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in 2012 a team of Japanese and Danish
researchers set a world record
transmitting one pet a bit of data
that's 10,000 hours of hi-def video over
a 50 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 for decades
long-distance communications between
cities and countries were carried by
electrical signals in wires made of
copper this was slow and inefficient
with metal wires limiting data rates and
power lost as wasted heat but in the
late 20th century engineers mastered a
far superior method of transmission
instead of metal glass can be carefully
melted and drawn into flexible fiber
strands hundreds of kilometers long and
no thicker than human hair and instead
of electricity these strands carry
pulses of light representing digital
data but how does light travel within
glass rather than just pass through it
the trick lies in a phenomenon known as
total internal reflection
since Isaac Newton's time lens makers
and scientists have known that light
bends when it passes between air and
materials like water or glass when a ray
of light inside glass hits its surface
at a steep angle it refracts or bends as
it exits into air but if the rate ravel
at a shallow angle it'll bend so far
that it stays trapped bouncing along
inside the glass under the right
condition something normally transparent
to light and instead hide it from the
world compared to electricity or radio
fiber-optic signals barely degrade over
great distances a little power does
scatter away and fibers can't bend too
sharply otherwise the light leaks out
today a single optical fiber carries
many wavelengths of light each a
different channel of data and a fiber
optic cable contains hundreds of these
fiber strands
over a million kilometers of cable
crisscross our ocean floors to link the
continents that's enough to wind around
the equator nearly 30 times with
fiber-optics
distance hardly limits data which has
allowed the internet to evolve into a
planetary computer increasingly our
mobile work and play rely on legions of
overworked computer servers we're housed
in gigantic data centers flung across
the world this is called cloud computing
and it leads to two big problems eat
waste and bandwidth demand the vast
majority of Internet traffic shuttles
around inside data centers where
thousands of servers are connected by
traditional electrical cables half of
their running power is wasted as heat
meanwhile wireless bandwidth demand
steadily marches on and the gigahertz
signals used in our mobile devices are
reaching their data delivery limits
it seems fiber optics has been too good
for its own good
fueling overly ambitious cloud and
mobile computing expectations but a
related technology integrated photonics
has come to the rescue
light can be guided not only in optical
fibers but also in ultra thin silicon
wires silicon wires don't guide light as
well as fiber but they do enable
engineers to shrink all the devices in a
hundred kilometer fiber-optic network
down to tiny photonic chips that plug
into servers and convert their
electrical signals to optical and back
these electricity to light chips allow
for wasteful electrical cables in data
centers to be swapped out for power
efficient fiber photonic chips can help
break open wireless bandwidth
limitations to researchers are working
to replace mobile gigahertz signals with
terahertz frequencies to carry data
thousands of times faster but these are
short-range signals they get absorbed by
moisture in the air or blocked by tall
buildings with tiny Wireless to fiber
photonic transmitter chips distributed
throughout cities terahertz signals can
be relayed over long range distances
they can do so
a stable middleman optical fiber and
make hyper fast wireless connectivity a
reality for all of human history light
has gifted us with sight and heat
serving as a steady companion while we
explored and settled the physical world
now we've saddled light with information
and redirected it to run along a
fiber-optic superhighway with many
different integrated photonic exits to
build an even more expansive virtual
world check out this playlist to learn
about other inventions that have helped
shape the modern world and some that
could help change the future
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