![]() When it comes to scientists, one of the most recognized names in our world is that of Albert Einstein. Einstein, who won the Nobel Prize in Physics in 1921, is the creator of the theory of relativity which led to the prediction of amazing things such as deflection of light by gravity, gravitational lensing, black holes, gravitational waves, and the expanding universe, all of which have all been proven by many observations and experiments. Einstein ushered in a revolution in physics. He clearly was a genius, but in some aspects the way his mind worked was no different from that of any average human being. Deflection of Light Both Newton’s theory of gravitation and Einstein’s theory of relativity predicted that light would be deflected by a strong gravitational field, but Einstein’s theory predicted that light would be deflected by an amount roughly double of that predicted by Newton’s theory. In 1919 during a solar eclipse, it was observed that indeed light from stars close to the sun was deflected by an amount compatible with Einstein’s theory. This result, which made Einstein a worldwide sensation, has been verified with increasing accuracy many times since then. But what is less well known is that Einstein had originally made a calculation error which led him to find a deflection value no different from that predicted by Newton’s theory. This meant that the observation of the deflection of the light of stars by the sun would have disagreed with both theories. Thankfully, by the time the observation was made, Einstein had corrected his mistake, and the actual magnitude of the deflection agreed with his theory. Gravitational Lensing Einstein had figured out that, according to his theory of relativity, the strong magnetic field of a star could act as a lens and amplify the light of other distant stars behind it. But he realized the effect would be very small and fleeting, so did not deem it worthwhile publishing anything about it. However, in 1936 an amateur scientist named Rudi W. Mandl also figured out that this was one of the consequences of Einstein’s theory. He contacted Einstein who agreed the effect was indeed predicted by his theory and, after some pestering, consented to write an article about it. Einstein wrote the article acknowledging Mandl’s contribution, but stated in it that there is no chance of observing this phenomenon. At the time Einstein wrote this, he was thinking in terms of stars because the realization that there were distinct galaxies beyond our own was relatively new, and astronomers had not yet understood the real vastness of the universe. But astronomers eventually figured out that entire galaxies could act as gravitational lenses, and the first example of such a lens was discovered in 1979. Black Holes Another consequence of the theory of general relativity was the possibility of the existence of black holes, but Einstein was also dismissive of these entities, and he published an article in 1939 using his own theory to argue that black holes did not exist. In the decades after Einstein’s death in 1955, the evidence for the existence of black holes accrued until 2019 when a black hole was photographed for the first time. Gravitational Waves Einstein’s theory of relativity included the possibility of the existence of gravitational waves, but he confided to some colleagues that he was skeptical about their existence or the possibility that they would ever be detected. He followed this by another article where he specifically examined the math behind such waves, but in this article, as was pointed out to him by other scientists, he made a calculation error. Two years later, he published another article where he corrected his previous error and finally laid down the correct mathematical framework for describing gravitational waves. However, Einstein remained skeptical about the reality of such waves. Two decades later, in 1936, Einstein revisited the issue of gravitational waves in another article where he argued that the math really did not favor of the existence of such waves after all. He sent this article for publication in a science magazine, but the magazine sent the article to a reviewer who found a mistake in Einstein’s calculations. When Einstein redid the calculations, he found that the math did support the existence of gravitational waves after all! Still, the whole notion of the existence of gravitational waves was too outrageous for Einstein to accept. Untill the day of his death, he remained skeptical that these waves were anything but a mathematical construct, and even if they were real, he thought that they would be so faint that it would be impossible to detect them. The first gravitational waves were detected in 2015. Expansion of the Universe In 1917, Einstein wrote an article where he used his theory of general relativity to examine the universe. To his surprise, he found that the math indicated that the universe would expand forever. However, astronomical knowledge at the time indicated that the universe was supposed to be unchanging, so Einstein came up with a mathematical solution. He included a “cosmological constant” in the calculations, which prevented the universe from expanding forever. Other scientists challenged Einstein on this notion to the point that he conceded his original math without the constant was right, but he still doubted the reality of his conclusions. It was only after Edwin Hubble demonstrated in 1929 that the universe is indeed expanding that the prediction of Einstein’s theory were found to be right. The above reveals how one of the greatest minds that humanity has ever seen worked. Einstein made mistakes. He was unsure about the implications of his theory. He changed his mind several times. He doubted or dismissed the existence of some of the very things that he is credited with predicting, and he sometimes even lacked the vision to imagine future realities. This is how real science works and what real scientists are like. Science is messy. Scientists screw up. They vacillate, they change their minds, and sometimes they are unable to grasp the real consequences of the very things they propose. This IS normal, and is something that happens to everyone. But in the current poisoned climate where scientists on the “wrong” side of the culture wars are attacked for making mistakes, flip-flopping, or saying the wrong thing during an interview and so forth, one wonders if, for example, the discoveries that Einstein made would have been possible if he had been subjected to the scrutiny and slander that some scientists are subjected to nowadays. The photograph of Albert Einstein by Orren Jack Turner obtained from the Library of Congress is in the public domain because it was published in the United States between 1923 and 1963 and the copyright was not renewed.
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The universe is big, but this is the mother of all understatements. There are really no words to describe how mind bogglingly huge the universe is. It is beyond mammoth, cyclopean, gargantuan, colossal, titanic, monumental, and Brobdingnagian all put together. How immensely ginormous and humongously gigantic and vast the universe is may well be beyond the ability of our minds to understand. Consider that unit of measurement, the mile. The moon is 238,900 miles away from Earth, and we regard placing a man on the moon as one of the greatest technological feats in the history of humanity. But astronomers don’t use miles to measure distances in the universe, they use light years. The distance light travels in one year, a light year, is 5.88 trillion miles. So by this token, placing a man on the moon, which is 1.25 light seconds away from the Earth, doesn’t sound very impressive. However, it gets worse (much worse). Pluto, the furthest planet (yes, I maintain it’s a planet!) is 5.5 light hours away from Earth. The NASA New Horizons probe travelling at 36,400 miles per hour took 9.5 years to reach Pluto! Another probe, the Voyager 1 probe, is the furthest object that humanity has sent into space. Voyager 1 was launched 45 years ago in 1977, and is currently travelling at 35,000 miles per hour. The probe has so far covered 14.5 billion miles, which is 21.6 light hours. To put in perspective this “achievement”, just consider that the nearest star to Earth, Alpha Centauri is 4.24 light years away! But it gets worse (much, much, worse). Our sun is one of the stars in a spiral galaxy called the Milky Way. The Milky Way has several arms, and our sun is located in a minor arm of the galaxy about 28,000 light years from the galactic center. Within 12.5 light years of our sun, there are 33 stars. Within 250 light years of our sun, there are 260,000 stars. And within 5,000 light years of our sun, there are 600 million stars. All in all, the Milky Way galaxy contains a total of 200 billion stars and as many planets, and is roughly 100,000 light years across. The Milky Way, in turn, is surrounded by a number of the so call “dwarf galaxies” that orbit around it within a distance of 500,000 light years. Each of these dwarf galaxies contain only a few tens of millions of stars and take billions of years to orbit the Milky Way. Did I mention it gets much worse (much, much, much, worse)? Galaxies associate themselves into groups of galaxies. The Milky Way is part of a group of galaxies called the Local Group which is made up of the Milky Way and two other large galaxies, Andromeda and the Triangulum galaxy, along with their entourage of dwarf galaxies. The Local Group of galaxies spans a distance of 5 million light years and encompasses 80 galaxies and 700 billion stars. But it gets…yes, you got it. Groups of galaxies tend to associate into clusters of galaxies which in turn associate into superclusters of galaxies. The Local Group of galaxies is part of the Virgo Supercluster of galaxies which contains 100 galaxy groups and clusters. The Virgo Supercluster has a diameter of 110 million light years and harbors 200 trillion individual stars. But…you know the drill. The Virgo Supercluster is but a minor lobe of an even greater supercluster of galaxies known as the Laniakea Supercluster which is made up of about 100 superclusters of galaxies containing 250,000 trillion stars and which stretches over 500 million light years. Superclusters of galaxies in turn associate gravitationally with each other to form the largest known structures in the universe which are variously called galaxy filaments, walls, or sheets. These walls, filaments, and sheets are separated from each other by large voids of space with few galaxies which gives the observable universe a honeycomb appearance. The Laniakea Supercluster forms part of a galaxy filament called the Pisces–Cetus Supercluster Complex. This galaxy filament stretches 1 billion light years across space. To get a feeling for its size, just consider that the Virgo Supercluster, which contains the Local Group of galaxies, which includes the Milky Way Galaxy, which is where our sun is, represents only 0.1% of the total mass of the Pisces–Cetus Supercluster Complex! And the Pisces–Cetus Supercluster Complex is but one filament among tens of thousands. Astronomers calculate that the universe visible from Earth is comprised of 10 million superclusters of galaxies, which are made up of 25 billion galaxy groups, which harbor 350 billion large galaxies and 7 trillion dwarf galaxies, which all together contain a total of 30 billion trillion stars! The James Webb Space Telescope has been able to peer further back into the dark abysses of spacetime than any other telescope before it. The photo below covers an area of the universe equivalent to the area occupied by a grain of sand held at an arm’s length. There are galaxies here that are billions of light years away with the furthest one being a staggering 13.5 billion light years away. And even in this photograph there are faint smudges in the background that probably represent galaxies that cannot be resolved by the optics of the telescope! There are simply no units of measure or descriptors of size in our language that can help the human mind to comprehend the size of the universe. I think that in order to truly be able to grasp the sheer enormous immensity of the universe, we first have to lose our minds. So I will settle for crazy. The universe is crazy big! The image of galaxy cluster SMACS 0723 is by NASA and the Space Telescope Science Institute (STScI), and is in the public domain. |
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