If you enjoy this, you might like to read about the Zimmermann Telegram - British SIGINT that took advantage of this network, bringing the USA in to World War I.
The British empire's resilient subsea telegraph network
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Re: The British empire's resilient subsea telegraph network
#32here's an interesting series of videos on undersea cables, as described by... Tool Time from Home Improvement
Re: The British empire's resilient subsea telegraph network
#33The Cable that Changed the World (2024) is pretty nice on the topic. Shows us how, again, most of the things we consider "new" or at even revolutionary most showcase how historical ignorance.
Re: The British empire's resilient subsea telegraph network
#34in this context: https://www.submarinecablemap.com/
Re: The British empire's resilient subsea telegraph network
#35Earlier quoted context omitted.
I should have definitely qualified that statement. Technically, electrical signals over copper are "slowed down" less than light through fibre optic cables. However there's attenuation, electromagnetic interference, and other signal loss for electrical signals that (for long haul cables) will mean you will need repeaters that add significant amounts of latency. On top of that, the higher you try and up the frequencie…
That's the point of hollow-core fibre which is absolutely being used where decreasing latency even by small amounts is worth it.
> That's the point of hollow-core fibre
Ok, how does that work though? I understand the concept of lower attenuation since air/vacuum has less molecules to get in the way. Less repeaters, should have less system latency.
What I don't understand is how light is moving through what is a hollow bendable medium. Is the tube that it's in reflective and there's just less time it's passing through it? I guess that's the main one in commercial use to shave some time off, reading about it here: https://en.wikipedia.org/wiki/Photonic-crystal_fiber
Re: The British empire's resilient subsea telegraph network
#36An interesting book on the subject of telegraph networks is The Victorian Internet by Tom Standage [1]. As well as the technical and commercial drivers, it also describes how the telegraph forced people to confront concepts like simultaneity, information being distinct from its physical medium, privacy, early approaches to encryption, etc. A fascinating book. [1] https://en.wikipedia.org/wiki/The_Victorian_Internet
That book led me to Gutta Percha, the plastic-like coating on the wires used in these cables which was quite the innovation and made this all possible. Vulcanized rubber was the other option but performed poorly in cables and was harder to work with. https://atlantic-cable.com/Article/GuttaPercha/ The above is a fascinating and depressing history of the Gutta Percha factory that made all these cables, after joining w…
At least in the UK the fact that the Victorians and others used a lot of child labour is well and widely known.
Blake wrote the poem The Chimney Sweeper about boys sold into the trade long before the 1850s and Elizabeth Barrett Browning published The Cry of the Children in Blackwood's magazine in 1843. Charles Kingsley used his The Water Babies to question child labour and England's treatment of the poor in general in 1862-3.
No one with any pretensions to knowledge of those times can claim not to know about child labour.
Re: The British empire's resilient subsea telegraph network
#37Earlier quoted context omitted.
That book led me to Gutta Percha, the plastic-like coating on the wires used in these cables which was quite the innovation and made this all possible. Vulcanized rubber was the other option but performed poorly in cables and was harder to work with. https://atlantic-cable.com/Article/GuttaPercha/ The above is a fascinating and depressing history of the Gutta Percha factory that made all these cables, after joining w…
At least in the UK the fact that the Victorians and others used a lot of child labour is well and widely known. Blake wrote the poem The Chimney Sweeper about boys sold into the trade long before the 1850s and Elizabeth Barrett Browning published The Cry of the Children in Blackwood's magazine in 1843. Charles Kingsley used his The Water Babies to question child labour and England's treatment of the poor in general i…
I imagine the percent of people who know these telegram cables were made by children is a very low percentage.
Re: The British empire's resilient subsea telegraph network
#38Earlier quoted context omitted.
That's the point of hollow-core fibre which is absolutely being used where decreasing latency even by small amounts is worth it.
> That's the point of hollow-core fibre Ok, how does that work though? I understand the concept of lower attenuation since air/vacuum has less molecules to get in the way. Less repeaters, should have less system latency. What I don't understand is how light is moving through what is a hollow bendable medium. Is the tube that it's in reflective and there's just less time it's passing through it? I guess that's the mai…
It works in that light will travel faster in a less dense medium. Remove the relatively denser glass for gas/vacuum.
Also the way fibre works is commonly misunderstood. The light isn't bouncing.
Re: The British empire's resilient subsea telegraph network
#39[deleted]
Re: The British empire's resilient subsea telegraph network
#40Is the latency the same now as it was for the signal itself? Obviously the throughput is rather different.
My understanding was that the latency was much higher due to manual repeating at stations along the way.
Eg. when the London-Mumbai telegraph was new it took around 45 minutes in one direction.