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សម្រស់ និង សុខុមាលភាព
សិប្បកម្ម
វប្បធម៌ និង ប្រវត្តិសាស្ត្រ
ការកម្សាន្ត
បរិស្ថាន
ម្ហូប និង ភេសជ្ជៈ
វិស្វកម្មបញ្ច្រាស
វិទ្យាសាស្ត្រ
កីឡា
បច្ចេកវិទ្យា
ប្រដាប់ដែលស្លៀក
Morse Code
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បង្កើតដោយ

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21. សីហា 2026FI
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Morse Code

The code, not the machine. Morse assigns each letter a pattern of short and long marks, and — this is the part that matters — the commonest letters get the shortest patterns. E is one dot, T is one dash, while Q and X run four elements long. The result is that ordinary English sends in far fewer elements than a fixed-length scheme would need. Because the alphabet lives in the timing rather than in the equipment, the same code travels down a wire, out of a lamp shutter, through a whistle, along a tapped pipe, or by a hand squeezing a shoulder. Alfred Vail and Samuel Morse worked out the frequency weighting around 1838 by counting type in a printer's case rather than by theory.
ចាប់ផ្តើម
1 hour

ការណែនាំ

1

Count letters and derive the weighting yourself

Do what Vail did — count, then assign.

  1. Take a page of ordinary English and tally how often each letter appears.
  2. Rank the letters from commonest to rarest.
  3. Assign your own codes: one element to the top two letters, two elements to the next four, and so on.
Your ranking will put E and T at the top, which is exactly where Morse put them. Vail reportedly settled the weighting by looking at the quantities of type in a newspaper compositor's case — the printer had already done the frequency count, for entirely different reasons.

Materials for this step:

Graph PaperGraph Paper1 pad
Graphite Pencil SetGraphite Pencil Set1 ឈុត
2

Learn the timing, because the timing IS the code

Five durations carry the whole system.

  1. A dot is one unit.
  2. A dash is three units.
  3. The gap between elements inside a letter is one unit.
  4. The gap between letters is three units.
  5. The gap between words is seven units.
Set any unit length you like and everything scales with it — the code is defined by RATIOS, not by absolute speed. That is why it survives a bad wire, a tired hand and a flickering lamp: a receiver only has to judge short against long, never measure anything.

Materials for this step:

StopwatchStopwatch1 ដុំ
3

Send it four different ways

Prove that the code is independent of the channel.

  1. Tap a short message on a table with a pencil.
  2. Send the same message by covering and uncovering a lamp.
  3. Send it by voice, saying dit and dah.
  4. Send it by squeezing a partner's hand.
All four carry the identical message because all four can express short, long and silence. This is the property the telegraph blueprint cannot show on its own — there the code and the apparatus arrive together, so it is easy to mistake one for the other.

Materials for this step:

Cardstock Assorted Pack (50 Sheets)Cardstock Assorted Pack (50 Sheets)1 កញ្ចប់
4

Measure the saving against a fixed-length code

Put a number on what the frequency weighting buys.

  1. Encode a 100-letter passage in Morse and count the total time units.
  2. Now encode the same passage giving EVERY letter the same five-element length, as Baudot does.
  3. Compare the totals.
Morse comes out substantially shorter for ordinary text — that is the whole point of the weighting. But note the cost: variable lengths mean the receiver must detect where one letter ends, which is why the inter-letter gap has to be policed so carefully. Baudot's fixed five bits are longer but need no gaps at all, which is precisely what let it be machine-printed. Neither is better; they trade human skill against machine simplicity.
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History and context

Alfred Vail and Samuel Morse developed the code around 1838; the frequency weighting is generally credited to Vail. The original American Morse used internal spaces within some letters, which machines handled badly. The International Morse agreed at Berlin in 1851 removed those and is the version still in use.

The code outlived its machine by a century. The telegraph is a museum piece; Morse is not. It stayed in maritime service until 1999, remains in amateur radio, and is still specified for aviation navigation beacons, which identify themselves in Morse to this day. Its endurance comes from the property in step 3: any channel that can be turned on and off can carry it, and a human ear can pull it out of noise that would defeat a voice transmission entirely.

Where it sits among neighbours in this catalogue: Baudot uses fixed-length codes so a machine can print without judging gaps; Huffman coding computes the provably shortest variable-length code for a specific message rather than for English in general; barcodes apply the same short-and-long idea to space instead of time. Morse's region is the one where a person is the receiver, the channel is poor, and the equipment might be nothing more than a torch.

A note on SOS: it stands for nothing. It was adopted in 1906 because three dots, three dashes, three dots is an unmistakable rhythm, easy to send and hard to confuse — the letters were chosen to fit the pattern, not the other way round.

សម្ភារៈ

4

ប្លង់ពាក់ព័ន្ធ

ប្លង់ទាំងនេះចែករំលែកចំណេះដឹង — បច្ចេកទេស សម្ភារៈ ឬគោលការណ៍

Morse Telegraph

Morse Telegraph

ដោយ EdFI

បច្ចេកវិទ្យា

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Baudot Code and the Teleprinter

Baudot Code and the Teleprinter

ដោយ PixelFI

ឌីជីថល

20
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CC0 សាធារណៈ

ប្លង់នេះត្រូវបានចេញផ្សាយក្រោម CC0។ អ្នកមានសិទ្ធិចម្លង កែប្រែ ចែកចាយ និងប្រើប្រាស់ដោយមិនចាំបាច់សុំអនុញ្ញាត។

គាំទ្រអ្នកបង្កើតដោយទិញផលិតផលតាមរយៈប្លង់របស់ពួកគេ ដែលពួកគេទទួលបាន កម្រៃជើងសារអ្នកបង្កើត កំណត់ដោយអ្នកលក់ ឬបង្កើតកំណែថ្មីនៃប្លង់នេះ ហើយបញ្ចូលជាការតភ្ជាប់ក្នុងប្លង់របស់អ្នកដើម្បីចែករំលែកចំណូល។

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