Difference between revisions of "ICT student textbook/Science Technology and Society"

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{{Navigate|Prev=Additional readings|Curr=Science Technology and Society|Next=What students need to know about ethics of technology}}
  
{{font color|purple|'''Notes for the students'''<br> This chapter is meant for you to read, with your friends and teachers, to develop an understanding of the way technology in society.  Your teacher will introduce some of these readings, as part of activities.  Do not worry if some of these terms are new - as you complete the ICT course, you will understand more; please keep this chapter as a ready reference and come back to read it.}}
 
  
 
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===Science and technology===
 
===Science and technology===
Many times you hear the word science and technology together. What is the connection between the two? Do you know? Study of science includes a method of observing things around us, thinking about why those events happen, explaining why the events happen, recording information about the events and also predicting what might happen. Often, scientists imagine what might be the solution and what might be the answer to the puzzles around us. The understanding of phenomena can lead to the development of tools – this is  what we call technology. The technology can provide us more methods of observing, experimenting and recording.  And this in turn results in the advancement of science.  Thus, science and technology share a symbiotic relationship.
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Many times you hear the word science and technology together. What is the connection between the two? Do you know? Study of science includes a method of observing things around us, thinking about why those events happen, recording information about the events, explaining why the events happen and also predicting what might happen. Often, scientists imagine what might be the solution and what might be the answer to the puzzles around us. The understanding of phenomena can lead to the development of tools – this is  what we call technology. The technology can provide us more methods of observing, experimenting and recording.  And this in turn results in the advancement of science.  Thus, science and technology share a symbiotic relationship.
  
 
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Can you think of examples of where technology has helped the growth of science? One area is that of cell biology. Until the microscope was invented by Robert Hooke and Anthony Leeuwenhoek, the study of cells was not possible. Now we study structure of cells, growth of cells, disease-affected cells, cell reproduction, gene sequencing and [https://en.wikipedia.org/wiki/DNA DNA] using many advanced microscopes, cameras; the data and images are analysed using computers.
+
Can you think of examples of where technology has helped the growth of science? One area is that of cell biology. Until the microscope was invented by Robert Hooke and Anthony Leeuwenhoek, the study of cells was not possible. Now we study structure of cells, growth of cells, disease-affected cells, cell reproduction, gene sequencing and [https://en.wikipedia.org/wiki/DNA DNA] using many advanced microscopes and cameras; the data and images are analysed using computers.
  
<gallery>
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<gallery mode=packed heights=150px>
 
File:Robert-Hookes-microscope-287x300.jpg|First microscope designed by Robert Hooke
 
File:Robert-Hookes-microscope-287x300.jpg|First microscope designed by Robert Hooke
 
File:1Old-microscopes.jpg|Old Microscopes, 1750
 
File:1Old-microscopes.jpg|Old Microscopes, 1750
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</gallery>
 
</gallery>
  
As you can see the microscope started with simple magnification; now,the images captured by the microscope and camera can be input into the computer for further study and research. It has even become possible to scan parts of the body for diagnosing illnesses. Many complex problems in biology are being studied through the use of computers. Some of these areas include cancer research, study of how certain diseases develop and development of medicines.   
+
As you can see the microscope started with simple magnification; now,the images captured by the microscope and camera can be input into the computer for further study and research. It has even become possible to scan parts of the body for diagnosing illnesses. Many complex problems in biology are being studied through the use of computers. Some of these areas include study of how certain diseases, such as cancer develop, and the development of medicines.   
  
 
Similarly, our understanding of astronomy has been expanded after the invention of the telescope. But to make a telescope or microscope, we need to understand the properties of light. We must understand how a lens works, how light travels. Thus, science and technology are very closely connected.   
 
Similarly, our understanding of astronomy has been expanded after the invention of the telescope. But to make a telescope or microscope, we need to understand the properties of light. We must understand how a lens works, how light travels. Thus, science and technology are very closely connected.   
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Your teacher will discuss with you more examples of how technology has impacted the way we understand many natural phenomena.
 
Your teacher will discuss with you more examples of how technology has impacted the way we understand many natural phenomena.
  
===Information and communication technologies (ICTs)===
+
===Information and communication technologies (ICT)===
  
Information is not new for human beings; communication has been known since the time human beings lived in caves. Thus ICT are as old as human beings themselves; human beings needed to communicate with one another, beginning with symbolic (non verbal) ways, before language was invented. The language we speak could be seen as first 'ICT', it  enabled (oral) communication amongst human beings. Writing and script was the next technological advancement - around 5000 years ago - which enabled information could be created and communicated at different times and in a different place. Oral communication does not have this benefit,  Writing also enabled easier recording of human history and thus the invention of script was a landmark in the history of ICTs.  Next came printing which made it possible replicate writing. The invention of radio and television was the next advancement in ICT as it became possible for more and more people to access information.
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Information is not new for human beings; communication has been known since the time human beings lived in caves. Thus ICT are as old as human beings themselves; human beings needed to communicate with one another, beginning with symbolic (non verbal) ways, before language was invented. The language we speak could be seen as first 'ICT', it  enabled (oral) communication among human beings. Writing (script) was the next technological advancement, around 5,200 years ago, which enabled information could be created and communicated across time and place, which is not possible in the case of oral communication. Writing also enabled easier recording of human history and thus the invention of script was a landmark in the history of ICTs.  Next came printing which made it possible replicate writing on a large scale. The invention of radio and television (called '[[wikipedia:Mass_media|mass media]]') was the next advancement in ICT as it became possible to share information with more and more people. Thus, the technology for information creation and communication has been changing. We are now in the middle of the transformation in ICT, through the introduction of digital technologies.
 
 
Thus, the technology for information creation and communication has been changing, connected with the advancements in scientific knowledge. Changes happened in the way computing evolved and changes happened in the way communication technology evolved, each impacting the other to produce the ICT environment we are now in; and which is still changing rapidly.
 
  
 
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Throughout history, people have been counting and making devices to help counting and to perform calculations.  Initially these devices were based on physically changing things or moving things to represent the various phenomena and perform calculations.     
 
Throughout history, people have been counting and making devices to help counting and to perform calculations.  Initially these devices were based on physically changing things or moving things to represent the various phenomena and perform calculations.     
  
Can you guess what these two images are?  The one on the left is called the Abacus which was used to perform calculations with numbers by moving the beads.  The one on the right is called the Antikythera machine which was used in Greece to calculate the positions of astronomical objects. Over the years, computational technologies and devices continued to develop, some for general calculations like the slide rule or Napier's calculating tables and some for specific applications like predicting tides.   
+
Can you guess what these two images are?  The one on the left is called the Abacus which was used to perform calculations with numbers by moving the beads.  The one on the right is called the Antikythera machine which was used in Greece to calculate the positions of astronomical objects. Over the years, computational technologies and devices continued to develop, some for general calculations like the [[wikipedia:Slide_rule|slide rule]] or Napier's calculating tables and some for specific applications like predicting tides.   
  
 
Many such analog devices were used for performing different calculation tasks like the ones shown below:       
 
Many such analog devices were used for performing different calculation tasks like the ones shown below:       
<gallery>
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<gallery mode=packed heights=200px>
 
File:South-pointing_chariot_(Science_Museum_model).jpg|Model for pointing out direction, China, 200-265
 
File:South-pointing_chariot_(Science_Museum_model).jpg|Model for pointing out direction, China, 200-265
File:Torquetum.jpg| Torquetum for astronomical instruments,1100-1200
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File:Torquetum.jpg| Torquetum for astronomical instruments,{{nowrap|1100-1200}}
 
File:Sliderule_2005.png|Slideruler for calculations, 1630
 
File:Sliderule_2005.png|Slideruler for calculations, 1630
 
File:Napier's_calculating_tables.JPG|John Napier's calculating tables, 1642
 
File:Napier's_calculating_tables.JPG|John Napier's calculating tables, 1642
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|}       
 
|}       
  
During the mechanical and electric analog phases of technology, information was created by a series of physical changes converted into electrical impulses for storing and  machine, and each analog information storage required a specialized equipment to decode and read the information. A cassette player or a gramophone disc is an example of such a device.  Analog machines could be programmed for specific applications as well as for general computing.  Since information was being represented physically, results were not always accurate as they could not be replicated exactly.Such a device is called an [[wikipedia:Analog_computer|analog computer.]]
+
During the mechanical and electric analog phases of technology, information was created by a series of physical changes converted into electrical impulses for storing and  machine, and each analog information storage required a specialized equipment to decode and read the information. A cassette player or a gramophone disc is an example of such a device.  Analog machines could be programmed for specific applications as well as for general computing.  Since information was being represented physically, results were not always accurate as they could not be replicated exactly.Such a device is called an [[wikipedia:Analog_computer|analog computer.]]
 
+
[[File:Early SSA accounting operations.jpg|center|thumb|284x284px|Punched cards for accounting calculations, 1920s]]
 
 
File:Early_SSA_accounting_operations.jpg|Punched cards for accounting calculations, 1920s
 
 
 
  
  
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====Development of the digital computer====
 
====Development of the digital computer====
We saw earlier how analog machines worked and what were the difficulties. With the discovery of electricity and circuits, it became possible to represent things using electric signals. Using a series of circuits and electrical signals, it became possible to perform calculations, bringing in the electro-mechnical analog computers.
+
We saw earlier how analog machines worked and what were the difficulties. With the discovery of electricity and circuits, it became possible to represent things using electric signals. Using a series of circuits and electrical signals, it became possible to perform calculations, bringing in the electro-mechanical analog computers.
  
When Alan Turing developed a theory that a computer can be programmed to solve any problem, the development of modern computers as we now know it began. The use of Boolean algebra, which helped developing logical circuits for electrical signals launched the digital revolution. Boolean logic uses the binary system where information is represented as a series of "0"s and "1"s thus allowing information to be accessed through only a combination of "1"s and "0"s. This allowed information to be communicated in discrete bits which could be combined and recombined. Such a computer which uses "0"s and "1"s to perform computations is a digital computer.  
+
When Alan Turing developed a theory that a computer can be programmed to solve any problem, that can be defined mathematically, the development of modern computers began. The use of Boolean algebra helped developing logical circuits for electrical signals and launched the digital revolution. Boolean logic uses the binary system where information is represented as a series of "0"s and "1"s thus allowing information to be accessed through only a combination of these two digits. This allowed information to be communicated in discrete bits which could be combined and recombined. Such a computer which uses "0"s and "1"s to perform computations is a digital computer.  
  
What makes our society now different from ever before is the presence of digital technologies. This development came with the development of new methods of designing circuits like transistors and micro chips; thus giving birth to the digital computer. 
+
This improved the reliability and ease of computations significantly over the analog machines and led to the growth of computers as we know it - from large clunky computers to the computer on your desktop to the laptop and now the smart phone. What makes our society now different from ever before is the presence of these digital technologies.   
 
 
This improved the reliability and ease of computations significantly over the analog machines.  This has led to the growth of computers as we know it - from large clunky computers to the computer on your desktop to the laptop and now the smart phone.   
 
 
====Watch the timeline of computer history====
 
====Watch the timeline of computer history====
 
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====Impact on communication technologies====
 
====Impact on communication technologies====
  
What is the word that comes to your mind when you say communication?  The phone, precisely the cell phone. We will now look at how the communication technologies evolved.
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What is the word that comes to your mind when you say communication?  The phone, precisely the cell phone. We will now look at how the communication technologies evolved.
  
 
=====Radio communication=====
 
=====Radio communication=====
 
The earliest electronic communication devices functioned using radio technology. Many communication devices we know today also function through radio waves. Radio waves are [https://en.wikipedia.org/wiki/Electromagnetic_radiation electromagnetic waves].  Radio waves carry a certain amount of energy and can travel over large distances. When the wave reaches the destination, the receiver gets the amount of information. We cannot see radio waves but we can detect them by building receivers that can detect them. These are called as antennae. They scan the environment for radio signals and respond when they find a signal.  
 
The earliest electronic communication devices functioned using radio technology. Many communication devices we know today also function through radio waves. Radio waves are [https://en.wikipedia.org/wiki/Electromagnetic_radiation electromagnetic waves].  Radio waves carry a certain amount of energy and can travel over large distances. When the wave reaches the destination, the receiver gets the amount of information. We cannot see radio waves but we can detect them by building receivers that can detect them. These are called as antennae. They scan the environment for radio signals and respond when they find a signal.  
  
You must be thinking if this is similar to how we hear sound.  Sound is a pressure wave – when we produce a sound it travels by disturbing the air particles. If there is no medium, sound cannot travel. What happens when we hear something on a radio?  Originally sound is produced and then it converted into radio waves. These waves are sent and received through instruments called antennae. When your radio antennae receives this radio wave, this is converted back into sound and is played.  <br>
+
You must be thinking if this is similar to how we hear sound.  Sound is a pressure wave – when we produce a sound it travels by disturbing the air particles. If there is no medium, sound cannot travel. What happens when we hear something on a radio?  Originally sound is produced and then it converted into radio waves. These waves are sent and received through instruments called antennae. When your radio antennae receives this radio wave, this is converted back into sound and is played.   
  
 
=====Telephone=====
 
=====Telephone=====
Before the cell phone came, most of the long distance voice communication was through the regular telephone. This was based on the idea of travelling sound waves. They cause the mouthpiece to vibrate and this vibration is carried to the receiver at the other end. When a call came from one number, there will be an operator who sits at an office who will connect the call to another receiving number. Now this is different with automatic switches which connect the calls. The transmission of the signals has also become different now with voice being converted into electrical signals. All these transmissions used to happen through physical cables. These cables were either made of copper or optical fibres.   
+
Before the cell phone came, most of the long distance voice communication was through the regular telephone. This was based on the idea of travelling sound waves. They cause the mouthpiece to vibrate and this vibration is carried to the receiver at the other end. When a call came from one number, there would be an operator who sat at an office and connected the call to another receiving number. Now this is different with automatic switches which connect the calls. The transmission of the signals has also become different now with voice being converted into electrical signals. All these transmissions used to happen through physical cables. These cables were either made of copper or optical fibres.   
  
When you make a phone call, the voice signals from your phone get transmitted through these fibres to the nearest telephone  exchange and through a series of switches sent to the receiver. Usually the first few numbers in our telephone number indicates the exchange information.  In the earlier days, long distance calls (outside of the local exchange) could only be made by booking a trunk call.  The users had to 'book' or rent the line through which the call can be made and this used to be done manually by the telephone operators in the exchange.  Now-a-days, with automatic switches, long distance calls can be made directly to any number, even outside the country.  
+
When you make a phone call, the voice signals from your phone get transmitted through these cables to the nearest telephone  exchange and through a series of switches sent to the receiver. Usually the first few numbers in our telephone number indicates the exchange information.  In the earlier days, long distance calls (outside of the local exchange) could only be made by booking a trunk call.  The users had to 'book' or rent the line through which the call can be made and this used to be done manually by the telephone operators in the exchange.  Now-a-days, with automatic switches, long distance calls can be made directly to any number, even outside the country.  
  
 
=====The cell phone=====
 
=====The cell phone=====
The telephone and the radio came together - And we call that the cell phone! We saw how a telephone works.  We also saw what radio waves are and we have some idea of what frequencies mean. There are many frequencies available for the users to talk on. Any geographic area is divided into small plots, and in each area a fixed number of frequencies is used. Each of these areas are called cells. The cell phone is called a cell phone because it functions by dividing a geographical area into small plots or cells through which the transmission takes place. It is possible to make and receive calls when there is a cell phone tower near your area for receiving and sending that frequency. Now do you understand what we mean when we say 'my cell phone has no coverage here'?  It is because of this also that cell phones sometimes do not work inside buildings when the radio signals are disturbed. Just like an exchange for regular telephone calls, there is a mobile switching that allows you to make calls even when you move from one cell  to another!
+
The telephone and the radio came together - And we call that the cell phone! We saw how a telephone works.  We also saw what radio waves are and we have some idea of what frequencies mean. There are many frequencies available for the users to talk on. Any geographic area is divided into small plots, and in each area a fixed number of frequencies is used. Each of these areas are called cells. The cell phone is named as such because it functions by dividing a geographical area into small plots or cells through which the transmission takes place. It is possible to make and receive calls when there is a cell phone tower near your area for receiving and sending that frequency. Now do you understand what we mean when we say 'my cell phone has no coverage here'?  It is because of this also that cell phones sometimes do not work inside buildings when the radio signals are disturbed. Just like an exchange for regular telephone calls, there is a mobile switching that allows you to make calls even when you move from one cell  to another!
  
 
Can you make a list of all the things a cell phone does?  
 
Can you make a list of all the things a cell phone does?  
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===What can ICT do===
 
====ICT have changed the society====
 
Look around you - can you make a list of things that have digital technologies involved in them?  Yes, that is right.  Starting from the computer in your school, television, movies, videos and other materials for subject learning mobile communication, Aadhar card, land records, bank accounts, pension accounts and so many more things, ICT have become integrated into society in many ways.   
 
 
{{font color|purple|'''1. ICT can help create:'''}}
 
ICT can create information in so many different ways - maps, audio, video, text, numeric data.  Expressing yourself and creating materials is not limited only to text.  This means newer and newer methods of knowledge creation and sharing. You can learn in different ways.  How we learn and what is needed to be learnt have become different. For example, we no longer need to learn about a withdrawal slip, we need to know how to use the ATM.  Your teacher can now take a video of a class in your school and share it.  Different devices and applications are coming together - a mobile is approaching the computer, the internet is taking over.  <br><br>
 
 
{{font color|purple|'''2. ICT can help connect and communicate:'''}}
 
The most important thing about ICT today is the internet.  The internet has changed the way we think of communicating.  Talking to a friend through whatsapp or telegram chats, emailing or making a video call are just some of the ways in which the internet has changed the way we interact with each other in society.  With the internet, you can connect to any computer in the world and access information.  You can join other friends, form groups to learn about many things.  Internet is also allowing new methods of learning through online courses and resource repositories.     
 
 
{| class="wikitable"
 
|-
 
| style="width: 20%;" |[[File:Emojione 1F914.svg|center|thumb|75x75px]]
 
| style="width: 20%;" |[[File:Potter working, Bangalore India.jpg|frameless|250x250px]]
 
| style="width: 20%;" |[[File:Potter and his work, Jaura, India.jpg|frameless|250x250px]]
 
| style="width: 40%;" |The potter was gathering data about the mud, the water, the texture and he was making the pot.  Now you have a photo of the pottery making and it is possible to know about the pot by looking a picture and reading about it.  Is there any difference between what you know and what the potter knows?
 
|}
 
#{{font color|purple|'''What are the ways in which ICT can help the potter create knowledge?'''}}
 
#{{font color|purple|'''What are the ways in which ICT can help connection and communication for the potter?'''}}
 
 
If so many things are impacted by ICT, it is important to understand how these work, and how they should be used [[ICT_student_textbook/What_students_need_to_know_about_ethics_of_technology|ethically and safely]]. Technology should be treated like a common resource of society, where everyone can access it, interact with it, benefit from it and contribute to it.  More and more people should be able to use ICT in a manner appropriate for their needs, for this, access to ICT should be treated like a public good, like public education or public health.
 
 
===What is the internet===
 
{| class="wikitable"
 
|-
 
|[[File:Internet Key Layers.png|thumb|Key layers of the internet]]
 
|If you want information about some book available in your library, you can connect to the library's computer from home and get the information that you want. There are many such computers in different organisations giving us different types of information. These computers are connected to one another, their network is called the Internet. The Internet is a physical network of millions of computers across the world, each of which has a unique identifier. Some of these computers act as 'servers', they store data which can be accessed by other computers, hence the internet is like a huge library with information on almost any issue. 
 
|-
 
|[[File:Herramientas web 2.0.jpg|thumb|World Wide Web]]
 
|Initially the internet was a set of computers connected by one another and information requests were sent, using specific text commands, and received through networks. But this was difficult to do.  In 1989 Sir Timothy Berner Lee developed a system by which the computers can transfer information through a method called '''Hyper Text Mark-up Language'''.  <br>
 
He developed the application  called the "World Wide Web - www".  Yes, the "www" is an application on the internet to access the Internet in the form of a web page, using an application called the Web Browser.  There are millions of pages of shared information on the computers in the network, created by many people and organizations, in the form of 'web pages' accessed using a software application called a '''web browser'''.<br>
 
This makes connection between computers more accessible to all and it allows different kinds of content to be shared across the internet.
 
|-
 
|[[File:Internet of Things.jpg|thumb|Internet of things]]
 
|Now can you think of all the places the internet is being used:
 
<br><br><br><br><br><br>
 
|}
 
  
 
===References===
 
===References===
 
#[https://en.wikipedia.org/wiki/Analog_computer Analog computer]
 
#[https://en.wikipedia.org/wiki/Analog_computer Analog computer]
 
#[https://en.wikipedia.org/wiki/History_of_computing_hardware History of computing hardware]
 
#[https://en.wikipedia.org/wiki/History_of_computing_hardware History of computing hardware]

Revision as of 04:18, 13 March 2017

ICT student textbook
Additional readings Science Technology and Society What students need to know about ethics of technology


Science and technology

Many times you hear the word science and technology together. What is the connection between the two? Do you know? Study of science includes a method of observing things around us, thinking about why those events happen, recording information about the events, explaining why the events happen and also predicting what might happen. Often, scientists imagine what might be the solution and what might be the answer to the puzzles around us. The understanding of phenomena can lead to the development of tools – this is what we call technology. The technology can provide us more methods of observing, experimenting and recording. And this in turn results in the advancement of science. Thus, science and technology share a symbiotic relationship.

A symbiotic relationship is when two phenomena work together and one affects the other. This term originated in biology and ecology to describe interactions between different organisms.

Watch the attached video for examples of symbiotic relationship.

Can you think of examples of where technology has helped the growth of science? One area is that of cell biology. Until the microscope was invented by Robert Hooke and Anthony Leeuwenhoek, the study of cells was not possible. Now we study structure of cells, growth of cells, disease-affected cells, cell reproduction, gene sequencing and DNA using many advanced microscopes and cameras; the data and images are analysed using computers.

As you can see the microscope started with simple magnification; now,the images captured by the microscope and camera can be input into the computer for further study and research. It has even become possible to scan parts of the body for diagnosing illnesses. Many complex problems in biology are being studied through the use of computers. Some of these areas include study of how certain diseases, such as cancer develop, and the development of medicines.

Similarly, our understanding of astronomy has been expanded after the invention of the telescope. But to make a telescope or microscope, we need to understand the properties of light. We must understand how a lens works, how light travels. Thus, science and technology are very closely connected.

Your teacher will discuss with you more examples of how technology has impacted the way we understand many natural phenomena.

Information and communication technologies (ICT)

Information is not new for human beings; communication has been known since the time human beings lived in caves. Thus ICT are as old as human beings themselves; human beings needed to communicate with one another, beginning with symbolic (non verbal) ways, before language was invented. The language we speak could be seen as first 'ICT', it enabled (oral) communication among human beings. Writing (script) was the next technological advancement, around 5,200 years ago, which enabled information could be created and communicated across time and place, which is not possible in the case of oral communication. Writing also enabled easier recording of human history and thus the invention of script was a landmark in the history of ICTs. Next came printing which made it possible replicate writing on a large scale. The invention of radio and television (called 'mass media') was the next advancement in ICT as it became possible to share information with more and more people. Thus, the technology for information creation and communication has been changing. We are now in the middle of the transformation in ICT, through the introduction of digital technologies.

Long Waves of Social Evolution.jpg Growth of ICT can be seen to be broadly in terms of 4 ages
  1. premechanical
  2. mechanical
  3. electromechanical and
  4. electronic

While technology for information creation, storage and processing has been developing continuously, one important development which changed the course of technology is the development of digital technologies in the electronic area. Whereas during the electromechanical area, information was stored largely stored in analog formats. During the electronic age, information was stored in analog and digital formats.

Analog and digital technologies

The Antikythera Mechanism (3471171927).jpg

Impact on computing and development of computers

Abacus 6.jpg

Throughout history, people have been counting and making devices to help counting and to perform calculations. Initially these devices were based on physically changing things or moving things to represent the various phenomena and perform calculations.

Can you guess what these two images are? The one on the left is called the Abacus which was used to perform calculations with numbers by moving the beads. The one on the right is called the Antikythera machine which was used in Greece to calculate the positions of astronomical objects. Over the years, computational technologies and devices continued to develop, some for general calculations like the slide rule or Napier's calculating tables and some for specific applications like predicting tides.

Many such analog devices were used for performing different calculation tasks like the ones shown below:

All of these are examples of analog devices that could perform calculations, in other words, these are analog computers.

Think and write

Can you look at each of these pictures and think what might be the process by which analog computers work. Write down what they measured, how they may have measured, and how they gave results.

Emojione 1F4DD.svg









During the mechanical and electric analog phases of technology, information was created by a series of physical changes converted into electrical impulses for storing and machine, and each analog information storage required a specialized equipment to decode and read the information. A cassette player or a gramophone disc is an example of such a device. Analog machines could be programmed for specific applications as well as for general computing. Since information was being represented physically, results were not always accurate as they could not be replicated exactly.Such a device is called an analog computer.

Punched cards for accounting calculations, 1920s


Development of a programmable computer
Emojione 1F914.svg

Watch these videos and discuss with your teacher why this is considered important in the history of computer hardware. Can you guess what programming means?



While analog machines continued to perform calculations and operate machines, people were beginning to work on computing and how to develop a machine that could perform general purpose calculations.


Lego Model of Difference Engine

A model in the Computer History Museum of the Difference Engine, evaluating polynomials
Emojione 1F914.svg

Watch these videos. Can you make out any similarity between the looms and this machine? Can you discuss with your teachers what programming means?

The first programmable computer was invented by Charles Babbage, that could perform a series of calculations, in 1833. Input was through punched cards and output was through a plotter and bell. This was a big achievement in the history of development of computers.

Development of the digital computer

We saw earlier how analog machines worked and what were the difficulties. With the discovery of electricity and circuits, it became possible to represent things using electric signals. Using a series of circuits and electrical signals, it became possible to perform calculations, bringing in the electro-mechanical analog computers.

When Alan Turing developed a theory that a computer can be programmed to solve any problem, that can be defined mathematically, the development of modern computers began. The use of Boolean algebra helped developing logical circuits for electrical signals and launched the digital revolution. Boolean logic uses the binary system where information is represented as a series of "0"s and "1"s thus allowing information to be accessed through only a combination of these two digits. This allowed information to be communicated in discrete bits which could be combined and recombined. Such a computer which uses "0"s and "1"s to perform computations is a digital computer.

This improved the reliability and ease of computations significantly over the analog machines and led to the growth of computers as we know it - from large clunky computers to the computer on your desktop to the laptop and now the smart phone. What makes our society now different from ever before is the presence of these digital technologies.

Watch the timeline of computer history

Emojione 1F914.svg
slideshow - http://www.computerhistory.org/timeline/computers/

See the slideshow here for a glimpse of computer history and discuss the most important developments with your teacher'

Impact on communication technologies

What is the word that comes to your mind when you say communication? The phone, precisely the cell phone. We will now look at how the communication technologies evolved.

Radio communication

The earliest electronic communication devices functioned using radio technology. Many communication devices we know today also function through radio waves. Radio waves are electromagnetic waves. Radio waves carry a certain amount of energy and can travel over large distances. When the wave reaches the destination, the receiver gets the amount of information. We cannot see radio waves but we can detect them by building receivers that can detect them. These are called as antennae. They scan the environment for radio signals and respond when they find a signal.

You must be thinking if this is similar to how we hear sound. Sound is a pressure wave – when we produce a sound it travels by disturbing the air particles. If there is no medium, sound cannot travel. What happens when we hear something on a radio? Originally sound is produced and then it converted into radio waves. These waves are sent and received through instruments called antennae. When your radio antennae receives this radio wave, this is converted back into sound and is played.

Telephone

Before the cell phone came, most of the long distance voice communication was through the regular telephone. This was based on the idea of travelling sound waves. They cause the mouthpiece to vibrate and this vibration is carried to the receiver at the other end. When a call came from one number, there would be an operator who sat at an office and connected the call to another receiving number. Now this is different with automatic switches which connect the calls. The transmission of the signals has also become different now with voice being converted into electrical signals. All these transmissions used to happen through physical cables. These cables were either made of copper or optical fibres.

When you make a phone call, the voice signals from your phone get transmitted through these cables to the nearest telephone exchange and through a series of switches sent to the receiver. Usually the first few numbers in our telephone number indicates the exchange information. In the earlier days, long distance calls (outside of the local exchange) could only be made by booking a trunk call. The users had to 'book' or rent the line through which the call can be made and this used to be done manually by the telephone operators in the exchange. Now-a-days, with automatic switches, long distance calls can be made directly to any number, even outside the country.

The cell phone

The telephone and the radio came together - And we call that the cell phone! We saw how a telephone works. We also saw what radio waves are and we have some idea of what frequencies mean. There are many frequencies available for the users to talk on. Any geographic area is divided into small plots, and in each area a fixed number of frequencies is used. Each of these areas are called cells. The cell phone is named as such because it functions by dividing a geographical area into small plots or cells through which the transmission takes place. It is possible to make and receive calls when there is a cell phone tower near your area for receiving and sending that frequency. Now do you understand what we mean when we say 'my cell phone has no coverage here'? It is because of this also that cell phones sometimes do not work inside buildings when the radio signals are disturbed. Just like an exchange for regular telephone calls, there is a mobile switching that allows you to make calls even when you move from one cell to another!

Can you make a list of all the things a cell phone does?

Mindmapofcellphone.jpg A cell phone functions like a phone, a camera and a computer. Yet, it does all of this using a few components. If you open up a cell phone, you will see the following parts:
  1. A circuit board : This is the brain of the cellphone, which contains a set of integrated circuits for giving instructions to the cell phone. A computer has a similar circuit board also.
  2. A keyboard : This is also very similar to the computer keyboard and you use the key board to operate the cell phone.
  3. Display : This is similar to the computer monitor.

Other parts include a microphone, antenna, speaker and a charger. One of the important parts of the cell phone is called the SIM card. The SIM card connects the phone to the network, your location. This helps the phone connect to a cell phone network and can also store phone numbers. It can be removed from one phone and put in any other cell phone.


References

  1. Analog computer
  2. History of computing hardware