The hidden network that makes the internet possible - Sajan Saini
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0:07 - 0:08In 2012,
-
0:08 - 0:13a team of Japanese and Danish researchers
set a world record, -
0:13 - 0:16transmitting 1 petabit of data—
-
0:16 - 0:19that’s 10,000 hours of high-def video—
-
0:19 - 0:23over a fifty-kilometer cable, in a second.
-
0:23 - 0:24This wasn’t just any cable.
-
0:24 - 0:27It was a souped-up version
of fiber optics— -
0:27 - 0:30the hidden network that links our planet
-
0:30 - 0:32and makes the internet possible.
-
0:32 - 0:33For decades,
-
0:33 - 0:36long-distance communications
between cities and countries -
0:36 - 0:39were carried by electrical signals,
-
0:39 - 0:40in wires made of copper.
-
0:40 - 0:42This was slow and inefficient,
-
0:42 - 0:48with metal wires limiting data rates
and power lost as wasted heat. -
0:48 - 0:50But in the late 20th century,
-
0:50 - 0:54engineers mastered a far superior method
of transmission. -
0:54 - 0:55Instead of metal,
-
0:55 - 1:00glass can be carefully melted and
drawn into flexible fiber strands, -
1:00 - 1:05hundreds of kilometers long
and no thicker than human hair. -
1:05 - 1:06And instead of electricity,
-
1:06 - 1:11these strands carry pulses of light,
representing digital data. -
1:11 - 1:16But how does light travel within glass,
rather than just pass through it? -
1:16 - 1:22The trick lies in a phenomenon known
as total internal reflection. -
1:22 - 1:23Since Isaac Newton’s time,
-
1:23 - 1:27lensmakers and scientists have
known that light bends -
1:27 - 1:32when it passes between air and
materials like water or glass. -
1:32 - 1:36When a ray of light inside glass hits its
surface at a steep angle, -
1:36 - 1:40it refracts, or bends
as it exits into air. -
1:40 - 1:43But if the ray travels at a shallow angle,
-
1:43 - 1:46it’ll bend so far that it stays trapped,
-
1:46 - 1:49bouncing along inside the glass.
-
1:49 - 1:50Under the right condition,
-
1:50 - 1:56something normally transparent to light
can instead hide it from the world. -
1:56 - 1:58Compared to electricity or radio,
-
1:58 - 2:02fiber optic signals barely degrade
over great distances— -
2:02 - 2:04a little power does scatter away,
-
2:04 - 2:07and fibers can’t bend too sharply,
-
2:07 - 2:08otherwise the light leaks out.
-
2:08 - 2:13Today, a single optical fiber carries many
wavelengths of light, -
2:13 - 2:15each a different channel of data.
-
2:15 - 2:19And a fiber optic cable contains hundreds
of these fiber strands. -
2:19 - 2:23Over a million kilometers of cable
crisscross our ocean floors -
2:23 - 2:25to link the continents—
-
2:25 - 2:29that’s enough to wind around the
Equator nearly thirty times. -
2:29 - 2:31With fiber optics,
-
2:31 - 2:33distance hardly limits data,
-
2:33 - 2:37which has allowed the internet to evolve
into a planetary computer. -
2:37 - 2:38Increasingly,
-
2:38 - 2:43our mobile work and play rely on legions
of overworked computer servers, -
2:43 - 2:47warehoused in gigantic data centers
flung across the world. -
2:47 - 2:49This is called cloud computing,
-
2:49 - 2:51and it leads to two big problems:
-
2:51 - 2:54heat waste and bandwidth demand.
-
2:54 - 2:59The vast majority of internet traffic
shuttles around inside data centers, -
2:59 - 3:04where thousands of servers are connected
by traditional electrical cables. -
3:04 - 3:06Half of their running power
is wasted as heat. -
3:06 - 3:10Meanwhile, wireless bandwidth demand
steadily marches on, -
3:10 - 3:14and the gigahertz signals used in our
mobile devices -
3:14 - 3:16are reaching their data delivery limits.
-
3:16 - 3:20It seems fiber optics has been too good
for its own good, -
3:20 - 3:25fueling overly-ambitious cloud and mobile
computing expectations. -
3:25 - 3:30But a related technology, integrated
photonics, has come to the rescue. -
3:30 - 3:33Light can be guided not
only in optical fibers, -
3:33 - 3:36but also in ultrathin silicon wires.
-
3:36 - 3:40Silicon wires don’t guide light
as well as fiber. -
3:40 - 3:42But they do enable engineers to shrink
-
3:42 - 3:46all the devices in a hundred kilometer
fiber optic network -
3:46 - 3:49down to tiny photonic chips that plug
into servers -
3:49 - 3:53and convert their electrical signals
to optical and back. -
3:53 - 3:59These electricity-to-light chips allow for
wasteful electrical cables in data centers -
3:59 - 4:03to be swapped out for
power-efficient fiber. -
4:03 - 4:07Photonic chips can help break open
wireless bandwidth limitations, too. -
4:07 - 4:11Researchers are working to replace mobile
gigahertz signals -
4:11 - 4:13with terahertz frequencies,
-
4:13 - 4:16to carry data thousands of times faster.
-
4:16 - 4:18But these are short-range signals:
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4:18 - 4:20they get absorbed by moisture in the air,
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4:20 - 4:22or blocked by tall buildings.
-
4:22 - 4:25With tiny wireless-to-fiber photonic
transmitter chips -
4:25 - 4:27distributed throughout cities,
-
4:27 - 4:31terahertz signals can be relayed over
long-range distances. -
4:31 - 4:34They can do so via a stable middleman,
-
4:34 - 4:39optical fiber, and make hyperfast
wireless connectivity a reality. -
4:39 - 4:41For all of human history,
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4:41 - 4:44light has gifted us with sight and heat,
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4:44 - 4:49serving as a steady companion while we
explored and settled the physical world. -
4:49 - 4:53Now, we’ve saddled light with information
and redirected it -
4:53 - 4:56to run along a fiber optic superhighway—
-
4:56 - 4:59with many different integrated
photonic exits— -
4:59 - 5:03to build an even more expansive,
virtual world.
- Title:
- The hidden network that makes the internet possible - Sajan Saini
- Speaker:
- Sajan Saini
- Description:
-
View full lesson: https://ed.ted.com/lessons/the-hidden-network-that-makes-the-internet-possible-sajan-saini
In 2012, a team of researchers set a world record, transmitting 1 petabit of data— that’s 10,000 hours of high-def video— over a fifty-kilometer cable, in a second. This wasn’t just any cable. It was a souped-up version of fiber optics, the hidden network that links our planet and makes the internet possible. What is fiber optics and how does it work? Sajan Saini explores the vital technology.
Lesson by Sajan Saini, directed by Artrake Studio.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:03
lauren mcalpine edited English subtitles for The hidden network that makes the internet possible | ||
lauren mcalpine approved English subtitles for The hidden network that makes the internet possible | ||
lauren mcalpine accepted English subtitles for The hidden network that makes the internet possible | ||
lauren mcalpine edited English subtitles for The hidden network that makes the internet possible | ||
Tara Ahmadinejad edited English subtitles for The hidden network that makes the internet possible | ||
Tara Ahmadinejad edited English subtitles for The hidden network that makes the internet possible | ||
Tara Ahmadinejad edited English subtitles for The hidden network that makes the internet possible |