Comment by js2 | Hacker News Reader

Comment by js2 | Hacker News Reader

The argument is pedantic. It may not be Morse, but it's definitely possible to communicate by tapping on the wall. Imagine tapping out all of Anna Karenina to save a fellow inmate's life.

https://www.npr.org/2017/09/11/550058353/rough-translation-h...

https://www.bbc.co.uk/programmes/p03ttfks

One of my college classes was network communications and for a group project, we had to devise how to transmit a binary message visually standing across from each other by 100 yards or so. Four people to a group, split two and two.

The idea was to get us to strike a balance between speed of encoding/decoding, ability to distinguish symbols, and how many bits to encode in each symbol.

I think my group came up with a system to transmit 3 bits at a time which failed spectacularly on the windy day we had for showing it off. My recollection is we had a big box with neon colored flaps that we could fold in/out.

I wish we'd researched prior works of art. To this day, I have no idea why we didn't just learn flag semaphores. Maybe there was a rule against using existing systems though?

>The argument is pedantic. It may not be Morse, but it's definitely possible to communicate by tapping on the wall.

IMO the article made a useful distinction. The whole second half covers "tap code", as is used in prisons, etc. I've known Morse for decades but somehow hadn't bumped into tap code before.

I'm confused. Semaphore is not a binary system.

But you could use it to encode 4 (or with the full list of signs and something additional) even 5 bits at once (as he said, they had a system of 3 already).

The message we had to transmit was given to us as 1's and 0's. But we could transmit as many bits per symbol as we wanted. I think we were scored based on speed and error rate, so it did you no good to finish first if the message was garbled.

This was almost three decades ago and I'm working from memory so I may very well have some bits wrong.

Ah, that makes sense. Semaphore would have been ideal, then.

https://en.wikipedia.org/wiki/Semaphore#/media/File:Semaphor...

You should re-read the article. It didnt reject communications via tapping is NOT POSSIBLE. It is saying it is unrealible and can confuse the messages as some tappings are hard to distinguish. Next time, try to use a successful example to back your argument. The article is stressing the fact that Morse code cannot be use to transmit message reliably over a pipe via tapping. It is not refuting doing this communication is IMPOSSIBLE. Explain to me how you are going to do flags over pipes or walls. Stay within the context of discussion.

If "Morse code cannot be use to transmit message reliably over a pipe via tapping", then morse via the tapping of a sounder would also be impossible.

The original morse sounders used a large relay which went "Click" when operated and another "Click" when released.

So a Dit sounds like Click/Click, while a Dah sounds like Click ..... Click.

Which is how only one sound (plus spaces) can encode morse.

In other words it's all in the rhythm of the sounds.

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