Fact: Broadband really does work over a piece of wet string

And it's faster than kilobit speed dial-up internet.
Written by Liam Tung, Contributing Writer

Techies at UK ISP Andrews & Arnold have demonstrated that ADSL broadband can work over a wet string.

An inquisitive engineer at the company this week decided to test whether wet string could work in place of twisted-pair copper for an ADSL connection.

Using a two-meter (6ft 7in) length of wet string, the engineer was able to reach a downlink speed of 3.5Mbps, which is slow by today's standards but way faster than yesteryear's dial-up internet speeds, albeit over a short distance.

While the test was just a "fun" experiment, the engineer was testing a figure of speech probably only heard among network engineers. As the ISP's boss explains in a blogpost, one of ADSL's main qualities is that can adapt to function on a really poor line -- so bad that it's been said it will even work on a bit of wet string.

The 'fiber' connection test failed using fresh water, but a second try with salty water did the trick thanks to salt's better conductive properties.


Using a length of wet string, the engineer was able to achieve a downlink speed of 3.5Mbps.

Image: Andrews & Arnold

The ISP techie behind the test described the experiment in a string of tweets yesterday. A pair of two-meter lengths of string were dunked into salty water and then connected side by side between two routers.

Professor Jim Al-Khalili from the University of Surrey's department of physics explained the science behind the experiment to the BBC.

"Although wet string is clearly not as good a conductor of electricity as copper wire, it's not really about the flow of current," he said.

"Here the string is acting as a waveguide to transmit an electromagnetic wave. And because the broadband signal in this case is very high frequency, it doesn't matter so much what the material is."

Previous and related coverage

Wi-Fi problems? You can boost signals with this $35 tinfoil 3D-printed reflector

Researchers have created a cheap way to boost and secure your Wi-Fi network.

Now you can 3D-print things that connect to Wi-Fi without batteries or electronics

Scientists print mechanical objects that can communicate with Wi-Fi devices.

Read more on broadband

Editorial standards