Archimedes of
Syracuse (Greek: Ἀρχιμήδης; c. 287 BC – c. 212 BC) was a Greek mathematician,
physicist, engineer, inventor, and astronomer. Although few details of his life
are known, he is regarded as one of the leading scientists in classical
antiquity.
Evolution of Bicycles
Walk up to your bicycle and ask yourself
the question, is there any other design possible for my bike?
·
Can I
make it faster, cooler and smarter?
·
Why
is the design the way it is?
·
Why do I need 2 wheels?
·
Do
they have to be of the same size?
·
Why is the seat somewhere in the middle of the
wheels?
·
Why is the handle bar on the front wheel?
·
Why can’t we control the back wheel in the
same way?
Andromeda Galaxy
The Universe is made up of many
Galaxies, Stars and other things. Do you have any idea that which is the
nearest galaxy our own milky way? It is the Andromeda Galaxy.
It is around 2.5 million light years
away from earth. Yes it’s the big spiral
known as ANDROMEDA GALAXY also known as MESSIER it is the galaxy nearest to our
MIKYWAY. Andromeda is the largest galaxy of the Local Group, which consists of
the Andromeda Galaxy, the Milky Way, the Triangulum Galaxy, and about 30 other
smaller galaxies. Although the largest, Andromeda may not be the most massive,
as recent findings suggest that the Milky Way contains more dark matter and may
be the most massive in the grouping.
The Doppler Effect
Two countries A and B are at war with each other. Since both of them are equally matched in air and on land, they decide to fight at sea. You are a citizen defending country A which has better naval fleet than B. On the verge of defeat, as a last resort, country B sends one of their best submarines to attack from below. How do you employ the physics of sound as a weapon at this decisive moment, to save your nation? Read on to discover...
Non-Conserative Induced Electric Field
We always encounter situations that deviate from the normal. Doesn’t it seem bizarre that a voltmeter connected across two points can actually show two different values depending on how it is connected? Sounds strikingly similar to the mechanical equivalent, where friction does varying amounts of work between two points depending on the path taken to move a body. Doesn’t it? Yes. The culprit is a non-conservative force in action.
Consider a circuit with a 10V battery and two resistors R1=80 ohms and R2 =20 ohms. If we are to calculate the current i through the circuit, applying the Kirchhoff’s loop law yields this:
If we were to find the potential difference between A and B as shown,we have two paths at our disposal, namely, 1 & 2:
By following path 1, we get Va - Vb = 80(0.1) = 8 V
By following path 2,we get Va - Vb = 10 - 20(0.1) = 8 V
Any path taken gives the same value of Va - Vb. With further deductions, we can understand that this must hold good because electric field produced by the battery or, in general, any static charge is conservative.
Now, consider the case of magnetically induced electric fields. Are they conservative or non-conservative? To analyze their nature, utilize a similar setup without the battery. Instead, there is a changing magnetic field through the loop.
Consider the instant when the rate of change of the flux through the loop is exactly 10V. According to Faraday’s Law, EMF induced in the loop will be 10V. Again, we find the current i through the loop, which comes out to be 0.1 A. Let the two digital voltmeters be connected across the two resistors as shown.
We may judge that both the voltmeters will show the same reading as they are connected across the same points. Surprisingly, this is not so!
The voltmeters show entirely different readings .This is rationalized by these calculations.
We found that the current in the circuit is 0.1A. So, if we go trace path 1 we get
Va - Vb = 80(0.1) = 8 V,
which will be the same reading as that of the voltmeter V1.
By path 2,we get
Va - Vb = -20(0.1) = -2 V
Evidently, this dissimilarity points to the fact that we ‘removed’ the battery voltage source (and replaced it with something else). So, voltmeter V2 shows -2V.
Summing it up, we get two voltmeters attached across the same two points showing different readings. What is the mystery behind this baffling complication?
Well, magnetically induced electric fields are non-conservative. When we calculate potential difference between two points taking two different paths, we get different answers unlike the electric field created by charges. Thus, magnetically induced fields are non-conservative in nature and forms loops. This property is different from the conventional electric fields, which emerge at a positive charge and end at a negative charge. Can you find out some more anomalies of non-conservative fields?
Our Solar System
Mankind has always been making discoveries about the celestial bodies that surround us. The solar family is a blend of opposites – of unimaginable giants, of hundred metre asteroids, of extremely hot lands and of freezing cold atmospheres. So, who are these members journeying around the sun?
OUR SOLAR SYSTEM
The solar system consists of the sun and other astronomical bodies orbiting around it under the influence of its gravitational field. These celestial bodies include the planets, their satellites and meteorites. While satellites revolve around their planets, and the planet around the sun, it is intriguing to note that the solar system too, keeps revolving around the nucleus of Milky Way at a distance of about 30,000 light years. So, what is a light year? To analyse astronomical distances the units that we come across daily viz., metre, foot are extremely inadequate. Instead, imagine the distance light could travel in a year when it can cover 30,00,00,000 m in a second! As the name says, this is what is termed as a light year.
The sun, which has a diameter that can fit hundred and nine earth-sized bodies, is the ultimate fuel for life on earth. Contrary to the popular belief that the sun is a stationary star, it moves with the solar system at a spectacular speed of 828,000 km/hr!
What seem to be merely floating about the Sun, are not just some spherical masses of various sizes. Unique in their own way in almost every aspect, these distant bodies have kept people right from the ancient times to the modern ages wondering about their veiled mysteries, giving rise to fascinating mythologies and startling scientific discoveries.
MERCURY VENUS
Mercury, the planet closest to the sun is a god of trade in Roman mythology. (Doesn’t the name sound similar to ‘merchant’?) Venus, though resembles the Earth in many ways, is highly uninhabitable – it has a dense atmosphere of carbon-dioxide and sulphur brought about by extensive volcanic activity.
MARS JUPITER
The red planet Mars, is usually associated with wars and masculinity in mythologies. Mars has the same colour as that of rust. Can you now guess what could be the compound behind its brilliant hue?
While planets closer to the sun, namely, Mercury, Venus, Earth and Mars are ‘terrestrial’, the outer planets, Jupiter, Saturn, Neptune, and Uranus are actually ‘gas’ giant. (Pluto is no more considered a planet now.) In fact, the ringed-planet Saturn is so gaseous that, it is buoyant enough to float on water! (No, Jupiter sinks!) The answer lies in Archimedes’ Principle. The hint is, Saturn’s average density is 0.7g/cm3 and Jupiter’s is 1.4g/cm3.
SATURN
Accompanying these planets, we have a belt of asteroids located roughly between Mars and Jupiter. These bodies have no regular shape and can have mean diameters of more than 400km.
URANUS NEPTUNE
Uranus, the god of the skies in Greek mythology, has an almost horizontal axis of rotation! Neptune is a near-twin to Uranus. This was the first planet to be ‘mathematically predicted’ from unexpected changes in Uranus’s orbit.
- Edited by Vaishnavh
Electrostatics-Introduction
*This article will give you a brief insight about the notion of charge and its effect on surrounding charges.*
Electrostatics is all about the interaction of charges with its neighboring charges which includes calculating the forces experienced or the energy of a system.This brings us to a basic question as to what is a charge?..Can we see it?..feel it?..