Earthquakes in a day?

Just a couple of days back an earthquake of sygnificant intensity had its epicenter at Andaman. Its effect went up to Jharkhand and Tata Steel had to shut down its plant for a day. Had the epicenter been a more habited place, the end-result and impact would have been much worse.

And I would not have come to know about this till one of my friends buzzed me about the earthquake. So was just wondering, how many such earthquakes happen without notice.

According to a table cited by SERI

Description	Magnitude	Frequency per year
Great	8.0+	1
Major	7.0-7.9	18
Large (destructive)	6.0-6.9	120
Moderate (damaging)	5.0-5.9	1,000
Minor (damage slight)	4.0-4.0	6,000
Generally felt	3.0-3.9	49,000
Potentially perceptible	2.0-2.9	300,000
Imperceptible	less than 2.0	600,000+

Classical elements

Many philosophies and worldviews have used a set of archetypal classical elements, most developed sets of the simplest essential parts and principles of which anything consists or upon which the constitution and fundamental powers of anything are based. There are several approaches (Ancient, Medieval, and Modern), the most frequently occurring theories of classical elements are held by the Ancient systems of thought. In use as an the explanation for patterns in nature, the word element refers to a substance that is either a chemical compound or a mixture of chemical compounds, rather than a chemical element of modern physical science.

The most frequently occurring theory of classical elements, held by the Hindu, Japanese, and Greek systems of thought, is that there are five elements, namely Earth, Water, Air, Fire, and a fifth element known variously as space, Idea, Void “quintessence” or Aether (the term “quintessence” derives from “quint” meaning “fifth”).

In Greek thought the philosopher Aristotle added aether as the quintessence, reasoning that whereas fire, earth, air, and water were earthly and corruptible, since no changes had been perceived in the heavenly regions, the stars cannot be made out of any of the four elements but must be made of a different, unchangeable, heavenly substance.

The pancha mahabhuta, or “five great elements”, of Hinduism are [Shristi] or bhumi (earth), ap or jala (water), agni or tejas (fire), marut or pavan (air or wind), or akasha (aether). Hindus believe that God used akasha to create the other four traditional elements; each element is then used to create the next, each less subtle than the last. It is also a religious and spiritual belief by most people that the human body is made up of these five essential elements and according to Hinduism, the human body dissolves into these five elements of nature, thereby balancing the cycle of nature, set in motion by the greater Lord God of this world.

Each of the five elements are inherently connected with one of the five senses, and acts as the gross medium for the experience of it; the basest element, earth, was created out of all more subtle elements, and is accessible to all the senses, including scent. The next higher element, water, has no smell (being more subtle than earth) but can be tasted. Next, fire cannot be tasted or smelled, but can be seen (and is associated with sight). Air can be heard or felt, and akasha, being space or ether, is the medium of sound but is inaccessible to all other senses.

In the Pali literature, the mahabhuta (“great elements”) or catudhatu (“four elements”) are earth, water, fire and air. In early Buddhism, the four elements are a basis for understanding suffering and for liberating oneself from suffering.

The Buddha’s teaching regarding the four elements is to be understood as the base of all observation of real sensations rather than as a philosophy. The four properties are cohesion (water), solidity or inertia (earth), expansion or vibration (air) and heat or calorific content (fire). He promulgated a categorization of mind and matter as composed of eight types of “kalapas” of which the four elements are primary and a secondary group of four are color, smell, taste, and nutriment which are derivative from the four primaries.

Many philosophies and worldviews have used a set of archetypal classical elements, most developed sets of the simplest essential parts and principles of which anything consists or upon which the constitution and fundamental powers of anything are based. There are several approaches (Ancient, Medieval, and Modern), the most frequently occurring theories of classical elements are held by the Ancient systems of thought. In use as an the explanation for patterns in nature, the word element refers to a substance that is either a chemical compound or a mixture of chemical compounds, rather than a chemical element of modern physical science.

The most frequently occurring theory of classical elements, held by the Hindu, Japanese, and Greek systems of thought, is that there are five elements, namely Earth, Water, Air, Fire, and a fifth element known variously as space, Idea, Void “quintessence” or Aether (the term “quintessence” derives from “quint” meaning “fifth”).

In Greek thought the philosopher Aristotle added aether as the quintessence, reasoning that whereas fire, earth, air, and water were earthly and corruptible, since no changes had been perceived in the heavenly regions, the stars cannot be made out of any of the four elements but must be made of a different, unchangeable, heavenly substance.

The pancha mahabhuta, or “five great elements”, of Hinduism are [Shristi] or bhumi (earth), ap or jala (water), agni or tejas (fire), marut or pavan (air or wind), or akasha (aether). Hindus believe that God used akasha to create the other four traditional elements; each element is then used to create the next, each less subtle than the last. It is also a religious and spiritual belief by most people that the human body is made up of these five essential elements and according to Hinduism, the human body dissolves into these five elements of nature, thereby balancing the cycle of nature, set in motion by the greater Lord God of this world.

Each of the five elements are inherently connected with one of the five senses, and acts as the gross medium for the experience of it; the basest element, earth, was created out of all more subtle elements, and is accessible to all the senses, including scent. The next higher element, water, has no smell (being more subtle than earth) but can be tasted. Next, fire cannot be tasted or smelled, but can be seen (and is associated with sight). Air can be heard or felt, and akasha, being space or ether, is the medium of sound but is inaccessible to all other senses.

In the Pali literature, the mahabhuta (“great elements”) or catudhatu (“four elements”) are earth, water, fire and air. In early Buddhism, the four elements are a basis for understanding suffering and for liberating oneself from suffering.

The Buddha’s teaching regarding the four elements is to be understood as the base of all observation of real sensations rather than as a philosophy. The four properties are cohesion (water), solidity or inertia (earth), expansion or vibration (air) and heat or calorific content (fire). He promulgated a categorization of mind and matter as composed of eight types of “kalapas” of which the four elements are primary and a secondary group of four are color, smell, taste, and nutriment which are derivative from the four primaries.

Selenography

I have always been enchanted by the moon and as a kid wanted to be an astronaut and visit the moon! 🙂 That dream did not get fulfilled but then decided to dedicate a post to it.

Selenography is the study of the surface and physical features of the Moon. Historically, the principal concern of selenographists was the mapping and naming of the lunar maria, craters, mountain ranges, and other various features. This task was largely finished when high resolution images of the near and far sides of the Moon were obtained by orbiting spacecraft during the early space era. Nevertheless, some regions of the Moon remain poorly imaged (especially near the poles) and the exact locations of many features are uncertain by several kilometers. Today, selenography is considered to be a subdiscipline of selenology, which itself is most often referred to as just “lunar science.”

Craters as we know are any depression, natural or manmade, resulting from the high velocity impact of a projectile with larger body. In most common usage, the term is used for the approximately circular depression in the surface of a planet, moon or other solid body in the Solar System, formed by the hyper-velocity impact of a smaller body with the surface.

The lunar maria are large, dark, basaltic plains on Earth’s Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for “seas”, by early astronomers who mistook them for actual seas. They are less reflective than the “highlands” as a result of their iron-rich compositions, and hence appear dark to the naked eye. The maria cover about 16 percent of the lunar surface, mostly on the near-side visible from Earth. The few maria on the far-side are much smaller, residing mostly in very large craters where only a small amount of flooding occurred.

I have always been enchanted by the moon and as a kid wanted to be an astronaut and visit the moon! 🙂 That dream did not get fulfilled but then decided to dedicate a post to it.

Selenography is the study of the surface and physical features of the Moon. Historically, the principal concern of selenographists was the mapping and naming of the lunar maria, craters, mountain ranges, and other various features. This task was largely finished when high resolution images of the near and far sides of the Moon were obtained by orbiting spacecraft during the early space era. Nevertheless, some regions of the Moon remain poorly imaged (especially near the poles) and the exact locations of many features are uncertain by several kilometers. Today, selenography is considered to be a subdiscipline of selenology, which itself is most often referred to as just “lunar science.”

Craters as we know are any depression, natural or manmade, resulting from the high velocity impact of a projectile with larger body. In most common usage, the term is used for the approximately circular depression in the surface of a planet, moon or other solid body in the Solar System, formed by the hyper-velocity impact of a smaller body with the surface.

The lunar maria are large, dark, basaltic plains on Earth’s Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for “seas”, by early astronomers who mistook them for actual seas. They are less reflective than the “highlands” as a result of their iron-rich compositions, and hence appear dark to the naked eye. The maria cover about 16 percent of the lunar surface, mostly on the near-side visible from Earth. The few maria on the far-side are much smaller, residing mostly in very large craters where only a small amount of flooding occurred.

How much current does a lightning carry?

Was watching one of the earliest of the rains this season and this question occurred to me. Probably we all would have read it in Physics in school but giving myself the liberty to judge everybody else’s memory by the quality of mine, I allowed myself to post the answer. 🙂

An average bolt of negative lightning carries an electric current of 30 kiloamperes (kA), and transfers a charge of fivecoulombs and 500 MJ. Large bolts of lightning can carry up to 120 kA and 350 coulombs. The voltage is proportional to the length of the bolt.

An average bolt of positive lightning carries an electric current of 300 kA or about 10 times that of negative lightning.

Just as an addendum…this is how thunder is produced.

Lightning rapidly heats the air in its immediate vicinity to around 20,000 °C (36,000 °F) – about three times the temperature of the surface of the Sun. This compresses the surrounding clear air and creates a supersonic shock wave which decays to an acoustic wave that is heard as thunder.

How are cyclones named?

Few weeks back cyclone Aila had struck south West Bengal. Let’s not get into how much damage and destruction it caused in the villages, how many days the Calcutta municipality took in removing the fallen trees from the middle of busy roads, how fast electricity was restored in certain pockets of the city or how many millions of protests and demonstrations followed leaving the ever hapless citizens stranded! What struck me was the name of the cyclone. The last cyclone I had heard of was Bijli…and I could get the connotation of the name. But Aila???

Some research and here is what I found.

There is a procedure to name the cyclones in an ocean basin by the Tropical Cyclone Regional Body responsible for that basin. The storms that trigger cyclones in the North Indian Ocean zone are named by members of eight South Asian countries which are members of the World Meteorological Organization (WMO). The member countries are India, Bangladesh, Maldives, Myanmar, Oman, Pakistan, Sri Lanka and Thailand. The list of names for cyclones that originate in the Arabian Sea and Bay of Bengal are decided well in advance by WMO members. The name Aila was coined by the Met officials of the Maldives. Similarly some of the names of storms of the future are Phyan (Myanmar), Ward (Oman). Laila (Pakistan), Bandu (Sri Lanka) and Phet (Thailand).

Why does Sun rise from the east?

Think one thing that is taken for granted is that Sun rises in the east. In Vaastu this plays a significant role in deciding how the house must be structured.

But why? Must have read in 5th standard but then I-am-not-smarter-than-a-fifth-grader u c. I know it must be connected to moving of earth and some direction in which it is moving and all… But lemme figure out why exactly this happens.

According to this article

Have you ever noticed that as the seasons change, the sun seems to move a little on the horizon? Maybe not. But the Earth is tilted on its axis about 23½ degrees and the orbit of the Earth around the sun is elliptical. These factors effect the apparent position of the sun in the sky. On the Equinox in March and September the sun does rise in the east. At all other times it is slightly north or south of east. At the Summer Solstice and the Winter Solstice in June and December, the sun is significantly shifted from due east. How far? Paste the address below into your browser or click the related link below to see.

So Sun does not really rise from the east always, but then what governs this whole phenomenon. Interestingly, not only Sun, but moon, planets and most of the stars also appear to rise from the east and set in the west.

According to NASA

Earth rotates or spins toward the east, and that’s why the Sun, Moon, planets, and stars all rise in the east and make their way westward across the sky. Suppose you are facing east – the planet carries you eastward as it turns, so whatever lies beyond that eastern horizon eventually comes up over the horizon and you see it!

Fair enough.