My Science School

Data, in any form, has become one of the most valuable things in the online world. Many websites thrive on the data of their users, using it to make their browsing experience better, while also selling it to third-party websites for targeted advertisements. More websites do these with the help of cookies. Cookies are small pieces of data sent by a website to your browser which stores it on your computer. The next time you visit the website, it uses these cookies to enhance your browsing experience. This is done using first-party cookies. However, there is another type of cookies called third-party cookies. These cookies are created by sites other than the one you are visiting. These third parties can insert additional tracking methods to record what you do online. While cookies in themselves are not harmful, it can annoy some users when it comes to targeted ads. If you are one among such users, here are a few ways in which you can prevent websites from tracking you.

Adjust browser settings

Whether you are using Google Chrome or Mozilla Firefox, all browsers have settings that offer you the choice to block cookies. First, delete the cookies your browser has stored so far. You can do this by visiting the history settings on your browser. Once you are done with that, you can go to your privacy and security settings to disable third-party cookies.

There is also an option called ‘Do not track’ on most browser settings. In this, the browser requests a website not to track using cookies; however, the website might not heed the request as it is not mandatory for websites to abide by the ‘Do not track’ rule.

Use Incognito mode

Today, almost all browsers allow you to browse in private/incognito mode. When you browse in this mode, there is no history of the sites you have visited and a website cannot track you unless you voluntarily provide your data.

In Google Chrome, pressing Ctrl+Shift+N opens the browser in incognito mode, while in Mozilla Firefox and Internet Explorer, Ctrl+Shift+P opens the private window.

Use add-ons to block trackers

Most browsers provide add-ons or extensions that let you customize your browsing experience. Ad blockers are one such. Most ad blockers block advertisements on a website and also prevent third parties from tracking you, unless you choose to give out data.

However, remember that certain websites will not allow you to access their content unless you turn off ad blocker or give them permission to disable ad blocker on their site.

Ensure mobile data is secure

Most of us browse the web from our smartphones as well. However, browser settings adopted on the computer do not hold good for smartphones. You will have to go to your smartphone settings and customize it again.

Remember that browsers on the smartphones also offer private browsing. So, whenever possible, choose to use it.

 

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A telephone works by sending and receiving electrical signals that represent sounds, including the human voice. When the required number is dialled, a signal passes to the called telephone, causing it to ring, buzz, flash a light, or even vibrate to attract the attention of the person using it. When the telephone is picked up or switched on, a connection is made, and a conversation can take place.

Messages reach the right telephone by means of a dialled number. Pressing the keys of the telephone causes different electrical pulses or varying tones to pass to electronic equipment at the telephone exchange. This “reads” the pulses or tones and routes the call to the correct area and telephone.

The Transmitter of a telephone serves as a sensitive "electric ear." It lies behind the mouthpiece of the phone. Like the human ear, the transmitter has an 14 eardrum." The eardrum of the telephone is a thin, round metal disk called a diaphragm. When a person talks into the telephone, the sound waves strike the diaphragm and make it vibrate. The diaphragm vibrates at various speeds, depending on the variations in air pressure caused by the varying tones of the speaker's voice.

Behind the diaphragm lies a small cup filled with tiny grains of carbon. The diaphragm presses against these carbon grains. Low voltage electric current travels through the grains. This current comes from batteries at the telephone company. The pressure on the carbon grains varies as sound waves make the diaphragm vibrate. A loud sound causes the sound waves to push hard on the diaphragm. In turn, the diaphragm presses the grains tightly together. This action makes it easier for the electric current to travel through, and a large amount of electricity flows through the grains. When the sound is soft, the sound waves push lightly on the diaphragm. In turn, the diaphragm puts only a light pressure on the carbon grains. The grains are pressed together loosely. This makes it harder for the electric current to pass through them, and less current flows through the grains.

Thus, the pattern of the sound waves determines the pressure on the diaphragm. This pressure, in turn, regulates the pressure on the carbon grains. The crowded or loose grains cause the electric current to become stronger or weaker. The current copies the pattern of the sound waves and travels over a telephone wire to the receiver of another telephone. For more modern phones that have a telephone answering service, the sound wave is captured on a recording device which allows for the operator of the phone to playback at a later time.

The Receiver serves as an "electric mouth." Like a human voice, it has "vocal cords." The vocal cords of the receiver are a diaphragm. Two magnets located at the edge of the diaphragm cause it to vibrate. One of the magnets is a permanent magnet that constantly holds the diaphragm close to it. The other magnet is an electromagnet. It consists of a piece of iron with a coil of wire wound around it. When an electric current passes through the coil, the iron core becomes magnetized. The diaphragm is pulled toward the iron core and away from the permanent magnet. The pull of the electromagnet varies between strong and weak, depending on the variations in the current. Thus, the electromagnet controls the vibrations of the diaphragm in the receiver.

The electric current passing through the electromagnet becomes stronger or weaker according to the loud or soft sounds. This action causes the diaphragm to vibrate according to the speaker's speech pattern. As the diaphragm moves in and out, it pulls and pushes the air in front of it. The pressure on the air sets up sound waves that are the same as the ones sent into the transmitter. The sound waves strike the ear of the listener and he hears the words of the speaker.

Semaphore is a means of signalling using pairs of flags. Different flag positions stand for different letters and numbers. Semaphore signals are useful when the signaller is within sight of the receiver of the message but too far away to call out. It was widely used between ships sailing near each other in the days before ship-to-ship radio.

In programming, especially in UNIX systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources. A semaphore is a value in a designated place in operating system (or Kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.

Semaphores are commonly used for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or "functions" for managing semaphores.

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The layer of the Earth’s atmosphere called the ionosphere can reflect some radio waves back to Earth. This is used for sending messages over fairly short distances, but for messages to travel further across the Earth, the radio signals can be bounced off a satellite, orbiting almost 36,000km (22,000 miles) above the Earth’s surface. Several satellites, in different orbits, are required to give coverage over the whole globe, and different satellites are used to reflect signals for different media, such as telephone messages and television pictures.

A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals through a transponder. It basically creates a communication channel between a source transmitter and a receiver at different locations on earth. Communications satellites are used for television, telephone, radio, internet, and military applications. There are currently 2,134 communications satellites in the earth’s orbit and these comprise both private and government organizations. Several are in geostationary orbit 22,236 miles (35,785 km) above the equator, so that the satellite appears stationary at the same point in the sky. The orbital period of these satellites is the same as the rotation rate of the Earth, which in turn allows the satellite dish antennas of ground stations to be aimed permanently at that spot; they do not have to move along and track it. Since the high frequency radio waves used for telecommunications links travel by line of sight, they get obstructed by the curve of the earth. What these communications satellites do is they relay the signal around the curve of the earth thus making possible communication between widely removed geographical points. Communications satellites use a wide range of radio and microwave frequencies. To avoid signal interference, international organizations have regulations stating which frequency ranges (or bands) certain organizations are permitted to use. This allocation of bands reduces the chances of signal interference.

A group of satellites working together is called a satellite constellation. Two such constellations are supposed to offer satellite phone services (mainly to remote areas), are the Iridium and Global star systems. The Iridium system has 66 satellites. It is also possible today to provide discontinuous coverage using a low-earth-orbit satellite that can store data received while passing over one part of earth and transmitting it later while passing over another part. The CASCADE system being used by Canada’s CASSIOPE communications satellite is an apt example.

A satellite in orbit has to operate continuously over its entire life span. It needs internal power to be able to operate its electronic systems and communications payload. The main source of power is sunlight, which is harnessed by the satellite’s solar panels. A satellite also has batteries on board to provide power when the Sun is blocked by Earth. The batteries are recharged by the excess current generated by the solar panels when there is sunlight.

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Modern communications have affected our lives in numerous ways. Being able to pass information down telephone wires or via satellites means that some people can work from anywhere in the world and still keep in constant touch with their offices. A surgeon in Arizona, via a satellite link, can assist a colleague in Beijing with a complicated operation. News can travel halfway around the world as quickly as it can reach the next town. Perhaps the biggest effect of communications has been to make us all feel that the world is a smaller place, and that we need to be concerned about its future and the futures of people thousands of miles away.

The Internet has turned our existence upside down. It has revolutionized communications, to the extent that it is now our preferred medium of everyday communication. In almost everything we do, we use the Internet. Ordering a pizza, buying a television, sharing a moment with friend, sending a picture over instant messaging. Before the Internet, if you wanted to keep up with the news, you had to walk down to the newsstand when it opened in the morning and buy a local edition reporting what had happened the previous day. But today a click or two is enough to read your local paper and any news source from anywhere in the world, updated up to the minute.

Technology has improved communication, especially in recent years. We’ll always have so much information readily available at our fingertips. Writing letters to relatives living hundreds of miles away is so old-school! Instead, you can talk to them through a video call or instant messaging. This change in communication has completely changed relationships all over the world.

Services like Facebook and Twitter have also become a big part of our everyday lives. These sites allow people to see a lot of information and photos at once and are enjoyable by design. When you upload a photo to the Internet, it doesn’t simply go away. It stays for a long time. This means you can use technology to store memories that are important to you, like family photos.

With modern technology, we can live much healthier lives. Those who have fitness trackers can see how active they are. Seeing that can encourage us to be even more active. Some fitness trackers like the Apple Watch even gamify health with competitions and points!

New technology can help create cures and medicines. Someone who is sick in modern times is much more likely to be cured than someone in past times. Modern technology can automate just about anything, from turning on a light to ordering a pizza. With automation, we can do so much more in such a small amount of time. For example, you can use your voice to start the coffee maker while you’re still getting dressed.

Only a few hundred years ago, the fastest way that a piece of news could travel was to be carried by a person on horseback. Messages sent overseas could only travel as fast as the fastest sailing ship and were at the mercy of the wind and weather. The development of steam locomotives and steamships made it possible for information to move around the world more quickly, but it still had to travel physically from one place to another, as a letter. The breakthrough came with the invention of the electric telegraph and messages in Morse code. The message was sent down a wire in bursts of electric current. Today, images of written documents, sound recordings or television pictures can be flashed around the globe in less than a second by means of satellites and radio communications.

It seems like advancements in technology and changes in communication always go hand in hand. When science was working to introduce new tools to let distant people contact each other, the landlines replaced telegraph and subsequently, cell phones replaced landlines. When the Internet arrived, it not only brought revolution in the sales industry but also opened new doors of personal communication. When science was looking for more convenient ways to send messages, e-mails replaced postal emails and social media replaced text messages. So it would not be wrong to say that technology has been shaping the communication industry for over a hundred years.

Previously, there were not much mediums of communication and today we are completely overwhelmed with the disparate mediums, thanks to the ever-changing technology! From Facebook to Instagram and skype to Whatsapp, we now have the limitless database of communication tools that have brought us closer to the entire world. All these communication mediums have also impacted our lives in different ways. For example, it’s true that Smartphones have brought us closer to our friends and relatives living in distant places, but at the same time, they have also made our society somewhat impersonal. Although they have helped increasing workplace engagement and productivity, they have also given rise to certain security and privacy issues.  While some of these issues are relatively minor, but some may have profound effects on the lives of users.

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The most common password

Do you know the most commonly used email password? 123456! Yes, this was found in 2009, when over 10,000 hotmail passwords were exposed online. Today, however, most websites have several rules to be followed when creating a password.

How many email accounts are there?

There are billions of people worldwide, but not everyone has access to the Internet and emails. So, can you guess how many email accounts are there worldwide? There are over 3.17 billion email accounts worldwide! That’s greater than the population of most countries in the world.

Spam alert!

Call them junk or spam, these malicious emails can be found aplenty in all email accounts. They constitute nearly 55% of all emails received. This explains why you get more spam mails than regular emails in a day.

A mail from space

The first email from space arrived in 1991. The crew if STS-43 Atlantis used AppleLink software on a Macintosh Portable to transmit the message.

Computer or mobile?

With the emergence of smartphones, emails, which were once read only on computers, began following people wherever they went. Today, over 66% of emails are read on mobile devices.

Simpson’s email account was hacked!

Homer Simpson, a famous animated character that features in the show The Simpsons, was caught in a soup when his email account was hacked. A Simpsons writer used to reply to messages in-character from the ID chunkylover53@aol.com. This was until the sheer volume of emails became too high to respond to, in 2009.

Who’s behind the spam?

If you get spam mails, it means it is generated somewhere. Did you know that the United States was once the highest spam generator in the world? It is in close contest with China, which is currently in number one spot. Following these two countries is Russia, at number three.

 

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Most of us have multiple social media accounts these days. From Facebook to Instagram, social media has become a part and parcel of people’s lives. But it is also a source of cybercrime. From sensitive data being captured, to terrorists being hired, to pictures being morphed, social media has seen it all. Hence, it is necessary to be cautious when you post anything online. Here are a few tips to keep in mind when you use social media.

Keep details personal

Most social media platforms need you to fill in basic details like Name, age, Email address and Phone number. While it is okay to furnish these details for opening your account, remember to never share it on your news feed or your wall. If anyone asks you for personal details, give it to them in a chat window, provided you know who the person is.

Do not defame anyone

Refrain from defaming someone online. Yes, someone might have offended you or hurt you, but voicing it out on social media is not always the right thing to do. Millions of people use social media, and tomorrow, your prospective employer may also go through your social media handles. In such a case, defaming someone could be held against you.

Have you done your check-in?

Yes, we all travel or go out to restaurants to eat. But we don’t need to tell the world where we are at all times. Sometimes, people can keep a track of your profile – the places you visit, with whom, why – and use it against you. So, avoid checking-in everything.

Keep privacy settings at maximum

All social media platforms like Facebook, Whatsapp and Instagram let you set the privacy settings of your profile to protect your information. Use this and ensure you safeguard all that you post by allowing only your friends’ circle to access the information you post.

Do not post personal pictures

While it is okay to share pictures on social media, avoid sharing personal pictures, or turn on the privacy settings to allow only people you know to access your pictures. There are several cases of images being morphed and used for illegal purposes. So, think before you post a picture online.

Don’t start conversations with strangers

Social media is a thriving ground for cyber criminals. When we join a social media platform, it is normal for us to get friend requests from different people, we may or may not know. However, avoid adding strangers as much as possible since you cannot establish their authenticity or profile. If you do add, remember to never share your personal details with them.

When in doubt, report abuse

If a social media account is posting things that are harassing someone, or posting something illegal, report abuse immediately. Even if you don’t have the proof, you can still report the profile if you feel something doesn’t seem right. You may end up saving yourself or someone else from a crime.

 

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The term ‘meme’ was coined by Richard Dawkins in his 1976 book The Selfish Gene. It describes an idea that spreads among people via the Internet. It could be a word, symbol, image, video, story – anything that becomes an instant cultural phenomenon.

A meme (rhymes with ‘team’) can be sent through email, social networks, blogs, instant messages, etc. and can spread across the globe rapidly within days. Hence, memes are a popular tool for viral marketing to create awareness about a new product among the masses.

An Internet meme may remain the same or it may evolve as it spreads. Users my tweak or it may evolve as it copying. For example, after the South Korean rapper Psy’s ‘Gangnam Style’ video vent viral on YouTube, memes were created showing various personalities in the horse-dance pose – one showed an animated Batman hopping a la ‘Gotham Style!’

Memes are popular among teenagers for their humour quotient or shock value.

 

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The internet is a global network of millions of computers that can communicate with one another. Information can he sent and received across the network in the form of text, pictures, video and sound. Home computers often connect to the Internet using a normal phone line and a modem — a device that connects the computer to an Internet Service Provider (ISP). Businesses and other large organizations may have their own network, known as a Local Area Network (LAN), which connects to an ISP with a high-speed link.

Everyone’s talking about the internet and whether, or how, it should be regulated. But not enough people know how the internet actually works—or what exactly the internet is.

You probably have your own “local area network” at home, and it’s made up of all the devices connected to your router, which connects to the internet. The word “internet” refers to a worldwide system of “interconnected computer networks”.

That’s all the internet really is—a large number of computer networks all over the world, connected together. Of course, there’s a lot of physical hardware—from the cables under your city streets to the massive cables on the ocean floors to satellites in orbit around the planet—that makes this communication possible. There’s also a lot of software at work in the background, allowing you to type in a website address like “google.com” and have your computer to send information to the physical location where that website is located in the fastest way possible.

Even when you’re just connecting to a single website, there’s a lot more going on under the hood. Your computer can’t directly send a piece of information, or “packet” of data, to the computer hosting the website. Instead, it passes a packet to your home router with information about where it’s going and where the web server should reply. Your router then sends it to the routers at your internet service provider (Comcast, Time Warner, or whoever else you use), where it’s sent to another router at another internet service provider, and so on, until it reaches its destination. Any packets sent back to your system from the remote server make the reverse journey.

To use an imperfect analogy, it’s a bit like sending a letter in the mail. Your local postal employee can’t just grab the letter and take it directly across the country or continent to its destination address. Instead, the letter goes to your local post office, where it’s sent to another post office, and then another one, and so on, until it gets to its destination. It takes longer for a letter to get to the other side of the world than the other side of the country because it has to make more stops, and that’s generally true for the internet as well. It will take a bit longer for packets to go longer distances with more transfers, or “hops”, as they’re called.

Unlike with physical mail, sending data packets is still very fast, though, and it happens many times a second. Each packet is very small, and large numbers of packets are sent back and forth when computers communicate—even if one is just loading a website from another one. A packet’s travel time is measured in milliseconds.

Are they the same?

Although the world wide web and the internet are used alternatively, the two are not the same. Internet is a network of networks that links computers together. The world wide web on the other hand is a collection of lined pages that are accessed using the Internet and a web browser.

WWW for free

The World Wide Web was made available to the public for free in 1993. Initially, it was meant only for physicists at the European organisation for nuclear research (CERN) to share data.

Biggest medium of communication

The WWW is the fastest growing communication medium of all time. Imagine, it took a WWW only four years to reach 50 million people. In contrast, it took the radio 38 years and television 13 years to reach the same number.

The Apple connection

Did you know that the entire world wide web stored on a NeXT computer when it was created? NeXT was the company started by Steve Jobs after he was ousted from Apple Inc.

What’s in a name?

Before the name World Wide Web was finalised, there were other options such as Mine of Information, Information Mine, and Mesh. These names don’t sound cooler than the World Wide Web, do they?

 

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A person declares ‘email bankruptcy’ when he/she has decided to clear the inbox by deleting all the mails up to a particular date. Such a decision may be necessary if the person has been inundated with thousands of emails and has failed to respond on time. Such a backlog is generally attributed to information overload as many high-profile persons receive hundreds of emails everyday. A person may have also fallen behind in reading and answering emails during long vacations or illnesses.

While declaring bankruptcy, the person sends a mass email to senders informing them that their email is being detected and that they may send it once again if they expect a response.

Harvard professor and political activist Lawrence Lessig first coined the term in 2004 when he expressed inability to go through the email backlog and deleted them en masse.

 

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Many websites often give a brief synopsis of a story and work as springboards offering a link to another website which carries the whole story. Interested readers click on the link leading to them to the referenced site. When large masses of users flock to the site at the same time, it overloads the site, causing it to slow down or even temporarily close. This is called the Slashdot effect and the site is said to be Slashdotted.

The phenomenon has been named after Slashdot, an award-winning technology-related news website launched in 1997. The website’s readers submit stories with links, inviting comments to start threaded discussions among users. The trouble starts when an article on the front page attracts an unusually large number of hits and causes a temporary surge in traffic on the linked website.

Major news sites or corporate websites are designed to deal with such large number of hits and therefore do not normally experience this effect. Websites with small bandwidths, however, are ill equipped to deal with this kind of traffic jam. They are used to getting only a few thousand hits a day and when the Slashdot effect occurs, the numbers can range from several hundred to several thousand hits per minute!

 

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IoT offers several benefits for consumers and businesses. For a business, an IoT device can help it understand its consumers and their choices, as the device constantly tracks usage and sends them the data required to build things that are needed.

For the user, an IoT device can give him real-time data based on his requirements, making it easier for him to take quick decisions.

It can also help him become more productive due to automation of tasks, leaving him with more time to focus on important things.

Examples of IoT at home

Here’s a simple example to understand how IoT can help you at home.

You have to be in school by 8 a.m. so you up on time, but it is pouring outside, there is heavy traffic and your school metro train is delayed due to technical issues. Unfortunately, you do not know that. Hence, you end up late to school.

If you have an IoT-enabled alarm clock at home, it would have known about the delayed schedule of the metro train and the traffic on the way to the station as it is connected to several other devices on the IoT platform. So, it would have woken you up earlier to prepare you for the traffic and the delayed train. All this, without you having to do a thing!

 

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The Internet of Things (IoT), as the phrase suggests, is an ecosystem where physical things (objects) are connected to a computer or other devices using the Internet.

Just as the Internet in our computer enables us to connect to other computers and send and receive data, it can also be used to connect other devices to the network to transmit data.

From smart speakers on your desktop that play songs on command, to self-driving cars with complex sensors that detect objects on its path, IoT devices come in all shapes and sizes with an on/off switch. Simply put, they are smart things which facilitate remote monitoring.

Smart devices and objects with built-in sensors are connected to an IoT platform. These devices are constantly collecting data about their use and transmitting it over the Internet. The IoT platform integrates data from several such devices and uses analytics to share the most valuables information with applications that help humans understand and comprehend the data.

 

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