Naked singularity
- In 2019, astronomers of the Event Horizon Telescope captured the first ever image of a supermassive black hole (M87*) which was located at the center of a galaxy Messier 87 (M87).
- This black hole is calculated to be 6.5 billion times the Sun’s mass and is 55 million light years away from the Earth.
- A paper published in The European Physical Journal brings in an alternative explanation for the compact object that was imaged by the Event Horizon Telescope.
- The authors say it (M87*) is not necessarily a black hole but could even be a “naked singularity with a gravitomagnetic monopole.
- When stars much more massive than the Sun reach the end of their lives, they collapse under their own gravity, and the product of this collapse, most astronomers believe is a black hole.
- A black hole has two parts: At its core is a singularity a point that is infinitely dense, as all the remnant mass of the star is compressed into this point.
- Then there is the event horizon an imaginary surface surrounding the singularity, and the gravity of the object is such that once anything enters this surface, it is trapped forever.
- Not even light can escape the pull of the singularity once it crosses the event horizon.
- That is why, we cannot see the singularity at the heart of a black hole but only see points outside the event horizon
- In many scenarios of stellar collapse, the event horizon does not form, and the singularity is exposed to the outside, without any event horizon shielding it.
- A specialist in general theory of relativity and cosmology, calls this “naked singularity” a “troublesome sibling” of a black hole.
- M87* could be either a black hole or a naked singularity and each of these possibilities could be plain or coupled with what is called a gravitomagnetic monopole.
- In the nineteenth century, James Clerk Maxwell unified electricity and magnetism as one combined phenomenon, showing that light is an electromagnetic wave.
- But there is an asymmetry between electricity and magnetism. While positive and negative electric charges can be found to exist independently, the poles of a magnet are always found in pairs, north and south bound together.
- Dr Chakraborty draws upon an analogy between gravitational force and electromagnetism to explain that in 1963, Newman, Tamburino and Unti (NUT) proposed a theoretical concept called a “gravito-magnetic charge” also called a gravitomagnetic monopole.
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Zika virus
- Viruses are ubiquitous, most are innocuous and some, such as SARS CoV-2, turn out to be pernicious.
- Zika virus, first detected in rhesus monkeys in the Zika forest in Uganda in 1947 and then identified in humans after a few years, appears to be repositioning itself.
- Outbreak was associated with higher incidences of microcephaly (a condition which results in a small brain in the fetus) as well as the increased neurological symptoms such as Guillain-Barre syndrome and neuropathies in adults and children infected with the virus.
- Guillain-Barre syndrome (GBS) is a rare neurological disorder in which the body’s immune system mistakenly attacks part of its peripheral nervous system the network of nerves located outside of the brain and spinal cord.
- The first two outbreaks of Zika virus infections in India were reported in 2017.
- Knowing that the vector for Zika virus, the Aedes mosquito is present in all States of India, there is a need for stepping up preventive and public health measures.
- India should use the recent disease outbreaks as an opportunity to strengthen the disease surveillance system and health data recording and reporting systems in the country.
- The laboratory capacity for COVID-19, developed in the last 18 months, needs to be optimally used to conduct testing for other emerging infections.
- One of the key considerations is that the outbreak which had started in Brazil in 2015 was caused by a new variant of Zika virus, termed as American lineage.
- Though originated from South Asian lineage, it has crucial mutation S139N, attributed to higher incidences of microcephaly and other neurological conditions.
- All previous outbreaks in India have been due to South East Asian lineage and no case of microcephaly has been reported from the country.
- However, there is a need for a systematic surveillance of evolutionary trends in Zika virus, which can be built upon newly developed genetic sequencing capacity for SARS CoV2.
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Fighting mosquito borne disease
- The R21 vaccine (malaria vaccine) has shown an efficacy of 77%, and targets the ‘circumsporozite’ protein (CSP) of the malarial parasite, Plasmodium falciparum.
- The sporozoite stage of this parasite secretes CSP. Mosquito bites transfer the CSP and sporozoite into the human bloodstream, and the CSP nudges the parasite towards the liver, where it enters liver cells, matures and proliferates.
- The release of mature merozoites marks the onset of the symptoms of malaria.
- The WHO has just cleared another vaccine, called Mosquirix, from Glaxo Smith Kline (GSK) of the U.K.
- Another rapidly spreading disease is dengue. It is spread by Aedes aegypti mosquitoes, which happily grow in small stagnant pools of water, such as in discarded tyres.
- Four serotypes of the dengue virus are found. Serotypes make vaccine development difficult, as a different vaccine is needed against each serotype.
- A vaccine against dengue, DENGVAXIA, from Sanofi Pasteur, is approved in several countries and shows efficacies ranging from 42% to 78% against the four serotypes of the virus.
- In India, Zydus Cadilla has been developing a DNA Vaccine against dengue
- Other innovative methods to fight dengue have been in the pipeline.
- One particularly interesting strategy involves a bacterium, Wolbachia pipientis, an intracellular parasite commonly found in many insects, but not in the dengue-carrying mosquito.
- When introduced into this mosquito’s cells, this parasite competes successfully against other parasites such as the viruses that cause dengue, chikungunya, yellow fever and Zika.
- Aedes mosquitoes, doped with Wolbachia in the laboratory, are released in localities where the disease is prevalent.
- They quickly spread the bacterium to native Aedes mosquitoes, and the incidence of new dengue cases starts to decline.
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Circumbinary stars
- Planets that orbit a pair of stars are called circumbinary stars. Though such objects were thought to be confined to science fiction, using NASA’s KEPLER and TESS mission’s data, astronomers have detected 14 such systems so far.
- Difficult to detect, a 2020 paper in The Astronomical Journal came up with a method.
- The scientific objective of the Kepler Mission is to explore the structure and diversity of planetary systems. This is achieved by surveying a large sample of stars to: Determine the percentage of terrestrial and larger planets that are in or near the habitable zone of a wide variety of stars.
- The TESS Mission is designed to survey over 85% of the sky (an area of sky 400 times larger than covered by Kepler) to search for planets around nearby stars (within ~200 light years). TESS stars are typically 30-100 times brighter than those surveyed by the Kepler satellite.
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Davemaoite
Clue in a diamond
- A greenish, octahedral-shaped diamond that was found decades ago at the Orapa diamond mine in Botswana contained small black specks that turned out to be a mineral identified in nature for the first time.
- This discovery was reported in Science, and the mineral, named Davemaoite, cannot exist on Earth’s surface, but plays a major role in heat flow deep inside the Earth.
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Microbes and coal
- Microbes may have been behind the first stages of coal creation, finds a study published in Science.
- Studying methoxyl groups in coal samples, researchers showed that organic material eventually becomes coal through the action of anaerobic microbes that consumed the methoxyl groups, transformed the coal and made methane.
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Eggshell planets
Eggshell planets
- A small subset of extrasolar planets are likely to have thin crusts, a new modelling study published in the Journal of Geophysical Research finds.
- Since these eggshell planets are unlikely to show plate tectonics, such worlds are unlikely to be habitable, the study surmises. At least three such worlds may have been found so far.
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