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On this day in 1520, the Magellan Expedition continued sailing South along the East Coast of Brazil, heading toward Puerto San Julian
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31 March 1520: The fleet enters Puerto San Julian (in 49 degrees 30 minutes South)
The next landfall is reported as 49 degrees 30 minutes South, on March 31st. Google Earth reports this location as Puerto San Julian at S49 degrees 18 minutes.
The Expedition record of 49 degrees 30 minutes south does not correspond to the GPS coordinates reported today. The difference may be accounted for by the limitations of the mechanical navigation instruments of the day.
Since the purpose of this thread is to consider alternative futures for humans expanding away from Earth, and since the technology of atom assemblers has been introduced previously as a logical and attractive way for a community away from Earth to maintain a high technology while at the same time distributing the means of production equitably across the population, I would like to focus today on the topic of long term digital data storage. Elsewhere in the Forum, Dave Z has recently reviewed the current status of work on using DNA (or similar chemical structures) to hold large amounts of data for extended periods. Results to date seem promising. Wide spread adoption and use of the techniques under study may be a few years away.
As an alternative, I'd like to introduce the idea of creating a "memory thread" of a stream of three kinds of atoms which would encode the very simple 300 baud protocol which became popular in the years just before the invention of the Internet. The Bell 103 modem dates to 1962. The Bell 101 dataset dates to 1958. It ran at a rate of 110 baud.https://en.wikipedia.org/wiki/Bell_103_modem
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The Bell 103 modem used audio frequency-shift keying to encode data. Different pairs of audio frequencies were used by each station:
The originating station used a mark tone of 1,270 Hz and a space tone of 1,070 Hz.
The answering station used a mark tone of 2,225 Hz and a space tone of 2,025 Hz.
The communications protocol implemented on sound based modems such as the Bell models cited above was RS-232.https://en.wikipedia.org/wiki/RS-232
an ASCII "K" character (0x4B) with 1 start bit, 8 data bits, 1 stop bit.
There were at least two arrangements of bits for serial transmission, EBCDIC and ASCII. EBCDIC was developed by IBM (International Business Machines) and it remains in use in 2017.
However, ASCII seems to be more widely used in 2017. https://en.wikipedia.org/wiki/ASCII
The committee considered an eight-bit code, since eight bits (octets) would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal. However, it would require all data transmission to send eight bits when seven could suffice. The committee voted to use a seven-bit code to minimize costs associated with data transmission. Since perforated tape at the time could record eight bits in one position, it also allowed for a parity bit for error checking if desired.:217, 236 § 5 Eight-bit machines (with octets as the native data type) that did not use parity checking typically set the eighth bit to 0. In some printers, the high bit was used to enable Italics printing.
The element I would like to call out from the quotation above is the option to use the 8th bit as a parity bit, which was an elementary form of data integrity checking. Far more sophisticated data integrity systems have evolved over the years since, and indeed, I would expect them to be used in the data storage system this message is intended to describe.
The storage system I would like to propose here could be implemented in a first generation of Atom Assemblers. It would extrude a thread of atoms with three optically identifiable characteristics, so that a base state would provide a base for sequential location and spacing of information carrying elements. Of the two atoms types to be blended into an alloy with the base material, one would represent a one bit or an ON state, while the other bit would represent a zero bit or an OFF state.
While the encoding of data using this system would normally be quite slow, reading of the resulting thread might be much faster. What I am concerned with in this design, is planning for the simplest possible means of decoding the stored data after thousands of years of storage. The atoms chosen would have distinctive spectrographic signatures, so that a person (human or otherwise) could pull out the data a bit at a time by examining the thread under a microscope.
The base atoms would be chosen for strength and durability, and for chemical compatibility with the two data atom types to be bonded with the base.
After reviewing a description of the method of data encoding chosen for USB, prepared by Jan Axelson in her book "USB Complete Fourth Edition", I realized that the information storage system based upon sequences of atoms is NOT limited to the restricted environment of serial communications in electronic devices.
Instead, there are ample supplies of atoms of various kinds that may be considered for the application.http://education.jlab.org/glossary/abund_ele.html
The list provided at the jlab.org page above includes: Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Magnesium, Potassium, Titanium and Hydrogen
The digital storage application described above would benefit by having at least three atom types, but a better design would employ five atom types:
1. ON Bit (value is 1)
2 OFF Bit (Value is 0)
3 Low order bit marker (signals start of a byte at the low order end)
4 High order bit marker (signals end of a byte at the high order end)
5 Base material
The goal here is to develop a digital storage system that will last for 10,000 years at a minimum, and which will be easy for people (human or alien) to decode using optical spectroscopy.
The thread extruded by an atom assembler for this purpose would be readable by "hand" using a microscope with a prism to distribute reflected light for identification of atoms in particular positions.
The length of the segments for the five meanings should be adjusted to provide for separation by crude equipment.
Certainly for maximum information density, the segments could be made much shorter, and machinery could be used to extract the data.
Perhaps threads could be encoded with a "hand" readable introduction which would describe the format of the dense section following.
May every member of The Knowledge forum grow financially, intellectually, socially and beyond.