How Max Planck Discovered Quantum Theory

German physicist Max Planck (1858-1947) was born in a traditional, intellectual family. Religion played a big part in the Planck household as both his great grandfather and grandfather were theology professors.

In 1867, Planck was enrolled in the Maximilians gymnasium school, where he came under the guidance of Hermann Müller, a mathematician who immediately recognized Planck's genius.

It was from Müller that Planck first learned the principle of conservation of energy as a 10 year old - that energy can neither be created nor destroyed. This is how Planck first came in contact with the field of physics.

Planck's big problem

When Planck expressed desire to pursue a career in physics, a professor Philipp von Jolly advised him against it, saying: "In physics, almost everything is already discovered."

Planck did not intend to make a discovery of new kind... he simply wanted to study physics deeply. In 1877, aged 19, Planck came under the mentorship of such renowned German scientists as Hermann von Helmholtz and Gustav Kirchhoff.

Max Planck, 1878

Planck was a devoted student with a knack for solving problems. By 1880, he had earned two of the highest degrees offered in Europe - a PhD degree and a qualification for professorship in Universities.

In 1894, Planck started working on the problem of black body radiation as classical theory of light had failed to explain what all was happening.

What is a black body?

A hypothetical black body can absorb all the energy that comes in contact with it, and then because of the laws of thermodynamics, this ideal body must also re-emit as much light as it absorbs.

Spectrum of a near perfect black body at an arbitrary constant temperature is shown below:

All objects actually emit radiation if their temperature is greater than absolute zero. An iron horseshoe, a ceramic cup and even people. The blackbody spectrum tells what is the peak wavelength emitted by that object at that temperature.

Very hot objects will glow - like Tungsten filament in a light bulb at 3300 Kelvin. Human body would emit invisible infrared radiation at 310 Kelvin.

It is important to note that all black body distributions look alike, except that they "peak" in different wavelength regions of the electromagnetic spectrum.

Classical VS quantum

In 1893, Wilhelm Wien had introduced Wien's law, which correctly predicted the behavior of black body at high frequencies - smaller wavelengths, but failed at low frequencies.

The Rayleigh–Jeans law of 1900 agreed with experimental results at low frequencies (below 100 THz), but created an "ultraviolet catastrophe" at higher frequencies.

There was no single law or theory that agreed with experimental data at all the values of frequency. Planck was determined to find a solution and at the turn of the century - he did.

In 1901, by assuming that radiation cannot be emitted continuously, as taught by classical physics, but in discrete packets or quanta.

Thus, energy is quantized according to Planck's law.

Planck considered quantization as being purely a mathematical trick and didn't really believe it to be anything more - it just fit the data at hand. In Planck's own words, energy quantum was "purely a formal assumption".

After all, physics is not really about "why" something is true but more about "how" does it work part. Ultimately, by moving away from classical theory Planck was able to explain the shape of black body spectrum to a high degree of accuracy.

Few years later, when Einstein solved another phenomenon where classical theory failed - the photoelectric effect - he gave physical meaning to Planck's energy quantum. The term "photon" was coined and a whole new quantum revolution began.

Who Was Alexander Friedmann?

Alexander Friedmann (1888–1925) was a Russian scientist who was the first to propose the theory of expanding universe, discovering a set of equations, now called Friedmann equations – before dying prematurely aged only 37.

Not only that, Friedmann also gave lectures on aeronautics for pilots and flew aircraft during the first world war. His students included such distinguished scientists as George Gamow and Vladimir Fock.

Early years

Friedmann was born to a very artistic household – his father was a professional ballet dancer while his mother was a trained pianist. From an early age, he was interested in the arts, sciences and politics. When he was 17, Friedmann was a student leader at his high school.

In 1907, when Friedmann had freshly joined the St Petersburg university for a physics degree, his father passed away suddenly. Consequently, Friedmann had to work part time as a tutor, earning a small salary that would support his education.

Friedmann received a bachelor's degree in 1910 and quickly joined Saint Petersburg Mining Institute as a lecturer.

Training

By 1913, Friedmann also completed his master’s degree and began taking part in flight lessons to study meteorology. This training came handy during the first World War, because Friedmann decided to volunteer in the air force. He was soon involved in bomb raids.

Friedmann used his physics knowledge in modelling bombing targets and helped other pilots too. Considering his aviation, scientific and leadership skills, Friedmann was promoted to the topmost position in an airplane factory.

His love of the pure sciences encouraged Friedmann to exchange letters, while fighting the war, with mathematician Vladimir Steklov – a friend from college days, in order to stay updated on new activities in the world of physics.

A new theory

German-born physicist Albert Einstein published a ground-breaking theory of gravity in 1916 that made him a celebrity figure. After the world war was over, Friedmann regretted participating, "I achieved what I set out to do, but what’s the use of it all now?" Friedmann decided to return his focus on physics.

In 1919, Arthur Eddington confirmed Einstein's theory by observing how stars near the sun were displaced from their original positions, due to curvature by mass. Friedmann wrote to Paul Ehrenfest a year later regarding his interest in the general theory of relativity.

In June of 1922, Friedmann introduced his own idea that the entire universe’s curvature could be a function of time.

Friedmann solved the field equations in general relativity to suggest three cases: 1) The universe could be expanding over time. 2) The universe could be shrinking over time or 3) The universe’s curvature could change periodically over time.

Revolt

Einstein, a supporter of steady state theory, did not view Friedmann’s evolving universe work favorably. Friedmann immediately wrote a letter to Albert Einstein requesting him to reconsider.

He wrote: “Should you find the calculations presented in my letter correct, please be so kind as to inform the editors of the Zeitschrift für Physik about it, and publish a correction to your statement.”

The letter reached Berlin, but since Einstein was touring Japan at the time, he did not read it until six months later. In 1923, Einstein admitted his error and wrote to Zeitschrift für Physik:

“My earlier criticism was based on an error in my calculations. I consider that Mr Friedmann’s results are correct and shed new light.”

Friedmann gained a widespread recognition in the scientific community as a result of proving Einstein wrong. He was invited to colleges across Europe to explain his findings.

Sadly, Friedmann died in 1925 because of a misdiagnosed typhoid fever. He was only 37 years old. Friedmann's theory was verified by Edwin Hubble 4 years later, who discovered red shift in the galaxies – implying an expanding universe.

Summing up

If Alexander Friedmann were alive in 1929 when Hubble found evidence for a changing universe, he should have won the Nobel Prize in physics. He was an adventurous man who did the most amazing work in the last few years of his life.

Friedmann received many honors after death, including a crater on the Moon which is named after him. Also, a prestigious Friedmann Prize is awarded once every three years to a single scientist for outstanding work done in cosmology.

10 Kip Thorne Facts That You Didn't Know

Kip Thorne is a celebrated American theoretical physicist who won the Nobel Prize in 2017 for his role in the detection of gravitational waves. He is also well known outside the realm of physics as Thorne is a man of many talents.

Born in 1940, Thorne grew up in a highly academic environment. His father was a professor of soil chemistry and his mother was a famous economist. Although his upbringing was in the Latter-day Saints faith, Thorne became an atheist later on.

When Kip was 8 years old, he attended a children's lecture on solar system and fell in love with astronomy. He wanted to uncover the secret of the stars (and so he did). Following are 10 facts related to Kip Thorne that will blow your mind.

1. Thorne received his bachelor of science degree from Caltech and his PhD from Princeton University. He was ONLY 30 years old when he joined Caltech as one of the youngest Professors in the institute's history.

2. Thorne is remembered by his students as someone with the ability to make a mundane topic exciting and fun to learn. In his illustrious academic career, Thorne has assisted at least 50 physicists in obtaining their Ph.D. at Caltech.

3. Thorne was trained under John Wheeler, renowned physicist who coined the term black hole. Thorne was among the first scientists to research on black holes, time travel and worm holes. He accurately predicted that red supergiant stars existed.

4. Thorne was friends with Stephen Hawking and Carl Sagan. In the movie The Theory of Everything, Thorne was played by actor Enzo Cilenti. Thorne had contributed ideas on wormhole travel to Carl Sagan for use in his novel, Contact.

5. The story of record breaking movie Interstellar (2014) was conceived by producer Lynda Obst and physicist Kip Thorne. Thorne acted as an executive producer and scientific consultant on the film. He also wrote a book explaining the science of Interstellar.

6. Not only Interstellar, Kip also helped Nolan for the movie Tenet on the ideas of quantum physics and time. Christopher Nolan said in an interview: I've been very inspired by working with great scientists like Kip Thorne.

7. Thorne has also acted. He appeared in The Big Bang Theory when the Coopers are trying to get some Nobel winners on their side to counter their rivals. Kip breaks Sheldon's heart by refusing his gift (or bribe) but it was a fun collaboration nonetheless.

8. Kip loves to write. He even resigned from his position at Caltech to pursue a career in writing and making movies for the big screen. Thorne is the winner of Phi Beta Kappa Science Writing Award, one of the most prestigious recognitions in America.

9. Thorne also became a Nobel laureate, the highest honor in physics, for decisive contributions to the LIGO detector and the observation of gravitational waves, an extraordinary journey of over 30 years of work, displaying incredible persistence.

10. Not proven yet, but Thorne has a theory that predicts the existence of a universally anti-gravitating matter, the element which is causing the universe to expand at accelerated rate and might make warp drive and worm hole travel a possibility.

Deepak Dhar First Indian To Win Boltzmann Medal

Austrian physicist Ludwig Boltzmann (1844-1906) who is well known for presenting the logarithmic connection between entropy and probability in his kinetic theory of gases, was never properly recognized during his lifetime.

In celebration of his ground-breaking work, Boltzmann medal is awarded once every three years by IUPAP in the field of statistical mechanics. In 2022, Deepak Dhar became the first Indian physicist to win the Boltzmann medal, sharing it with American physicist John Hopfield.

Deepak Dhar is famous among his students as a loveable science teacher. He was also a teaching assistant to Nobel laureate Richard Feynman when he completed his PhD from Caltech in 1978.

Deepak was born in Oct, 1951 to an average Indian household in the northern state of Uttar Pradesh and showed proficiency in mathematics from an early age. He completed his bachelor degree from the prestigious Allahabad University in 1970.

Deepak moved to the US after getting master's degree in physics from IIT-Kanpur in 1972. He returned to India the same year he completed his PhD from Caltech, where he held Richard Feynman fellowship. This shows his undying love for the motherland and a desire to teach in India.

Deepak became a full-time research fellow at TIFR, Mumbai where he was later promoted as an associate professor in 1991. He also served as visiting professor at the University of Paris during this time.

Post retirement, Deepak Dhar is a distinguished visiting faculty member at the Indian Institute of Science Education and Research, Pune. After winning Boltzmann medal, Deepak said: It is always nice to win but the award was never the driving force.

Quoting Isaac Newton, Dhar added: I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the seashore, whilst the great ocean of truth lay all undiscovered before me.

Dhar was previously honored with Satyendra Nath Bose medal by the government in 2001. He feels that much work can still be done in statistical mechanics, a field pioneered by Bose in India. Science needs to be loved, Dhar feels, and not something students are afraid of.

Deepak is known for his research on stochastic processes or random systems, that are part and parcel of day to day life. Examples include stock market, blood pressure, movement of a gas molecule, etc.

Deepak Dhar feels that physics has a lot new opportunities that are screaming for attention. But we are short-changing younger generation with low quality education, he says. Why would students pursue career in physics if their interest is killed at early stage?

5 Important Discoveries By Heinrich Rudolf Hertz

Heinrich Hertz (1857–1894) was a renowned German experimental physicist whose discoveries over a period of 10 years served as the foundation stones of modern communication technology and quantum mechanics.

Hertz was home schooled from age 15, as he was an outstanding student who showed proficiency not only in the sciences but also in foreign languages, such as Arabic and Sanskrit. In 1930, the SI unit of frequency was named Hertz in his honor.

1. Inertia of electricity

Hertz studied under physicist Hermann von Helmholtz at the University of Berlin. In 1878, Helmholtz was involved in a fierce debate with a colleague: Does electric current have mass? He announced a prize to anyone who could answer the question.

At that time, electron was not yet discovered so it was a big ask. Hertz accepted the challenge as it gave him immense pleasure in learning directly from nature through well thought out experiments.

After one year of hard work, Hertz settled the debate by showing in a series of experiments that if electric current had any mass at all, it must be negligibly small. Nearly 20 years later, electron was discovered by J.J. Thomson.

2. Radio waves

Hertz was 7 years old when James Clerk Maxwell wrote the famous equations of electromagnetic theory. No one was able to generate electromagnetic waves until Hertz in 1887. Hertz was 30 years old at the time.

Hertz was demonstrating electrical sparks to his students in 1886. He noticed during the lecture that sparks produced a regular electrical vibration within the electric wires.

Hertz thought that this vibration was caused by accelerating and decelerating electrical charges. If Maxwell was right, this would radiate electromagnetic waves through air.

When Hertz was asked in an interview the use of electromagnetic waves, he replied: Nothing I guess. This is just a home-made experiment that proves Maestro Maxwell right.

3. Electromagnetic spectrum

Hertz calculated the speed of radio waves he created and found it to be the same as the speed of light. This was an experimental triumph as he had proved yet another prediction of Maxwell.

Hertz also showed that the waves radiating from his oscillator could be reflected, refracted, polarized and produced interference patterns like light.

In 1890s, Hertz also worked with ultraviolet and x-ray. He concluded that UV, radio, x-ray and light are part of a large family of waves which is today called the electromagnetic spectrum.

4. Photoelectric effect

In 1887, Hertz observed that an electrically charged metal when put under ultraviolet light lost its charge faster than otherwise. This is called photoelectric effect.

As Hertz was an experimental physicist he did not try explaining the phenomenon. Theoretical physicist Albert Einstein was a young boy in Munich at this time.

In 1905, Einstein wrote the theory of photoelectric effect and won the Nobel Prize for the same in 1921. This work played a key role in the development of quantum mechanics.

5. Contact mechanics

Hertz wrote a paper in 1881 outlining the field of contact mechanics. Contact mechanics is a part of mechanical engineering in which engineers study the touch points of solids.

The principles of contact mechanics are useful in applications such as rail-wheel contact, braking systems and tyres.

Summing up

Heinrich Hertz was only 36 years old when he died of complications in surgery to fix his constant migraines. In just 15 years of his scientific career Hertz made pioneering contributions to various fields of physics.

From Maxwell to Einstein, Hertz is the famous experimenter whose observations either confirmed a previous theory or laid groundwork for a new theory. Hertz is among the few scientists in whose honor an SI unit is named.

Japan's First Nobel Laureate Survived Two World Wars

Hideki Yukawa (1907-1981) was the first Japanese Nobel laureate who won the Nobel Prize for physics in 1949. This recognition was a silver lining to the devastating second world war that destroyed Japan's cities. Yukawa inspired a whole new generation of children to look up to scientists.

Childhood

Hideki Yukawa was born on January 23 in Tokyo as Hideki Ogawa to a middle class Japanese family of academicians that belonged to the Samurai clan.

While he was not as outstanding a student as his older brothers, Hideki showed an aptitude for mathematics and the sciences.

When Hideki was 8 years old, the first world war broke out in which Japan participated in an alliance with Entente Powers. By the time war ended, Yukawa was already a teenager in Kyoto.

Yukawa's geologist father wanted him to become a mathematician. Hideki ditched that idea in high school after his teacher marked his exam answer incorrect when he proved a theorem in a different manner than the teacher expected.

Education

Yukawa graduated from Kyoto University at age 22 where he stayed on as a teacher for four years, until 1933. During this time, he also married Sumi Yukawa in accordance with Japanese customs.

Since his father-in-law had no sons, Hideki Ogawa was adopted by the Yukawa family and thereby a name change from Ogawa to Yukawa. The couple had two sons.

In 1933, Yukawa moved to Osaka University where he earned his doctorate in 1938, aged 31. He rejoined Kyoto University in 1939 as a professor of theoretical physics.

Major works

In 1935, during his time at Osaka University, Yukawa proposed a theory of nuclear forces in which he predicted the existence of a carrier particle of strong and weak interactions.

The particle's predicted mass was between that of the electron and that of the proton. It was named meson taken from mesos, the Greek word for intermediate.

Yukawa returned to Kyoto University in 1939 but could not continue his research work as the second world war broke out. One of Yukawa's younger brothers died in the war.

With most physicists working in applied projects for wartime necessities, Yukawa who grew up resenting the war, spent this time with his family.

Good news came after the war ended as Meson was discovered in 1947 in the cosmic radiation showers by British experimental physicist Cecil Frank Powell. Yukawa went on to be the first Japanese Nobel laureate in 1949.

In 1955, Hideki Yukawa signed the Russell–Einstein Manifesto, issued by British polymath Bertrand Russell calling for nuclear disarmament. Yukawa retired from Kyoto University in 1970 as a Professor Emeritus.

Nobel laureate Yukawa, who survived two world wars, became an inspiration for modern Japan. Since his victory, 20 Japanese nationals have won Nobel Prize in the sciences. In 1977, Yukawa was awarded Order of the Rising Sun, one of the highest honors in Japan.

Google Honors Stephen Hawking With New Doodle

Renowned astrophysicist, Stephen Hawking was nicknamed Einstein at school because he did fairly well in scientific subjects. He was inspired by his maths teacher Dikran Tahta to pursue a degree in mathematics.

However, Hawking's father Frank (who was a medical researcher) advised his son to study medicine instead, as jobs were very few for maths graduates. Stephen showed no interest in biology and so he found a middle ground...

Hawking graduated with a bachelor degree in physics from Oxford University in 1962. This feat was overshadowed by the diagnosis of Lou Gehrig's disease, a condition in which motor neurons get damaged leading to paralysis.

The crippling disease did not dishearten Stephen Hawking for long – not when he completed his doctorate in physics from Cambridge University, 1966. Or when later in life he went on a zero gravity flight:

Hawking authored several best-selling books on physics and astronomy. His most successful written work A brief history of time sold more than 25 million copies, making him an international celebrity. In 2014, a film depicting hawking's battle with the Lou Gehrig's disease was also released.

Hawking said: The downside of my celebrity is that I cannot go anywhere in the world without being recognized. It is not enough for me to wear dark sunglasses and a wig. The wheelchair gives me away.

Because of his excellent sense of humor, Hawking starred on such TV shows as Futurama, The Simpsons and The big bang theory as himself. Hawking said: Humor is what keeps me going, and life would be tragic if it weren’t funny.

In 2022, on Hawking's 80th birthday, Google has honored the legendary astrophysicist with a doodle on their homepage and a heartwarming video to top it off.

The doctor had given Stephen just a few years to live in his twenties credit to the life threatening disease. Not only did Hawking beat the odds but also revolutionized physics for next half a century.

His work with mathematician Roger Penrose about the universe's origins and the theorems on black holes made Hawking an undeniable force in the field of physics.

Following are 5 motivational Stephen Hawking quotes:

1. Look up at the stars and not down at your feet. Try to make sense of what you see, and wonder about what makes the universe exist. Be curious.


2. However difficult life may seem, there is always something you can do and succeed at. It matters that you don't just give up.


3. One of the basic rules of the universe is that nothing is perfect. Perfection simply doesn't exist.....Without imperfection, neither you nor I would exist.


4. We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special.


5. It surprises me how disinterested we are today about things like physics, space and philosophy of our existence. I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.

When Stephen Hawking abruptly passed away in 2018, he left a many in tears... an aching void in the scientific world that still needs to be filled. Because, Hawking was the most beloved scientist of this generation, rightly on par with Einstein.

10 Roger Penrose Facts That You Didn't Know

Nobel – British mathematician and physicist Sir Roger Penrose is popularly known for black hole singularity theorems which later on inspired Stephen Hawking's singularity theorem for the entire universe. In 2020, Penrose won the physics Nobel Prize for work done in the 1960s. Yes, it took that long.

Childhood – Penrose spent his early childhood during the second World War in Canada. It is quite surprising to know that Penrose was not always the brilliant man he is today. After winning the Nobel prize, in an interview, he revealed: "I was always very slow. I was good at maths, yes, but I didn't necessarily do very well in my tests."

Genius family – There also was added pressure due to the fact that he was born in the Penrose family, a family of artists, scientists and chess players.

Penrose's paternal grandfather was a famous portrait artist while his maternal grandfather was a physiologist and an early biochemist.

His father Lionel was a geneticist whose interests extended well beyond his profession and included such fields as geometry and chess, which he often shared with his children.

No surprise that Penrose's older brother went on to become a distinguished physicist himself. The younger brother and sister became Chess grandmaster and geneticist respectively.

Love of geometry – As a student, Penrose used to create illusory objects like the Penrose Triangle and the Penrose stairs. Several artworks by the renowned Dutch artist M.C. Escher were in part inspired by Penrose's impossible figures.

PhD – Post graduation, Penrose came under the supervision of mathematician W. V. D. Hodge. Though after one year, he was "thrown out" of the class for not being able to find solution to the problem assigned to him. "I decided that the problem Hodge suggested had no solution but he didn't believe me."

For the next two years, Penrose worked under geometer John Todd and in 1958 finished his doctorate degree with a thesis on tensor methods in algebraic geometry.

Inspiration – Roger Penrose was encouraged by his cosmologist friend Dennis Sciama to work alongside Stephen Hawking on the problems in astrophysics. "What are you doing with this pure mathematics nonsense? Come and work on physics and cosmology."

Lectures on quantum theory by Paul Dirac and on general relativity by Hermann Bondi influenced Penrose further. In the 1960s, he joined Sciama and Hawking to derive the Penrose–Hawking singularity theorems using Indian physicist Amal Kumar Raychaudhuri's namesake equation.

Consciousness – Apart from the problems in physics, Penrose has also explored the nature of consciousness, especially in his 1989 book: The Emperor's New Mind.

He was partly motivated to write the book after hearing computer scientist Marvin Minsky, one of the fathers of artificial intelligence, say: Human brain is just a computer made up of meat.

Minsky was of the belief that human intelligence could be mimicked artificially in accordance with a learning program. Roger Penrose argued against that viewpoint, saying: Human thought and intelligence cannot be simulated artificially.

In 1997, Penrose devised a theory of consciousness based upon quantum gravity. However, it failed to garner critical or experimental support. Hawking commented: Penrose's argument seemed to be that consciousness is a mystery and quantum gravity is another mystery so they must be related.

Religion – Roger Penrose regards himself as an agnostic. During an interview with the BBC in 2010, he stated: "I'm not a believer myself. I don't believe in established religions of any kind." Penrose is also a well-known supporter of Humanists UK organization.

Cycle of time – According to Penrose, the universe keeps dying and being reborn. In 2010, he reported possible evidence based on the data from cosmic microwave background, of an earlier universe existing before the Big Bang.

His conformal cyclic cosmology model although derives inspiration from Hindu-Buddhist philosophies is built within the framework of general relativity. Penrose has popularized the theory in his 2010 book Cycles of Time: An Extraordinary New View of the Universe.

Architecture – Believe it or not but Roger Penrose has made a remarkable contribution to architecture as well. Penrose tiling, a covering of the plane by non-overlapping polygons, is quite a popular choice for floor designs.

According to one alumnus, the campus of Indian Institute of Information Technology, Allahabad was inspired by Penrose architecture. "The domes and the corridors were the nodes and connections respectively of the Penrose architecture."

Similarly, Miami University in Ohio, Andrew Wiles Building at the University of Oxford and Mitchell Institute for Fundamental Physics and Astronomy (as seen in the picture) make use of Penrose Tiling.

Maxwell, Great Physicist Who Died Too Soon

James Clerk Maxwell was a renowned Scottish mathematician who built upon the works of English scientist Michael Faraday and revolutionized physics in whatever little time he spent on Earth.

His most important contribution was the unification of electricity, magnetism and optics into one coherent body of knowledge. Maxwell's research paved the way for technologies like radio, television, mobile phones and infrared telescopes.

Einstein said of Maxwell: The special theory of relativity owes its origins to Maxwell's Equations of the electromagnetic field. Planck added: He achieved greatness unequalled.

Early genius

When Maxwell was 13 years old, he won the Mathematics Medal and the first prize in both English and poetry. Following is one of his short poems:

The world may be utterly crazy

And life may be labour in vain;

But I'd rather be silly than lazy,

And would not quit life for its pain.

He published his first scientific paper at 14. The paper was written on a series of oval curves that could be traced with pins and threads, showing his love for geometry.

Professorship

When he was 24, Maxwell used to set up examination papers for Trinity College. A year later, he became a professor of natural philosophy at Aberdeen University aged 25. Maxwell was at least 15 years younger than his colleagues.

There he studied the nature of Saturn’s rings for almost two years and compiled his observations in a detailed essay, titled: The Stability of Saturn’s Rings.

When Voyager spacecrafts went to space in the 1980s, they confirmed many of the conclusions that Maxwell had made over a century before.

Electromagnetism

Maxwell joined King's College, London in 1860. Here he forayed into works published by Faraday and also met him on several occasions. Michael Faraday, who was 40 years older than Maxwell, became an admirer.

Maxwell examined the behavior of electric and magnetic fields in his 1861 paper: 'On physical lines of force'. In 1862, while giving a lecture, he calculated that the speed of propagation of an electromagnetic field is same as the speed of light.

Thus, he went on to conclude that light is itself an electromagnetic disturbance which propagates through the space according to electromagnetic laws.

Last years

Maxwell resigned in 1865 and returned to his home in Scotland. He also frequented to Cambridge where he was supervising the construction of Cavendish Laboratory.

In 1871, aged 40, he was elected the first Cavendish Professor of Physics. Here he wrote three popular books called Theory of Heat, Matter and Motion and A Treatise on Electricity and Magnetism.

His famous twenty equations, which in their modern form are four partial differential equations, known as Maxwell's equations, first appeared in 1873.

In 1879, Maxwell reported difficulty in swallowing food. It was found that he had abdominal cancer, to which he succumbed the same year, at the age of 48.

Legacy

In 1884, five years after Maxwell's death, Heinrich Hertz, a German physicist successfully produced electromagnetic waves in a laboratory as predicted by Maxwell.

Physicists say that Maxwell achieved for light what Newton had achieved for gravity: Unification. It took Maxwell's genius to collect the laws from the scattered pile of experimental evidence then at hand.

American physicist Richard Feynman wrote: Maxwell's equations didn't just change the world. They opened up a new one. Feynman labeled it the 'most significant discovery' of the 19th century.

Today, world's largest single-dish telescope that operates in submillimeter wavelengths of the electromagnetic spectrum is called James Clerk Maxwell Telescope in his honor.