68. Erbium: Hyperlink

Element 68 plays an important role in stitching together the World Wide Web — for better or for worse.

Featured above: An early map of the first transatlantic telegraph cable.

Show Notes

It feels good to be back in the saddle again! The past few weeks have been unbelievably busy, but with any luck, the house hunt that occupied so much time is now done. Fingers crossed!

Wired On Wired: Coincidentally or not, I wound up referencing a lot of articles from Wired Magazine for this episode. None was more impressive than Mother Earth Mother Board, a 56-page behemoth written by science fiction legend and self-styled “hacker tourist” Neal Stephenson. If you’re interested in a detailed exploration of how these cables work, it’s a good way to kill several hours.

They Must Not Have Had Time To Write A Short One: The messages between Queen Victoria and President Buchanan were so long, and spent so many words saying really not very much at all. To wit:1

The Queen To The President

The Queen desires to congratulate the President upon the successful completion of this great international work in which the Queen has taken the deepest interest.

The Queen is convinced that the President will join with her in fervently hoping that the Electric Cable, which now connects Great Britain with the United States, will prove an additional link between the new nations, whose friendship is founded upon their common interests and reciprocal esteem.

The Queen has much pleasure in thus directly communicating with the President, and in renewing to him her best wishes for the prosperity of the United States.

The President To The Queen

To Her Majesty Queen Victoria, Queen of Great Britain.

Washington City.

The President cordially reciprocates the congratulations of her Majesty the Queen on the success of the great international enterprise accomplished by the skill, science, and indomitable energy of the two countries.

It is a triumph more glorious because far more useful to mankind than was ever won by conqueror on the field of battle. May the Atlantic Telegraph under the blessing of heaven prove to be a bond of perpetual peace and friendship between the kindred nations, and an instrument destined by Divine Providence to diffuse religion, civilisation [sic], liberty, and law throughout the world.

In this view will not all the nations of Christendom spontaneously unite in the declaration that it shall be for ever neutral, and that its communications shall be held sacred in passing to the places of their destination even in the midst of hostilities?

James Buchanan.

How purple, and more than a little optimistic on Buchanan’s part.

Oh hey! Here’s a shark attacking a submarine cable:


Episode Script

We’ve dedicated plenty of time already to the absurd abundance of elements named after the Swedish mining village of Ytterby, and it can be difficult to keep them straight. Not only because of their maddeningly similar names, but as lanthanides, they exhibit similar behaviors. They get used in very similar ways — on the rare occasion that they get used at all. And you could be forgiven for thinking you’ve already heard the story of how element 68 was discovered: By performing repetitive, monotonous, endless laboratory work, Carl Gustaf Mosander found a new chemical element within a sample of the mineral gadolinite.

Even contemporary scientists were confused by the resemblance among this handful of elements. Due to a mix-up in the lab, what Mosander had dubbed “erbium” became known as “terbium,” and what Mosander had called “terbium” became known as “erbium.” After thirty years of chaos, the elements had their names officially swapped to align with what everyone was already calling them anyway.

But there’s something interesting and unique to say about every element on the periodic table, and today’s subject is no exception. In fact, in a very real way, today’s episode — and everything else you find online — makes its way to you thanks to erbium.

You’re listening to The Episodic Table Of Elements, and I’m T. R. Appleton. Each episode, we take a look at the fascinating true stories behind one element on the periodic table.

Today, we’re doing a deep dive on erbium.

Have you heard of the Trans-Pacific Express? This 17,000 kilometer-long route makes stops at Shanghai, China; Qingdao, China; Maruyama, Japan; Geoje, South Korea; New Taipei City, Taiwan; and Nedonna Beach, Oregon. It ferries its cargo along the ocean floor far faster than any truck, boat, or airplane. And you have probably used it thousands of times.

That’s because the Trans-Pacific Express is one of over 200 submarine fiberoptic cables that knit together the global internet. Running hundreds of thousands of total kilometers, these cables transmit over ninety-nine percent of all international data, sending rapid pulses of light from cosmopolitan cities to remote island facilities at speeds of 200,000 kilometers per second.

Even as we festoon the skies with communications satellites, wireless networks simply can’t compete with hardwired connections in terms of raw bandwidth. And transoceanic cables are as tried as they are true: the first one was laid more than 150 years ago, and it was a monumental accomplishment.

Linking the continents by wire was a natural idea. Samuel Morse first suggested doing so in 1840, and by the 1850s, an entrepreneur named Cyrus West Field was ready to put money behind it.

Terrestrial connections were already commonplace, and submarine connections between Great Britain with Ireland, Belgium, and the Netherlands proved the concept could work. But conducting such an experiment on a global scale would run into unique problems.2 3

For instance: how to ensure the signal could actually make it from one side of the ocean to the other? There were two schools of thought on the matter: Morse and British physicist Michael Faraday believed that the cable should be made as narrow as possible, while William Thomson, the future Lord Kelvin, recommended the widest copper wire possible. The former approach was considerably cheaper than the latter, so it won out.

The project began in earnest on August 5, 1857, when the USS Niagara and HMS Agamemnon set out from Queenstown, Ireland… and less than five miles out, the cable snapped. The ships returned to port and started over.

They next ran into trouble in the middle of a stormy night on August 11, when, again, the cable broke and was lost. Field and his team went back to the drawing board.

On June 25, 1858, the team tried a new approach: The USS Niagara and HMS Agamemnon met in the middle of the Atlantic Ocean, each carrying half the total length of cable. They spliced the ends together and sailed off — the Agamemnon toward Ireland, and the Niagara toward Newfoundland.

Two days later, both ships noticed that the cable had failed, but they couldn’t figure out why. Each assumed that the other had caused the problem. Unable to figure out what had happened, they abandoned the 100 kilometers of cable they had just laid and began yet again.

When the cable snapped once more on June 29, Field’s investors were starting to express some doubt that the endeavor would ever succeed. So it must have seemed like a not-so-minor miracle when finally, on August 10, 1858, engineers were able to relay the first test messages back and forth between Valentia Island, Ireland, and Heart’s Content, Newfoundland.

Terrestrial cables carried the connection all the way from London to New York City and beyond, and on August 16, Queen Victoria and President James Buchanan exchanged the world’s first intercontinental telegraph messages.

Both messages were quite verbose, taking as long as 16 hours to transmit, but shared a sentiment of goodwill between nations. Modern archaeologist Cassie Newlands says the occasion was “The Victorian equivalent of the Apollo mission,” and it must have truly seemed like this cable had folded time and space.4

And there was much rejoicing.  New York City held a parade and set off fireworks with such abandon that the dome of City Hall caught fire. Tiffany & Co. bought up the remaining length of cable, splitting it into ten-centimeter pieces that they sold for fifty cents apiece.

The craze did not last long, however, because only a few weeks later, the cable failed. This may have happened because one of the chief engineers would sometimes overload the cable with electrical power in order to allow the faint signal to travel all the way across the ocean — at least, that’s who received most of the blame at the time.

Private investors were uninterested in in funding a new cable, and that might have been the end of the line, so to speak. But the British government saw value beyond potential profit and funded the project’s continuation. Finally, in 1866, Europe and the Americas were linked with a much more durable cable, and instant communication has continuously joined the two continents ever since.

Nowadays, data is transmitted as pulses of light down fiberoptic cables, rather than electricity across copper wire. But the laws of physics are still a problem: how to get the signal to travel such long distances?

The answer is erbium. Around every fifty kilometers, the signal hits a special length of cable containing erbium ions that get pumped full of energy, exciting the electrons around that erbium. When the light traveling down the fiberoptic cable hits the erbium, its electrons fall back down to a lower energy state and emit light — the exact same pattern of light as the original signal, but strengthened enough to travel fifty more kilometers, until it gets amplified again.5 6

It turns out these erbium outposts dotting the seascape tend to attract a lot of attention.

You might’ve caught that these amplifiers require power — quite a lot of it, actually. Since there aren’t power plants located every fifty kilometers along the ocean floor, these submarine cables carry the necessary electricity as well as data.

This infrastructure hasn’t been laid in a desolate wasteland, though. Rather, we’ve plowed right through well established neighborhoods, and it’s honestly kind of upsetting to some of the residents. Namely, sharks.7

Sharks possess a sensory organ that can detect electromagnetic fields in the water. It helps them pinpoint the location of prey based on the faint amount of electricity generated by their twitching muscles. Introducing a cable carrying 10,000 volts to their environment can be confusing, to say the least, and it’s not unheard of for these cables to suffer damage caused by curious sharks. For that reason, it’s become standard practice to wrap submarine cables in a sheath of kevlar to protect all those precious ones and zeroes.8

And they are precious. Following an earthquake in 2006, damage to four major cables disrupted the flow of data to half a dozen countries in Asia, and phone circuits as far away as Europe were overloaded.9 10 Similar circumstances have led to continent-wide data blackouts in Africa and Asia, and this damage often takes weeks or months to repair.11 12 13

It’s worth noting that sharks are practically never responsible for these outages. Usually something like a ship’s anchor or fishing lines are to blame.

But clearly, these are critical lines of communication, and they sometimes find themselves the target of more nefarious activity. The United States became the first belligerent to pursue that kind of activity, even before the 19th century came to a close. In 1898, during the Spanish American War, the US comprehensively attacked Spanish cables, severing all communications to Puerto Rico, Cuba, and the Philippines.14

That kind of thing doesn’t happen so often these days, though, because what’s more valuable than destruction is interception. The National Security Agency pioneered the art of undersea wiretapping in 1972 with Operation Ivy Bells. Targeting a Soviet cable, the NSA deployed highly specialized equipment — some of which had been used previously in Project AZORIAN, which we learned about in episode 25, Manganese. They covertly installed a recording device… and since it was 1972, every month thereafter, a diver would retrieve the tape, revealing intelligence on everything from operational tactics to Soviet commanders’ love affairs.15

The US government found this information to be especially valuable. According to one of the divers, “We didn’t know… how much we were frightening [the Soviets]… until we listened to these tapes. Very quickly, we pulled back from the brink. … I think finding this information turned out to be the thing that let the Cold War end.”16

Operation Ivy Bells was terminated in 1980, when a former NSA employee in dire financial straits revealed its existence to the Soviet Union in exchange for $35,000.17

Since Ivy Bells came to an end, underwater wiretapping has only become more sophisticated and far more comprehensive. Surveillance agencies aren’t just monitoring the communications of foreign governments — they’re listening in on civilian traffic, too, including and especially that of their own citizens.

In a prior age, such a claim would have sounded like the stuff of far-fetched conspiracy theories. But not only is such an idea entirely plausible in 2020, it’s effectively public knowledge.

Explicit details of mass surveillance became widely known in 2013, when former CIA employee Edward Snowden revealed information about several such wide-reaching programs to the public — although at least as far back as 2005, the Associated Press published reports on a then-new nuclear submarine with the ability to tap fiberoptic cables.18

The information provided by Snowden was revelatory not so much because it exposed the existence of mass surveillance, but the extensive scope of that surveillance. It is essentially complete. The NSA and its partner agencies are able to target anyone in the world and monitor everything they do via telephone and internet. As The Guardian reported, “This includes recordings of phone calls, the content of email messages, entries on Facebook and the history of any internet user’s access to websites.”19 20 21 22 23 24 25

Interestingly, the NSA does not deny that they have these capabilities, they merely claim that they’re used as part of the agency’s “lawful foreign signals intelligence collection system.”26

Intelligence agencies conduct this surveillance by capturing all data traveling across those fiberoptic cables that connect the world. Sometimes this surveillance is conducted with the knowledge of local governments, and other times it’s done more surreptitiously, by tapping those lines, like a much grander version of Operation Ivy Bells.27

When fiberoptic cables are tapped, it’s usually done at one of the points where the signal is amplified using erbium-doped fiber. At these “regeneration stations,” individual wires within the cable are already separated out to boost the signal inside. This makes it easy for the interested party to access and tamper, often simply by bending the wire enough that a small amount of light leaks out of the wire, ready to be siphoned away by the listening device while leaving little evidence of any interference.28 29

From there, the surveillance device scoops up hundreds of petabytes worth of information each day, storing it for as long as possible for the benefit of government agents. So to any agents associated with the NSA and its allied organizations in the UK, Canada, Australia, and New Zealand: Thank you for downloading my podcast.

There are few locations less accessible than the bottom of the ocean, but that’s not the only place you can find erbium-doped fiber amplifiers. They’re used wherever fiberoptic cable is used to connect distant locations. Unfortunately, they’re still pretty specialized equipment, so they tend to run a couple thousand dollars apiece.

The optical properties that make erbium so useful in fiberoptics also makes it useful as a component of certain lasers, and even as a colorant for glass. Of course, this is far from unique among the lanthanides. Many of them wind up in lasers, and the pink color erbium lends to glass makes it pretty similar to neodymium. So when adding erbium to your collection of elements, you’ll want to first collect plenty of intelligence that indicates you’re working with a reputable source.

Thanks for listening to The Episodic Table of Elements. Music is by Kai Engel. To read the full exchange of messages between the United States and United Kingdom on August 16, 1858, visit episodic table dot com slash E r.

Thank you, as well, for enduring the brief hiatus in between the last episode and this one. We should be back on our regular schedule now, so check back in two weeks to hear the legend of thulium.

Until then, this is T. R. Appleton, reminding you to communicate via services that employ end-to-end encryption whenever possible.


  1. The Nautical Magazine And Naval Chronicle, p. 502. 1858.
  2. Wired UK, How The First Cable Was Laid Across The Atlantic. Duncan Geere, January 18, 2011.
  3. IEEE Spectrum, The First Transatlantic Telegraph Cable Was A Bold, Beautiful Failure. Allison Marsh, October 31, 2019.
  4. The Conversation, How The Victorians Cheated Time And Space By Laying The First Trans-Atlantic Telegraphy Cable. Cassie Newland, September 29, 2016.
  5. FiberLabs Inc. Glossary, Erbium-Doped Fiber Amplifier (EDFA).
  6. LaserFocusWorld, Optical Amplifiers Speed Data Flow Undersea. Ying Wa Wong, August 1, 1997.
  7. The New York Times, Phone Company Finds Sharks Cutting In. Peter H. Lewis, June 11, 1987.
  8. Wired, Sharks Want To Bite Google’s Undersea Cables. Robert McMillan, August 15, 2014.
  9. The New York Times, Asian Quake Disrupts Data Traffic. Choe Sang-Hun and Wayne Arnold, December 28, 2006.
  10. Submarine Cable Networks, Submarine Cables Cut After Taiwan Earthquake In Dec 2006. Winston Qiu, March 19, 2011.
  11. Africa Times, Undersea Cable Break Leaves Africans Waiting For Service, Repairs. January 17, 2020.
  12. Wired, Fiber Optic Cable Cuts Isolate Millions From Internet, Future Cuts Likely. Ryan Singel, January 31, 2008.
  13. Wired, Why Undersea Internet Cables Are More Vulnerable Than You Think. Alexandra Chang, April 2, 2013.
  14. War On The Rocks, Silencing The Enemy: Cable-Cutting In The Spanish-American War. Jonathan Reed Winkler, November 6, 2015.
  15. Military.com, Operation Ivy Bells. Matthew Carle.
  16. Popular Mechanics, How Secret Underwater Wiretapping Helped End The Cold War. Matt Blitz, March 30, 2017.
  17. U.S. News & World Report, Ronald Pelton, Convicted Of Spying For Soviets, Freed From US Custody 30 Years After Arrest. Eric Tucker, November 24, 2015.
  18. The New York Times, New Nuclear Sub Is Said To Have Special Eavesdropping Ability. The Associated Press, February 20, 2005.
  19. The Guardian, XKeyscore: NSA Tool Collects ‘Nearly Everything A User Does On The Internet’. Glenn Greenwald, July 31, 2013.
  20. The Guardian, GCHQ Taps Fibre-Optic Cables For Secret Access To World’s Communications. Ewen MacAskill, Julian Borger, Nick Hopkins, Nick Davies, and James Ball, June 21, 2013.
  21. The Washington Post, NSA Slide Shows Surveillance Of Undersea Cables. Craig Timberg, July 10, 2013.
  22. The Atlantic, The Creepy, Long-Standing Practice Of Undersea Cable Tapping. Olga Khazan, July 16, 2013.
  23. The Intercept, New Zealand Launched Mass Surveillance Project While Publicly Denying It. Glenn Greenwald and Ryan Gallagher, September 15, 2014.
  24. NDR, Snowden-Interview: Transcript. January 26, 2014.
  25. ABC News, Glenn Greenwald: Low-Level NSA Analysts Have ‘Powerful And Invasive’ Search Tool. Kari Rea, July 28, 2013.
  26. CNN Business, New Snowden Leak: NSA Program Taps All You Do Online. Amanda Wills, August 1, 2013.
  27. Wired, U.K. Spy Agency Secretly Taps Over 200 Fiber-Optic Cables, Shares Data With The NSA. Kim Zetter, June 21, 2013.
  28. Deutsche Welle, Tapping The World’s Fiber Optic Cables. Fabian Schmidt, June 30, 2016.
  29. The Fiber Optic Association, Inc., Topic: How To Tap Fiber Optic Cables.

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