The Economist UK - 14.03.2020

72 The EconomistMarch 14th 2020

1

T

here is twiceas much water on Earth

as land. Oceanographers are neverthe-

less fond of saying that science knows less

about the high seas than it does about the

moon. If John Waterston gets his way,

though, that could soon change.

Mr Waterston is the head of the “Ocean

of Things” project at the Defence Advanced

Research Projects Agency (darpa), an

American military think-tank that has

helped develop everything from the inter-

net to stealthy fighter planes. The project’s

name is a play on the “Internet of Things”,

the awkward phrase which describes the

trend for stuffing sensors and an internet

connection into all manner of ordinary ob-

jects, from cars and toothbrushes to factory

robots and doorbells. The Ocean of Things

aims to likewise wire up the high seas with

swarms of floating, connected sensors.

Such devices are not in themselves new.

There are around 6,000 floating sensors

deployed around the world’s oceans, run by

navies and research institutes. What is un-

precedented is the scale of Mr Waterston’s

ambition. Over the next few years he hopes

to deploy 50,000 sensors across 1m square

kilometres of sea, an area considerably

larger than Texas. The eventual goal—

much more distant—is to enable the con-

tinuous monitoring and analysis of a sig-

nificant fraction of the world’s oceans.

Peering into Neptune’s kingdom

The project’s main aim, mindful of the “d”

in darpa’s name, is tracking ships. But

rather than building something that can do

just one job, Mr Waterston wants the Ocean

of Things to supply a wealth of other infor-

mation, from water temperature to wave

heights, weather conditions, nearby wild-

life and more. All this would then be made

freely available to scientific and commer-

cial users.

Existing “floating instrument pack-

ages”, known as floats or drifters, are often

custom-built, and usually contain the

highest-quality instruments available.

They therefore tend to be expensive, and

are bought only in small numbers. A typi-

cal existing float, designed for scientific re-

search, is the Argo. It costs around

$20,000, and can measure water tempera-

ture and salinity.

The Ocean of Things takes the opposite

approach. The aim is to cram as many

cheap, off-the-shelf components as possi-

ble into a single low-cost package. Current

float prototypes cost around $750, and Mr

Waterston hopes that economies of scale

could drive the cost down further. That

would allow tens of thousands to be de-

ployed without breaking the bank. Large

numbers are crucial for coverage. They also

help compensate for inaccuracies in indi-

vidual instruments. “Can a $5 sensor do the

same things as a $1,000 temperature

gauge?” Mr Waterston asks rhetorically.

“The answer is ‘yes’ if you have a lot of

them, because you can cross-correlate.

Maths solves the problem for you.”

The project’s researchers are evaluating

three designs from different manufactur-

ers, ranging in size from about six to 18 li-

tres. One, proposed by Xerox’s Palo Alto Re-

search Centre, is made of glass, like a

traditional Japanese fishing float. A sec-

Big wet data

An ocean of things

Compared with the land, the seas are poorly monitored. That is about to change

Science & technology

73 Why turtles eat plastic

74 Miniature nuclear reactors

74 The smallest dinosaur?

Also in this section