Friday, January 22, 2010

Northwest Passage: Tokyo-London fiber optics

The Canadian Press and others have given us an answer to the question whether the warming - or a mere feeling that it's warming - is a good or bad thing.

These days, the information between London and Tokyo travels for 42,000 kilometers to close a round trip. The delay is therefore 0.14 seconds.

Kodiak-Kenai Cable Co. plans to spend $1.2 billion to reduce this delay to 0.088 seconds which is equivalent to 26,000 kilometers (round trip). The optical fibers will simply go from Japan to the Bering Sea, get re-energized in Alaska, and will continue through the Northwest Passage and North Atlantic Sea to England.

Asia and England may get much closer for the money that is spent (or wasted) for the fight against global warming in one or two days. The company believes that it's significantly easier to get through the Arctic ice these days, so let's wish them good luck.

Note that the distance between London and Tokyo along the surface is 9,600 kilometers, not much smaller than the 13,000 of the new cable's path. If you could send signals through the Earth, the distance would drop to 8,600 km or so (somewhat shorter than a quadrant, i.e. sqrt(2) times 6,378 km).

Update: Wolfram Alpha now suggests that the light speed in the fiber is 0.75c only, rather than close to c, so it's fair to say that most numbers above may be incorrect, including the statement that the delays refer to a round trip. ;-) Your clarification will be appreciated.

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