5 Major Differences Between Sgr A* and M87*

Take a close look at the two black hole images and you can ascertain a few differences by your own. Notice the speed of accretion disk, which is a gas-like flow around the black hole. Or the size of dark spots in the center that give you a faint idea of the black hole event horizon.

The latest image by event horizon telescope is that of Sagittarius A*, a black hole in the center of our Milky Way galaxy. That this is a supermassive black hole was first recognized by physicists Reinhard Genzel and Andrea Ghez, for which they won the Nobel Prize in 2020.

Event horizon telescope or EHT is a worldwide network of radio telescopes that took the first ever picture of a black hole in 2019. It was that of M87*, an enormous supermassive black hole in the heart of Messier 87 galaxy in the constellation Virgo.

While the two black hole pictures look almost similar, for the laws of physics that govern their behavior are the same, the new image is more exciting than before. For one, it is located in our neighborhood; and second, it was way too difficult to catch a glimpse of.

1. Schwarzschild radius: It is the size of the sphere from which even light will fail to escape. For supermassive M87* this is 18 billion km, four times the radius of our solar system! For Sgr A*, Schwarzschild radius is only 12 million km.

2. Relative size: Our black hole is 31 times wider than the Sun, as shown in the figure below. Whereas the black hole in Messier 87 is 27,000 times wider than the Sun. If Sgr A* was the size of a doughnut, then M87* would be the size of a football stadium.

3. Distance: Our neighborhood black hole Sagittarius A* is obviously closer, located 25,000 light years away from the earth. Whereas M87* is 55 million light years away! So if it took 1 hour to get to Sgr A*, then it would take 91 days to reach M87*.

Despite being closer, observing Sgr A* was more challenging than expected. Scientists had to look through the galactic plane and filter out the noise from intermediate stars and dust clouds in their data, collected across continents.

4. Mass: M87* is 6 billion times more massive than the Sun whereas Sgr A* weighs 4 million Suns. Thus, our black hole Sgr A* is 1500 lighter in comparison.

5. Speed: Around the black hole is a bright ring of materials that swirl at great velocities. The material disk of M87* rotates over a course of many days at roughly 1,000 km/s, while it takes only a few minutes for material to move around Sagittarius A* because it is much smaller.

Why is the picture of our black hole kind of blurry? One of the reasons is that we don't have a direct view of the object while sitting on one of the arms of the galaxy and secondly, its accretion disk is spinning very fast compared to M87* so it's like taking a picture of a toddler who cannot stand still.

Why You Should Read Physics of The Impossible

Do you happen to be a Doctor Who or a Star Trek fan? Have you ever wondered how force field, time travel, teleportation or invisibility could become a reality without breaking the laws of physics? If yes, then this book by Michio Kaku is a must for you!

Physics of the impossible discusses technologies of tomorrow by introducing topics of fundamental physics to the reader, such as relativity, uncertainty principle and how LASER works, etc. This book will help one grasp how physics is applied to the advancement of human civilization.

The guiding philosophy of the book is: If, in principle, something is possible, then it can be achieved. Like going to the moon was possible but only an engineering problem. In similar way, futuristic tech may only be an engineering solution away.

One can divide technology into three different classes of impossibilities, meaning how unlikely they are going to be, given our current understanding of physics.

• Class I impossibilities are "technologies that are impossible today, but that do not violate the known laws of physics."
• Class II impossibilities are “technologies that sit at the very edge of our understanding of the physical world."
• Class III impossibilities are “technologies that violate the known laws of physics but their development would mean a crucial shift in our understanding of physics!"

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The author of the book is renowned American theoretical physicist Michio Kaku who is known for his contributions to the string field theory. Physics of the impossible is primarily aimed for aspiring physicists, that is, undergraduate and graduate students; but engineers will also enjoy it maximum.

Why did Kaku decide to write a whole 350-pages book predicting the technology of tomorrow? Because, he's am ardent science fiction fan and strongly believes that what is impossible today, might be commonplace tomorrow.

For example: William Thomson Kelvin, a mathematical physicist and creator of the Kelvin scale had declared that “heavier than air” flying machines would be impossible.

Ernest Rutherford, the physicist who discovered nucleus of an atom and won the Nobel Prize always thought the idea of atom bomb was impossible and compared it to moonshine (a crazy thought).

Such technologies were considered impossible because the basic laws of physics and science were not understood as well at the time as they'd subsequently be.

Michio Kaku has shown in the book, with numerous examples, how scientists and technicians around the world are trying to realize technology of tomorrow...today...in their own individual laboratories.

There is also something for history fans in the book. Historical development of telepathy and artificial intelligence has been described in a manner that makes you want to keep on reading on. It gives you a sense of fulfilment to have learned what all has been done.

And as you unravel the secret of alien technologies (which you might only have seen on TV shows and movies so far) you will be inspired to join forces with scientists and engineers to harness the true power of nature.

The book Physics of the impossible will surely renew your confidence in the endless possibilities of physics. The phrase, "one of a kind" is well suited for such a book because not only it entertains you but also teaches a multitude of things about how science works.

7 Funny Quotes By Physicist Wolfgang Pauli

Wolfgang Pauli was one of the greatest physicists of the 20th century who played critical role in the development of quantum mechanics. He won the Nobel Prize in 1945 after being nominated by Albert Einstein for the discovery of exclusion principle.

Pauli was infamous for his supposed tendency to cause equipment failure whenever he was around. Stories like, his new car failed during a honeymoon without apparent reason, and a cyclotron at Princeton University burnt in 1950 in his presence.

Once at a reception party, his colleagues decided to parody the Pauli effect by deliberately dropping a chandelier upon Pauli's entrance. But to everyone's surprise, the chandelier stuck instead, becoming yet another example of the Pauli effect.

Hence, Pauli was a really mysterious person whose proximity was disliked by experimental physicists. In this post, let us delve into interesting anecdotes and funny quotes of Austrian physicist Wolfgang Pauli, the most legendary scientist of the past century.

Prophet Dirac

In the 1927 Solvay conference, Paul Dirac said: If we are honest, and scientists have to be, we must admit that religion is a jumble of false assertions, with no basis in reality. The very idea of God is a product of the human imagination.

Wolfgang Pauli had kept silent. When asked for his opinion, Pauli jokingly replied: Our friend Dirac has a religion of his own and its guiding principle is, "There is no God and Dirac is His prophet." Everybody burst into laughter, including Dirac and Heisenberg.

Dirac, Pauli

Elusive Neutrino

Pauli said in 1930: I have done a terrible thing. I have postulated a particle that cannot be detected. After proposing the existence of neutrino, an extremely light electrically neutral particle, that does not participate in the strong interaction and weak force is very short range, so it is very hard to find.

Trolling Heisenberg

Werner Heisenberg claimed to a journalist that Pauli and he had found a unified field theory, but just some technical details were missing. Pauli wrote in a letter, drawing a big rectangle, that "This is to show that I can paint like Titian. Only technical details are missing."

Bohr, Heisenberg, Pauli

Parity violation

If a system behaves in the mirror image as it normally would, it is said to respect parity symmetry. In 1956, Chinese American physicist Chien-Shiung Wu discovered parity violation, leading Pauli to comment: "I cannot believe God is a weak left-hander!"

Bad science

Wolfgang Pauli was known for his colorful objections to careless thinking. When a colleague showed Pauli his paper, Pauli said after reading: This paper is not only not right; it is not even wrong. The phrase caught on to describe bad science or statements that don't satisfy falsifiability.

Why so serious?

Wolfgang Pauli recalled this incident. A person observed that Pauli was strolling aimlessly in the streets of Copenhagen, and said: You look very unhappy. Pauli replied seriously: How can one look happy when he is thinking about the anomalous Zeeman effect?

Pieter Zeeman discovered in 1896 the splitting of a spectral line into several components in the presence of a static magnetic field. For this discovery, he was awarded Nobel Prize in 1902.

On knowledge

Wolfgang Pauli was of the belief that there is no limit to knowledge. However, as one goes deeply into learning a subject, the ambiguity also increases, since every new answer might open the door to a hundred new questions.

Pauli said: "The best that most of us can hope to achieve in physics is simply to misunderstand at a deeper level." This means that at least we have reached a deeper level to be amazed and confused by the result, so it's worth something.

10 Biopics on Scientists You Should Watch

Biopics are inspiring in ways that other genre of films simply aren't. For one, they capture the essence of a person's life journey. As a result, there is so much to learn from real experience. And two, biopics are a treat for history and cinema buffs.

Lately, science based biographical films are getting popular and obscure scientists are becoming mainstream. A recent news of Cillian Murphy roped in as Robert Oppenheimer for Christopher Nolan's next broke the internet, for example.

Science biopics are amazing as they demonstrate that there is always an unknown narrative behind every life decision made by the scientist. In this post, let us quickly go through 10 best biopics on scientists you should be watching.

Einstein and Eddington

Starring actors David Tennant and Andy Serkis as physicists Arthur Eddington and Albert Einstein respectively, this movie is set against the backdrop of the first World War.

Their collaboration (and friendship) was crucial not only to the birth of modern physics, but to the survival of science as the world prepared for the great war. The powerful climax is very special and is a treat for physics lovers.

The Theory of Everything

Based on a book by Jane Hawking, Travelling to Infinity: My Life with Stephen, it deals with Stephen's fight against the dreaded motor neuron disease and his relationship with his wife and his work at the Cambridge University. The film stars Eddie Redmayne and Felicity Jones in the lead roles.

The Imitation Game

This movie depicts story of English mathematician and computer scientist, Alan Turing, who builds a machine to crack the secret German enigma code during World War II. The name of the film is taken from Alan Turing's answer to the question, Can machines think?

Radioactive

This 2019 film starring Rosamund Pike as Marie Curie and Sam Riley as Pierre Curie was praised specifically for performance by Pike as a "sincere tribute" to the brilliance of Curie. It portrays Madame Curie's accomplishments, including two Nobel Prizes, and the sacrifices she made along the way.

Infinity

Based on the autobiography of Richard Feynman, What do you care what other people think? describing the role of his father in shaping his character and relationship with the love of his life, Arline, who died of tuberculosis. It stars Matthew Broderick as Feynman and Patricia Arquette as Arline Greenbaum.

October Sky

Released in 1999 starring Jake Gyllenhaal and Laura Dern, this is a film about a coal miner's son who wants to become a NASA engineer, against his father's wishes. This is true story of a former NASA engineer Homer Hickam who was inspired by Russia's Sputnik, a deeply motivational movie for growing minds.

Tesla (2020)

Starring Ethan Hawke, this biopic is an artsy one as it captures the life and struggle of brilliant but eccentric inventor Nikola Tesla. The movie covers Tesla's initial genius and later tall claims. A brave portrayal of Tesla, that how he was wrong on so many occasions, so Tesla fans might not enjoy. But a science student should give this movie a try.

Agora

Starring Rachel Weisz, this 2009 film covers the life of Hypatia, a mathematician and astronomer in the 4th century. She was among the first to investigate the flaws of Ptolemaic model and support the sun-centric system.

The movie also highlights how religion overpowered scientific endeavor in ancient Europe and how Hypatia desperately tries to save knowledge from the hands of religious dogma.

Hidden Figures

Inspiring story of three African American mathematician and engineers who worked at NASA during the space race between US and Russia in the 1960s. The film depicts how they have to deal with racial discrimination at work while launching successful space projects.

The man who knew infinity

This is a movie on exceptionally talented young Indian mathematician Srinivasa Ramanujan and his relationship with his teacher and friend, English mathematician G.H. Hardy. Performances by Dev Patel and Jeremy Irons were praised by audiences and critics alike.

Why You Should Read The Order of Time

The nature of time has always been a source of mystery for scientists and philosophers. There is no concise answer to the question, What is time? On one hand, time is a physical quantity that can be measured, say, by the movement of the Sun.

On the other hand, time may be described as the measure of entropy, what distinguishes the past from the future, as entropy tends to increase with time giving it a particular direction.

This 250-pages book by renowned Italian physicist Carlo Rovelli discusses the various aspects of time and is probably the most succinct book ever written on the nature of time.

That feeling of growing old, the distinction between the past and the future, is there a universal time, what may be the origin of time, is it possible to travel in time, or to exist outside of it, what would a world without time be like; questions of such nature have been answered in the book, The Order of Time.

Carlo Rovelli is the founder of loop quantum gravity, which competes with string theory as a candidate for the theory of everything. In his book, Rovelli has charmingly simplified his work in order to explain to us ordinary folks what time is.

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Rovelli has derived inspiration from anecdotes in his own life that elicit a bonding with the author; and thus Irish Times wrote: Physics has found its poet in Carlo Rovelli. It almost feels like Carlo is narrating an epic poem that he composed out of complex, theoretical physics.

The language used throughout the book is layperson friendly, subject matter is complimented by witty illustrations; all of this put together weave a beautiful picture of time in the manner such that you cannot put the book down but keep on reading on.

By the end, you may even wish to greet Carlo Rovelli in person and probably give him a warm grateful hug, because this is not just an ordinary physics book, his writing is like storytelling; there are ups and downs throughout the book, and much like in life it will make you cry on some pages and smile on other.

According to Ian Thomson from Observer, "Not since Stephen Hawking's A Brief History of Time has there been so genial an integration of physics and philosophy." Which is exactly the point but the difference though is that, while A Brief History of Time was a general guide to the universe with only one chapter dedicated to time, this book on the contrary is the complete package.

Benedict Cumberbatch, who is famous for having played characters like Sherlock, Doctor Strange, Hawking and Khan Noonien Singh, has recorded the audio version of the book in his iconic baritone voice. He said, "Time is something we think we know about instinctively; Rovelli shows how profoundly strange it really is!"

Source: Penguin

Carlo Rovelli has filled the gap of wanting to learn about time with his ground-breaking book. There are a great number of popular science books in the market but The order of time really stands out as it's likely the only book to teach about time in this much detail and friendliness.

Rovelli argues, that time is like an onion with many layers. To understand time, we must patiently uncover each layer one by one, so each chapter is devoted to that. When all the layers are gradually understood, the concept of time will no longer be the mystery that it is. But regardless of whether or not you are into physics, this book should definitely be on your list.

5 Life Lessons You Can Learn From Marie Curie

Marie Curie (1867-1934) was denied higher education in her native Poland for she was a woman. She had to attend a secret underground university but times changed and Marie emerged as one of the greatest scientists of the 20th century, winning two Nobel Prizes in a span of less than 10 years.

It was a period of very limited opportunities for women in all spheres, yet in an academic world that predominantly belonged to men, Curie made an everlasting mark. Following are five inspiring quotes by Madame Curie that each teach you a valuable lesson in life.

1. To her two daughters – Life is not easy for any of us. But what of that? We must have perseverance and above all confidence in ourselves. We must believe that we are gifted for something, and that this thing, at whatever cost, must be attained.

Irene and Eve grew up to be distinguished figures in their own fields. While Irene became famous for her scientific achievement, Eve worked for UNICEF providing help to mothers in the developing countries.

2. On curiosity – Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less. If I see anything vital around me it is precisely this spirit of adventure, which seems indestructible and is akin to curiosity, that guides me.

According to Madame Curie: We only fear that we do not yet understand. Curie was exposed to Radiation in her scientific investigation of elements. Later on, she was exposed to X-ray when she served as a medical doctor during the first World War.

3. On scientific beauty – I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale.

All my life the new sights of nature made me rejoice like a little child. So we should not allow it to be believed that all scientific progress can be reduced to mechanisms, machines, gearings; even though such machinery also has its beauty.

4. On usefulness of science – We must not forget that when radium was discovered no one knew that it would prove useful in hospitals. The work was one of pure science. And this is a proof that scientific work must not be considered from the point of view of the direct usefulness of it.

Apart from its medical application, Radium was increasingly used in industries such as timekeeping. The radium watch first produced in 1916 became a highly profitable commodity. However, Marie and her husband Pierre benefited little as they refused to patent their discovery of Radium.

5. On her wedding dress – I have no dress except the one I wear every day. If you are going to be kind enough to give me one, please let it be practical and dark so that I can put it on afterwards to go to the laboratory.

Marie and her husband Pierre came together through common love of science and research. They shared the Nobel Prize in 1903 in recognition of their extraordinary services to the study of radiation phenomena. For their honeymoon, Marie and Pierre took a bicycle tour around the French countryside in 1895.

One can know of her dedication to science by the fact that Curie survived on buttered bread and tea to be able to afford her education. Denied access in early years, she received her doctorate of science only at the age of 36. The way of progress is neither swift nor easy, Curie used to say.

Before her untimely death in 1934, Marie Curie founded the Radium Institute in 1932 as a specialized research institute and hospital. Hugely inspired by her drive and intellect, Albert Einstein said: Of all celebrated beings, Madame Curie is the only one whom fame has not corrupted.