By Kirthi Tennakone –
Prof. Kirthi Tennakone
Black holes are no longer curious imaginations fitting into realm of science fiction. This year Physics Nobel Prize was awarded to the mathematical physicist Roger Penrose and two astronomers Reinhard Genzel and Andrea Ghez for demonstrating the reality of black holes as objects existing in the universe. Fascinating black holes needed convincing evidence to prove their existence
Nobel prizes are awarded for extraordinary breakthroughs in science – after strict scrutiny of the validity of the finding to satisfaction of the peers and the Nobel Committee.
Science require irrefutable evidence. Even if one is a genius, his or her finding will not be accepted as truth, unless proven right – very different from other human affairs where people endorse hearsay, traditions and ideologies without questioning.
Black hole scientists who won 2020 physics Nobel Prize (Roger Penrose, Reinhard Genzel, Andrea Ghez)
Verification of Einstein’s Theory
In 1915 Albert Einstein formulated his famous theory of general relativity. It is an elegantly consistent theory successful in removing a major discrepancy in our understanding of gravitation – the force determining the large scale structure of the universe and its origin. Theory challenged the conceptual basis of Sir Isaac Newton’s mechanics, predicting new phenomena.
According to Einstein’s new theory, light, just like materials objects has to be attracted by the sun and other massive bodies. Einstein suggested, the predicted effect could be tested during a total eclipse of the sun as an apparent change in the position of a star shining close proximity to the solar disc.
To test Einstein’s assertion, the renowned English astronomer Arthur Eddington conducted observations in the island of Principe near west coast of Africa at the time of the total solar eclipse 29th May 1919. After a quick analysis of results obtained, he immediately declared the theory of Einstein has been confirmed – agitating scientific community as well as general public.
Nobel Prize awarded to Einstein was not for his Theory of Relativity
After Eddington’s announcement, Albert Einstein, not so well known to the world was elevated to a scientific celebrity overnight. Newspaper headlines all over the world covered the event sensationally – implicating the intellectual giant Sir Isaac Newton has been dethroned. Nevertheless, the scientific elite hesitated to acknowledge the result without further confirmation. Despite nominations and much lobbying, the physics Nobel Prize 1919 or the following year was not awarded to Einstein.
The Nobel committee was concerned of the of the accuracy of 1919 eclipse measurement and probably influenced by the thinking at the time, the theory of relativity amount to a faith rather than a subject of physical reality testable by experiment. World astronomers decided to repeat the experiment during the next total solar eclipse forecasted to happen 21st September 1922, visible to Christmas Island and Southern Australia. Observatories in Europe and United States arranged expeditions to conduct measurements at the time of the eclipse.
Unlike prompt disclosure of the results of 1919 eclipse experiment at the Island of Principe, the astronomers who observed the 1922 eclipse in Australia were cautious to announce a premature result – no news of the measurement as late as October 1922, worrying Einstein. As physics Nobel Prizes are normally announced in October each year. The prize meant more than prestige to Einstein. The divorce settlement with his first wife Mileva Meric has been, the money he gets from a future Nobel Prizes goes to her and two sons under her custody. Prevailing uncertainties for persons of Jewish origin in Germany also bothered Einstein – the warning that his name is in a Nazi hit list.
Considering the predicament, Einstein decided to be away from Germany for a while and accepted an invitation to tour Japan. Enroute Japan, Einstein and his second wife Elsa arrived in Colombo 28th October 1922. A reporter from Times of Ceylon interviewed him questioning results of the eclipse experiments. Einstein had responded saying the Christmas Island experiment failed owing to cloudy weather but he expects a good result from the Australian experiment.
The ship departed Colombo next day, about a week later the captain of the ship met Einstein and handed over a telegram from Stockholm.
Unexpectedly, the Nobel Prize was not for his theory of relativity. The award citation said he has been honored for explaining photoelectric effect (how metals shined with light emit electrons) and contributions to theoretical physics. Why was Einstein’s major contribution, the theory of relativity omitted from the citation? To the scientific establishment, theory seemed to be radically away from the mainstream thinking and barely supported by experiment.
Relativity succeeded in understanding expansion of the universe concluded by observation of Edwin Hubble. However mathematically awesome theory faced a major difficulty.
Endless contraction of massive objects by their own gravitation creates black holes
Einstein’s theory tells that stars and other astronomical objects much heavier than sun, should contract endlessly under their own gravitation. Upon reaching a critical radius, the gravitational pull turns so strong counteracting even emission of light. Resulting formation of a boundary of no return termed the event horizon. Such elusive objects known as black holes aroused curiosity motivating best minds to ponder. A problem that remained difficult to resolve was, the theory required the contraction to continue even after crossing the event horizon – crushing matter virtually to a point – mathematically referred to as a singularity. Physically such a consequence would be an impossibility – casting much doubt on reality of black holes or even the validity of the general theory of relativity.
The idea of cosmic censorship – You needn’t worry about hypothesized happenings that are unobservable
English mathematical physicist Roger Penrose provided a lasting solution to the puzzle of the reality of black holes in 1965. Penrose proved that irrespective of shape and extent of the event horizon, continuation of collapse leading to a point like crushing or a singularity is inevitable. However, any information related to happenings inside the region bounded by the event horizon remain inaccessible observers outside. As you cannot pass the event horizon and return, observing existence of singularity is forbidden. Penrose referred to this phenomenon as ‘cosmic censorship’. The idea has profound philosophical implications. You needn’t worry about hypothesized happenings that forbid observation. A good lesson for many of us who believe in happenings that can never be seen to happen.
The work of Penrose dispelled the doubt that black holes are unreal and encouraged astronomers to search them and their effects.
Black holes found and problems of Einstein’s theory finally resolved
Until 2015 Einstein’s relativity theory continued to face another problem. As shown by Einstein in 1916, his theory demanded existence of gravitational waves – to and fro undulations of space – time itself. Close motion of very massive astronomical objects and their collisions create these waves, shaking stars and planets far away. In 2015 an intricate detector set-up in United States, after years of research, recorded gravitational waves emanated from a catacalmic event happened in the universe eons ago – a signal consistent with impinging of two black holes rotating around each other. Three American physicists received 2017 Nobel Prize for this work.
After the monumental contribution of Roger Penrose, physicists realized black holes are not mere mathematical artifacts of the general theory of relativity, but an inescapable consequence of endless contraction of gigantic agglomerations of matter under their own gravitational attraction – persuading astronomers to look for them among diverse variety of mysterious structures in the universe.
Since 1990 astronomers Reinhard Genzel and Andrea Ghez, working in Germany and United States studied motion stars at the center of galaxy. Their analysis concluded an invisible supermassive object, heavier than 4 million times the mass of the sun, sitting at the center of the galaxy – a black hole, pulling and orbiting stars in the vicinity. The black hole will continue to grow eating nearby stars!
Proving the existence of black holes and finding them revealing an enormously massive black hole at the center of our galaxy is a remarkable milestone of human advancement. Physics Nobel Prize 2020 recognized this accomplishment. Einstein’s general theory of relativity, not honored by a Nobel Prize had passed all tests, including existence of black holes, stubbornly resisting refutation.
Ferryman / October 16, 2020
Considering your third paragraph on science, evidence and IDEOLOGIES, perhaps the views of Sir Roger and his colleague Stephen Hawking and their thinking may be of value.
The Penrose triangle, also known as the Penrose tribar or the impossible tribar, is a and triangular impossible object, an optical illusion consisting of an object which can be depicted in a perspective drawing, but cannot exist as a solid object.
Penrose shared the Wolf Prize for physics with Stephen Hawking for this work on the Penrose-Hawking singularity theorems. Stephen Hawking was Director of Research at the Centre for Theoretical Cosmology at the University of Cambridge and he and co-author Leonard Mlodinow posited in the 2010 book, “The Grand Design,” that the big bang was inevitable. Hawking declared himself an atheist.
“Because there is a law such as gravity, the universe can and will create itself from nothing,” the book states. “Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.”
Mr. Penrose himself has mused that his cosmology is “a bit more like Hindu philosophy” than anything in the Judeo-Christian traditions, but he has no particular religious leanings.
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S. C. Pasqual / October 16, 2020
Actually it is two different Penroses. A father and son.
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Psychiatrist Lionel Penrose and Mathematician Sir Roger Penrose.
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It is Sir Roger Penrose who won the Nobel Prize.
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Ferryman / October 17, 2020
The triangle was devised and popularized in the 1950s by psychiatrist Lionel Penrose AND HIS SON, prominent Nobel Prize-winning mathematician Sir Roger Penrose.
Just for the record.
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Ferryman / October 17, 2020
Lionel Penrose passed away in 1972.
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Kirthi Tennakone / October 16, 2020
Thanks for the valuable comment
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Mallaiyuran / October 16, 2020
“Einstein suggested, the predicted effect could be tested during a total eclipse of the sun as an apparent change in the position of a star shining close proximity to the solar disc. “
Doesn’t this sound like on the eclipse day, Sun would be looking like a cluster of star? The star’s light comes from back side of the sun (Not right behind). On that day, Sun is hidden over by moon and if any light is bent into the sun’s sphere, shouldn’t that to be hidden by our moon because, the Moon is too close to us? The Star that can be seen on that day time is, possibly its light bent by Sun first and then by moon or even most possibly by moon, but no Sun’s effect. That should be case of the Black Hole. It shouldn’t look like a dark globe, but as cluster of stars of the other side of the galaxy.
Why would somebody thinking that Black hole Black because the light is not able radiate out of here. For atomic reaction, atoms have to move around and collide with one another. But atoms moving in Black Hole are not possible, 1. Too Compact, no space. 2) Extreme gravity which’s power is capable of sucking back even light particles. So Black Hole is black because lack of atomic reaction on its surface to glare.
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Ferryman / October 17, 2020
“For atomic reaction, atoms have to move around and collide with one another. But atoms moving in Black Hole are (is) not possible.”……………..
Only in Newtonian era was an atom the smallest particle. Now it goes down to hadrons. Much simpler to realise that a hydrogen atom with a proton and electron is not an incompressible entity. Inside the atom the distance of the proton and electron is 2.08×10−9 in. An atom is small and these distances are extremely small, but they are revolving apart from each other. There is a small space.
So the compacting takes place when a star burns up its fuel to form a mass of massive density.
May be reference to Stephen Hawking’s book “Black Holes and baby Universes” would shed “light on black holes.”
During an eclipse, observations of the phenomenon, of the apparent amount of “red shift” is made as red light tends to be affected by higher gravity than blue light. The simple prism breaks up the white light into rainbow colours by travelling through clear glass. Violet (Blue) on one end and Red on the other. The wave length of the red end of the spectrum of white light, increases, but not the speed. This is one the measurements that confirm Einstein’s theory.
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Kirthi Tennakone / October 17, 2020
Ferryman. Thanks for providing answers to questions and for your comment
Tennakone
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KA / October 18, 2020
Thank you Ferryman.
However, I have some questions.
“During an eclipse, observations of the phenomenon, of the apparent amount of “red shift” is made as red light tends to be affected by higher gravity than blue light.”
Going by prism refraction, it must have been blue (or violet) light that would be closest to the gravitational field? So, why red light is most affected?
The other question is bout speed of light.
The bending of light is explained by geodetic paths (i.e. shortest paths ) in spacetime curvature and the least energy.
Does the speed of light slow down in absolute terms? I know that the speed of light itself is a tensor, which I did not bother to look as I am looking for a short qualitative explanation.
Or, is it (i.e. speed of light slowing down) an appearance because the light has to now traverse a bent path for an observer in a local reference?
My understanding is that the local references are absolute key in GR theory, and one can only realise it when one realises how Euclidean geometry fails to address geometry at a cosmic scale (one can start with the size of the earth).
Thanks in advance if you can answer in a few sentences.
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Ferryman / October 18, 2020
The error is in thinking of “Going by prism refraction”. These are two different events – not be taken together as one event. I gave prism refraction only as an example of the different colours comprising white light and not directly connected to the red shift by the sun’s gravity.
The light from a normal star has all colours and then the red shift of that beam of white light takes place as it passes the suns gravity field.
Red light has a longer wavelength than blue light. Red light has a lower frequency and is associated with less energy than blue light. Hence EFFECT of the gravity field on the wavelengths of the two colours as white light passes by is different, and evidenced by spectrum analysis.
The speed of light in a vacuum is supposedly (at this time) considered fixed but when it travels through different media there is a very minute slowing down. Further according to GR theory, the speed of the observer makes it relative to the observer.
“My understanding is that the local references (Observers) are absolute key in GR theory.” Yes – This is the key.
In the final analysis, if none of us exist to observe, WOULD there be an “observable universe” with no one to observe it.!!
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KA / October 20, 2020
“Red light has a longer wavelength than blue light. Red light has a lower frequency and is associated with less energy than blue light. Hence EFFECT of the gravity field on the wavelengths of the two colours as white light passes by is different, and evidenced by spectrum analysis.”
Thank you for the explanation.
Your explanation implies that if the gravitational field strong enough (say for example in the neighbourhood of an event horizon of a black hole) the other colour lights will be shifted as well.
Of course, we can never see that and deducing it is a possibility.
You might know examples of where other colour lights are shifted.
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SJ / October 18, 2020
KA
Thanks for raising relevant issues.
However, terrestrial problems can still be solved without a hitch with Euclidean geometry and Newtonian mechanics.
Einstein becomes most relevant in matters on a much larger scale.
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We have here many who are incapable of using common logic– I do not mean not those who reject a mechanistic use of logic but those who are simply incapable of plain honest reasoning.
So we believe in miracles and magic– I would rather we addressed that as a priority.
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Ferryman / October 18, 2020
Very true. Both these are simpler and reasonably good for work which does not need high accuracy.
But Euclidean Geometry is not valid for curved surfaces while Newton’s laws are valid when, the distances with which one works must be much greater than the size of atoms and molecules.
Actually Einstein or quantum mechanics becomes most relevant in matters on a much smaller scale. (not larger).
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old codger / October 17, 2020
Malli oh Malli,
“On that day, Sun is hidden over by moon and if any light is bent into the sun’s sphere, shouldn’t that to be hidden by our moon .”
The moon is much too close and not massive enough to do that.
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Stanley / October 17, 2020
‘The star’s light comes from back side of the sun (Not right behind).’
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Brilliant comment. Black Holes were first discovered by Tamil astronomers in 2000 BC.
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Agnos / October 18, 2020
Prof. Tennakone,
“Newspaper headlines all over the world covered the event sensationally – implicating the intellectual giant Sir Isaac Newton has been dethroned. “
I believe the use of “implicate” to mean “imply” is an outdated usage.
But it is good to read something on the history of science on CT for a change.
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Kirthi Tennakone / October 18, 2020
Thanks for commenting on words usage
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Agnos / October 18, 2020
Prof. Tennakone,
Subramaniam Chandrasekhar’s work involved black holes as well. You mention Eddington without talking about how he belittled Chandrasekhar’s work, partly motivated by racism in the UK. Chandrasekhar was then offered a position at University of Chicago and he won the Nobel prize long before Penrose did. Any article on black holes should include a reference to Chandrasekhar’s work.
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SJ / October 19, 2020
Agnos
Several decades ago, when I was at school, I saw a book for the layman about the greatest scientists, the section on Chandrasekhar carrying a graph, one of whose axes he labelled in Tamil.
I am not sure why, but it made me feel proud.
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Kirthi Tennakone / October 19, 2020
I have not belittled Chandrasekhar. This particular work only Eddington was involved. In short article you cannot include everything
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Agnos / October 20, 2020
Prof. Tennakone,
I didn’t say you belittled Chandrasekhar. If you re-read my comment, you will see that I said Eddington belittled him ( and actually made it impossible for him to find an academic position in the U.K.) And I accept your explanation for not referring to Chandrasekhar in the article.
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Mallaiyuran / October 18, 2020
Thanks for everybody for responding. I moved away from science with A/L. The topics currently interesting prevented me from returning to science. So I missed Prof. Hawking’s book. I had a faint memory of protons start the reaction in ordinary bombs and reactors. I goofed it there.
Thanks again.
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Ferryman / October 18, 2020
Wonderful attitude Mallai. Sometimes when an opposite view is expressed, the return is an unacceptable response of name calling nothing to do with the subject at issue.
Your response is heartening and feel there is indeed space for valuable exchange of ideas and fellowship in CT. Thank you.
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SJ / October 18, 2020
F
I wonder if that freak event will be sustained.
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Ferryman / October 18, 2020
PS.
For return to Science, a good start will be Stephen Hawking’s “Brief History of Time”. A little out of date now 22 years since publication but good enough to move forward. It beat every record and spent 147 weeks on the New York Times bestseller list and a record-breaking 237 weeks on the Times of London bestseller list.
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old codger / October 18, 2020
Malli oh Malli,
“On that day, Sun is hidden over by moon and if any light is bent into the sun’s sphere, shouldn’t that to be hidden by our moon .”
The moon is much too close and not massive enough to do that.
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SJ / October 19, 2020
OC
How dare you contest traditional wisdom that the Sun was gobbled up by Rahu and soon vomitted out!
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old codger / October 20, 2020
SJ,
Isn’t “wisdom” a bit of an exaggeration?
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