Traffic light

Did you know the first traffic light actually exploded injuring its operator?

The first traffic light ever was installed on December 9, 1968 in London outside the House of Parliament to control the traffic in the nearby three streets.

Based on all the future developments, traffic lights can be classified in various ways.

Traffic light

Traffic light

Classification on the basis of the automation of traffic lights:

There are two categories of traffic control system: A fixed system and a dynamic one. The dynamic traffic control systems can be further classified based on the types of detectors used in them.

The fixed traffic light control system is configured to switch lights after a certain period of time. The time interval depends on the region and traffic values. It has a controller that moves with dial timers to be able to display a certain color for a small interval of time.

Dynamic traffic control systems, on the other hand, are more appropriate as they are able to adapt their settings according to the crowd present at different times of day.

When a car passes over the Embedded Detector, it simply sends the information to the traffic light. In this way, the traffic system which can already control the timing by itself, knows for sure that there’s a line of cars waiting for the signal to go green. This kind of detector is generally expensive due to its cost installation and maintenance.

Mounted Detectors are quite affordable and its installation is not affected by any other systems located in its proximity. Not only these are inexpensive, but they also send over more information to the traffic lights which include real-time photos.

Classification on the basis of the use of a traffic signal

Let’s look at the following categories:

Junction Signal:

This signal control vehicles coming towards a certain junction in a contradictory manner. With the help of a camera mounted on it, it monitors and responds to the flow of traffic, whether heavy or light.

Pelican:

It facilitates the street crossing for people. This signal displays a digital dotted green-man signal or a red-man signal crossing for a fixed interval of time. Hence, it indicates for common people, according to its color, when it is safe to cross the street and when not.

Toucan:

This signal controls a shared crossing for common people and cyclists. It is usually wider than the Pelican Crossing mentioned above. It has standard red/green/yellow signals with a green digital cycle next to the man hence controlling the traffic of both of them (Cyclists and Pedestrians) at the same time. When the Toucan is busy, detectors help it by increasing the crossing time.

Equestrian Crossing:

This is mainly used by horse riders and more than often referred to as Pegasus crossing. Red and green horse signal display helps the riders to know when you can cross the street and when not.

Zebra:

Last, but not least, this is the one we all are very familiar with. It is again a pedestrian crossing facility. This mostly works in combination to the traffic light. When a pedestrian steps on to this area, a motorist has to give way. This crossing also has orange flashing light at both its end to indicate the presence of the crossing.

Zebra crossing

Zebra crossing

Traffic Signal Color Coding:

Red was the color that denoted blood and thus it was selected to stop the vehicles. It became the symbol of danger. Also, even in misty environment, red color could be seen from far distance and hence avoided fatal collisions.

Green symbolizing nature was chosen as signal for relaxing as observed by human emotions. And it was clearly visible at the night time and since it is quite a contrast in comparison to red and yellow, it would never create confusion for the drivers.

As for Yellow, most people believe that it symbolizes sun and is taken as a sign of caution.

Over the years, traffic lights have evolved although maintaining the basic colors to accommodate people suffering from color blindness. Red-green color blindness, these days, is the most common form of visual impairment. Hence the red light comes with a little orange and green comes with a little blue to address this socio-medical issue.

We can conclude that traffic lights were a great invention for all of us. But what if I tell you can build one too? That way you could teach him about this simple invention that we use in our day to day lives. Don’t worry; you can get the raw materials from Projects For School-Traffic light DIY Kit. If you are a parent who believes in “Practical is always better than just theory “then this is the ‘go to’ place for you.  Explore it. You just might find a great science project for your kids this semester!

 References

http://www.theguardian.com/notesandqueries/query/0,5753,-1460,00.html

http://www.autoevolution.com/news/how-do-traffic-light-control-systems-work-41839.html

http://www.rulesoftheroad.ie/rules-for-driving/traffic-lights-and-signals/traffic-lights.html

http://www.drivingtesttips.biz/pelican-crossing.html

https://www.safedrivingforlife.info/blog/whats-difference-between-zebra-puffin-and-pelican-crossings

 

 

Telescope

Telescope and it’s applications

Do you remember the time you’d sit on your bed pretending to steer an imaginary ship? Your younger siblings used to yell, “Aye, Captain!” while you did your best imitation of Popeye. You’d roll a newspaper and peer out of one end spotting a whale through your makeshift telescope. And then one fine day, you were thrilled (maybe not so thrilled!) to discover what exactly a telescope is? Well Watson, time for us to show to the young ones (siblings, kids or cousins) interesting things about the telescope!

What is a telescope?

It is an optical instrument designed to make distant objects appear larger. It contains an arrangement of lenses, or curved mirrors and lenses, by which rays of light are collected and focused. The resulting image gets magnified.

On the lighter note, it’s a tube with two lenses that makes you see objects that are faaaaar away (yep, that far, really!) and makes them look BIG (yep, that big too!). Without this tube, the objects would be just little dots in the sky or the sea. Since I know you’re already rolling your eyes at me, so I promise to be all so serious as I describe the telescope.

Telescope

Telescope

How a Telescope Works

When you hold a magnifying glass a few inches away from a notebook page, the words on the page appear magnified. When you look at a distant object through the same magnifying glass, you see an upside-down image of the object.

Astronomical telescope

An astronomical telescope makes use of two lenses, one of which works in each of these ways. The lens in the front of the telescope (the objective lens) produces an upside-down image of the object. The lens near the eye (the eye lens) magnifies that upside-down image. As a result, you see distant objects closer.

Telescope

Astronomical telescope

Optical telescope

An optical telescope however, gathers and focuses light from the visible part of the electromagnetic spectrum, to create a magnified image.

Telescope

Optical telescope

There are 3 primary types of optical telescope:

  • Refractors, which use lenses
  • Reflectors, which use mirrors
  • Catadioptric telescopes, which use a combination of both lenses and mirrors

These telescopes increase the apparent size of distant objects as well as their apparent brightness.

History

          The first optical telescope was basically constructed by the lens-grinder Dutchman, Hans Lippershey in 1608. Interestingly, Galileo Galilei is sometimes wrongly credited with its invention. He built the first astronomical telescope from a tube containing two lenses of different focal lengths aligned on a single axis in the following year.

Galileo's Telescope

Galileo’s Telescope

With this telescope, he made the first telescopic observations of the sky. He discovered lunar mountains, four of Jupiter’s moons and sunspots. We learnt that Saturn had rings and that the Milky Way was not a cloud but a collection of stars! It was a revolution in the scientific world!! The secrets of the heavens finally seen! Since then, telescopes have increased in size and improved in image quality. Computers are now used to take photographs of the observations made with the help of telescopes.

Now that we know what the lens / mirror tube is all about and who made it, why not also discover what it does?

Applications of telescopes

  • They are used by astronomers most importantly, to discover the cosmic world in great detail. The Hubble telescope was used to discover galaxies beyond our own.
  • Before GPS, radar and sonar, the humble telescope was used to spot land by navigators in a ship. It was also used by merchant ship sailors, explorers and pirates. (Arrrr!!).
  • Telescopes are basically also used by ornithologists (bird scientists) for spotting rare birds from far away.

I sometimes wonder how astonishing it must’ve been for astronomers – to peer through a telescope and glimpse the true beauty of the heavens! The explorers of the past have relied on this invention to help them sail through uncharted waters. The telescope truly changed the way we humans viewed the world!

Oh and before I sign off, do check out this cool kit at (link) to make your own telescope!

We love to assist our visitors, students, parents in their quest to learn science, you are welcome to leave your questions / comments. Chat with us, use contact us from here or on our facebook page (www.facebook.com/projectsforschool/). In conclusion, drop us an email for any other queries and we would certainly reply with an answer to your queries!!

Irrigation

Irrigation and methods

Our unpredictable Mumbai monsoon teaches us that we cannot rely on just rain for water. So what about the Indian farmer whose livelihood depends on water? Gone are the days when Bhuvan in ‘Lagaan’ would sing “Kale megha, Kale megha, Paani toh barsao” and it would rain cats and dogs! After all, life isn’t like the Bollywood dreamland. No? So, to manage their crop, farmers go for what is called irrigation.

What is irrigation?

It is the artificial application of water to the soil. It is used to assist the growing of agricultural crops.

The different methods of irrigation are:

  • Surface irrigation

Surface irrigation consists of methods in which water is distributed over the soil surface by gravity. The water flows through furrows or pipes and advances across the fields. It is best suited to fine textured soil types which promote lateral spread of water down the furrow row.

Irrigation

Surface Irrigation

  • Sprinkler irrigation

It is a method in which water is sprayed, or sprinkled through the air and falls like rain on fields. The sprinkling devices can be permanently set in place (solid set) and then moved after a particular amount of water has been applied (portable set).

Irrigation

Sprinkler Irrigation

  • Subsurface irrigation

In this process, water is applied below the soil surface. This is done through buried plastic tubes which contain embedded emitters located at a regular spacing. Its efficiency is great resulting in water savings of 25-50% as compared to other techniques.

Irrigation

Subsurface irrigation

  • Drip irrigation

In this process water is dripped through emitters to the soil surface as tiny drops. The discharge rate of the emitters is low so this method can be used on all soil types. This is one of the most common and useful methods.

Irrigation

Drip irrigation

Facts:

Modern methods are a boon to agricultural industry and small time farmers. With its help, the dependence on rain has decreased and so have the worried faces of farmers praying to the heavens. In fact the Andhra Pradesh State government has even taken up the integration of two major rivers Godavari and Krishna with a mission to make Rayalaseema drought free. It will make agriculture flourish. The project name is Pattiseema Project and it is India’s fastest built mega project!

We city people live in pigeon holes where nothing more than a potted plant can grow. But don’t despair, try out the drip irrigation set from http://www.projectsforschool.com and experience first-hand how this process works.

We love to assist our visitors, students, parents in their quest to learn science, you are welcome to leave your questions / comments. Chat with us, use contact us from here or on our facebook page (www.facebook.com/projectsforschool/). Drop us an email, and we would certainly reply with an answer to your queries!!

Solar Power

Applications of Solar Power

The sun has always been regarded in all the civilizations that have inhabited the earth. Almost every civilization has most importantly worshipped the sun as God. This practice is prevalent even now. It is the source of life on earth. But the true impact of Sun on our earth is yet to be dully discovered.

At any moment, the sun emits about 3.86 x 1026 watts of energy. That’s 386000000000000000000000000 watts!! Quite a whooping number of zeroes, right? We still struggle around such an unimaginably large an amount of energy!

Most importantly, Solar energy is also the cleanest source of renewable energy. The development of affordable and clean solar energy technologies will enhance sustainability, reduce pollution and the use of fossil fuel.

Solar Power

Solar Energy

In light of the numerous and global effects of solar energy, scientists are trying to create ways of harnessing it. They have discovered that photovoltaic cells can be used to harness it . A photovoltaic cell most importantly absorbs light and converts it into electricity. A group of photovoltaic cells is called a solar panel. When sunlight (photons) strikes PV cells, they excite electrons. The electrons flow creating an electric current. PV cells are made up of semiconductor materials like silicon and alloys of indium and gallium. Crystalline silicon is the commonly used.

In this article, let us look at some very common and simple applications of solar power.

Applications of solar power

1) Solar calculators

Solar calculators are hand-held electronic calculators powered by solar cells mounted on the device. Amorphous silicon is used as a photovoltaic solar cell material for devices which require less power such as these pocket calculators. They use liquid crystal displays as they are efficient and operate in the low voltage range of 1.5–2 V. However, they may not work well in indoor conditions.

Solar Power

Solar calculators

2) Solar car

How cool it would be to zip around in a solar car! Most importantly it looks futuristic and funky in addition to making every road trip guilt-free.

 

Solar Power

Solar Car

3) Solar inverter

It converts the variable direct current (DC) of a photovoltaic solar panel into an alternating current (AC) that basically can be fed into a commercial electrical grid.

Solar Power

Solar inverter

4) Solar cooker

Solar cooker is a device which uses direct sunlight to heat or cook food. Many solar cookers currently in use are relatively inexpensive devices. Some are as powerful as traditional stoves. An advanced, large-scale solar cooker can cook for hundreds of people. They use no fuel. Costs nothing to operate therefore, helps reduce fuel costs and air pollution. This also prevents deforestation caused by gathering firewood for cooking. It’s Eco-friendly and pocket-friendly.

Solar Power

Solar cooker

Because of this, many still think that it is not a commercially viable technology. However, that’s not the case now. Most importantly, it’s the need of the day for more and more people to opt for solar energy. Otherwise, we might find our earth turning into wasteland before our eyes.

If you want your kids to most importantly become solar energy friendly, you may therefore want to begin with sensitizing them to the use of solar energy.

In conclusion, especially relevant for more ideas related to science projects and science fairs you can visit http://www.projectsforschool.com.

We love to assist our visitors, students, parents in their quest to learn science, you are welcome to leave your questions / comments. Chat with us, use contact us from here or on our facebook page (www.facebook.com/projectsforschool/). Drop us an email, and we would certainly reply with an answer to your queries!!

 

Ten most important scientific discoveries

Ten most important scientific discoveries 

Talking about ten most important scientific discoveries, we will begin by asking a question. Can you imagine the world without medicines and antibiotics? Diseases that have been now eradicated most of all like Polio, Bubonic, Typhus, were epidemics at one point. Ailments that killed human beings have a cure only because of the persistence and hard work of man. However, that is not all. There is much more to scientific discoveries and inventions, beyond just medicines and antibiotics. There’s the Physics, the Chemistry, Scientific Phenomena and much more! In this article, let us look at 10 such game changing scientific discoveries of man.

  1. The Copernicun System

On his deathbed, Polish astronomer Nicholas Copernicus published his theory that the sun is at the center of the solar system, with the planets revolving around it. Before the Copernican system was introduced, astronomers believed the earth was at the center of the universe. If not for this, we’d still go around thinking that the sun revolves around the earth rather than the other way round.

The Copernicum System

The Copernicun System

  1. Gravity

In 1664, Isaac Newton, an English mathematician and physicist Newton figured out that gravity is the force that draws objects toward each other. As a result, law of gravitation came to be known. If not for gravity, I wonder if we could figure out how to go to the space.

Gravity.jpg

Gravity

  1. Electricity

Michael Faraday discovered that when a wire carrying an electric current is placed next to a single magnetic pole, the wire rotates. He therefore produced an electric current by moving a wire consequently through a magnetic field, creating the first generator. As a result, his discovery revolutionized the entire electricity generating process.

Electricity

Electricity

  1. Evolution

Charles Darwin, the British naturalist, came up with the theory of evolution. It states that all organisms evolve very slowly over time. Due to these changes allow a species to adapt and survive in its environment. If a species doesn’t adapt, it may become extinct. He therefore, called this process natural selection. It’s often called the survival of the fittest. It was this discovery that helped us finally reach an acceptable line of conclusion regarding how humans probably came into being.

Human Evolution

Human Evolution

  1. Bacteria

Before French chemist Louis Pasteur began experimenting with bacteria in the 1860s, people did not know what caused disease. He discovered that disease came from microorganisms and that bacteria could be killed by heat and disinfectant. Most relevantly, doctors now sterilize their instruments saving millions of lives from epidemics of past!

Bacteria

Bacteria

  1. Theory of Relativity

Albert Einstein published the theory of relativity in 1905. It furthermore explains the relationships between speed, time and distance. The complicated theory states that the speed of light always remains the same—300,000 km/second regardless of how fast someone or something is moving toward or rather away from it. Not just that, relativity became one of those philosophical understandings which could bring into perspective therefore brought much more about life than mere physics!

Theory of Relativity

Theory of Relativity

  1. The Big Bang Theory

In 1927, Georges Lemaître proposed the Big Bang theory of the universe. The theory says that all the matter in the universe was originally compressed into a tiny dot. In a fraction of a second, the dot expanded, and all the matter instantly filled what is now our universe. The event marked the beginning of time. As a result, scientific observations seem to confirm the theory.

The Big Bang Theory

The Big Bang Theory

  1. Penicillin

Antibiotics are powerful drugs that kill dangerous bacteria in our bodies curing disease. Alexander Fleming discovered the first antibiotic, penicillin, which he grew in his lab using mold and fungi. Most noteworthy with this game changer that the entire human civilization consequently found a higher life expectancy and protection against almost many bacterial infections that were most probably yet fatal.

Penicilin

Penicilin

  1. DNA

On February 28 1953, James Watson of the United States and Francis Crick of England basically discovered the double-helix structure of DNA. Furthermore, DNA became the most important segment of the human beings.

DNA

DNA

  1. Periodic Table

Russian chemist Dmitry Mendeleev had noticed that, when arranged by atomic weight, the chemical elements lined up to form groups with similar properties. He was able to use this to predict the existence of undiscovered elements.

Periodic Table

Periodic Table

Therefore in conclusion, at http://www.projectsforschool.com, we decided to bring to you some interesting snippets from the world of science. This article seems like has covered these amazing discoveries; man wouldn’t be leading a comfortable and long life. Furthermore, we have the previous generations to thank for these discoveries. They have transformed our entire life!! Keep a watch on this section for more such interesting pieces!