10 Best Astrophysics Books For Students

10 best astronomy books astrophysics books for students

Books break the shackles of time... one glance at a book and you are inside the mind of another person, maybe somebody dead for thousands of years. A book is proof that humans are capable of working magic.

That is how astronomer Carl Sagan described his love of books in the popular TV show Cosmos: a personal voyage. As per him, a book allows reader to see back in time much like a telescope, binding together people who never knew each other, citizens of distant epochs.

In this post, let us take a look at 10 great astronomy and astrophysics books that every science student should read. These highly popular books were written by famous scientists of this generation, so without further ado...

Astrophysics for people in a hurry

An essential text on the subject by American astrophysicist Neil deGrasse Tyson – from the Big Bang to black holes, from quarks to quantum mechanics, and from the search for planets to the search for life in the universe.


A brief history of time

This classic book was written by Stephen Hawking for non-specialist readers with no prior knowledge of physics and astronomy. Hawking has touched upon his own research on black holes in the book as well for more experienced students.


The first three minutes

Written by Steven Weinberg, a Nobel laureate, this book describes what happened immediately after the big bang. Weinberg elaborately explains the evidence in support of the big bang theory and takes us back in time to the origin of the universe.


Cosmos

This book by astronomer Carl Sagan covers astronomy, physics, chemistry, biology, psychology and philosophy of the universe. In one sentence, it is amalgamation of the sciences in one book, a story of 15 billion years of cosmic evolution, science and civilization.


Special and general relativity

You can gain insights into the theory of relativity from its creator, Albert Einstein, by reading this book he authored in 1916. Einstein wrote this book for interested students who are not yet comfortable with the mathematical apparatus of theoretical physics.

A universe from nothing

This book by physicist Lawrence M. Krauss answers the deep philosophical question - why there is something rather than nothing? It is again a text that takes us back in time to the origin of the universe when there was practically none of space and time.

Dark matter and dark energy

This book by Brian Clegg is about the hidden 95% of the universe that astronomers have been confused by since the 1970s. It explores why the expansion of the universe is accelerating at a faster and faster rate and what causes it. This book is a treat for modern physics students.

The elegant universe

In this international bestseller, Brian Greene, one of the world's leading string theorists explains what the string theory is in layman's terms. He unravels the eleven hidden dimensions of the universe and introduces the superstring theory in this book.

Parallel worlds

This book by Michio Kaku covers M-theory and Everett interpretation (many worlds) of quantum mechanics. It also discusses creation of wormholes and hyperspace (a 11-dimensional wormhole) to enable humanity survive big freeze - end of the universe.

Black holes reith lectures

In 2016, Stephen Hawking delivered the Reith Lectures on a subject that fascinated him for decades - black holes. He argues that by understanding black holes we can unlock the secrets of space and time that make up the universe.

Why James Webb Telescope Is Better Than Hubble

james webb space telescope launch 22 december successor of Hubble telescope

The James Webb space telescope (JWST) is named after the longest serving NASA administrator and is the official successor to the Hubble space telescope. JWST is the costliest astronomy project having spent nearly three decades in the making.

The largest and the most powerful telescope in the world is scheduled to be launched in December 2021 after many delays since completion. The JWST will be able to look back in time closer to the Big Bang than ever before.

Comparison


JWST was built by NASA in collaboration with European Space Agency and Canadian Space Agency. It will explore the universe in the infrared region, something that Hubble space telescope is incapable of doing. The mirror size is 6.5 meters - three times the size on the Hubble telescope but it weighs half of Hubble.

Protection


To make observations in the infrared part of the electromagnetic spectrum, JWST must be kept under 50K or −223°C which is extremely cold. It uses a cryocooler and a large five-layer sunshield to block light and heat from the Sun, Earth and Moon to maintain a stable temperature.

Mission


The objectives of JWST include detecting clues to the origins of the universe, like observing infant galaxies and their evolution. As well as locating earth like planets outside the solar system and study the origins of life.
Hubble space telescope is capable of observing events that happened in space some 500 million years after the Big Bang, whereas Webb telescope can go back even further to around 100 million years after that event.

Instruments


JWST has a near infrared camera for observation of faint extrasolar planets very close to the bright stars. It also has a near infrared spectrograph capable of measuring spectrum of faint stars and galaxies. A fine guidance sensor helps the telescope stay pointed at whatever it is commanded to look at.

Challenges


It was scheduled to launch before but accidental tears in the delicate sunshield in 2018 delayed the project. Controversy also erupted over naming of the telescope as activists alleged that James Webb had discriminated against LGBTQ scientists during his term.

james webb telescope big bang hubble telescope

The mirror in JWST will be folded before launch. It is made up of 18 hexagonal segments - shaped so to join without gaps in between them. The mirror will unfold after the launch and it will take at least two weeks before the telescope becomes operational in orbit.

How it works


When picture of a galaxy is taken we see it the way it was millions of years ago because light takes time to travel. It is like finding a picture of a child dated from 1900 but if that child was still alive, they would be among the oldest people on the planet.

As the light travels, it becomes red-shifted due to expansion of the universe. So, objects at extreme distances are easier to see in the infrared. We can see these objects the way they were millions of years ago, that is, when that galaxy was fairly young.
JWST's infrared capabilities will allow humans to see back in time to the first galaxies for the first time. Infrared astronomy will also help us to learn how stars and galaxies have evolved over time. By overcoming all the challenges, JWST is set to launch in December 2021.

10 Engineers Who Won Nobel Prize In Physics

top 10 engineers who won nobel prize in physics

It is not surprising that there are many engineers whose first passion is physics (or mathematics). However, under unavoidable circumstances, they end up doing engineering instead. For example: did you know that Paul Dirac's father wanted him to become an electrical engineer?

After graduating, Dirac was without job. He decided to shift his attention to his first love-physics and the rest is history. Today we know Dirac as one of the founders of quantum mechanics. So, even if you might be clueless in life right now, your passion will find you in the end.

John Bardeen

Bardeen is the only person in history to have won two Nobel Prizes in physics. He received his bachelor and master degrees in electrical engineering in 1928 and 1929 respectively from the University of Wisconsin-Madison.

At first, John was employed by Gulf Oil corporation where he worked for four years. But he switched career by enrolling at Princeton University in 1933 to obtain a degree in mathematical physics. John went on to win Nobel Prizes in 1956 and 1972.

Henri Becquerel

top 10 engineers who won nobel prize in physics

Henri Becquerel was born into a family which produced four generations of physicists. He specialized in civil engineering at one of the most prestigious institutions in France. Becquerel was appointed as chief engineer at the Department of Bridges and Highways in 1894.

Around the same time he was investigating the properties of chemical elements. In 1896, he stumbled upon a new phenomenon that was named radioactivity by Madame Curie. The 1903 Nobel Prize in physics was awarded to Becquerel and the Curies.

Wilhelm Röntgen

Röntgen was a student of mechanical engineering at ETH Zurich. He was a contemporary of Becquerel... in fact, their ground-breaking discoveries were apart by only a few months. In 1895, Wilhelm produced very high energy waves called the x-rays, an achievement that earned him the inaugural Nobel Prize in 1901.


Eugene Wigner

Eugene Wigner was a Hungarian-American theoretical physicist who won the Nobel Prize in physics in 1963 for contributions he made to nuclear physics, including the formulation of the law of conservation of parity.

Wigner enrolled at the Budapest University of Technical Sciences in 1920 but he was unhappy there and decided to drop out. In 1921, as guided by his parents, he joined the Technical University of Berlin where he studied chemical engineering.

Wigner accepted this offer because he was able to attend weekly conferences of the German Physical Society that hosted leading physicists of the time including Max Planck, Werner Heisenberg and Albert Einstein.

Paul Dirac

As mentioned before, Dirac studied electrical engineering at the University of Bristol. He graduated in 1921 but despite having a first class honors in engineering, he was unable to find work as an engineer in the post-war Britain.

top 10 engineers who won nobel prize in physics

Dirac again enrolled for a bachelor degree, this time in mathematics at the University of Bristol. He was allowed to skip a year as well as study free of charge because he was an exceptional student during his engineering years.


In 1923, Dirac once again graduated with a first class honors. Several years later, he became part of the quantum revolution that engulfed Europe. In 1928, Dirac predicted the antimatter which was discovered within few years by Carl Anderson in America.

Dennis Gabor

Dennis Gabor was a Hungarian-British electrical engineer and physicist who won the Nobel Prize in physics in 1971 for the invention of Holography, a technique he created in 1948 to create photographic recording of a light field.

Jack Kilby

Kilby was an American electrical engineer who was one of the inventors of the integrated circuit, for which he won the Nobel Prize in 2000. Jack also invented hand-held calculator and thermal printer. He had completed bachelor and master degrees in engineering in 1947 and 1950 respectively.

Simon van der Meer

Dutch scientist Van der Meer was born in a family of teachers. He received an engineer's degree in 1952 from Delft University of Technology, which is the largest public university in the Netherlands. Simon joined CERN in 1956 and remained there until his retirement in 1990.

top 10 engineers who won nobel prize in physics

In 1984, he shared the Nobel Prize in physics with Italian physicist Carlo Rubbia for contributions to various projects at CERN that led to the discovery of the W and Z particles, which play a role in the weak nuclear force.

Shuji Nakamura

Nakamura was a Japanese-American electronics engineer who holds over 100 patents. He won the Nobel Prize in 2014 for the creation of blue laser diodes in the early 1990s that were later on used in the HD-DVD and blue-ray technologies.

Shuji Nakamura obtained his bachelor and master degrees in electronics engineering from the University of Tokushima in 1977 and 1979 respectively. Nakamura was also awarded a D.Eng. degree from the University of Tokushima in 1994.

Ivar Giaever

Ivar Giaever is a Norwegian-American engineer who shared the 1973 Nobel Prize in physics with Esaki and Josephson for their discoveries regarding electron tunneling. Giaever had earned a bachelor degree in mechanical engineering from the Norwegian Institute of Technology in 1952.

5 Discoveries at CERN That Changed The World

discoveries by CERN that changed the world

More than 12,000 scientists from 110 nationalities work at CERN whose discoveries shape the future of technology and advance our understanding of the universe. Founded in 1954, the facilities at CERN include one of the largest and most advanced particle accelerators in the world.

Higgs Boson


The 2012 detection of Higgs Boson was groundbreaking for two reasons. Firstly, the elusive particle was postulated in 1964, almost five decades prior to discovery. Its search required big budget and collaboration of many countries.

Secondly, because the Higgs Boson explains as to how fundamental particles such as electrons and quarks have mass. Due to its pervasive nature, Higgs particle was termed the God Particle by several scientists. However, Peter Higgs himself didn't endorse the name.

World Wide Web


It was physicist Tim Berners-Lee who developed the concept of hypertext at CERN in 1989. Many engineers including Robert Cailliau chipped in and the first website was ready by 1991, as a tool to allow scientists to share information.

The world wide web was made freely available to the world in 1993 so that anyone anywhere could connect to the internet. Not only www, the scientists at CERN have also helped develop technologies like PET scans, which is used to detect cancers.

Antimatter


Antimatter was theoretically described by physicist Paul Dirac in 1928. Creation of antimatter could shed light on why almost everything in the known universe consists of matter.

In 1995, scientists at CERN successfully created a stable antihydrogen for the first time. In 2002 they produced antihydrogen atoms in large quantities, but for an incredibly short lifespan, just several milliseconds.

In 2011, scientists were able to maintain antihydrogen atoms for more than 15 minutes, a historic feat. This will allow them to conduct a more detailed study of the antimatter and to create stable antimolecules soon.

Weak Neutral Current


Weak neutral current, a prediction of electroweak theory, is how subatomic particles interact with one another using the weak force. Here, the word current only implies the exchange of Z particle and has nothing to do with electrical current.

In 1973, weak neutral currents were detected by CERN in a neutrino experiment and confirmed the electroweak unification theory by Salam, Glashow and Weinberg who were recognized by the Nobel Prize in 1979.

New State of Matter


In the 1970s and early 1980s, cosmologists theorized the conditions immediately after the Big Bang. They predicted the existence of a new state of matter, a quark-gluon plasma in which quarks, instead of being bound up into protons and neutrons, are liberated to roam freely.
One of the objectives at CERN is to mimic those early universe conditions. In doing so, detection of quark gluon plasma was confirmed in 2000. The then director general of CERN called it an important step forward in the understanding of the early evolution of the universe.

Summing up


You will be surprised to know that of all the people working at CERN, only 3% are physicists. They employ technicians, engineers, IT specialists, writers, etc. who not only aid the advancement of physics but also help change the world by innovating medical, computing and aerospace technologies.

10 Famous Physicists Who Played Chess

famous nobel prize winning physicists who played chess

Chess is a tactical board game that is enjoyed by professionals and hobbyists all over the world. It is well known that chess playing not only develops concentration but also improves memory. In this post, let us look at ten physicists who enjoyed the game of Chess.

Paul Dirac


Growing up, Dirac played Chess on the Sundays with his father. He learned it quickly and went on to become the president of chess club of St. John’s College, Cambridge. Paul Dirac also played chess with the Nobel Prize winning physicist friend Pyotr Kapitsa.

nobel prize winning physicists who played chess

Roger Penrose


He won the Nobel Prize for physics in 2020 for the work done on black hole singularities. His brother is the chess Grandmaster Jonathan Penrose. Their love for chess emerged thanks to their father Lionel Penrose who was a geneticist, mathematician and chess theorist.


Stephen Hawking


Hawking played chess just for fun with his youngest child, Timothy.

famous physicists who played chess
picture credit: pinterest

Albert Einstein


The renowned physicist was friends with German chess player and world champion Emanuel Lasker. In 1933, Oppenheimer played against Einstein in Princeton, USA and lost by resignation. Einstein was a good player but played very little chess.

Richard Feynman


American physicist Richard Feynman was drawn to chess in the high school. He was particularly interested in observing the chess gameplay. In one interview, Feynman said, in regards to physics: The gods are playing a great game of chess and the scientists are merely observers trying to figure out the rules of the game.


Werner Heisenberg


As a young boy, Heisenberg spent his free time in the evenings playing chess against neighborhood friends. His love of the game grew and became intolerable for teachers and professors. Especially Arnold Sommerfeld, Heisenberg's doctoral advisor, forbade him to play chess.

Edward Teller


Hungarian physicist Edward Teller learned to play chess from his father at the age of 6. Like his doctoral advisor Werner Heisenberg, Teller was also an avid chess player. Unfortunately, he could never beat Heisenberg at chess, though he was able to defeat Heisenberg in table tennis.

famous physicists who played chess
picture: ESVA

William Henry Bragg


He won the Nobel Prize in physics along with his son for their work in the analysis of crystal structure using X-rays. He was the secretary of the Adelaide University Chess Association.

Erwin Schrödinger


Erwin Schrödinger shared the 1933 Nobel Prize in physics with Paul Dirac. He once wrote "I do like chess, but it has turned out to be not the appropriate relaxation from the work I am doing."

Max Planck


German physicist Max Planck, who proposed the quantum theory, played chess with the world chess champion and mathematician Emmanuel Lasker.

Climate Scientists Win Nobel Prize In Physics

climate science physics nobel prize 2021 georgio parisi syukuro manabe klauss hasselmann

In 2020, mathematician Roger Penrose was bestowed upon the most prestigious honor in science along with Andrea Ghez, who became only the fourth woman laureate in physics and Reinhard Genzel of the Max Planck Institute, for furthering our understanding of the black holes.

This year, the Nobel Prize foundation has again elected three joint winners. One half of the Nobel prize to climate scientists Syukuro Manabe of U.S.A and Klaus Hasselmann of Germany and the other half to Italian physicist Georgio Parisi.


We have all read about the global warming in our school textbooks, that humans are influencing the climate and the earth's temperature by burning fossil fuels. But how did the scientific community arrive at that conclusion in the first place?

The answer is, works of notable scientists like Syukuro Manabe, who is a senior meteorologist at the Princeton University, have helped establish humanity's increasing role in much of everything that is gone wrong with this planet.

Starting in the 1960s, Manabe pioneered the use of computers to simulate climate change. He demonstrated in 1970 that increase in the amount of carbon dioxide levels will rise global temperatures by 0.57°C by 2000. He was spot on as the earth had warmed by 0.54°C.

Klaus Hasselmann, leading oceanographer in Germany and the then director of the Max-Planck-Institute of Meteorology, also arrived at the same conclusion. He showed that despite short term weather fluctuations, climate models are reliable in long term.

Their studies further revealed that the global temperature is projected to increase by an additional 2°C – 3°C during the 21st century. So, we may take climate change lightly today but in the future its dangers will be observable in day to day life as the scientists have warned.

The third winner is Geogio Parisi whose research areas include statistical mechanics and complex systems. He has developed a mathematical model in order to understand complex systems such as the earth's global climate, the human brain and ultimately the entire universe.

Did you know that total 115 Nobel prizes in physics have been awarded since 1901? The winners this year include some of the oldest awardees. Manabe and Hasselmann are 90 and 89 respectively, while Parisi is relatively younger at 73 years.

Their recognition by the Nobel Prize committee shows that our knowledge about the climate change is built upon strong scientific foundations. Thus, no matter how much the politicians, the industrialists or the others deny climate change, it is happening at every moment.

After the announcement, Giorgio Parisi said in relation to climate change: “It is very urgent that we take strong decisions and move at a very strong pace. It is clear for future generations that we have to act now to tackle the climate change."

How to become a physicist like Isaac Newton?

how to become physicist like isaac newton

Did you know that Isaac Newton's mother wanted him to become a farmer? He was 16 at the time and busied himself by building model windmills and sundials to take his mind off farming, an occupation he hated.

Was Newton a child prodigy? Well, his teachers did think so and he invented calculus by the age of 22, so the answer to that question might be yes. However, one can imbibe Newton's three qualities as a teenager to become a physicist like him...

Curiosity


Newton was way more inquisitive than his schoolmates. He always wanted to get to the bottom of things and never gave up before quenching his curiosity. This would sometimes cause him to end up alone though.

It was one summer afternoon that he was resting in the shade of an apple tree in their farm. It is said that a fall of an apple encouraged Newton to investigate the force of gravity. Was this the first time that things fell to the ground?

No. Millions saw the apple fall before Newton, but nobody ever bothered to ask why it did. This questioning attitude is the hallmark of a physicist or any scientist for that matter.
There might not be immediate answers to most your questions. However, when all other people give up chasing them the scientist continues to dig deeper – it's a game after all. As Feynman said: There is a pleasure in finding things out.

Experiment


How to feed curiosity? By experimenting. Experiments come in two kinds: theoretical or practical. And Newton was well versed in both. That is why, he not only invented something as complicated as calculus but also Newton's disc, as shown below:

how to become physicist like isaac newton disc

Once again the idea was inspired by nature itself. Newton was mesmerized whenever he saw the rainbow over his house in Woolsthorpe. This led him to questions about the behavior of light which he investigated with glass objects.

After completing experiments, Newton illustrated his findings with a color circle, popularly known as Newton's disc, in 1704. He divided the circle into component colors and it would appear white when spun really fast.

Approach


Newton was a keen observer of things so he carried around pocket notebooks to record any interesting activities of the day. After he obtained his BA degree in 1665 the university shut operations due to the ongoing plague.

He returned to his village and revisited the notes from his university days. It was there and then in Woolsthorpe that private studies of his notes would lead him to discover the binomial theorem which in turn gave rise to calculus later.

Newton also had recorded life and work of notable previous philosophers such as Descartes, Kepler and Galileo. Hence, his most famous saying: If I have seen further it is by standing on the shoulders of giants.

Newton took great pleasure in writing or drawing things down. Taking notes would ensure that he wouldn't miss any good ideas. For example, the following is an original drawing of Newton's reflecting telescope:

how to become physicist like isaac newton

Newton would spend most of his time alone, thinking. He would completely engulf himself in the process of ideation. Much of the human civilization today is built upon Newton's ideas and drawings. We enjoy our lives at his expense.

Summing up


Sure one has to go through college and rigorous training in order to become a professional physicist. But we can learn from Newton that ideas are lying around everywhere, waiting to be noted down and drawn.

He famously said: To myself I am only a child playing on the beach, while vast oceans of truth lie undiscovered before me. So, let's mimic Newton's infinite curiosity, adopt his approach and do experiment in the backyard. For who knows what is possible?

5 Applications of Dimensional Analysis

applications of dimensional analysis physics engineering

The concept of dimensional analysis was introduced by French mathematician Joseph Fourier in 1822. It is a useful method in physics and engineering to identify the relationships between various physical quantities by analyzing their base quantities.

There are seven base or fundamental quantities of primary importance in physics. The rest of all the physical quantities are derived, that is, written in terms of the following base quantities:

  1. Mass (M)
  2. Length (L)
  3. Time (T)
  4. Temperature (K)
  5. Electric current (A)
  6. Amount of substance (Mol)
  7. Luminous intensity (Cd)
Others are derived quantities, for example: Speed is distance upon time, where distance is a type of length. So, the dimension of speed in terms of base quantities is [L][T]-1

1. Find dimension of unknown quantity


Example: To increase the temperature of a substance by Î”T, heat required is given by Q=mSΔT where m is mass and S is specific heat capacity of the substance. We can find the dimension of S by doing simple algebra.

S=Q/mΔT

S=[M L2 T-2]/[M][K]

S=[L2 T-2 K-1]

Since heat (Q) is a type of energy we have used the dimension of energy [M L2 T-2]. Knowing the dimensional dependence is useful while performing experiment in laboratory.

2. Find unit of physical quantity


Example: The dimension of force is [M L T-2]. Therefore, the unit of force in the standard MKS system is kg.m.s-2 corresponding to the base quantities used. Likewise, the unit of force in the French CGS system is g.cm.s-2

3. To check correctness of formula


In an equation, the left hand side should match the dimensions on the right hand side. That's because, you can't have apples on one side and oranges on the other. This is useful in multiple choice questions as it helps in eliminating the wrong options.

Example: Is force F=mv2/r correct? where m is mass, v is velocity and r is radius. To find out, we start by writing the dimensions on both sides.

[M L T-2] = [M][LT-1]2/[L]

[M L T-2] = [M][L2T-2][L-1]

∴ [M L T-2] = [M][L][T-2]

The formula is correct. In fact, it is the centripetal force if you might recall, which acts upon a body directed towards a fixed center, thus keeping it in orbit.

4. To roughly derive formula


Example: Suppose that the time period of a simple pendulum is dependent on mass of the bob, length of the string and gravitational acceleration due to earth.

time period of simple pendulum dimensional analysis applications physics

Let's assume that the time period is proportional to some powers of mass, length and gravity: t∝malbgc

To find the formula of time period, we must obtain values for a, b and c. We start by writing the dimensions on both sides.

[M]0[L]0[T] = (constant)[M]a[L]b[LT-2]c

The dimension of constant is 1. So,

[M]0[L]0[T] = [M]a[L]b[LT-2]c

Comparing the exponents on both sides, we get:

a=0, b+c=0 and -2c=1

On solving we obtain values of a=0, b=1/2 and c=-1/2. Now, putting back in the original equation t∝malbg gives:

∝ m0l1/2g-1/2

t=(constant) l1/2g-1/2

Thus, time period of a simple pendulum is independent of mass of the bob. This is because, physically speaking, mass is both the cause of swinging motion and the resistance to swinging motion, so it cancels out.

5. To express in new base quantities


This type of questions can come up in competitive exams like the JEE-Main. Example: If pressure, velocity and time are taken as base quantities, then what would be the dimension of force?

Let's start by assuming powers

Force = Pavbtc

And write dimensions on both sides

[M L T-2] = [ML-1T-2]a[LT-1]b[T]c

[M L T-2] = [M]a[L]-a+b[T]-2a-b+c

Comparing powers on both sides

a=1, -a+b=1 ⇒ b=2 and -2a-b+c=-2 ⇒ c=2

∴ Force = Pv2t2

How Antimatter Was Discovered By Carl Anderson

positron antimatter carl anderson paul dirac

British physicist Paul Dirac showed in 1928 that every particle in the universe should have an antiparticle with the same mass as its twin, but with the opposite electrical charge. Across the pond, an American physicist would detect the first such particle, four years later.

Carl Anderson, inspired by the work of his Caltech classmate, Chung-Yao Chao, set up an experiment to investigate cosmic rays under the supervision of physicist Robert Millikan. In 1932, he won the Nobel Prize in physics at the age of 31, becoming one of the youngest recipients.

Discovering the positron was no easy feat but the mechanism he employed to do so was fairly simple and ingenious enough to overcome the limited budget. He found the mysterious particle almost by accident with the help of his own improved version of the cloud chamber.

A cloud chamber is a sealed box with water vapor. When a charged particle goes through it, the vapour is ionized and leaves behind a trail. Thus, the trajectory of the particle can be seen virtually. Carl used a mixture of water and alcohol to get clearer photographs.

carl anderson cloud chamber positron antimatter paul dirac

Carl included a Lead plate in the middle to slow down the particles and surrounded the chamber with a large electromagnet, which caused the paths of ionizing particles to curve under the influence of magnetic field.

As can be seen in the picture, the radius of curvature of the track above the plate is smaller than that below. Thus, the particle entered from the bottom, hit the Lead plate and came to a halt above it due to loss of energy. This and the direction in which the path curved helped in identifying that the charge was positive.

That it was antielectron and not proton was determined by the observation that the upper track was much longer in length than predicted for proton. A proton would have come to rest in a much shorter distance, since it is heavier. The trajectory observed was that of a particle much much lighter than the proton.

So, that's how the first antimatter was found and Dirac was proven right within a matter of few years. Furthermore, antiproton and antineutron were discovered in 1955 and 1956 respectively. The first antiatom was produced by CERN in 1996.

Why antimatter is important? Because, studies related to antimatter will help in our understanding of the early universe. Also, Positron emission tomography or PET scan is used to detect early signs of cancer. Scientists hope that some day, antimatter may be used for the treatment of cancer. Who knows!?
© 2019-2022
made with by vedang