binary representation of information and the protocols for sending and receiving data will likely remain the same.

Outlines

00:00

💻 Introduction to Internet Communication

In this paragraph, Tess Winlock, a Google software engineer, introduces the concept of how information, like pictures, text messages, or emails, is transmitted over the Internet. She explains that the Internet is a physical system designed to move information, similar to a postal service, but instead of sending physical objects, it transmits binary information in the form of bits (ones and zeros). These bits are the fundamental building blocks of all digital information on the Internet, including text, images, and videos.

05:01

🌐 Physical Transmission of Bits

This paragraph delves into the physical methods of transmitting bits, highlighting the use of electricity, light, and radio waves. Winlock uses an analogy of turning on a light to represent a bit (1) and turning it off to represent a bit (0). She discusses the importance of timing and synchronization (using a clock) to ensure accurate transmission of multiple bits. The paragraph also introduces the concept of bandwidth and latency, explaining how they affect the speed and efficiency of data transmission. The discussion transitions to the need for faster transmission methods, leading to the use of fiber optic cables for long-distance communication, where bits are sent as light beams.

📡 Wireless Transmission and Future Innovations

This paragraph explores the wireless transmission of bits through radio signals, explaining how machines convert binary data into radio waves and then back into binary at the receiving end. Winlock emphasizes that despite the convenience of wireless communication, it has limitations, such as limited range and reliance on wired infrastructure for long-distance transmission. The paragraph concludes by speculating on future technologies that might change how we send information, like lasers between satellites or radio waves from drones, but reinforces that the underlying binary representation and protocols will remain consistent.

Keywords

💡Internet

The Internet is described as a tangible physical system designed to move information from one place to another. It is compared to the postal service, where instead of sending physical items like letters or packages, it transmits binary information. The video highlights how the Internet relies on various physical methods, such as electricity, light, and radio waves, to send this information across the globe.

💡Binary Information

Binary information is the fundamental data format used on the Internet, represented by bits. A bit can be in one of two states: 'on' or 'off,' typically represented by 1 or 0. The video explains that all digital content, whether it’s a text message, picture, or email, is ultimately converted into this binary format for transmission over the Internet.

💡Bits and Bytes

Bits are the smallest unit of binary information, with each bit representing a single 'on' (1) or 'off' (0) state. Eight bits grouped together form a byte, which is used to encode more complex data. The video emphasizes that everything on the Internet, from emails to videos, is made up of bits and bytes, which are the building blocks of digital communication.

💡Electricity

Electricity is one of the physical mediums used to send bits of information over the Internet. In the video, the example of two light bulbs connected by a copper wire is used to illustrate how electrical signals can represent binary data. When electricity flows through the wire, the light bulb turns on, signaling a '1', and when there is no electricity, it signals a '0'.

💡Light (Fiber Optic Cables)

Light, specifically through fiber optic cables, is another medium for transmitting data. Fiber optic cables use light beams to send information over long distances without significant signal loss. The video describes how light bounces along the cable’s length, allowing for high-speed data transmission across vast distances, such as under the ocean between continents.

💡Radio Waves

Radio waves are used in wireless communication to transmit bits of information over the air. The video explains that machines convert binary data into radio waves of different frequencies, which are then sent to a receiving device that converts them back into binary information. This method enables mobile and wireless Internet connections but has limitations in terms of range and signal clarity.

💡Bandwidth

Bandwidth refers to the maximum transmission capacity of a device or communication medium, typically measured in bits per second. The video explains that higher bandwidth allows more data to be sent in a shorter period, which is crucial for faster Internet speeds. For example, downloading a 3-megabyte song in three seconds requires a bandwidth of about 8 million bits per second.

💡Latency

Latency is the time it takes for a bit of information to travel from the source to the destination. The video contrasts latency with bandwidth, explaining that while bandwidth measures speed in terms of data transfer rate, latency measures the delay before the data begins to move across the network. Lower latency is critical for real-time applications, such as video conferencing or online gaming.

💡Signal Loss

Signal loss occurs when the strength of a signal diminishes as it travels over a distance, which is particularly problematic with certain types of cables like copper wires. The video mentions that while copper cables are common, they suffer from measurable signal loss over just a few hundred feet, making them less ideal for long-distance data transmission compared to fiber optic cables.

💡Wireless Routers

Wireless routers are devices that transmit bits wirelessly within a local area, such as in a home or coffee shop. The video explains that while wireless communication allows for mobile Internet access, the data eventually needs to be transferred to a physical wire to travel long distances across the Internet. Wireless routers are thus a key component in connecting wireless devices to the broader wired Internet infrastructure.

Highlights

The Internet is a tangible physical system made to move information, similar to the postal service but using binary data instead of physical packages.

Information on the Internet is represented as bits, which are the basic units of data. A bit can be either 'on' (1) or 'off' (0).

Eight bits together make one byte, and larger data sizes like kilobytes, megabytes, and gigabytes are formed by grouping bytes.

Whether it's a picture, video, or song, everything on the Internet is transmitted as bits, the fundamental units of information.

Bits can be sent using electricity, light, or radio waves, with different physical methods for different situations.

Electricity can send bits using simple systems like light bulbs connected by copper wire, with 'on' representing 1 and 'off' representing 0.

To accurately transmit sequences of bits, a timer or clock is used so both sender and receiver can synchronize the timing of each bit.

Bandwidth, the maximum transmission capacity, is measured in bit rate, which defines how many bits can be sent per second.

Latency measures the time it takes for a bit to travel from the source to the destination, affecting the speed of communication.

Fiber optic cables are used to send bits as light beams, allowing for high-speed transmission over long distances without significant signal loss.

Fiber optic cables are crucial for global communication, as they connect continents and allow the Internet to function worldwide.

In 2008, a cut in a fiber optic cable near Alexandria, Egypt, disrupted Internet service for much of the Middle East and India, highlighting the Internet's fragility.

Wireless communication, like Wi-Fi, converts bits into radio waves, allowing for mobility, but it still relies on wired connections for long-distance transmission.

While the methods for sending bits may evolve, the underlying principles of binary information and data transmission protocols remain consistent.

Everything on the Internet, from emails to videos, is transmitted as ones and zeros through various physical mediums like electronic pulses, light beams, and radio waves.

Transcripts

My name is Tess Winlock. I'm a software engineer at Google.

Here's a question, how does a picture, text message or email gets sent from one place to another?

It isn't magic. It's the Internet,

a tangible physical system that was made to move information.

The Internet is a lot like the postal service,

but the physical stuff that gets sent is a little bit different.

Instead of like boxes and envelopes the Internet ships binary information.

Information is made of bits.

A bit can be described as any pair of opposites -

"on" or "off".

"Yes" or "no".

We typically use a one meaning "on" or a zero meaning "off".

Because a bit has two possible states, we call it binary code.

Eight bits strung together makes one byte.

1000 bytes all together is a kilobyte.

1,000 kilobytes is a megabyte.

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!

But it's not like we're physically sending ones and zeros from one place to another,

one person to another.

So what is the physical stuff that actually gets sent over the wires and the airwaves?

Well let's look at a small example here of how humans can physically communicate

to send a single bit of information from one place to another.

So say we could turn on a light for a 1 or off for 0.

Or use beeps or similar sort of things of like Morse code.

These methods work but they're really slow, error-prone totally dependent upon humans .

What we really need is a machine.

So throughout history we've built many systems that can

actually send this binary information through different types of physical mediums.

Today we physically send bits by electricity, light and radio waves.

To send a bit via electricity, imagine that you have two light bulbs

connected by a copper wire.

If one device operator turns on the electricity then the light bulb lights up.

No electricity, no light.

If the operators on both ends agree that light on means one

and light off means zero then we have a system for sending bits

of information from one person to another using electricity.

But we have a problem.

Let's say that, y'know, we want to send five zeros in a row.

Well how can you do that in such a way that either person

can actually count the number of zeros?

Well the solution is to introduce a clock or a timer.

The operators can agree that the sender will send one bit per second

And the receiver will sit down and record every single second and see what's on the line.

To send five zeros in a row you just turn off the light...

wait five seconds...

the person on the other end of the line will write down all five seconds

say zero zero zero.

And for ones do the opposite - turn on the light.

Obviously we'd like to send things a little bit faster than one bit per second.

So we need to increase our bandwidth:

the maximum transmission capacity of a device.

Bandwidth is measured by bit rate,

which is the number of bits that we can actually send over a given period of time,

usually measured in seconds.

A different measure of speed is the latency

or the amount of time it takes for one bit to travel from one place to another,

from the source to the requesting device.

In our human analogy one bit per second was pretty fast

but kind of hard for a human to keep up with.

So let's say that you want to actually download a 3 megabyte song

in like three seconds.

At 8 million bits per megabyte

that means a bit rate of about 8 million bits per second.

Obviously humans can't send or receive 8 million bits per second.

But a machine can do that just fine.

But now there's also a question of

what sort of cable to send these messages over?

And how far the signals can go.

With an Ethernet wire, the kind that you find in your home or office or school,

you see really measurable signal loss over just a few hundred feet.

So if we really want this Internet thing to work over the entire world

we need a different way of sending this information really long distances.

I mean like across an ocean.

So what else can we use?

Well what do we know that moves a lot faster than just like electricity through a wire?

Well... light!

We can actually send bits as light beams from one place to another

using a fiber optic cable.

A fiber optic cable is a thread of glass engineered to reflect light.

When you send a beam of light down the cable

light bounces up and down the length of the cable until it is received on the other end.

Depending on the bounce angle we can actually send multiple bits simultaneously,

all of them traveling at the speed of light.

So fiber is really, really fast.

But more importantly the signal doesn't really degrade over long distances.

This is how you can go hundreds of miles without signal loss.

This is why we use fiber optic cables across the ocean floors

to connect one continent to another.

In 2008 there was a cable that was actually cut near Alexandria, Egypt,

which really interrupted the Internet for most of the Middle East and India.

So we take this Internet thing for granted but

it's really a pretty fragile physical system.

Fiber is awesome but it's also really expensive and hard to work with.

For most purposes you're gonna find copper cable.

But how do we move things without wires?

How do we send things wirelessly?

Wireless bit sending machines typically use a radio signal

to send bits from one place to another.

The machines have to actually translate the ones and zeros

into radio waves of different frequencies.

The receiving machines reverse the process and convert it

back into binary on your computer.

So wireless has made our Internet mobile but a radio signal doesn't travel all that far

before it completely gets garbled.

This is why you can't really pick up a Los Angeles radio station in Chicago.

As great as wireless is, today it still relies on the wired internet.

If you're in a coffee shop using Wi-Fi then the bits get sent

through this wireless router and then are transferred

to the physical wire to travel the really long distances of the Internet.

The physical method for sending bits may change in the future.

Whether it's lasers sent between satellites or radio waves from balloons or drones.

But the underlying binary representation of information and the protocols for sending that information

and receiving that information have pretty much stayed the same.

Everything on the Internet

whether it's words, emails, images, cat videos, puppy videos...

all come down to these ones and zeros

being delivered by electronic pulses, light beams, radio waves

and you know lots and lots of love.