Computer Science 1
Computer Science 1
Embedded Files
Information Transmission
Sept. 23rd & 24th
Information Transmission
Sept. 23rd & 24th
Two day task
I didn't feel like breaking this one up across the
two days, just work on it both class days.
Two day task
I didn't feel like breaking this one up across the
two days, just work on it both class days.
Today's Goal
Today's Goal
Learn a bit about the history
of transmitting information.
Completed
What is information?
Number Bases & Overflow Errors
Encryption vs Encoding
Cryptography in History
Caesar Cipher in Python
Today
Information Transmission
Morse Code
Upcoming
Numbers to Letters and Back
Typing Practice
Typing Practice
Start with typing:
https://shaunwegs.github.io/2024/cs/t/index.html
Keep your screenshot, you'll need it later.
An Urgent Message
An Urgent Message
Beacon Hill, near Loughborough, in Leicestershire, England, is a popular country park. It is one of several beacon hills in the United Kingdom. It is part of Beacon Hill, Hangingstone and Outwoods Site of Special Scientific Interest.
The current year is...
I don't know... like, a long time ago...
... like before cell phones,
and computers, and stuff.
You've been appointed to help with the security of your country.
An unknown group has crossed into your country.
You must send a message to the head of government.
What's the best way to do this?
What's the best way to do this?
The speed of light is the fastest way to send a message.
It's also one of the oldest ways to send important and urgant military messages.
What?
great-wall-ted.mp4While used in ancient times, line-of-sight information gathering and transmission is not limited only to ancient times. They were also used during the American Civil War, and is still used today as well.
The use of an apparatus to create a visual signal transmitted over distance is called semaphore. Flag semaphore, he telegraphy system conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands, is one of the most well known and widely used. The Japanese Merchant Marine and Armed Services have adpated this system to the Japanese language as well.
Another technology that proved paramount during the Civil War was the telegraph.
The telegraph was a new way to send communication over long distance. The telegraph, and other similar telecommunication systems is also what caused the decline of semaphore systems.
The telegraph wires couldn't support voice like telephone lines, or digital signals can today. So, it had to be done a different way. This is where Morse Code comes in. You probably know at least a little about it already.
It's important to note that Morse Code is NOT encryption.
Morse Code was designed to convert letters into a different format that could be sent over telegraph wires. It's intent was to transmit information, not specifically to hide it. How to encode and decode Morse Code was not a secret. When we talk about transforming data from one format to a different format, that is encoding. However, if we are changing content specifically to hide it, then that is encryption.
Morse Code with Python, ver. 1
Morse Code with Python, ver. 1
Let's make our own Python program that will encode a message with Morse Code. We are going to do this with an online tool; replit. We could use TextEdit and the terminal, but there are also other tools that I want you to be aware of as well.
Once you've completed it, screenshot the program.
NOTE:
I'm using Replit, however, it seems they no longer have the online Python tool without logging in. You can try logging in and accessing it that way, or you can use this online Python code editor: Python Fiddle. On Python Fiddle, the terminal is at the button, and the RUN button is in the top left.
In your screenshot, make sure that I can see both your Python code, and the result running successfully in the terminal.
The video below will get you started, I'm using basically the same structure that you previously learned. I'm not going to finish the program, you should be able to apply your understanding of what we did previously to get this to work successfully.
As I've only shown you the Morse Code for a and e, you will need to check for the other letters.
Below is a tree diagram for morse code, this can be used to check how each letter is encoded in Morse.
You may be thinking...
how do I use this tree diagram?
No problem, see this video for help. Binary tree diagrams are not used exclusively for Morse Code, you need to understand how this diagram works. You'll need to know how use it in the future too.
morse-trees.mp4When finished, you should have a program that encodes a string with Morse Code. We are storing the original string in a variable called "clear_text". You'll sometimes also see "plain text". Clear text and plain text are often used interchangeably, but there is an actual specific difference.
Both clear text and plain text are unencrypted; however, plain text is intended to be encrypted (or it was before some decrypted it), where as clear text is usually not intended to be encrypted. In my Caesar Cipher video, I should have actually named the variable "plain_text" instead of "clear_text". Clear text is the correct term in my Morse Code video, as I'm not intending on encrypting it.
TASK
TASK
In Canvas, submit a screenshot showing the completed and successful Morse Code encoding program (written in Pycharm or Python Fiddle or wherever). In your screenshot, make sure that I can see both your Python code, and the result running successfully with the correct output.
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