Feeling Physics

A Glimpse At The Scientific Life Of Sir C V Raman

2018-07-31T09:23:00.000-07:00

Feeling Physics has completed it's one year on 28 July. And to celebrate this let's have a look at the scientific life of Sir C V Raman. This article is an extract from the 'C V Raman, A Biography' by Uma Parameswaran.

Look at the resplendent colours on the soap bubbles!

Why is the sea blue?

What makes diamonds glitter?

Ask the right questions, and nature will open the doors to her secrets.

‘I have panted a papaya tree today. I will not be here when it bears fruit, but there will be others to enjoy them.'

Chandrasekhara Venkata Raman ( 1888-1970) responded to beauty in nature and in the art with all his senses. He was all times a scientist, breathing and living science throughout his life, giving all he had- material, intellectual, and spiritual – to the cause of science. He made the Indian Association of Science in Calcutta everything that its founder, Mahendralal Sircar, had dreamt it would be. At the Indian Academy of Sciences that he founded in Bangalore, he continued to shape as per his own vision space where scientists could pursue their research without bureaucratic interference, where journals would publish research results expeditiously and where the physical environment was set against nature's unfailing beauty. The truest part of education, he maintained, was to cultivate ‘a love of the beauty’.

He often spoke about the links between art, aesthetics and science. The man of science, he once said, ‘seeks to resolve her (nature’s) infinite complexities into simple principles or elements of action which he calls the laws of nature. In doing this, the man of science, like the exponents of other forms of art, subjects himself to a rigorous discipline, the rules of which he had laid down for himself and which he calls logic….science…is a fusion of man’s aesthetic and intellectual functions devoted to the representations of nature. It is, therefore, the highest form of creative art’.

Raman won the Nobel Prize for Physics in 1930 for his observation of a phenomenon of light scattering, which was to be one of the most convincing proofs of the quantum theory. It was the culmination of seven years of work. During his sea voyage to England in 1921, he had wondered about the blueness of the Mediterranean sea. Unable to accept Lord Rayleigh’s explanation that the colour was just the reflection of the colour of the sky, Raman speculated that it was the result of the scattering of sunlight by water molecules. He published his speculation right away but it was another seven years before he could experimentally prove the details of the phenomenon. The Raman Effect discovered in Fabruary 1928.

His scientific work was in Physics, in the field of acoustics, optics and light scattering, ultrasonics and crystallography, vibrations of the crystal lattice in diamonds and other gems, optics of minerals and the physiology of vision. Even a cursory look at these and other subjects reveals his love of everyday wonders: the soap bubbles, the intricacies of musical instruments, the facets of gems and diamonda na dthe marvels of vision and sound and so on .

Raman made his major discovery in February 1928 at the laboratories of the Indian Association For the Cultivation of Science. The Raman Effect is the inelasctic stacrring of a photon . it questioned the phenomema known as Rayleigh Scattring . Which states that when the light is scattered from a molecule most are scattered elastically an that they have the same frequency and hence wavelength, as the incident photon. However, Raman founded that a small fraction of light scattered by liquids consists of photons with energies different from the incident ones. Each molecule has a unique Raman Spectrum. Since n two compounds have the same Raman spectrum, Raman spectroscopy can be used extensively in the qualitative and quantitative analysis of subatance in the calculation of thermodynamic properties and in the study of molecuaar structures.

After retiring from indian Institute in 1948, Raman opened his own Raman Research Institute in Bangalore n dengaged in his scientific intrests until death in 1970.

The Raman Research Institute is now a flourishing research center, a living monument to Raman’s legacy.

My first love letter

2018-06-06T05:16:00.000-07:00

Before you my life was like an open circuit, there were bulb, battery, wire and then you came like a switch. Suddenly the circuit was complete and the current started to flow my RBC's. When my eyes saw you at an elevation of theta degrees from my heart, my life became as stable as neon and electro-negativity reduced to Francium. You are the frequency my heart beats to. The range of my love for you extends to infinity. My feelings for you are like the graph between force and acceleration, always rising. My love for you is like the dark matter- You can't see it but it's always there.

You are a constant in the equation of my life. Your image on my heart is always at the centre of curvature, real yet inverted...after all love is never erect. Let the bond between me and you be as strong as the ionic bond between caesium and Florine. Your attacks on my heart are always from the front, just like SNi reaction. I know that I am sounding geek and some terms are complicated but I want you to know that my atoms are in love with your atoms and that -
You are my sine square theta, I am your cos square theta and together we make one.

- Yukta Sharma

The Sky Of January 2018

2017-12-31T07:47:00.000-08:00

This year 2018 is going to be very exciting for the sky lovers. Are you one a sky lover too? If yes, then you are at the right place now because this year is going to be full of celestial events. So here is the astronomy calendar of January 2018. If you don't want to miss any update from Feeling Physics including the astronomy calendars of every month then subscribe to the blog.

January 1- Mercury At Greatest Western Elongation

On this day i.e the very first day of the year the planet Mercury will be at the greatest western elongation . It is probably the best time to view to planet as it will be at it's highest point above the horizon in the morning sky.

January 2- Super Moon

This will be the first Super Moon among the two Super Moons of the year. The Moon will be at it's closest approach to the Earth and it will look brighter and larger than usual.

January 3- Meteoroid Shower

This is a meteoroid shower with up-to 40 meteoroids per hour at it's peak. It repeats annually from January 1-15. This year it's peak is on the night of January 3 and morning of January 4.

Due to the presence of the full moon the brightest meteoroid might get blocked but if you will be patient enough then you will be able to spot some. These meteoroids are produced by the dust grains of the extinct comet 2003 EH1.

January 17-New Moon

This is the best time to view the night sky. You can see some galaxy or star cluster because there will be no moon light to interfere.

January 31- Full Moon, Blue Moon, Super Moon And Total Lunar Eclipse

This might be the best day because on this day you will see Full Moon, Blue Moon, Super Moon and Total lunar eclipse!

Is Blue Moon really Blue?

The Blue Moon of January 31 refers to the second full moon of the same month. If you see the moon with a slight touch of blue then it is because of some rare dust in the atmosphere but the second full Moon of the month and the third full Moon in an astronomical season with four full moons are known as Blue Moon.
The Blue Moon of January 31 is likely to be blood red in color due to the Total Lunar Eclipse. This is known as Blood Moon.The Moon will be located on the opposite side of Earth as the Sun and will be fully illuminated.

The Dance Of Physics

2017-11-03T02:43:00.000-07:00

We all are familiar with many types of dance forms such as Kathak ( India form of dance) and Ballet. We have also seen the dancers taking endless turns at a particular position without any disturbance in their movement. How do they do it? Practice? Yes but their is something else also. So what is that something else? And how does it helps the dancer to perform those spectacular turns?

In the third act of the swan lake the black swan pulls of an endless series of thirty two turns at one pointed foot. It is probably the most toughest sequence in ballet. She is like a human top for the next few seconds. The dancer starts the motion by pushing the toe to generate torque but the friction between her pointed toe and the floor and also the friction between her body and the air reduces her momentum. So how does she manages to take those turns known as fouette?

While taking the turns the dancer stops for a very small fraction of second. In that second her foot flattens and then she pushes her foot against the floor which leads to the generation of a tiny amount of torque. Her arms also keep moving in order to maintain the balance. The fouettes are most effective when her center of gravity stays constant. Her pointed foot and the extended arm helps her to takes those turns.

Their is one more thing which most of the people fail to notice and that is that her other leg ( apart from the pointed foot) never stops moving. Her other leg helps her to gain momentum. When the leg is moving a certain amount of momentum gets stored in it and when she pulls that leg back towards her body the momentum gets transferred to her body.The more area the leg sweeps the more momentum she gains.

Their is one more way by which the ballerina can take turns that is by bringing her arms and legs closer to her body.The fouette is governed by the angular momentum (L) which is equal to the product of the angular velocity and the rotational inertia (I) i.e L= angular velocity X I. It is necessary for the angular momentum to stay constant while the dancer performs that means that her angular momentum needs to be conserved.

Rotational inertia is a body's resistance to rotational motion. It increases when more mass gets distributed further the axis of rotation i.e the radius increases and it decreases when the mass is distributed closer to the axis of rotation i.e the radius decreases. So when the ballerina brings her arms and legs closer to her body the rotational inertia decreases and in order to keep her angular momentum constant the angular velocity increases which allows her to take multiple turns similar situation can be noticed in ice skating also .

In Kathak also while taking the chakkars (turns at one leg) the dancer pushes her foot against the ground to gain torque and her hands keep coming closer to her body after a certain interval of time which increases her angular momentum and decreases the rotational inertia. This allows the dancer to perform the magical dance which does not happens due to some magic but Physics.

Bibliography-
ed.ted.com

Dark Matter - Something Yet Unseen

2017-10-04T03:44:00.000-07:00

I found something really interesting while turning the pages of my old note book of astronomy club. It was an article which I wrote during the winter vacation of 2013. It was the very first year when I heard of the term dark matter and dark energy ( this post will focus mainly on dark matter). When I asked my teacher about it she said the dark matter is like a glue to our universe. The matter we know i.e stars, planets, galaxies, atoms and us accounts only 5% of the known universe. 25% of our universe is dark matter and the rest 70% is dark energy.

What is this dark matter? Can we see it? if not then why? why do scientists think that it exists?

THE UNSEEN

Dark matter is the responsible for making it possible for the galaxies to exist. When is was calculated why the universe is structured the way it is, it was found that there is not just enough normal matter. It requires large gravitational force to form complex structured galaxies and the gravitational force of the visible matter is strong enough to form galaxies.

If there was only this force then stars would have been scattered all around the universe and not form galaxies. So now it is obvious for the scientists to think that there is something inside and around which is making the galaxies and this universe stick together. It is something we cannot see that means that it does not emit or reflect light, something dark. It is dark matter.

SEEING THE UNSEEN

Scientists have calculated the existence of dark matter and they have also detected some places with high concentration of dark matter. The light bends when passes near them. So there is something out there in this infinite universe that interacts with gravity.

Baryonic matter is the familiar material of the universe. It is composed of protons, neutrons and electrons. Most scientist think that dark matter is made up of Weakly Interacting Massive Particles
(WIMPS).WIMPS have 10 to 100 times the mass of proton but they are difficult to detect due to their weak interaction with the normal matter
Baryonic matter can also make up the dark matter, if they all tie up in small dense chunks of heavy metal or brown drafts known as MACHO's.

PROVING THE UNSEEN

According to stranded physics stars at the end of the spiral spinning galaxies should travel much slower than those near the galactic center (where the visible matter of the galaxy is concentrated) but through observations it was observed that stars travel approximately at same speed regardless of their position.And this can happen when the stars at the boundary are feeling the gravitational force of some unknown mass i.e dark matter.

Some certain optical illusions that are observed in the deep space can be explained by dark matter such as gravitational lensing. In pictures of the galaxies we must have observed some bend arcs of light. light bend when it comes from a massive galaxy to the observer. This bend can again be explained by dark matter. The light coming is experiencing the gravitational pull of some unseen mass i.e dark matter.

Many theories have been suggested to explain dark matter and it's properties but the none of them is perfect. Dark matter is still a mystery to the scientists who study this infinite universe.

Bibliography-
1) www.nationalgeogrephic.com
2) www.nasa.gov.com
3) www.space.com

Dark Matter

2017-10-01T06:41:00.001-07:00

I found something really interesting while turning the pages of my old note book of astronomy club. It was an article about dark matter which I wrote during the winter vacation of 2013. It was the very first year when I heard of the term dark matter and dark energy. When I asked my teacher about it she said the dark matter is like a glue to our universe. The matter we know i.e stars, planets, galaxies, atoms and us accounts only 5% of the known universe. 25% of our universe is dark matter and the rest 70% is dark energy.

What is dark matter? Can we see it? if not then why? Why do scientists think that it exists?

The effect of temperature on magnetic strength

2017-09-21T00:58:00.000-07:00

Magnets have became a part of our life now. We grew up playing with magnets. Our fridge, computers, discs etc. contain magnets. We all are surrounded by magnets . The modern life is incomplete without them. What are magnets? Can temperature have any effect ton them?

WHAT ARE MAGNETS?

Magnets are frequently used in daily life, even Earth itself is a magnet. A magnet is an object that produces a magnetic field. Some are permanent, they hold their magnetism with out any external current while others are temporary. A magnet can be created by exposing a piece of metal containing iron to a number of situations i.e repeatedly jarring the metal heating to high temperature. Materials which can be magnetized, which are also ones that are strongly attracted to the magnets are called ferromagnetic.

A magnetic field is the space surrounding a magnet in which magnetic force is exerted.The magnetic lines of force do not intersect each other. These lines originate from the north pole of the magnet and continue to the south pole.

TEMPERATURE Vs. MAGNETIC STRENGTH

Let's perform two experiments to know about the effect of temperature on magnets, cold process and hot process.

COLD PROCESS

1. Take a magnet and place it in a bowl full of paper clips.
2. Count the number of clips attached.
3. Remove the clips and place the magnet in fridge.
4. Set the lowest temperature possible.
5. Wait for approximately 20 minuets for the magnet to reach the temperature of the fridge.
6. Take the magnet out and place it in the same bowl of paper clips.
7. Allow the magnet to rest for five minuits.
8. Now count the number of clips attracted.
9. Take 3-4 readings with increasing temperature.

HOT PROCESS

1. Repeat the step 1 and 2 of the cold process.
2. Remove the clips and place the magnet in an oven.
3. Set the highest temperature possible.
4. Wait for approximately 20 minutes for the magnet to reach the temperature of the oven.
5. Take out the magnet and place it in a bowl of paper clips.
6. Allow the magnet to rest for five Minuits.
7. Now count the number of clips.
8. Take 3-4 readings with decreasing temperature.

WHAT DO WE OBSERVE?

After taking the readings we will observe that cold strengthens the magnets while heat can result in the loss of magnetic strength. Too much heat can completely ruin the magnet. A magnetic material should maintain a balance between temperature and magnetic domains. This balance is destabilized when exposed to extreme temperature.

Graphically the results will resemble an exponential curve with magnetic force decreasing as temperature increases. The independent variable is temperature so we will take it on the x-axis and the dependent variable is magnetism. Magnetism can be calculated by using the amount of paper clips that the magnet is able to collect at each measured temperature.

WHY ?

When we heat is provided the atoms speed up i.e their kinetic energy increases, the percentage of magnetic domain spinning in the same direction decreases. This lack of cohesion weakens the magnetic force and eventually demagnetizes it entirely.

When a magnet is exposed to cold, the atoms slow down i.e their kinetic energy decreases, so the magnetic domains are aligned and the magnetic strength increases.

The lord of patches - rainbow patches after rain

2017-09-20T05:05:00.000-07:00

I recall an incident of my childhood. After a heavy yet beautiful rainfall I went for ride on my bicycle. While riding I saw a beautiful colored rainbow patch on the road and after observing that patch questions started poping inside my mind. What are they ? Has someone droped his paint bottles? or is it some kind of omen? Being an eight year old child I thought that this is something which is visible only to me, so I never asked my questions to anyone because I thought that they will either laugh or they will think that I am mad. Funny,right? I then soon discovered that it's not just me who see these patches but everyone.

So what are these patches? How are they formed? Why do we seen them after rain? What is the mystery behind them?

IT'S ALL SCIENCE

These patches which we see after a rainy day are not some kind of omen or magic but pure science. It's all due to optics. It's a beautiful combination of oil, water and light.

Some amount of oil i.e lubricants from trucks, cars and bikes are always present on the roads. When it rains the oil droplets get collected and start floating on the water surface (Why?). Light which was first passing through just oil or just water has to pass through a layer of them now i.e light will now pass from a layer of air,oil and water. During this process light will not only undergo reflection but also refraction.

PHYSICS AT WORK

The oil film is thickest at the center of the patch and thinnest at periphery. let L' be the length when light ray travels from the top of the oil film and L'' be the length when light ray travels from the point of intersection of oil and water after getting reflected and refracted to our eyes. L' and L'' are slightly different. If the difference of L'and L'' is an integral multiple of the wavelength of light then constructive interference will occur, the rays will reinforce each other. Such phenomena won't be observed in the case of destructive interference.

The sun light has all the colors of the rainbow and each color has a different wavelength. The slight difference between the path length causes constructive interference of the colors. As a result of this we observe some beautiful color patches on the roads after rain. Different bands of oil produces different colors because the thickness decreases from the middle to periphery.

Knowledge Booster-

Why oil floats on water?

In simple words density can be defined as number of molecules per unit area. The density of oil is less that that of water. We can say that the oil is lighter then water. So, as a result oil and water don't g mix, oil floats on water.

What is light?

2017-08-18T07:02:00.000-07:00

What is Light? What is Light made of? Is it a wave or a particle? If both then how?

WHAT IS LIGHT?

In acient Greek Pythagoras proposed that light is emitted from the eye of a person which enables him to see whereas Epicurus argued that objects emitted light. These theories may seem pointless to many of us today but were a big deal at that time.The ray diagrams of light which quite successfully showed how light bounces of an object were given by Euclid.

In the beginning, we are taught that light is a form of energy which provides us with the sensation of sight but as we grow the definition changes and says that light is an electromagnetic radiation having a certain amount of electromagnetic spectrum. Now, what is radiation? The most simple words in which radiation can be defined is that it is the emission of energy as electromagnetic waves.

WHAT IS LIGHT MADE OF?

Today we say that Photon is the fundamental particle of visible light which travels at a speed of approximately 299,792 kilometres per second but the things were not same at the time of Newton. Newton believed that light is a collection of particles which he called corpuscles. According to him, these particles travelled in a straight line when not acted upon by any external force. No doubt that Newton strongly believed in particle nature of light. Now, the question arises is that what is the particle nature of light?

PARTICLE NATURE OF LIGHT

As already discussed above that light is made of Photons so it will show particle nature. The fact that light seems to travel in a straight line and casts a shadow behind the obstacles is one of the strongest evidence of this. Newton explained the laws of reflection of light on the basis of elastic collision of the particles of light with the surface it is incident upon and the laws of refraction were explained by assuming that the particles of light are strongly attracted by the particles of the denser medium which causes a bending at the surface.

WAVE NATURE OF LIGHT

Light is made up of particles and these particles have wave like motion because of the continuous collisions with other atomic particles. The wave length is so small that it 'seems' to be a straight line. So, light shows the wave-like nature due to the disturbance caused. Dutch physicist Christian Huygens was the first to suggest that light may be a wave phenomenon but his principal went unnoticed for almost a century. Newton's writings were then challenged by Thomas Young who conducted the double-slit experiment. This experiment established that light coming from two sources interferes and produce maxima and minima.this theory led to the establishment of light as a wave phenomenon.

So at the end, we can say that light has dual character (both wave and particle) not only light but all the matter around us shows this dual nature. Photo electric effect, reflection are some examples for its particle nature whereas the glaring example of the wave like nature of light is interference i.e they don't hit each other they interfere and then comes diffraction particles don't diffract waves do. Approximately 70% of the phenomena are explained by the wave nature and 30% by the particle nature.

What is light according to you? wave or a particle? let me know in the comments below.

Legends of the light- Northern lights

2017-08-08T10:29:00.001-07:00

The mystery of the beautiful northern lights has been disturbing many of us since our childhood. So let’s start from the very beginning-

What are northern lights?

Northen lights are the bright dancing lights giving a beautiful colour display on the poles, both northern and southern. They are known as 'Aurora borealis' in the north and Äurora australis'in the south. In the early 17th century Galileo called this phenomenon Aurora Borealis. Aurora was the roman goddess of dawn, and Boreas was the greek name for the north wind. He thought that an Aurora was caused by the sunlight reflected from the atmosphere.

What causes the northern lights?

The temperature above the surface of the sun is very high. At this temperature, collisions between gas molecules are frequent and explosive. Free electrons and protons are thrown from the sun's atmosphere by the rotation of the sun and escape through holes in the magnetic field.

These charged particles are blown towards our earth by the solar wind. The charged particles are then deflected by our earth’s magnetic field. However, the magnetic field is weaker at the poles (why?). So, some charged particles enter the atmosphere and start colliding with the gas particles. As a result of these collisions, light is emitted.

How is the colour variation caused?

Variation in colour depends on the type of the gas particles that collide. Oxygen molecules located at 60 miles above produce a pale yellowish-green colour ( the most common). The red auroras (rare) are produced by the Oxygen located at 200 miles above the earth. Blue and purplish red auroras are produced by the molecules of the nitrogen gas. The lights of the Aurora generally extend from 80 kilometres (50 miles) to as high as 640 kilometres (400 miles) above the earth's surface.

When can I see it?

As explained above these dancing lights can be seen on the north and south poles. Auroral displays can also be seen over the southern tip of Greenland and Iceland, the northern coast of Norway and over the coastal waters north of Siberia. Southern auroras are not often seen as they are concentrated in a ring around Antarctica and the southern Indian Ocean. Areas in the north, in smaller communities, tend to be the best. The auroral activity is cyclic, repeats after every eleven years. The last period was on 2013. Winter is the best season to observe these beautiful lights because of the extended and clear nights.

Knowledge Booster-

Why is Earth's magnetic felid weaker at the poles?

The magnetic field is strongest at the centre and weakest at the poles. It is because of the magnetic force lines that are vertical at the poles. These lines are parallel to the earth at the equator. The compass needle points most strongly at central low latitudes and gets progressively weaker as one gets more northerly and southerly.

Why do women distinguish colors better than men?

2017-08-02T09:09:00.000-07:00

She- Plum, Indigo, Aubergine, Lilac, Lavender.
He- Purple.
If you are male and always end up in a fight with your girlfriend about identifying the colours then it's not your fault my friend.Want to know why? here's the answer-

Your retina contains two types of photoreceptors, rods and cones. The rode is more sensitive than cones but they are not sensitive to colour. Rods can function in less intense light than cones.
The rear part of the eyeball's membrane contains 7 million cone cells.It's because of these cells that we are able to distinguish between colours. Information about these colour cells is contained in our X chromosome. Females have two of these chromosomes (XX) while men have only one (XY). This is the reason why females can distinguish more colours and shades.

Researchers from Brooklyn and Hunter Colleges of the City University of New York compared the vision of men and women. The volunteers were required to describe colours shown to them across the visual spectrum it became obvious that the colour vision of men was shifted, and that they required a slightly longer wavelength to experience the same hue as women.

After that, an image of light and dark bars was used to measure contrast-sensitivity functions (CSF).
Contrast sensitivity function is a measurement of a persons ability to detect low contrast pattern (usually decreasing shades of black to grey). A person with good contrast sensitivity can safely drive at night. This time performance of men was better than women.

So we can say that women are better at distinguishing colours and shades while men are better when it comes to intensity. Men notice details better than women.

Int-ball

2017-07-30T09:47:00.000-07:00

Internal ball camera

Japan never fails to surprise us!

Why is light so fast?

2017-07-30T07:59:00.001-07:00

What is the fastest thing ever? The Flash? Light? Light!
Light is the fastest of all and travels in a straight line. Do you know why? here's the answer- Fermat's principle of least time.
Fermat's principle of least time says that light is always in a hurry! it takes the quickest path despite the shortest. The shortest path is not always the quickest. If you have taken the shortest path to go to your favorite place but there is a lot of traffic so it doesn't come out to be the shortest. In a single medium the pathway is always a straight line but when traveling from one medium to another the fastest pathway is not a straight line.
Do you love light? What is your favorite topic in Physics? let me know in the comments below.

Feel infinite

2017-07-29T05:27:00.001-07:00

Hello everyone ! Hope you are all great. The main purpose of this blog is to sow the seeds of love for physics inside the heart of the people. It doesn't matter if you are a student of class five or a housewife or a retired adult. This is for everyone. From knowing the frequency of our heartbeat (1.17 Hz) to calculating our Earth's rotational speed (460 m/s)...it's all Physics! This blog will surely help you grow your love for this subject.If you have any questions or suggestions regarding anything feel free to email me at- yuktasbcsharma@gmail.com and if your question comes out to be beautiful it will be posted here. So let's feel the infinity - Feel infinite.

How much do you love Physics? let me know in the comments below!

Feel Physics

2017-07-28T07:38:00.001-07:00

Hey! Physics lovers...hope you are having a great day. Welcome to Feeling Physics! the only way to excel in Physics is to feel it, to love it deeply and unconditionally. So let's fall in love with physics but I won't blame gravity for this. Will you? let me know in the comments below.