Mastodawn

🅰🅻🅸🅲🅴 (🌈🦄)Feb 19

Hey @sunkat2048, thanks for the follow request! Unfortunately there's not enough vibe on your profile to check, so...

What's one of the coolest things you own?

I have a puzzle lockbox that was handmade by one of my friends, then delivered from Australia by another friend. It has three weird locks on it, one of which was designed and built by said friend, and the bitting on the key is shaped like my name. It's pretty fucking cool. I also have an amtique 8-lever padlock that's stamped with "Mastodon" from circa the late 1800s.

@alice I have a box of obsolete cables in my closet like everyone else, except mine are just a tad more obsolete than most

John Weston Feb 19

@dan @alice Continental drift is no joke!

Eldeberen Feb 19

@dan @alice Awesome :o

Dźwiedziu Feb 19

@dan
The only thing cooler would be a CT scan of it to have a framed cross-section.

Dan Ports Feb 19

@dzwiedziu @alice I have some others that are cut away so you can see the layers. This is a segment of TAT-1, the first transatlantic voice cable (1955/1956).

Layers from inside to outside:
- a copper wire wrapped in copper tape
- a thick layer of polyethlene (newfangled at the time!) serving as a dielectric
- a wrap of copper tape for the return path
- layers of cloth tape, steel wires, and jute fibers to serve as armor

Dźwiedziu Feb 19

@dan
Well, 75 years and I'm still in ave that it would just lie on thousands of km of oceanic floor and work.

The Orange Theme Feb 19

@dzwiedziu @dan @alice Especially in the 1850s! Before reading more about undersea cables, I would've said they were invented in like... 1920. It's amazing that they go back so much further.

Dan Ports Feb 19

@theorangetheme @dzwiedziu @alice Well, I didn't say the original 1858 cable was a *good* one. :-)

The first telegram it carried was a 98-word congratulatory note from Queen Victoria to James Buchanan. It took 16 hours to transmit.

It only lasted a couple months before one of the engineers, hoping to get a better signal, cranked the voltage way up and completely fried the cable.

Long undersea cables weren't really practical until they figured out how to add and power repeaters along the line, originally using miniature tube amps, closer to the 1950s.

The Orange Theme Feb 19

@dan @dzwiedziu @alice Undersea tube amps! That's so cool. Thanks for the history lesson. :)

Numerfolt Feb 19

@dan @dzwiedziu @alice That's actually really interesting! Do you know more about the return path? It seems strange to me that it seemingly uses less material for conducting the signal than the main wire 🤔

Dan Ports Feb 19

@Numerfolt @dzwiedziu @alice I think it's a combination of two things:

1) most of the current is carried in the outer skin of the conductor (but don't ask me to explain why, physics class was a long time ago!)

2) it might actually be the same amount of material. Wrapped around the much larger insulator, it doesn't take a very thick layer to make up the same cross-sectional area.

You can see this if you cut a regular household coax cable open, too... the return conductor is a thin braid around the cable.

Abhijit Menon-Sen Feb 19

@dan @dzwiedziu @alice Were these rings(?) added just to protect the ends of the cut-away, or are they something else?

Dan Ports Feb 19

@amenonsen @dzwiedziu @alice I would assume they're just there to keep it from unraveling

viernullvier Feb 19

@dan @alice Oh wow, that cable is way shorter than expected. I guess the world really was smaller back then.

Erik Nelson Feb 19

@dan @alice It also looks a little too short for that purpose