Stephen Hawking, 1942-2018

From the small town of Cambridge in England on Wednesday, March 14, 2018, came the sad news that was not really surprising but still stunned. The great physicist Stephen William Hawking passed away that day. He died calmly at his residence just two months after celebrating his 76th birthday. His health condition is getting worse in the last month.

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Soon the world wept for him. Hawking is not just a physicist. He is a legend. He passed away after more than half a century received a death sentence as ALS tragic. This is an acronym of Amyotrophic Lateral Sclerosis, a rare non-contagious disease with unknown causes that attacks the nervous system of the sufferer, causing muscle-related tissue to be immobilized and ultimately shrinking. Attacks always start from the peripheral nervous system, such as the fingers, feet, and hands and then progressively progress. Or to quote the words Premana Premadi, Indonesian female astronomer who is also ALS survivor, the attack of this disease slowly but surely make the nerve tissue in the spine sufferers become critical.

ALS is slowly paralyzing one by one organ sufferers. Gripping steadily until eventually the neural network of heart and lung control will be affected. The disease is more popularly known as Lou Gehrig's disease, as a posthumous honor to a legendary baseball athlete in the United States and is infected with the disease in the wake of World War 2.

The Theory of Everything film illustrates how Hawking was sentenced to this ALS illness. Her legs and hands begin to weaken and eventually as stiff as a board. Easy to fall even without any obstructions on his feet. The vocal cords start to strike so that Hawking's voice starts to break and hard to hear. The esophagus is also so, making it easy to choke and difficult to drink. And this choking business can be dangerous. This film and one of the neighbors who also suffered from a similar illness gave me a complete picture of ALS disease.

But Hawking is an anomaly for ALS disease. Diagnosed in 1964 at the age of 22 years, doctors sentenced him will not last more than 2 years. Statistically, the life expectancy of an ALS sufferer does not exceed 5 years since the diagnosis is established. But Hawking still survived until decades later. I do not know why. Decades later in an interview, Hawking said his hopes had plummeted to zero since the age of 22. What happens afterward is a bonus.

Bonus for him and also for human civilization. Because in the midst of the gloom, in the midst of physical condition that continues to weaken to paralyze and eliminate the ability to speak, Hawking still learn and work, trying to uncover the secrets and workings of the universe. The will of the steel is sweet. Nobody thought that a year later this half-paralyzed half-paralyzed figure eventually occupied the seat of Master's profession of mathematics for prestigious mathematics, at the Department of Applied Mathematics and Theoretical Physics at Cambridge's famous University. Three centuries earlier the seat was occupied by Isaac Newton, one of the giants in physics and the door opener to the world of large-scale structures of the universe. And three-quarters of a century earlier, the same seat had been occupied by Paul Dirac, another giant who grasped the micro-scale structure of the universe.

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Hawking died on the same date as the birth of another great legendary physicist, Albert Einstein. A coincidence? I do not know. But there are instances where great physicists seem to have an important moment in their life that crosses the same unit of time between each other. When Galileo Galilei died in 1642 while under house arrest for the Roman Inquisition, the same year a Isaac Newton was born in Great Britain. Later Newton not only fully supported Galileo's conclusions, but also expanded them to a level never imagined by mankind in his time. To this day the world continues to indebted to Newton through its classical mechanics that is able to explain the dynamics of the movement of our cars and motorcycles, our ships, our airplanes and the performance of our industrial machines.

Hawking and Einstein are the two great physicist figures who became the window of science in the 20th century. They are the face for the world of science, a lonely world that is sometimes scorned as ivory towers on the stretch of civilization. They are figures of scientists transformed from laboratory environments or theoretical work to lectures and world multimedia platforms with tremendous penetration power.

Hawking is not as glamorous as Einstein. Though his collection of awards is no less mountainous (including the English noble he politely rejected), Hawking never scooped Nobel Physics as Einstein. However, like it or not, through Hawking is the generation of the 20th century, especially generation X and generation Y, understand the world and the workings of the universe both in macro and micro scale. Hawking is also a figure who inspires science communication, specializing in conveying the work of scientists from behind the walls of his laboratory to the wider world in popular, visual and understandable languages.

The traces of Hawking's work in physics are exploring the symptoms of general relativity from Einstein. In this case Hawking's name is synonymous with black holes, exotic celestial bodies that up to half a century ago are still very faint and occupy the borders there and no. Hypotheses about black holes have been pioneered and built since before the outbreak of World War 2. Among others, by Robert Oppenheimer, a figure of genius who later gave birth to the nuclear age through his leadership in The Manhattan Project during the war.

The black hole is described as a small, very large sky body mass, creating a massive curvature of space-time around it in the perspective of general relativity. So great is its curvature that it becomes asymptotic, a bottomless well. As a result any material that goes into it will never escape. Including light beam though, the highest-speed object in the universe. So there is no way to prove its existence directly.

Such exotic celestial bodies are the product of massive mass evolution (mass more than 20 times our Sun). When the massive star runs out of its fusion fuel at the end of its life, the balance that governs its dimensions has been messy. The radiation pressure disappears so that the massive star can not resist the force of its own gravity. He began to shrink and culminate in the cosmic explosion of nan gigantik that spewed most of the material into the environment. But the core of the massive star is still left, with a mass more than 4 times the Sun, and continues to shrink by its own gravity. The nuclei of the atoms in the former massive mass cores are squeezed so violently that they are torn into elementary particles like quarks.

Hawking sees this kind of black hole hypothesis as having problems. There is a law of thermodynamics that is violated. In order to remain obeyed, he proposes that black holes should be detected directly. In other words there is a flow of information through the flow of energetic (high-energy) particles derived from black holes (especially the rotating black lubng). Although black holes can not escape any material and energy, quantum mechanics, through the principle of uncertainty, permits the situation. This is what became known as Hawking radiation. The radiation of Hawking, on paper, can actually reduce the mass of black holes following Einstein's equation of mass and energy E = mc2. Hawking calls it evaporation (evaporation) black hole. The smaller the mass of a black hole, the faster it evaporates.

Now the most advanced astronomy research institutions are actively detecting the presence or absence of Hawking radiation. Including NASA, through the operation of the Fermi space-telescope telescope that worked on the spectrum of gamma rays since 2008 ago. So far the results have not been satisfactory. But I see it is only a matter of time before Hawking radiation is actually found. For comparison, we have to wait for a century from the idea of ​​gravitational waves Einstein proposed until his invention through the observatory of gravity waves LIGO and Virgo on September 14, 2015 ago.

On the other hand, through its indirect symptoms through the circulation of stars around the galactic nucleus, the existence of hot burning discs and bursts of polarized material in a particular direction, the black hole is truly present in the universe. Very impressively, the first detection of gravitational waves also comes from the black-hole solah, precisely a pair of black holes (each with a mass of 36 and 29 times our Sun) that merges into the cosmic dance at a distance of 1.4 billion light-years from us.

The black hole became one of the interesting topics Hawking discussed in his magnum opus: A Brief History of Time. It's one of the best-selling science books of its time and has sold over 10 million copies in total. The book that has been translated also as the History of the Kala is a book that overshadows my high school years. Start reading it since grade 1 high school (now called class 10), with a mediocre brain capacity I was able to understand Hawking's exposure after graduation. Although this book, like Hawking's pledge, is written in full narration without any mathematical equations except E = mc².

In his book Hawking describes elegantly about general relativity and how it is tested. One of them (which is quite impressive) is the observation of stars that appear to be near the Sun in the event of Total Solar Eclipse. General relativity proposes that every light beam passing near the Sun will be deflected in such a way as to have no choice but to travel around the curved space-time around the Sun. When I watched the Total Solar Eclipse March 16, 2016 ago, I was overcome by the sensation of the starlight's deflection and in the performance of the universe. The sensations are also felt by colleagues in other observations and armed with the latest instrument, which brilliantly shows the light is indeed passing curved around the Sun as a massive celestial body large enough.

But not only galaxies and stars, Hawking also describes the micro-scale structure of the universe with a beautiful. It invites us into a world smaller than dust grains, into the atomic and subatomic worlds. How matter can be subdivided continues until it reaches its base, a substantive brick called a molecule. How the molecules can be split again into atoms. How the atoms can be split again into electrons, protons and neutrons. Until finally how they can be split back to produce ultimate bricks can be revealed, in the form of electrons, quarkas and gluons. The magical world, controlled by quantum mechanics, and contains a number of symptoms that often seem absurd. For example the uncertainty principle of Heisenberg, which makes the world according to quantum mechanics is not as smooth as the world in the view of general relativity.

Hawking also describes one of the greatest challenges of science, especially physics at this time is the unification of two different levels: quantum mechanics and general relativity. Classical mechanics or Newtonian mechanics can be identified with general relativity because they rely on the interaction of gravity, the difference being one of them only at the speed of the object. Until the second half of the 20th century, the universe (in physics view) was formed by four different interactions. Each of these gravitational interactions, electromagnetic interactions, strong nuclear interactions and weak nuclear interactions. In addition to gravity interactions, the other three interactions become the scope of quantum mechanics.

Unification attempts have been made. For example on the electromagnet interaction itself, which is a unification of the electrical interaction and magnetic interaction. This unification pioneered James Clerk Maxwell in 1879, the year of Einstein's birth, as well as the foundation of the development of relativity. A century later, in the decade of 1960s, other unification efforts by Abdus Salam, Steven Weinberg and Sheldon Glashow to fruition. Namely between the interaction of electromagnets with weak interactions that produce electrolemah interaction. Electrolysis interactions can only occur when photons (as particles of electromagnetic force carriers) and W bosons and Z bosons (as weak carrier particles) have very high energy, at least 246 Giga elektonvolt. That energy is correlated with the temperature of the universe of at least 1,000 trillion degrees Celsius, the temperature level that only occurred in 13.7 billion years ago. Or rather shortly after the birth of our universe.