Acceleration due to gravity

The acceleration produced in a body due to the force of gravity during free fall is known as acceleration due to gravity.It is denoted by g where g=9.8 m/s.
Calculation of acceleration due to gravity:

               According to newton's law of gravitation, the force between two bodies is directly proportional to the product of their masses and inversely proportional to the square of distance between  them.                                

Where G is the gravitational constant with the value
Now consider the earth and the particle going to have a freefall.Let the mass of the earth be M and mass of that particle be m.Let the particle be at the surface of the earth.Then the value of R will be the radius of earth, where earth is taken as a sphere.
                                          According to Newton's third law, Force F=ma.Let a=g.Then substituting it in the equation, we get mg=GMm/R^2 which is simplified to g=GM/R^2
Now we can calculate the value of g with the known values of G,M & R.
                      where M=5.98 *10^24 Kg (mass of the earth)

                                 R=63781*10^2 m (radius of earth)

 then acceleration due to gravity g is
For calculations: Use our Scientific calculator.

Periodic table of elements

In the modern periodic table, the elements are arranged accordingly with the increasing no. of atomic number (no. of protons) from first hydrogen to the 118th element.This periodic table reveals many properties of elements periodically.The basic periodical properties, that we can gain from this table are as follows.
1) Size of the atom.
2) Atomic radii
3) Ionization potential
                                                                             4) Electro negativity and
    Download periodic table software.                          5) Electron affinity
Size of the atom:
In the periodic table the size of the atom decreaes from left to right, and increases from top to bottom.It is a periodical one and there may be some breakage.
The size of an atom is inversely proportional to the effective nuclear charge.
Why it is?
The effective nuclear charge represents the electrostatic force of attraction between the protons and electrons.If the force between them is higher, i.e. effective nuclear charge is higher then they become more compact leading to decrease in size.
Ok.. then from top to bottom, why it increses?
You can see in the table that from left to right the principal quantum no. of the atom is same.For instance Li lithium has the value 1,2 and the same Ne neon has.But in case of moving from top to bottom the principal quantum no. increases constantly by one.This is the answer for the above question.
Atomic radii:
The atomic radii is directly proportional to size of the atom.
The radius of larger circle will be greater than the smaller one.Similarly the radius of large sized atom will greater than the smaller.

Scientific lines of tamil

"அணுவைத் துளைத்தேழ் கடலைப் புகட்டி குறுகத்தரித்த குறள்"

said by avvaiyar(ஒளவையார்) a tamil poet.
 "கடுகைத் துளைத்தேழ் கடலைப் புகட்டி குறுகத் தரித்த குறள்"
said by idaikkadar(இடைக்காடர்)

Meaning of those lines:

                               Both the lines are indicated to explain the well known Thirukkural.

The second line:

                   The idaikkadar says that if we store the huge ocean inside the small mustard, that will be equal to thirukkural. i.e You can see that a single kural is a two lined rhyme with only seven words(4in first & 3 in second) but this two lines have the capacity to describe a huge philosophy with an accurate example.

      e.g    ஈன்ற பொழுதின் பெரிதுவக்கம் தன்மகனைச்

                          சான்றோன் எனக்கேட்ட தாய்

              The mother, hearing her son's merit

              Delights more than when she begot

The first line:

                   The first line is similar to that of second but instead of mustard, avvaiyar(ஒளவையார்) used atom(அணு) which is fractionally smaller comparing with a mustard ball.

                   However, the first line linked the science with literature.It's great.....

                   Salute to ஒளவையார்.

Brahmagupta's Formula

Brahmagupta (598–668 CE) was an Indian mathematician and astronomer who wrote many important works on mathematics and astronomy.His famous work was Bhramasphuta-siddhanta.Its 25 chapters contain several unprecedented mathematical results.
 Brahmagupta's Formula:

So that the approximate value of the area of this cyclic quadrilateral will be letting it the exact value of the area is
 Statement:
The approximate area is the product of the halves of the sums of the sides and opposite sides of a triangle and a quadrilateral. The accurate [area] is the square root from the product of the halves of the sums of the sides diminished by [each] side of the quadrilateral

Ionic bond in NaCl

You can see the formation of Sodium(+) ion.Similarly Chlorine(-) ion forms by adding one more electron to chlorine atom.These two ion formation leads to attraction, since these two are with unlike charges.Moreover in sodium ion the space (orbital) of removed electron is now empty which tends to attract the extra electron of chlorine ion leading to formation of ionic bond to form NaCl molecule.

What differs atoms from ions?

Ions are nothing but atoms with either positive or negative charge.We can make a neutral atom into a positively charged ion(cation) by simply removing electrons or negatively charged ion(anion) by adding electrons, since removing electrons the no. of protons in that atom increases when compare to electrons leading to a cation.
This ion formation in Sodium atom and Chloride atom leads to the formation of Sodium chloride molecule through ionic bond formation commonly known as table salt.
Ionic Bond in NaCl

How to make a homemade antigravity toy?

Requirements:

• 3 very strong magnets
•  a pyrex cone bowl
• a copper wire
• a playing card 
• aluminium foil
• 4 flat & small neodymium magnets

How microwaveoven works?

How microwave oven works?
In microwave ovens, the two important things are presence of water molecules in the respective food stuff and the production of microwaves.The microwave acts like a magnetic field while the water molecules are compared to a magnetic dipole placed in a magnetic field.We know that when a magnetic dipole is placed in a magnetic field, it produces some torque.
Similarly when microwave is passed through the food stuff, the water molecules in the stuff reacts to release some energy, which is acquired by other particles in the food stuff leads to cooking of the food.

In the fig. the green lines indicates the microwaves, thus the watermolecules reacting to it.
For more

Largest Molecule Ever Known

Fullerene refers to any molecule that is made entirely of carbon atoms.They may be spherical, elepsoid or tube shaped.In developing nanotechnology carbon nanotubes is the familiar word which is one of the fullerene molecule as in fig.

The spherical shaped fullerenes are called as bucky balls, which is the largest molecule ever known.
In 2010, fullerenes (C₆₀) have been discovered in a cloud of cosmic dust surrounding a distant star 6500 light years away. Using NASA's Spitzer infrared telescope the scientists spotted the molecules' unmistakable infrared signature. Sir Harry Kroto, who shared the 1996 Nobel Prize in Chemistry for the discovery of buckyballs commented: "This most exciting breakthrough provides convincing evidence that the buckyball has, as I long suspected, existed since time immemorial in the dark recesses of our galaxy .

This figure shows the 3D structure of a bucky ball molecule with 60 carbon atoms.(C₆₀)
These bucky balls are more stable compare to anyother molecules ever known to man.

video from
NASA Jet Propulsion Laboratory California Institute of Technology

Evolution of Plants

 Evolution is started since, when the first atom is created !!!
The first evolutionary organism for both plants and animals are bacteria.Some bacteria evoluted to form the huge plant kingdom and some other as a seed for animal kingdom.Such bacteria which decided to form the plant kingdom are evoluted to fungi and algae, which are the first multicellular organization among the plant kingdom.But even today it is in a debate that fungi or algae which originated first?
Fungi:
The plant body of fungi is called mycelium.It is made up of mass of thread like filaments called hyphae.Hyphae is made up of mass of cells whose cell wall is made up of chitin or fungal cellulose.
Algae:
Algae are said to be unicellular plants which contains primitive chlorophyll pigments.They are the rich source of oxygen.Their habitat is aquatic.Their cell wall is similar to that of the higher plants.
Algae gave rise to a kingdom called bryophytes.These are considered as the amphibians of the plant kingdom, since this was the first step taken by algae to begin it’s terrestrial life.It is followed by pteridophytes,gymnosperms and at last higher plants called angiosperms.
Gymnosperms differs from angiosperms since it does not produces the fruit, but there is flower or may be inflorescence.pteridophytes are the first complete terrestrial organisms of the plant kingdom.They differs from their higher plants since they cannot able to produce the mature seed originated from ovule.Hence gymnosperms and angiosperms are together called as spermatophytes means seed producing plants.

First to say the speed of light

Do you know who is first to discover the speed of light?

  It's none other than  the great hindus of the Indian subcontinent.The speed of light is well mentioned in rig veda.
The fourth verse of the Rigvedic hymn 1:50 (50th hymn in book 1 of rigveda) is as follows:

तरणिर्विश्वदर्शतो जयोतिष्क्र्दसि सूर्य |
विश्वमा भासिरोचनम ||

taraNir vishvadarshato jyotishkrdasi surya |
vishvamaa bhaasirochanam ||

which means “Swift and all beautiful art thou, O Surya (Surya=Sun), maker of the light,
Illuming all the radiant realm.”

Commenting on this verse in his Rigvedic commentary, Sayana who was a minister in the court of Bukka of the great Vijayanagar Empire of Karnataka in South India (in early 14th century) says:
tatha ca smaryate yojananam. sahasre dve dve sate dve ca yojane
ekena nimishardhena kramaman.
which means “It is remembered here that Sun (light) traverses 2,202 yojanas in half a nimisha”
NOTE: Nimisharda= half of a nimisha
In the vedas Yojana is a unit of distance and Nimisha is a unit of time.

Unit of Time: Nimesa
The Moksha dharma parva of Shanti Parva in Mahabharata describes Nimisha as follows:
15 Nimisha = 1 Kastha
30 Kashta = 1 Kala
30.3 Kala = 1 Muhurta
30 Muhurtas = 1 Diva-Ratri (Day-Night)
We know Day-Night is 24 hours
So we get 24 hours = 30 x 30.3 x 30 x 15 nimisha
in other words 409050 nimisha
We know 1 hour = 60 x 60 = 3600 seconds
So 24 hours = 24 x 3600 seconds = 409050 nimisha
409050 nimesa = 86,400 seconds
1 nimesa = 0.2112 seconds (This is a recursive decimal! Wink of an eye=.2112 seconds!)
1/2 nimesa = 0.1056 seconds
Unit of Distance: Yojana
Yojana is defined in Chapter 6 of Book 1 of the ancient vedic text “Vishnu Purana” as follows
10 Paramáńus = 1 Parasúkshma
10 Parasúkshmas = 1 Trasareńu
10 Trasareńus = 1 Mahírajas (particle of dust)
10 Mahírajasas = 1 Bálágra (hair’s point)
10 Bálágras = 1 Likhyá
10 Likhyás= 1 Yúka
1o Yúkas = 1 Yavodara (heart of barley)
10 Yavodaras = 1 Yava (barley grain of middle size)
10 Yava = 1 Angula (1.89 cm or approx 3/4 inch)
6 fingers = 1 Pada (the breadth of it)
2 Padas = 1 Vitasti (span)
2 Vitasti = 1 Hasta (cubit)
4 Hastas = a Dhanu, a Danda, or pauruSa (a man’s height), or 2 Nárikás = 6 feet
2000 Dhanus = 1 Gavyúti (distance to which a cow’s call or lowing can be heard) = 12000 feet
4 Gavyútis = 1 Yojana = 9.09 miles
Calculation:
So now we can calculate what is the value of the speed of light in modern units based on the value given as 2202 yojanas in 1/2 nimesa
= 2202 x 9.09 miles per 0.1056 seconds
= 20016.18 miles per 0.1056 seconds
= 189547 miles per second !!
As per the modern science speed of light is 186000 miles per second !
And so I without the slightest doubt attribute the slight difference between the two values to our error in accurately translating from vedic units to SI/CGS units. Note that we have approximated 1 angula as exactly 3/4 inch. While the approximation is true, the angula is not exactly 3/4 inch.
NOTE: The original research in this direction was done by S.S. De and P.V. Vartak.

Aeroplane's take off

What is the principle behind the airplane's take off?

  It is what the Bernoulli's principle. Bernoulli's Principle states that as the speed of a moving fluid increases, the pressure within the fluid decreases.

The same principle served as the base for the manufacture of air crafts.

You can see that airplane's wings are made in such a way so that the velocity of air in upper portion is greater than the lower portion.This high velocity in the upper portion leads to lower pressure, while the lower velocity in the lower part of the wing leads to greater pressure when compare to the upper part.This pressure in the lower portion lifts the wings of the plane and so that of the plane.