Friday, 18 March 2022

SOLAR APPRECIATION DAY


"File:Artist’s impression of the TRAPPIST-1 planetary system.jpg" by ESO/N. Bartmann/spaceengine.org is marked with CC BY 4.0.

Solar Appreciation Day is celebrated on the 2nd Friday of March.

The Sun itself is just a huge ball of plasma made of hydrogen and helium held together by gravity and powered by nuclear fusion.

Around 4.5 billion years ago, when Earth's magma ocean was still cooling down, the sun was 30% dimmer than it is now, but the climate was as warm as it is now.

This dilemma is known as the "faint young Sun paradox."

The hazy atmosphere of early Earth was probably made of fewer reflective gases in the upper part of the atmosphere and powerful greenhouse gases in the lower parts.

Without greenhouse gases like methane, early Earth would have frozen into an ice ball for the first few billion years of its existence.

Even Carl Sagan got troubled by the "faint young Sun paradox". The most debated explanation is something called the Gaia hypothesis, is a weird concept but it says that all the life on Earth, especially the microbes that operate the Earth's life support system, can change the composition of the atmosphere and transform it such that it creates a nice climate on Earth.

The exact way, how microbes can do this is not completely understood by scientists yet.

One other thing that bothers me is that, just before the "Great Oxygenation Event," why did anaerobic bacteria allow oxygen-producing microbes to oxygenate Earth's atmosphere? which ultimately doomed most of the anaerobic bacteria.

The James Webb Space Telescope, launched last year on Christmas Day, is still cooling down in deep space to allow its infrared instruments to start operating.

The first images are expected in a few months. JWST also can study the earliest stars and planets, which can resolve some of the most debated issues in Astronomy, Astrobiology, Planetary Geology, and other unknown questions!

Tuesday, 8 March 2022

USE OF SLATES IN CONSTRUCTION

source (Ian Sanders)

Proterozoic slates from Himachal Pradesh have been used a lot in the Himalayas. 

These deposits occur in Himachal Pradesh’s Chamba, Kangra, Mandi, Kullu, Shimla, Sirmaur, Kinnaur, and Solan districts, they have been quarried since ancient times.

Shimla Town Hall Building, the Gaiety Theatre, Sarahan Palace and Bhimakali Temple, temples of Champavati and Laxmi Narayan are all made of this rock.

Slates are metamorphic rocks, it is highly fissile in nature, i.e. they can be split easily into thin, flat sheets with smooth surfaces. The sheets themselves on their own without any coating are strong, impermeable to water, and resistant to weathering, when built properly structures made from this rock can last several decades

This makes it the ideal material of choice for use in roofing, paving, fencing, and flooring as they are flexible and less prone to damage in hilly areas where the hazards from Earthquakes are high.

Some of these Slates could be from the Ediacaran Period 63 Crore years Old! when first complex life forms were still evolving, however usually fossils may not be preserved in slates. 

Monday, 7 March 2022

DECCAN TRAPS

 

A view of the Ajanta Caves excavated in the gorge wall of the Waghur/Waghora River. The caves, listed as a World Heritage Site, are excavated in compound lava flows. The Buddhist cave monuments date from 2nd century BCE to 6th century CE 
(Photo courtesy of Francesca Lugeri)

At the end of the Cretaceous, the western part of peninsular India underwent numerous volcanic eruptions that resulted in the formation of the Deccan Traps. A total of 48 lava flows have been identified within the Deccan Traps, with a maximum thickness of about 2.5 km on the western side of the plateau near Mumbai. The Deccan Traps are spread over half a million square kilometers in the west-central parts of India, and they occupy huge areas of the states of Maharashtra and Karnataka. India also has the longest lava flows known to be preserved. They are estimated to be 1500 km long and drain out into the Gulf of Bengal near Rajahmundry in Karnataka.

Many archaeological monuments like the Buddhist, Hindu, and Jain temples of Ajanta, Ellora, and Elephanta are the oldest in-situ basalt cave temples, dating back to the second century. They also have the oldest known cave paintings on the Indian subcontinent. However, this title could be snatched by the recent discoveries in Mangar Bani, near the outskirts of Delhi.

At least 4 of the UNESCO World Heritage Sites in India, like the Ajanta, Ellora, and Elephanta cave temples, and the Chhatrapati Shivaji Maharaj Terminus (formerly Victoria Terminus), is made of this basalt.

Deccan basalts are in high demand worldwide and are mined for a variety of purposes including masonry stone, road metal, and as a raw material for corrosion-resistant basaltic pipes and basalt wool.

Quarrying of Deccan basalt is done in the western Deccan Plateau region, especially around Navi Mumbai, Aurangabad, Jalgaon, Nashik, and Kolhapur.

Basalt is a dark-colored, fine-grained, extrusive igneous rock (i.e., the molten rock or lava cooled on the surface) 

Basalt flows cover about 70% of the Earth’s surface and huge areas of terrestrial planets.

They come from the mantle. When rocks melt under pressure and temperature, they then make their way up to the surface via ducts and feed fissure volcanoes on the surface.

Future studies could gather more evidence about the environmental conditions that led to the mass extinction of non-avian dinosaurs and gigantic reptiles. 

The massive Deccan volcanic mountain ranges of the Western Ghats (east of Mumbai) reach up to a height of 3500 m and consist entirely of layered lava flows. (photo courtesy of G. Keller)

Tuesday, 1 March 2022

HOW TO BYPASS NATURE JOURNAL PAYWALL

Here is one way to bypass the nature paywall and access articles published online on the website https://www.nature.com/

Open up the website



Choose the relevant article page

Edit the web address by putting the extension .epdf at the end and press enter



This will allow you to read single-page articles like research highlights free of cost, and give you unlimited access to supplementary data of research papers!  


Use these options when there is nothing on extensions like Unpaywall and pre-print servers etc.

NEW MINERAL DISCOVERY 101 : Kernowite

  Kernowite: Mineral information, data and localities. (mindat.org) Kernowite Formula: Cu2Fe(AsO4)(OH)4 • 4H2O  Colour: Emerald-green  Cryst...