Friday, September 25, 2009

The Human Eye


The eye as we all know is the one of the most important sense organ in our body. Thus knowing about it is always a pleasure. Therefore I take the opportunity to explain the structure and working of the eye in relation and not in relation to the brain.
The old saying that 'seeing is believing' defines the importance of sight which is provided by the eyes. The are located in two sockets of the skull. The eyeball is about one inch across and has muscles at the back which allow it to move up and down.
Outer protection to the eye is provided by a thin layer of skin called the eyelid and the hair at the end of eyelids are called eyelashes to prevent dust and other microorganisms to go into the eye. Tear glands located just above the eyes produce moisture and as we blink our eyes they get cleaned. The eyeball is padded with a layer of fat and on front ahas a hole called Pupil,this is surrounded by the Iris which makes the pupil smaller or bigger depending on the light outside. Located on the front of the eyeball is the cornea which is more like a transparent window, allowing partially focused light rays to enter the eye. Behind the cornea is a lens which focuses the light so that a fully focused but inverted image is formed on the Retina.
Located at the back the retina is made up of many rods and cones. The cones are sensitive to different colors while the rods are sensitive only to black and white, these rods and cones produce nerve signals when light reaches them through cornea. The inside of the eye contains a vitreous fluid which contains blood vessels for nourishing the eye. The retina is connected at the back to an optic nerve which inverts the image, right side up, while conveying the signals to the brain. Thus an upright image is formed by the brain giving us proper sight. The eyes work together duly controlled by the brain thus allowing us 'BINOCULAR VISION'.
This was the working of the human eye. Please relate the text to the diagram. I hope I have provided you with the adequate information you needed.
If yes please comment.
Thanking you,
Ishaan.
P.S Please click the diagram to view it fully.

Working of an Electric Bell


The electric bell works on the principle of electricity and magnetism or electromagnetism. It is a basic gadget and finds use almost everywhere. Thus it might be useful to learn about its working.
The bell has a circuit which is a path in which current travels. Turning the switch on completes the circuit and current flows through it. This activates the electromagnet inside the bell. An electromagnet is nothing but a solenoid which is made a temporary magnet as current passes through it.The electromagnet attracts to it the armature which further upward makes up the hammer.This hammer then strikes the gong which produces the sound. Behind the armature there is a contact screw which creates a gap to break the circuit so that the bell can be rung again. Thus the bell is set to work.
This principle of electromagnetism was discovered by Hans Christian Oersted.He was a well known scientist.This principle today also finds use in many other gadgets. Thus after reading this I am sure you have learned a lot about the working of an electric bell. I guess it is simple and most of us can make one.Do try and post pictures friends.
That's all I have in this article.
Thanking You,
Ishaan.

Wednesday, September 23, 2009

Introduction


Science
Science is a subject ,as I think, with no end at all.
It is like a vast ocean where depths cannot be found.
It is the study of life. We get to know our surroundings
better with this subject.From my point of view the subject
has caused humans to differ from animals.
So science mainly has three branches.Namely;
1.Biology
2.Physics
3.Chemistry.
These furthere have certain branches like
zoology,botany,astronomy etc.
1. Biology consists of the study of living beings.Plants and animals.
2. Physics consists of study on physical phenomenon like force,pressure,energy and work.
3. Chemistry is the study of chemical elements,matter and molecules which help in forensic and chemical jobs.

We would study about these branches and their further sub-branches in later.
If you need some information on somethings you are most welcome.Most of this was not of high standards but base forms the top and I needed to tell this to you .
Ishaan