Who discovered that we are made from star stuff?

Astronomer Carl Sagan popularized the phrase "We are made of star stuff" when he said: Nitrogen in our DNA, calcium in our teeth, iron in our blood and carbon in our food; were made in the interiors of collapsing stars.

However, most people wouldn't know the name of that scientist who actually found it out. It was German American physicist Hans Bethe (1906-2005) who wrote it in a paper titled "Energy Production in Stars" as early as in 1939.

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In 1930s, at the time when European scientists were debating quantum mechanics, Bethe migrated to United States and contemplated the stars. He thus became the first person to figure out that conversion of hydrogen into helium was the primary source of energy in a star.

The process is called nuclear fusion in which many nuclei combine together to make a larger one. It so happens that the resultant nucleus is smaller in mass than the sum of the ones that made it. So, by virtue of Einstein's equation E=mc², the mass is converted to energy.

When a star would eventually run out of hydrogen (its primary fuel) it would start converting helium into carbon, nitrogen, oxygen and so on, in order to keep itself hot.

However, those reactions themselves will halt at some point and the star would no longer be able to support itself against its own gravity and it will die in an explosion.

Therefore, it was proposed that most of the material that we're made from, came out of the dead stars which spewed out those chemical elements into the universe for further use. Hence, we are made of star stuff.

Bethe's groundbreaking paper not only helped in understanding the inner workings of the stars but also solved the age-old questions like: 'How do stars shine?' 'Where did the chemical elements come from?'

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He won the 1967 Nobel Prize in physics for this theory of stellar nucleosynthesis. Bethe would continue to do research on supernovae, neutron stars, black holes and other problems of astrophysics well into his late nineties.

Carl Sagan and Hans Bethe share the stage at Cornell

Now, Carl Sagan, who was earlier at Harvard University, joined Cornell in 1976 and became immediate colleagues with Hans Bethe who had been at Cornell since coming to America in 1935. While Bethe was a professor of physics, Sagan was a professor of Astronomy.

It was unfortunate that the general public still did not know about stellar nucleosynthesis despite Bethe discovering it some 40 years ago and winning the highest prize for it a decade ago. Carl Sagan changed this.

Their common interests in science and politics brought them even closer. Bethe was also a fan of Sagan's 1980 show Cosmos: A personal voyage. In one of the episodes, when Sagan said "We are made of star stuff", he immortalized Bethe's work in television history.

7 Lessons To Learn From Richard Feynman

Richard Feynman (1918–1988) was a Nobel Prize winning American physicist whose life was a combination of his intellect, uncertainty and a childlike curiosity.

Although he was a late talker and did not speak until after his third birthday, we know Feynman best as the chatty one.

His life is a story of constant growth: First, as a student, then as an eminent physicist and ultimately as a beloved teacher. Following are seven motivating lessons from Feynman's life.

1. Pursue a hobby

Feynman has said: "Fall in love with some activity and do it. Because, nobody ever figures out what life is all about and it doesn't matter." Feynman used to draw on canvas in spare time. He also learned Portuguese just so he could impress his colleagues in Brazil.

2. Explore the world

Everyone wants to win but no one wants to play the game. That's what Feynman meant when he said: "Everything is really interesting if you go into it deeply enough." Try new things and work as hard and as much as you want to on the things you like to do the best.

3. Carve your own path

The essence of Feynman's autobiography is: "Don't think about what you want to be, but what you want to do." Don't care about what others think. However, keep up some kind of a minimum, such as a degree, so that society doesn't stop you from doing anything at all.

4. Keep learning

Feynman has said: "It is important to admit when you do not know." There is no shame in not knowing. The only shame is when you pretend that you know everything. So, read as many books as you can. Be as practical as you need to be.

5. You only live once

Feynman was the first to profess this popular life mantra when he said: "Of course, you only live one life. So, make all your mistakes now, and learn what not to do." Thus, life is a process of constantly growing up.

6. Blind belief is dangerous

Feynman mentions in his autobiography: "Have no respect whatsoever for authority; forget who said it and instead ask yourself, Is it reasonable?" In other words, do not blindly believe anyone and make up your own mind about the world.

7. Enjoy the process

Feynman did not become a scientist for honors or recognition. He said: "My interest in science is to simply find out more about the world." So, no matter what you choose to become in life, do it because you love it deeply.

Engineer Who Won The Nobel Prize Twice In Physics

Winning the Nobel Prize once is no easy feat let alone winning it twice! The first ever person to do win the Nobel Prize twice was celebrated chemist and physicist Marie Curie as many of you might already know.

Similarly, John Bardeen has won the prestigious prize for physics not once but twice! If you ever watched The Big Bang Theory, a show in which engineering as a field is consistently made fun of, it might come off as surprising that Bardeen was an engineer by education and profession.

John Bardeen (1908-1991) completed his bachelor and master degrees in electrical engineering in 1928 and 1929 respectively. He was then employed by Gulf Oil Corporation where he worked for four years.

However, his love for physics was intact and urged him to go back to school. Therefore, he enrolled at Princeton University to study physics and mathematics in 1933.

There he wrote a thesis on solid-state physics under the guidance of Nobel laureate Eugene Wigner. After graduating in 1935, he was chosen as Junior Fellow at Harvard University, a position he held for three years.

In 1939, the second world war broke out and John could no longer facilitate his individual research interests. The big break came after the war in October 1945 when he started working at Bell Labs.

Along with colleagues William Shockley and Walter Brattain, John invented the first transistor in 1947. Their relationship, however, soured when Shockley tried to take most of the credit for the invention.

Replica of the first transistor

Shockley prevented both Bardeen and Brattain from working any further on the transistor technologies. So, John left Bell Labs in 1951 and accepted an offer from the University of Illinois to study superconductivity.

In 1956, he shared the Nobel Prize in physics with Shockley and Brattain for their work on the transistor. Today, as you might know, most of computing technologies are unimaginable without the transistor.

When Bardeen brought only one of his three children to the prize distribution ceremony, the King of Sweden ridiculed him, to which Bardeen candidly replied: "Next time I will bring them all to Sweden."

In 1957, John wrote a theory of superconductivity along with Leon Cooper and John Schrieffer. It ushered a new era of transportation and medical technologies such as MagLev and MRI respectively.

15 years later, John kept the promise he made to the King of Sweden when he took his three children to the Nobel Prize distribution ceremony in 1972.

John stayed as a professor of engineering at University of Illinois until 1975. In 1983, Sony corporation, which owed much of its commercial success to inventions by John, created an honorary John Bardeen professorship at the university.

It's similar to the Lucasian professor of mathematics at Cambridge University, a chair founded in 1663 and held by icons like Newton, Dirac and Hawking.

In a 1988 interview, when Bardeen was asked to comment on religion, he said: "I am not a religious person and so do not think about it very much." John was a very humble scientist who donated much of his Nobel Prize money. He enjoyed hosting cookouts for neighbours who were unaware of his scientific achievements.

If you make a list of people – politicians, scientists, sportspersons, etc – who have had the greatest impact on the 20th century, John's name would certainly make it to the top ten. Because, without his work, none of the modern technologies would be possible.

Oppenheimer Helped Feynman Meet His Hero

Paul Dirac and Richard Feynman were two different physicists in terms of approach. For Dirac, physics was a search of pretty mathematics. Feynman, however, always began his work from observations he made in the real world.

The two physicists were also poles apart when it came to informal speaking. While Dirac was a man of extremely few words and legendarily so; Feynman on the other hand was candidly chatty.

Yet, Dirac was Feynman's idol growing up.

Their first meeting in 1946 was very brief and unproductive. Dirac asked: "Do you have an equation?" Feynman being a beginner at the time didn't and so Dirac walked away after a silence.

In 1948, Feynman got a second chance to impress Dirac, thanks to his former boss at the Manhattan Project, Robert Oppenheimer, who also happened to be close friends with Dirac.

Oppenheimer successfully organized the first postwar physics conferences in the United States and brought together the most brilliant minds of his time such as Bohr, Fermi, Dirac and Bethe.

Under Oppenheimer's direction, physicists once again tackled the greatest unsolved problems of the pre-war. Some may consider it rather ironic that the same person who headed nuclear weapons program was also the one who helped revive collaborative work in physics.

During one of the conferences arranged by Oppenheimer, Feynman gave a lecture on quantum electrodynamics and introduced to the world for the very first time, Feynman diagrams.

He drew strange, unfamiliar drawings on the blackboard; lines in different shapes—straight, dotted, and squiggly—in the course of the lecture, as intellectuals, including Dirac, looked at him in bewilderment.

Feynman had succeeded in making a mark.

Their third meeting occurred in 1962 out of which came an iconic picture of the duo. It was taken by Polish photographer Marek Holzman during the relativity conference in Warsaw. The following conversation is said to have transpired.

Feynman: Hello again. I'm Feynman.

Dirac: I'm Dirac.

Feynman (admiringly): It must be wonderful to be the discoverer of that equation (he meant Dirac equation).

Dirac: That was a long time ago. (1928)

A pause.

Dirac: What are you working on now?

Feynman: Mesons.

Dirac: Are you trying to find an equation for them?

Feynman: No; it's very hard!

Dirac: One must try.

This was their last meeting. Feynman shared the 1965 Nobel Prize in physics with Julian Schwinger and Shin'ichirō Tomonaga for work done in quantum electrodynamics, a field of physics pioneered by Paul Dirac in the 1930s.

Feynman would later recall that those conferences organized by Oppenheimer were the best he had ever attended. That they were his first and the most important outings with the big men of physics.

Who was Joseph Fourier?

Joseph Fourier is a renowned name in the scientific world credit to Fourier series and Fourier transform. His work is useful to various problems in physics including (but not limited to) heat transfer and vibrations.

Apart from his scientific ventures, Fourier was also involved in French politics. He played a significant part in the French Revolution at his district and came to the notice of a young French revolutionary Napoleon Bonaparte.

Joseph Fourier was born on March 21, 1768 in Auxerre, France to a very poor family. He was orphaned at the age of nine. Fourier could not afford formal schooling as a result, however, he did receive an extensive training by the Church.

His exceptional mathematical prowess was recognized by those around. Fourier was appointed scientific advisor to Napoleon Bonaparte in 1798 at the age of 30. He was promoted by Napoleon to the post of governor in Southeastern France.

It was there, in his free time, that Fourier conducted experiments on heat transfer. In 1807, he submitted a paper on the same to Paris Institute and invented two important mathematical tools while doing so.

The first contribution is called Fourier series in his honor. The tool to make other functions by adding infinite sine (and/or cosine) waves. It was indeed a groundbreaking breakthrough at the time.

The second contribution was dimensional analysis i.e. an equation can be correct only if the dimensions match on both sides of the equality. This finds use in physics.

In the 1820s, Fourier made another contribution to math: finding real roots of polynomials. But, his major work in this decade was the discovery of and experiments on the greenhouse effect.

In 1827, Fourier published an article in which he claimed that the Earth's atmosphere might act as an insulator. This was his last major work as he died in 1830 aged 62.

10 Albert Einstein Quotes To Succeed In Life

Apart from making groundbreaking discoveries in physics, Albert Einstein also played the role of a motivational guru quite often. So, following are 10 Einstein quotes that will change your life.

1. Everyone sits in the prison of his own ideas; he must burst it open, and that in his youth, and try to test his ideas on reality. [Meaning: Don't keep delaying what you really want to do. Try it out for who knows what is possible?]

2. Joy in looking and comprehending is nature's most beautiful gift. Never lose a holy curiosity for it has its own reason for existing. [Meaning: Every child is born curious. Keep your mind open to new adventures.]

3. Try to become not a man of success, but try rather to become a man of value. Because, only a life lived for others is a life worthwhile. [Meaning: Our relationships are just as important as goals.]

4. Life is like riding a bicycle. In order to keep your balance you must keep moving. [Meaning: Enjoy the ride. Don't be afraid to fall.]

5. Don't think about why you question, simply don't stop questioning. Don't worry about what you can't answer, and don't try to explain what you can't know. [Meaning: Curiosity is a quality one must never let go of. Ask questions as they will lead you to life's answers.]

6. Blind obedience to authority is the greatest enemy of truth. [Meaning: Don't follow people blindly.]

7. The value of a college education is not the learning of many facts but the training of the mind to think. [Meaning: Learn how to think, not what to think.]

8. I never think of the future. It comes soon enough. [Meaning: Live in the moment. Act now.]

9. The mediocre mind is incapable of understanding the man who refuses to bow blindly to conventional prejudices and chooses instead to express his opinions courageously and honestly. [Meaning: Break the mould you were born into.]

10. If A is success in life, then A = x + y + z. Work is x, play is y and z is keeping your mouth shut. [Meaning: Work hard. Play hard. Stay humble.]

Five Interesting Facts About George Gamow

George Gamow (1904–1968) was an all-rounder in true sense of the word. He made contributions to many branches of physics as well as to the field of biology. Gamow was also quite funny and a well-known prankster as we shall see.

College life

Gamow studied under renowned Russian physicist Alexander Friedmann at the University of Leningrad. He made friends with Lev Landau and Matvei Bronstein and the trio came to be referred as the Three Musketeers.

After graduating, he started doing research into the atomic nucleus, which became the basis for his doctorate. From 1928 to 1931 he worked under Ernest Rutherford. In 1932, he built a draft for the first cyclotron in Europe which was completed in 1937.

Important contributions

In 1928, Gamow proposed an explanation for alpha decay of a nucleus by using quantum mechanical principles. He helped build the first cyclotron in Europe, an early version of the particle accelerator, which helped in further studies on radioactivity.

In 1940s, Gamow shifted his attention on cosmology. During this time, he worked with Lemaitre on the Big Bang theory. It was his idea that the early universe was dominated by radiation rather than by matter. He wrote in a paper the presence of background radiation (remnants of the big bang which were later discovered in 1965).

Gamow worked with Francis Crick and James Watson to understand the structures of DNA and RNA. His work played a key role in the formulation of genetic theory.

Writings

Gamow earned fame and recognition as a science writer. In 1956, he was awarded the Kalinga Prize by UNESCO for popularizing science with his books. He also sketched many cartoons and illustrations for his books which added quite a dimension to and complemented the text.

Educator

George Gamow had all the qualities of a great physics teacher. He conveyed a sense of excitement with the revolution in physics. His doctoral students included Ralph Alpher and Vera Rubin whose significant works were prediction of cosmic microwave background and detection of dark matter, respectively.

Personality

George Gamow was full of life much like Feynman never too dull or boring. He possessed an infectious, almost manic enthusiasm in whatever he did. American biologist James Watson described Gamow as card-trick playing, limerick-singing practical joker.

He loved the Greek letters and so much so that he called his wife Rho even though her name actually was Lyubov Vokhmintseva.

His most famous prank was the Alpher–Bethe–Gamow paper. He could not resist adding his colleague Hans Bethe to the list of authors, as a pun on the first three letters of the Greek alphabet: alpha beta gamma.

Who was Gustav Kirchhoff?

Most high school and engineering students know Gustav Kirchhoff by his namesake circuit laws. But there is more to him than that as we shall see. Gustav Kirchhoff was born on 12 March, 1824 in Prussia (now Germany).

Besides circuit laws, Kirchhoff is known for making pioneering contributions to spectroscopy. With scientist Robert Bunsen, he invented the spectroscope in its modern form. He used it to study the spectrum of the Sun.

In 1859, he showed that the Sun contained sodium apart from Hydrogen and Helium. His spectroscopic work earned him greater fame in his native country. Since 1990, a little over 100 years after his death, the Bunsen–Kirchhoff Award has been given for outstanding achievements in spectroscopy.

Now coming back to electricity. You will be amazed to know that Kirchhoff was only a student when he formulated the two circuit laws in 1845. It later became his doctoral dissertation as well. The two laws are as follows:

1. The algebraic sum of currents meeting at a point is zero.
2. The directed sum of the voltages around any closed loop is zero.

They can be used to solve many problems in physics and engineering. Let's have a crack at it with a simple example.

Since (i) the sum of currents at a point must be zero and (ii) currents i1 and i2 are incoming (positive) and i3 and i4 (negative) are outgoing...therefore: 3+9-5-i3=0. This gives i3=7 amp.

That was current law in its simplest form. But combined with voltage law they can be used to solve very complicated circuits.

Apart from spectroscopy and engineering, Kirchhoff made equally important contribution to the field of thermochemistry. In 1858, he gave a law: The overall enthalpy of the reaction will change if the increase in the enthalpy of products and reactants is different.

In 1860, Kirchhoff coined the term black-body radiation and postulated the existence of a perfect black-body, an object that absorbs all the incoming light and reflects none. His studies were used by Max Planck to formulate the Planck's law in 1900.

Although Kirchhoff has become most widely known for his circuit laws but you can realize now how important his other findings were. To the fields of spectroscopy and thermodynamics. Gustav Kirchhoff was a proper genius.