 Alright, buds, you gotta check this out. This map represents 750,000 miles of fiber optic cables that are currently running under our oceans. And when I think of the internet, I think of 5G, I think of Starlink satellites, I think of Wi-Fi, but I never think about what's inside all of these cables. And how the future of the internet, buds, it relies on these hair-thin, super durable strands of glass. The making of glass for mirrors, especially telescope mirrors. Optical fiber will play a central role in helping to modernize the country's telecommunication. Glass is a 5,000 year old material that has always had a rich history with technology. And without it, you wouldn't be watching this video right now. All modern means of communication is entirely enabled by glass and hundreds and hundreds of millions of miles of this stuff made every year. I'm John Bellotto. I'm a professor of material science and engineering at Clemson University. I'm also the Serene Endowed Chair of Optical Fiber. Buds, he knows a lot about glass. It never gets old. Since the first installation of fiber networks back in the 80s, we, the industry, have made 5 billion kilometers of optical fiber. We don't think about living in a wired world. We think about living in a wireless world. It's not strange to ask, well, where's the fiber in all of that? So what really happens is you have your tablet, you have your smartphone, you're downloading and uploading things. That information is being sent wirelessly using microwaves to a local router. And in most cases, it travels as electrons from the router to a centralized hub. And then out the back of that, that information is all converted into light, gets propagated around the world over a fiber made out of glass. This is a piece of optical fiber. This is telecommunications quality. It is a hair thin piece of glass and you will not break this. But to get to that super durable piece of glass, well, it starts out looking like this. That's a preform in John's hands and it's 20 years old, but the preforms used today can be up to two stories tall and much, much wider. Within that preform is a core that is pure glass surrounded by a glass cladding with a lower refractive index. This allows light to travel easily through the core without scattering or fading. The preforms are then pulled into hair thin strands of glass and then coated with a protective plastic housing. 99% of the material that goes into the glass optical fiber is by and large the same as it was 50 years ago. We've just gotten better at making more of it. Now let's talk about what's actually moving through that glass. As far back as the telegram, telecommunications has relied on a pattern of pulses similar to Morse code to relay information. So pulses are sent over great distances and then on the opposite end they're decoded to relay information. But we haven't always used glass to do that. The much more expensive, much heavier copper was once the standard for telephones, cable TV and the early stages of the internet. And copper is still used in a lot of connections today. But there are two main limitations with that. One, electrons along copper, they don't travel as quickly as light. And two, electrons cannot pass through one another. So a single copper wire, it just isn't as efficient in sending data back and forth. Light on the other hand can move far more freely through a single strand of glass. And crucially, light can carry more data because it has a higher frequency. And frequency just means the amount of wave cycles that occur within a certain amount of time. Here's how that works. And buds, I'm totally about to go verge science on you, but stick with me. This piece of paper represents an amount of time, like fractions of a second. Radio waves from a typical radio in your car are measured in megahertz. So for our example, they are 112 size font. I can fit about one alphabet in this amount of time. Then 5G can reach tens of gigahertz, a much higher frequency. Think like size 18 font. Now I can fit about 39 alphabets onto this page. And then light waves and fiber optics, light can have frequencies in the hundreds of terahertz, about size two font here. In that same amount of time, I'm sending way more data, about 1,276 alphabets in our analogy here. So if we want to speed up our connection, we need to figure out how to encode as much information within the frequency of light as possible. The reason we're doing research in optical fiber is that more of the demand for usage has exploded. That expansion is driving capacity by 60% per year. And it's been that way for 30 years and has no expectation of stopping. Todd Sizer leads a research lab at Nokia Bell Labs. And last March, a researcher from his team set a new company record when they transmitted 1.52 terabits per second of data over 80 kilometers of single mode fiber. It's about 1.5 million YouTube videos at once. That amount of information is higher than what is available today. We fully expect that in two or three years, my business will have it as a product. But for right now, it was a research experiment. We have to do that in order to meet that 60% per year curve. Are we going to need to update that material at some point? Is there a limit to the current fibers that we have? So there is a limit. The limit was actually defined 70 years ago in this very building by a mathematician called Claude Shannon. And what Claude Shannon said is that in any channel, whether it's a fiber optic connection or a wireless connection, there is a fundamental limit on how much information you can send over that. We've been following a curve towards getting towards Shannon's limit for the past decade. Now we've effectively reached it. And so we need to think differently. Vivian, what am I looking at right now? It's beautiful, but what is it? What you're looking at is an optical transmitter. What the transmitter does is to try to modulate the light and to encode information on the light. This is Vivian Shih-Chien. She's a scientist here at Nokia Belt Labs, and she's currently showing us how our data is converted into light and then passed through a fiber. If you observe, it has a fiber coming in, and the fiber goes out. The fiber coming in connects to a laser, and then it got modulated through this device. It changes the power of the light, and the output of the modulator typically going into your transmission fiber, and then you send it into that fiber link that is laid on the bottom of the ocean. And on the other side of the ocean, you will have an optical receiver that basically tries to do the reverse of this. Communication between machines is like communication between people. What we have is a language system. So at the very beginning, what we do is switch the light on and off, and the receiver detects the light is on, it recognizes it as the information bit one. And when the light is off, it's the information bit zero. And nowadays, you can do more than switching it on and off. You can switch it half on and half off, and you can make more levels, many, many levels in between, between the full on and the full off. In today's optical fibers, we carry at the same time several hundred colors of light, several hundred 1.6 terabit signals. And wouldn't it be nice if it wasn't just a hundred, but maybe a thousand colors you could send? That would help us for four or five years. Another way of thinking about it is to go into fiber that has no glass in the middle. It's called hollow core. It has actually air in the middle that might allow us to go faster as well. The future of the internet is going to physically need miles and miles of fiber optic cables and huge infrastructure changes. A few weeks ago, the Biden administration released an infrastructure plan that aimed for universal high speed internet. And it referred to broadband as the new electricity in terms of everyday need. It's unclear exactly how that allocated money will be distributed, but telecom companies are hoping it will help with fiber optic upgrades. Only about a third of nationwide coverage is on fiber now, and some major cities, they have even less than that. Manufacturers such as Corning and Sumitomo, they'll have to produce huge amounts of near perfect fiber optic cable before telecom companies can even install them. And as all of these changes happen, it's important to remember one thing. You could not do anything over the internet if not for glass. Even if you take a step back and think about, you know, the gorilla glasses on your phone, historically, people think in terms of material ages, the stone age, the bronze age, there certainly is something to be said about the glass age. Glass is important today as it was 5000 years ago, just in a different enabling way. Buds, thank you so much for joining me on this journey. It has been truly a labor of love. And I hope you guys enjoyed watching it as much as I enjoyed making it. Stay tuned to the Verge Science Channel because next week they're going to have something real special for you as well. And yeah, thank you guys. We'll see you in the next one.