How Ohm's Law Was Discovered?

Georg Simon Ohm was a German mathematician and physicist who discovered notably one of the most important laws in physics and engineering. Ohm's law is on every high school student's lips like A,B,C and that is what makes it so great - its simplicity and fundamental nature, qualities which make Ohm's law easily memorable.

V = IR

where,

V = voltage

I = current

R = resistance

Pretty neat, isn't it? But what does Ohm's law imply and how did Georg Ohm discover his now famous law?

Background of Ohm's law

Georg Ohm (1789 - 1854) was born to Johann Ohm, not formally educated and a locksmith by profession, who wanted his son to receive excellent education. Ohm's mother died when he was only 10.

In 1806, Ohm accepted a position as a mathematics teacher in a school in Switzerland. By the early 1820s, Ohm had also started teaching physics to high school students. Teaching high school science was a decent job, but Georg didn’t want to just teach - he wanted to make science.

Ohm was fascinated by electricity, which at the time was still something of an unknown magical force. The electrical battery had just been invented 20 years ago and there was a lot of scope of new discoveries in the field.

Discovering Ohm's law

Ohm didn’t have university funding or state-of-the-art equipment. He just wanted to do experiments at home for fun. Ohm only used a simple battery, copper wires and a home made galvanometer (a scale used to detect and measure small electric currents).

One day while testing different wires, Ohm connected a longer wire to his circuit, and the current dropped drastically. Initially Ohm thought that something had gone wrong with his archaic battery. But then he switched back to a much shorter wire and saw the current rise again.

At that time, it was not understood how or why electricity flowed through the wires... Ohm was puzzled at this strange phenomenon. Could it be that the length of the wire itself was resisting the flow of electricity?

Ohm began to systematically test wires of different lengths, materials, and thicknesses and jotted down the results of his experimentation.

Pattern of Ohm's law

Ohm noticed the following pattern:

1. The longer the wire, the less current was read by galvanometer.  

2. The thicker the wire, the more current.  

3. Different materials changed the flow too.

Ohm came to conclusion that each material offered different resistance to the flow of current. This quality is inherent to the material itself. Furthermore, length of the material also influenced the amount of current. 

Ohm was the first to describe electricity in mathematical terms, showing that: 

... the graph between current (I) and voltage (V) of battery was a straight line. When you divide voltage by current, you get a new physical quality - resistance - of the material used. Ohm's law can be visualized mentally as voltage pushing the current further down the wire, but the wire's resistance in turn preventing the flow of current.

Reaction to Ohm's law

The scientific community of Germany thought that Ohm’s work was too simple and too mathematical a result to have any great physical influence. One reviewer said it was "a fantasy, not physics." The rejection hurt Ohm so much that he resigned from his teaching post. Imagine discovering a law of nature… only to be told you're imagining things.

It wasn’t until a decade later, as electrical science progressed, that Ohm was recognized for his innovation. Scientists like Kirchhoff and Maxwell helped establish Ohm's law as undeniably right. In 1840s, Ohm had earned himself a position at the University of Munich.

Ohm's law today

Today, Ohm’s Law is taught in every physics classroom around the world. It’s one of the first scientific formulas students learn in physics and electronics. Ohm's fun with wires ultimately led to the creation of a formula which is taught to every high school physics student.

How Physics Affects Technology and Vice Versa

The knowledge of physics has resulted in a wide range of technological applications. Steam engine, for example, the first great industrial invention, arose from the discipline of thermodynamics, at the very start of eighteenth century. Within just a few decades, steam engines were being used in all sorts of applications including factories, mines, locomotives, and boats. Of course, the progress rate of human civilization increased manifold in a short time.

Then, in the nineteenth century, Faraday discovered the law of induction which became the basis for the invention of transformer. Further discoveries by Tesla and current war between Edison and Westinghouse led to the commercialization of electric power. Which created a ground-breaking change in the way we lived life as people. Radio came along soon when Hertz found the way to transmit and receive radio waves; the magic of long distance communication happened.

In first half of the twentieth century, two great inventions took the world by storm. Firstly, there was this enormous, uncontrolled atomic energy, employed as weapons of mass destruction in the second world war. Which would later be controlled in the nuclear reactors to harness clean electrical energy for the 21st century society. The second big invention of the early twentieth century was the television; all the world inside a box; first in greyscale then in color.

In next half of the twentieth century, humankind exceeded all their expectations. Landing on the moon, flying past the planet Saturn and invention of the internet. Towards the end of the twentieth century, personal computers became a reality. Productivity of man reached an all time high. Furthermore, the continually developing semiconductor physics led to manufacturing of even smaller computers and then ultimately smartphones.

From a mechanical age to electrical; from electrical to space age; and from space to a digital age; how far have we come; and marching onwards still! The main point is, that there is a fundamental connection between physics and technology. Without knowledge of physics, there could be no technological advances in the society. Let's see with the following table a list of some important technologies and the principles of physics they are based on.

Steam engine	Laws of thermodynamics
Nuclear reactor	Controlled atomic fission
Radio and TV	Generation, transmission and reception of electromagnetic waves
Laser	Stimulated emission of radiation
Computer	Digital logic
Rocket propulsion	Newton’s laws of motion
Radar and sonar	Reflection of sound
Ultra high magnetic field	Superconductivity
Electric generator	Faraday’s law of induction
Hydroelectric power	Conversion of energy
Airplane	Fluid dynamics
Particle accelerators	Lorentz force
Optical fibers	Total internal reflection
Electron microscope	Wave nature of matter
Photocell	Photoelectric effect
Fusion reactor	Magnetic confinement of plasma
Telescope	Reflection and refraction of light
Transistor	Semiconductor physics

 

Now a question arises: can technology give rise to new physics? Yes but rarely is it so. For example, measurement of time, an otherwise ancient technology, was perfected only in the era of Huygens and Galileo. This new form of technology was an accurate pendulum clock, which led Galileo to understand the physics of velocity and acceleration.

Another example of technology giving rise to new physics is the particle accelerator such as the large hadron collider. Inside a particle accelerator, there are a thousand possibilities; discoveries of strange particles. It is not surprising that whenever a new particle is found, new physics is unraveled.

Thus, the link is kind of two-way. However, physics leading to new advances in technology is far more likely than vice versa. Whatever is the case, the ultimate benefit, should be going back to the common people. It is the duty of those in power to make it so and to not misuse physics or technology to fulfill their eccentricities.

Feynman Diagrams Prank By Richard Feynman

Richard Feynman, a Nobel prize winning physicist, was best known for being a playful thinker. Feynman was a charismatic scientist whose ideas seemed radical at the time, but became mainstream later on. One such idea was Feynman diagrams, introduced in 1948, which is now essential to quantum mechanics.

Prior to Feynman diagrams, physicists generally relied on rigorous mathematical methods to describe particle interactions. Feynman who had an innate ability to make things simpler decided upon the idea of using squiggly lines to represent complex quantum processes. It was unconventional.

That is why, many top physicists of the time did not welcome the initial use of Feynman diagrams. They thought it was a practical joke or an unnecessary addition to the existing syllabus. On the other hand, younger and open minded physicists were amused at the idea.

The Purpose Behind Feynman Diagrams:

1. Understand particle interactions (such as those between electrons and photons),

2. Compute the probabilities of these interactions, and

3. Illustrate the relationships between particles in a way that could be directly tied to physical phenomena.

example of Feynman diagram

The beauty of the diagrams was that they allowed for calculation of probabilities for various particle interactions in a systematic way, and they were tied directly to experimentally measurable quantities.

However, the figures were too cartoonish to be taken seriously at first. In the world of theoretical physics, rigorous mathematical treatments were the gold standard, and Feynman’s diagrams did not fit the bill.

Feynman being a teacher at heart had always this goal of making things simpler and clearer for others. He wasn’t particularly bothered by the initial skepticism, as he was more focused on getting the results right.

By the early 1950s, Feynman diagrams had become mainstream in theoretical physics. By the 1960s, they were integral to many different areas, not just quantum electrodynamics but also in quantum chromodynamics, the study of the strong nuclear force.

Feynman diagram prank

At Caltech, Feynman would sometimes draw completely nonsensical diagrams on blackboards in the middle of discussions. These "diagrams" were visually similar to real Feynman diagrams, with particles and interactions depicted in the standard way, but they had no real physical meaning. It was all non sense.

Feynman would watch his colleagues trying to decipher what he had drawn, as they thought each diagram is a "puzzle" to a new breakthrough. It was a fun way for Feynman to mess with people, as they would overanalyze his absurd drawings, thinking they were part of some complex investigation. Feynman would then reveal that the diagram was just a prank, which caused everyone to laugh and realize they'd been fooled by his playful nature.

How A Rainbow Can Form Without Rain 😲

Rainbow is an optical phenomenon which is generally associated with rain, mist, and even fog. Some or the other form of water is thought to be required in order for a rainbow to form. But have you ever noticed a rainbow formation in a specific spot, like near a window at home? The conditions have to be just right, which makes it a cool little surprise when it happens!

Now, the sunlight keeps hitting the glass window all through the day so why is it that rainbow is only a rare occurrence? Dispersion or splitting of white light is a simple physical formation and yet rare to sight in day to day life. That is why, every time you spot a rainbow out of nowhere, it evokes a sense of joy and wonder isn't it?

For the rainbow effect to pop out, the light has to strike the glass window near a "critical" angle. The sun moves in the sky and it is only a specific moment in time when the angle of incidence is accurate enough for rainbow to appear. It is not a full arc like a sky rainbow because the geometry of a window pane is not the same as the spherical shape of a raindrop, but the physics is identical: refraction, dispersion, and a bit of reflection.

Why light splits into colors?

White light, or sunlight which is made up of all visible wavelengths, doesn’t bend uniformly, as each color, having different wavelength bends differently at a slightly different angle. As a general rule, shorter wavelengths, like blue, bend or refract more than longer ones like red.

Some cool facts about rainbow

1. No two people see the exact same rainbow since a rainbow is formed by light refracting through specific raindrops relative to your position. The exact rainbow you see depends on where you’re standing. Move a little, and it’s a different set of raindrops creating the effect.

2. The order of colors is always the same—red, orange, yellow, green, blue, indigo, violet, because of how light bends at different wavelengths.

3. A rainbow formed by light of the Moon, is called moonbow. The amount of light available even from the brightest full moon is far less than that produced by the sun so moonbows are incredibly faint and very rarely seen.

10 Inspiring Carl Sagan Quotes That Will Change Your Life

Carl Sagan was an American scientist who is best known for Cosmos: a personal voyage in which he kindled a public curiosity about science and astronomy through television. He became an inspiration for many aspiring students, including future astrophysicist Neil deGrasse Tyson.

Other than being an advisor to NASA, Carl Sagan also wrote award winning books, such as Dragons of Eden which won the Pulitzer Prize, and made sci-fi films, like Contact starring Jodie Foster and Matthew McConaughey.

Following are 10 quotes by Carl Sagan which will not only open your mind, but also change your life for real.

1. Somewhere, something incredible is waiting to be known.

This quote encourages us to explore the unknown with excitement. Many a times doctoral students lose hope because what an arduous journey it is to get a PhD. But Carl Sagan says there is always something new to discover, if we do not give up.

2. The cosmos is within us. We are made of star-stuff. We are a way for the cosmos to know itself.

A reminder that we are part of something much bigger, encouraging us to embrace our potential, which may now be hidden or dormant, and to explore our connection to the universe. It links personal ambition to grandeur of the universe.

3. Imagination will often carry us to worlds that never were. But without it, we go nowhere.

 

This quote is similar to Einstein's imagination is more important than knowledge. It is highlighting the power of creative thinking. In any sphere of life, imagination and creativity are of paramount importance.

4. For small creatures such as we, the vastness is bearable only through love.

This quote is my favorite. We are like butterflies who flutter for a day and think it is forever. This motivates students to find strength in connection and passion. Sagan believes that the power of love is a great motivating force, especially when faced with the enormity of existence.

picture by Kenneth C. Zirkel

5. The brain is like a muscle. When it is in use, we feel very good. Understanding is joyous.

Carl Sagan understands the significance of acquiring knowledge, celebrating the thrill of intellectual effort.

6. It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.

It is crucial for students to be critical, logical and inquisitive. This quote is urging students to seek truth over comfort.

7. We are star stuff which has taken its destiny into its own hands.

What a beautiful thought isn't it? This quote by Carl Sagan encourages self-empowerment, reinforcing that we have the potential to shape our own futures. Destiny is created.

8. We make our world significant by the courage of our questions and the depth of our answers.

This quote is pushing students to ask hard questions and seek profound solutions. The world only changes and evolves if we keep asking questions to authority unafraid. This passion, is precious....

9. The universe is not required to be in perfect harmony with human ambition.

..... however, passion may not always lead to the solutions we want. This quote is a reminder that the universe doesn't cater to our desires, so we must find our own path and purpose in the world. In our capacity we should do what we can without worrying about the result.

10. In the vastness of space and the immensity of time, it is my joy to share a planet and an epoch with you.

This Carl Sagan quote is a reminder that we only live once. Seize the moment and connect with others in the journey of learning. Do not wait for the next opportunity in the future while the present waits for you. Time is slipping away at the passing of every thought which did not turn into action.

How Squirrels Use Physice In Daily Life?

I was sitting in a park nearby my house, bored, having listened to all the trending songs in one go, when I saw a couple of Squirrels jumping from tree to tree. They reminded me of Toby Maguire and Andrew Garfield as Spiderman. More importantly, I was astonished at how they were using the principles of physics to go about their daily lives... 

Although squirrels or any other animal for that matter are not consciously aware of physics, they certainly interact with physical laws in fascinating ways. I am sure you, the reader, must have come across these 10 ways in which squirrels use physics in their everyday lives:

1. Parabolic Jumping: When squirrels jump from one branch to another, they follow a parabolic ttrajectory. Not only that, they spread their arms and legs as if they were birds to increase the surface area and lift force. I wonder if squirrels calculate the optimal angle and velocity needed to reach their destination.

2. Gravitational Potential Energy: When squirrels climb trees, they increase their potential energy. As they descend, they convert this energy into kinetic energy. I have seen them speed up and down the tree like it was nothing. Their bodies are also very elastic, which helps them in their daily chores. I wish I could climb a tree like that.

3. Friction for Grip: Have you noticed how Squirrels have sharp claws? Tiny but still firm. These claws allow them to grip surfaces with high friction. This friction is essential for climbing vertical tree trunks, allowing them to move quickly and stay stable while navigating tricky terrain. No wonder I can't climb with ease as my hands are always sweaty.

4. Elastic Potential Energy: Squirrels' tails act like a rudder and balance aid, but they also store and release elastic potential energy from their tail when the squirrel jumps or changes direction mid-air. This helps them land more precisely or correct their movement in mid-flight. The tail makes up and significant portion of their body weight and acts like a mechanism to (almost) fly.

5. Rotational Motion: When squirrels leap or fall, they can twist their bodies in mid-air, adjusting their orientation using their limbs and tail. This rotational motion allows them to land feet-first and avoid injury.

6. Energy Conservation: Squirrels run very fast, but for shorter periods of time. Like a Cheetah. This combination of high-speed running and short bursts of activity allows them to conserve energy while traveling long distances or evading predators.

7. Bouncing: When squirrels jump off hard surfaces or onto bouncy objects (such as a trampoline-like surface in a tree), their bodies absorb and release energy through elasticity, softening the landing and reducing the risk of injury.

8. Inertia and Momentum: When a squirrel is running at high speed and suddenly changes direction, its body mass and velocity create inertia, making it harder to stop. But with enough friction, it can quickly change direction without sliding, maintaining its momentum.

9. Gliding: There is a species of squirrels which flies, aptly called the flying squirrel. They have a fluffy membrane between their fore and hind legs, helping them to glide. The physics of air resistance helps them stay in the air longer and glide to distant points safely. Not all squirrels can glide long distances though, which is disappointing.

10. Balance and Center of Mass: Squirrels constantly adjust their center of mass as they move along narrow branches or leap across gaps. By shifting their body position and adjusting their posture, they maintain balance and stability to prevent falling. Have you noticed how they pose like Spiderman when they land? That's them adjusting their center of mass to make a safe fall.

In all these (and possibly more) ways, squirrels engage with the principles of physics in daily life, allowing them to thrive in their harsh environments.