0.1 Seconds Under the Sea
From Busan to the US: a 0.1-second trip under the sea
When you tap a video on a phone in Busan, Korea, the request travels by radio waves, buried cables and an undersea cable to a data center in the US, and comes back in about 0.11 seconds. Follow the real shape of the internet in 15 steps.
Watch from the start in 3DChapter 1 · Leaving Busan
0–6 ms. You tap the screen. The request flies as radio waves to a rooftop, then runs through a cable underground to a telecom building. (1 ms = one thousandth of a second)
- 1 You tap the screen
Your phone makes a request: "please send this video"
View in 3D → - 2 Radio waves reach the roof
The only part that flies through the air: a few hundred meters to a rooftop tower
View in 3D → - 3 The telecom building
Through a cable underground to a telecom building, where machines choose the path
View in 3D →
Chapter 2 · Into the Sea
6–10 ms. At the Busan shore, the request enters an undersea cable. We cut the cable open and look inside.
- 4 The door to the sea
At the Busan shore, the request enters an undersea cable
View in 3D → - 5 Cutting the cable open
In the deep sea, the cable is actually thin — about as thick as a garden hose
View in 3D → - 6 Light inside the glass thread
The request becomes flashing light that races down the glass thread
View in 3D →
Chapter 3 · Crossing the Pacific
10–52 ms. We pull back from the glass thread to the whole Earth, then dive thousands of meters down to the sea floor.
- 7 One line across the globe
The glass thread you just saw is one line across the Pacific
View in 3D → - 8 The sea floor
The cable simply lies on the mud thousands of meters down
View in 3D → - 9 Repeaters
About every 60 to 80 km, they brighten the faded light again
View in 3D →
Chapter 4 · A Data Center in the US
52–56 ms. The light comes ashore in the US and travels to a huge computer building by a river.
- 10 The data center
Ashore in the US, then on to a huge building by a river
View in 3D → - 11 The server answers
The computer that got the request splits the video into small boxes and sends them
View in 3D →
Chapter 5 · The Way Back
56 ms on. The video is split into small boxes that cross the same sea in reverse.
- 12 Back as light
The boxes cross the same sea in reverse, back to Busan
View in 3D → - 13 The video plays
About 0.11 seconds after you tap — the video appears
View in 3D → - 14 Actually, it is close by
Popular videos already have a copy inside Korea
View in 3D → - 15 Roads woven like a net
The whole world is linked by countless lines
View in 3D →
More in the series
Times are simplified values, calculated from a simplified route (Busan → south of Japan → Pacific → Oregon, about 9,200 km) and the speed of light in glass (about 200,000 km per second). Real times vary with the carrier, the route and traffic.