Science, Art, Litt, Science based Art & Science Communication
Some Qs. people asked me on science and my replies to them - Part 68
Interactive Science Series
Q: How can honeybees build perfect combs without measurements?
Krishna: The perfect hexagonal array of bees’ honeycombs, owes more to simple physical forces than to the skill of bees, according to a study (1).
According to the researchers, bees simply make cells that are circular in cross section and are packed together like a layer of bubbles. Then the wax, softened by the heat of the bees’ bodies, gets pulled into hexagonal cells by surface tension at the junctions where three walls meet. A regular geometric array of identical cells with simple polygonal cross sections can take only one of three forms: triangular, square or hexagonal. Of these, hexagons divide up the space using the smallest wall area, and thus, for a honeycomb, the least wax.
Q: I recently read in the news papers that comedians on TV make 20-80 lakhs per episode. Movie stars make crores. Just for silly act and talk! How much do scientists make for working so hard using their grey matter? Isn't that injustice?
Krishna: Thanks for your concern for scientists. Anyway who cares? Scientists are too busy to even think about it!
Of course good funds help scientists do better work. Go tell that to the people concerned.
Q: I have heard stories of patients feeling the presence of some people who are not actually present with them when they are in hospital and in the final stages of their lives. How does science explain this paranormal phenomenon?
Krishna: There are no paranormal phenomena involved. Severe in take of drugs cause hallucinations. Likewise when the neurons in your brain are misfiring when death is fast approaching, you feel such things. Scientists could replicate these things in labs.
Read these articles to know more about it ...
how-science-explains-near-death-experiences
Q: Can I do PhD in biochemistry after doing MTech in CSE?
Krishna: Yes, you can! That is if you have the confidence, knowledge and if a supervisor is willing to take you and if the university you are studying in allows you.
It depends on how well you can convince yourself, your guide, fund provider and facility provider. Not an easy task though.
People switch to other subjects to do research in the West. In India that is a difficult thing to do because you have lots of competition to beat from M.Sc. Biochemistry students.
Here is an useful tip …
If you can creatively connect CSE with Biochemistry to solve problems, you can really go places. And you can have your cake and eat it too!
Think about that. We love creative people in science.
Q: Why doesn't gold get spoiled easily or rust?
Krishna: Noble metals like gold, platinum, rhodium, palladium, are extremely stable, and inert even at high temperatures. This makes them inert in normal atmospheric temperature and pressure.
Pure gold is almost completely unreactive with oxygen. Rust commonly refers to oxidation. If the gold is not pure, the metals it is alloyed with could react with oxygen and moisture and other chemicals to cause the alloy to tarnish.
Gold is a noble element because "in chemistry, the noble metals are metals that are resistant to corrosion and oxidation in moist air (unlike most base metals )."
The list of chemically noble metals (those elements upon which almost all chemists agree) comprises ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au).
Q: Why does silver turn black?
Krishna: Metals have a tendency to change back to their original state of existence that is the ore from which these been extracted and they do so by their interaction with the environment. The atmospheric air contains moisture and certain dissolved gases like oxygen, carbon dioxide, sulphur dioxide, hydrogen sulphide and the like. Silver metal is extracted mainly from its sulphide ores like argentite (silver glance) as a white lustrous metal, which remains untarnished in air free from hydrogen sulphide.
But in the presence of trace amounts of hydrogen sulphide in atmosphere, silver forms a film of silver sulphide that is black.
Silver tarnish is the discoloration that occurs on silver. Silver is not appreciably affected by dry or moist air that is free from ozone, halogens, ammonia, and sulphur compounds. The presence of hydrogen sulphide in any material that silver comes into contact with is one of the prime reasons for silver tarnish. The hydrogen sulphide reacts with the silver to form silver sulphide.
2Ag + H2S --> Ag2S + H2
Silver sulphide is black. When a thin coating of silver sulphide forms on the surface of silver, it darkens the silver.
Rubber contains sulphur, which will cause silver to tarnish. This includes dishmats, placemats, silverware holders, latex gloves and rubber bands. Materials like wool, fuels derived from fossils, a few types of paints and rubber are some of the common materials that cause tarnishing of silver.
Certain foods like eggs, mayonnaise, mustard, table salt, olives, salad dressing, vinegar, fruit juices and onions also hasten the silver tarnish process. The sulphur in these foods will corrode silver. Flowers and fruits can etch the silver containers due to the acid produced as they decay.
Regular use of silver items prevents them from tarnishing.
There are two ways to remove the coating of silver sulphide. The first method involves polishing that removes the silver sulphide layer. Some silver is also lost in the process of polishing. The second method uses a chemical reaction to convert the silver sulphide back into silver, without removing any silver.
Some metals have a greater affinity for sulphur than silver does. Aluminium is such a metal. The silver sulphide reacts with aluminium. In the reaction, sulphur atoms are transferred from silver to aluminium, freeing the silver metal and forming aluminium sulphide. The process involves placing the tarnished silverware in a boiling solution of sodium carbonate, along with a wadded-up piece of aluminium foil. The silver tarnish is transferred to the aluminium. The more we use and handle our silverwares, the less chance there will be for tarnish to build up.
Q: What happens if a supernova happens nearer to us?
Krishna: According to a 2016 study, supernovae occurring as close as 50 light-years from Earth could pose an imminent danger to Earth’s biosphere—humans included. The event would likely shower us in so much high-energy cosmic radiation that it could spark a planetary mass extinction. Researchers have tentatively linked past instances of spiking extinction rates and plummeting biodiversity to postulated astrophysical events, and in at least one case have even found definitive evidence for a nearby supernova as the culprit. Twenty million years ago, a star 325 light-years from Earth exploded, showering the planet in radioactive iron particlesthat eventually settled in deep-sea sediments on the ocean floor. That event, researchers speculate, may have triggered ice ages and altered the course of evolution and human history.
The exact details of past (and future) astrophysical cataclysms’ impact on Earth’s biosphere depend not only on their distance, but also their orientation. A supernova, for instance, can sometimes expel its energy in all directions—meaning it is not always a very targeted phenomenon. Merging black holes are expected to emit scarcely any radiation at all, making them surprisingly benign for any nearby biosphere. A kilonova, however, has different physics at play. Neutron stars are a few dozen kilometers in radius rather than a few million like a typical stars. When these dense objects merge, they tend to produce jets that blast out gamma rays from their poles.
What it looks like to us, and the effect it has on us, would depend a lot on whether or not one of the jets was pointed directly at us.
Based on its distance and orientation to Earth, a kilonova’s jets would walk the fine line between a spectacular light show and a catastrophic stripping away of the planet’s upper atmosphere. If a jet is pointed directly at us, drastic changes could be in store. And we probably wouldn’t see them coming. A kilonova begins with a burst of gamma rays—incredibly energetic photons that, by definition, move at light-speed, the fastest anything can travel through the universe. Because nothing else can move faster, those photons would strike first, and without warning.
What the gamma rays would do, probably more than anything else, is dissolve the ozone layer. Next, the sky would go blindingly white as the visible light from the kilonova encountered our planet. Trailing far behind the light would be slower-moving material ejected from the kilonova—radioactive particles of heavy elements that, sandblasting the Earth in sufficient numbers, could still pack a lethal punch.
That’s if the kilonova is close, though—within 50 light-years, give or take. At a safer distance, the gamma rays would still singe the ozone layer on the facing hemisphere, but the other side would be shielded by the planet’s bulk. Most radiation happens very quickly, so half the Earth would be hidden. There would still be a momentarily blinding light. For a few weeks, a new star would burn bright in the sky before gradually fading back into obscurity.
But, don't worry, Kilonovae are relatively rare cosmic phenomena, estimated to occur just once every 10,000 years in a galaxy like the Milky Way. That’s because neutron stars, which are produced by supernovae, hardly ever form as pairs. Usually, a neutron star will receive a hefty “kick” from its formative supernova; sometimes these kicks are strong enough to eject a neutron star entirely from its galaxy to hurtle at high speeds indefinitely through the cosmos. When neutron stars are born, they’re often high-velocity. For them to survive in a binary is nontrivial. And the chances of two finding each other and merging after forming independently are, for lack of a better term, astronomically low (2).
Dr. Krishna Kumari Challa's art work based on the theme... Supernova Remnants
(From http://www.kkartfromscience.com )
Q: What is the science behind Karthika Pournami?
Krishna: What?! Please mention your question clearly.
If you are thinking about cultural and traditional aspects that are followed during the month of Karthik or on the full moon day of Karthik, there is no science behind it.
Scientifically speaking, Kartik Pournami is same as any other full moon day. No special significance is attached to it.
Please don’t try to scientifically authenticate the culture and traditions you follow. It becomes pseudo-science if you do so.
Q: How hard would it be to create a science based state, meaning a state that entirely devotes itself to research and progress without bogging itself down with politics and religion?
Krishna: Creating such a state would be a dream come true for several scientists!
But politics and religion won’t allow it happen. Why? Because, the politicians and religious leaders would lose their power and jobs if a completely science based state comes into existence.
People can no longer mislead others, make others their blind followers, they cannot manipulate things and situations, cannot manage things in the way they want.
As long as people refuse to to see the true picture and are willing to get manipulated, you cannot attain a scientifically inclined world.
Q: Aren't you tired of explaining so many things scientific to people? That too for nothing!?
What is the most tiring thing to explain?
Krishna: :) This what a science communicator should do. Explain things. No I am not getting tired. I love this job!
The most tiring thing to explain?
What real science is. And the difference between science and pseudo-science. Even some PGs in science don’t seem to understand the difference and properly analyse it when explained in clear terms!
Just a few minutes back I explained the same things I mentioned above to a PG in science here on this network when he asked me about them.
Not tired but getting shocked over and over again. Hmmm!
Q: Did Albert Einstein have any assistants during his discovery of relativity theory? How did he make his calculations?
Krishna: Apart from his friend and classmate Marcel Grossmann who helped Einstein in his work, Mileva Marić Einstein, Einstein’s first wife, who was a Physicist herself, helped him a lot.
While nobody has been able to credit her with any specific part of his work, their letters and numerous testimonies presented in the books dedicated to her (1-5) provide substantial evidence on how they collaborated from the time they met in 1896 up to their separation in 1914. Mileva helped him channel his energy and guided his studies as we learn from Albert’s letters, exchanged between 1899-1903 during school holidays: 43 letters from Albert to Mileva have been preserved but only 10 of hers remain(5). These letters provide a first-hand account on how they interacted at the time.
By the end of their classes in 1900, Mileva and Albert had similar grades (4.7 and 4.6, respectively) except in applied physics where she got the top mark of 5 but he, only 1. She excelled at experimental work while he did not. But at the oral exam, Professor Minkowski gave 11 out of 12 to the four male students but only 5 to Mileva. Only Albert got his degree.
On 13 December 1900, they submitted a first article on capillarity signed only under Albert’s name. Nevertheless, both referred to this article in letters as their common article.
Mileva probably wanted to help Albert make a name for himself, such that he could find a job and marry her. Dord Krstić, a former physics professor at Ljubljana University, spent 50 years researching Mileva’s life. In his well-documented book(2),he suggests that given the prevalent bias against women at the time, a publication co-signed with a woman might have carried less weight.
Albert Einstein himself accepted that they collaborated on special relativity when he wrote to Mileva on 27 March 1901: “How happy and proud I will be when the two of us together will have brought our work on relative motion to a victorious conclusion.”
Albert and Mileva married on 6 January 1903. Mileva assumed the domestic tasks. In the evenings, they worked together, sometimes late in the night.
Despite this, 1905 is now known as Albert’s “miracle year”: he published five articles: one on the photoelectric effect (which led to the 1921 Nobel Prize), two on Brownian motion, one on special relativity and the famous E = mc 2
. He also commented on 21 scientific papers for a fee and submitted his thesis on the dimensions of molecules. Much later, Albert told R. S. Shankland(6)
that relativity had been his life for seven years and the photoelectric effect, for five years. Peter Michelmore, one of his biographers(7), wrote that after having spent five weeks to complete the article containing the basis of special relativity, Albert “went to bed for two weeks. Mileva checked the article again and again, and then mailed it”. Exhausted, the couple made the first of three visits to Serbia where they met numerous relatives and friends, whose testimonies provide a wealth of information on how Albert and Mileva collaborated.
According to Mileva’s brother,during the evenings and at night, when silence fell upon the town, the young married couple would sit together at the table and at the light of a kerosene lantern, they would work together on physics problems. Miloš Jr. spoke of how they calculated, wrote, read and debated.”
So the story continued till Einstein started an affair with his cousin. Their marriage ended. Sadly, the collaboration too. The sacrifice and contribution his first wife made was forgotten by the world.
(1) Radmila Milentijević: Mileva Marić Einstein: Life with Albert Einstein, United World Press, 2015.
(2) Dord Krstić: Mileva & Albert Einstein: Their Love and Scientific Collaboration, Didakta, 2004.
(3) Desanka Trbuhović-Gjurić Mileva Marić Einstein: In Albert Einstein’s shadow): in Serbian, 1969, German, 1982, and French, 1991.
(4) Milan Popović: In Albert’s Shadow, the Life and Letters of Mileva Marić, Einstein’s First Wife, The John Hopkins University Press, 2003.
(5) Renn and Schulmann, Albert Einstein / Mileva Marić, The Love Letters, Princeton University Press, 1992.
(6) Peter Michelmore, Einstein, Profile of the Man, Dodd, Mead & Company, 1962.
(7) R.S. Shankland, Conversation with Albert Einstein, Am. J. of Physics, 1962.
CITATIONS:
1. , & J. R. Soc.
http://dx.doi.org/10.1098/rsif.2013.0299 (2013).
2. https://www.scientificamerican.com/article/a-nearby-neutron-star-co...
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