What Does 5G Really Mean?

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<p>You might have heard people talking about “5G,” but what does it actually mean?</p><p>The network of cell towers and mobile devices that makes life in the Internet Age possible is less than fifty years old. And about once per decade since it was first built, the telecommunications industry has announced plans for an upgrade. “5G” is just the latest iteration: It refers to the coordinated effort to develop and install a new “generation” of wireless communications technologies throughout the 2020s.</p><p>Each iteration gets more advanced, and the earliest versions made possible basic capabilities that we now take for granted. The first commercial cellular network could only support voice calls, and it was launched in Tokyo in 1979 by a company called Nippon Telegraph &amp; Telephone. By the mid-1980s, the technology used to create this network — later dubbed “1G” — had been adopted worldwide. Newly-built cell towers relayed calls made from devices like the Motorola DynaTAC, the first commercially-available (and extremely expensive) cell phone.</p><p>Later generations of mobile technologies improved on the basics. Cell phones became smaller and now function more like mini-computers than telephones. Download speeds also became much faster. New generations introduced functions like text messaging and internet-browsing — added in 2G and 3G, respectively — which are now standard features of phones, tablets, and other mobile technologies.</p>
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<p>The technologies considered to be part of 5G, the fifth generation, were first introduced in South Korea in 2019, and advances continue to be made by companies like Huawei in China. Download speeds for 5G can be as high as 10 to 20 gigabits-per-second — about 100 times faster than 4G download speeds and many orders of magnitude faster than 1G, which was about 2.4 kilobits-per-second. 5G also supports many times more users than 4G, allowing for up to 1 million devices per square kilometer.</p><p>In order to make 5G a reality, existing infrastructure will need to be replaced. Cell towers, for example, will need to be retrofitted with new antennas and other components, and new towers will need to be built. 5G’s higher speeds are made possible in part by transmitting data in a band of higher radio frequencies. Because these signals are easily blocked by surrounding objects, companies are installing smaller towers called “small cells” to provide more precise coverage at a higher band. The 5G system is smart enough to automatically switch to the band that will give you the best performance and speed, even if that’s not the highest frequency band.</p><p>This hardware update is already well underway in some locations, most of which are cities, and China has deployed the technology at a greater scale than any other country so far.</p><p>The scale required is part of the challenge. Worldwide, the number of devices connected to the Internet is predicted to reach 50 billion sometime this decade. As mobile technology finds its way into everything from your watch to your car to your refrigerator, 5G will need to be powerful enough to support a massive new generation of internet users.</p>
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<p data-block-key="4os6l">The next generation of wireless communication technology is much more advanced, but it requires a lot of new infrastructure.</p>

A 3D rendering of Earth and the Sun from outer space

How Earth Became a Water World

<p>Today, more than 70% of Earth is covered in liquid water. But long before the sea became a familiar feature of our planet’s surface, the water that now fills our oceans, lakes, and streams was swirling through the atmosphere and trapped in the molten rock beneath the surface.</p><p>Water is made of hydrogen and oxygen, and scientists think that both elements were present in some amount as Earth formed. It’s also possible that solar winds pushed additional <a href="https://www.scientificamerican.com/article/did-earths-water-come-from-meteorites/">H and O</a> towards our planet and likely that even more arrived in rock form, as meteorites containing these elements crashed into Earth.</p>
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<p>The early Earth churned with the energy from these collisions, and immense heat radiated into space. The early atmosphere was born as the Earth cooled, when gases from the hot interior bubbled up and escaped through vents in the surface like rifts and volcanoes. This atmosphere contained large amounts of water vapor alongside other gases like carbon dioxide and methane.</p>
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<p>Inside the first rainclouds, raindrops formed the same way they do today. Water vapor began clinging to the tiny specks of dust floating in the atmosphere to form droplets, and when these droplets collided with each other, they combined into raindrops that were heavy enough to fall to the surface.</p><p>The problem was that Earth was still much too hot to accommodate liquid water, so these droplets just evaporated and floated back into the sky.</p>
<p>WATCH: <a href="/wgbh/nova/series/ancient-earth/">ANCIENT EARTH FULL SERIES</a></p>
<p>Eventually, Earth had released enough of its heat into space for liquid water to remain on the surface. Massive rain storms flooded the young planet for millions of years, filling the cracks and basins in the rocky surface and creating the first streams and oceans. With that accomplished, the planet was ready to host life as we know it.</p>
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<p data-block-key="q1qnf">The ancient history of Earth’s deep blue sea.</p>

Why Is the Sky Blue?

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<p>The sky is blue. Now there’s something we can all agree on (although you’re welcome to poke your head outside and check). But there was a time when that wasn’t true.</p><p>The sky gets its color from the way sunlight interacts with the gas molecules that make up our atmosphere. But the atmosphere has changed a lot over the last 4.5 billion years. In fact, in the earliest stages of Earth’s history, there was no real atmosphere at all — no barrier between the ground and the infinite reaches of space. Like the rest of us, our planet began its life stark naked.</p><p><a href="/wgbh/nova/video/ancient-earth-may-have-had-red-oceans/">WATCH: Ancient Earth May Have Had Red Oceans</a></p><p>It was also piping hot. As the Earth cooled, molten rock bubbling up from the interior carried gasses like carbon dioxide and methane to the surface. The gasses were then released, but Earth’s gravity kept them close to the surface, ultimately forming that gassy shroud we call our atmosphere.</p><p>That early atmosphere was dense with methane, and when methane builds up in the atmosphere, sunlight can cause it to break apart and take on new forms — and new colors. As a result, the early Earth may have sometimes been covered in what we would have seen as waves of dense orange haze.</p><p><a href="/wgbh/nova/video/ancient-earth-was-a-hellscape/">WATCH: Ancient Earth Was a Hellscape</a></p>
<p>At some unknown moment during Earth’s first billion years, life emerged, and scientists believe that some early organisms may have emitted methane as a waste product, making the orange hazes even thicker.</p><p>But there was another ancient, microscopic life form that would eventually make the sky look more like the one we see today. Cyanobacteria were the first organisms known to have used the sun’s energy to combine carbon dioxide and water into sugar molecules. Called photosynthesis, this process releases oxygen into the atmosphere and makes life possible for the rest of us. It also changes the balance of gasses in the atmosphere, ultimately changing the way it interacts with light.</p><p><a href="/wgbh/nova/video/enzyme-driving-photosynthesis/">WATCH: Meet the Enzyme Driving Photosynthesis</a></p>
<p>Today, our atmosphere is made up of about 78% nitrogen, 21% oxygen, and 1% argon, with other gasses like carbon dioxide, methane, nitrous oxide, and ozone accounting for only a tiny fraction of a percent. Sunlight is a combination of all colors, and the longer wavelengths that represent colors like red and yellow reach the ground without a problem. But the shorter wavelengths that look blue to our eyes bounce off the molecules of nitrogen and oxygen in our atmosphere. As these beams of light are scattered around the sky, they create the familiar blue color that reminds us to breathe deep and be grateful.</p>
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<h4></h4><h4><b>Editor’s Picks</b></h4><p><a href="/wgbh/nova/video/mars-the-red-planet-was-once-blue/">Mars, the Red Planet, Was Once Blue</a><br/><a href="/wgbh/nova/video/new-eye-on-the-universe/">New Eye on the Universe</a><br/><a href="/wgbh/nova/video/making-north-america-origins/">Making North America: Origins</a></p>
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<p data-block-key="wszqn">The familiar sky we see today wasn’t always blue.</p>

Who was Ötzi the Iceman?

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<p>First spotted in 1991 by hikers traveling the Italian Alps, the mummified body of a man was soon excavated from the glacier where it had lain frozen for over five thousand years. That mummy became known as Ötzi the Iceman, and today, his remains are housed in the South Tyrol Museum of Archaeology in Italy. Here are some of the things we’ve learned about him since the discovery.</p>
<p><b>How long ago did he live?</b></p><p>Using carbon dating and other tools, scientists dated Ötzi’s corpse to around 3350-3120 BCE, during a period known as the Chalcolithic, or “Copper Age”.</p>
<p><a href="https://www.tiktok.com/@novapbs/video/7281699444691668255">WATCH: A 5,000-Year-Old Preserved Body</a></p>
<p><b>How old was he when he died?</b></p><p>Studies of Ötzi’s teeth and bones have shown that he was roughly 45 years old (give or take a year).</p>
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<p><b>What did he look like?</b></p><p>After sequencing Ötzi’s genome, researchers determined that he had darker skin than Europeans today and likely also had male-pattern baldness. He had a total of 61 tattoos on his legs, wrists, and back.</p>
<p><b>How did he die?</b></p><p>Buried in Ötzi’s left shoulder is an arrowhead, which severed a major artery and likely caused his death. He also suffered a major head wound and a cut to his right hand. These injuries have led scholars to conclude that Ötzi was murdered, perhaps at the end of a days-long chase.</p>
<p><a href="https://www.tiktok.com/@novapbs/video/7284353861412769067">WATCH: How Did Ötzi the Iceman Die?</a></p>
<p><b>What did he have with him?</b></p><p>Ötzi was well-prepared for the harsh life of the mountains. He was dressed in a coat, pants, and underwear sewn from goat and sheep hide as well as shoes made of deerskin and plant fibers. He also had a bearskin hat and another item made of woven grass, which may have been a cloak or a mat of some kind. A belt that he wore around his waist had a special pouch which contained various small stone and bone tools as well as two types of fungi he likely used as tinder for lighting fires and potentially for medical purposes. Entombed along with him were several weapons: a copper-bladed axe, a flintstone knife and sheath, a bow and a quiver with 14 arrows.</p>
<p><b>What was his last meal?</b></p><p>The contents of Ötzi’s stomach were well-preserved along with the rest of him. Scientists have determined that he ate meat from a deer and red ibex along with einkorn wheat and a small amount of bracken, a poisonous fern.</p>
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<p data-block-key="k2k5k">Meet Europe’s five-thousand-year-old murder victim.</p>

Abe Musselman

Articles

What Does 5G Really Mean?

How Earth Became a Water World

Why Is the Sky Blue?

Who was Ötzi the Iceman?

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