Arrrrrrrgggggggghhhhhhh... I'm back!!! with my good old blog layout... It's shocking and it's definitely not funny to hear my blog missing... Not missing actually, just left empty... It's fixed, I guess... My posts are back, the links are back and the site feeds are back... Ready for checking eh? It is... and it could never be funny to lose this freakin, year- round physics project...
At last, we're through with the first of Four Quarterly Hellgates... Periodic Examinations for short... And as expected, there were no light, no answers, and no passing scores... especially for me. 18 out of... out of... nah... I can't even remember the stinking hps of that test... I made it out alive and I'm keeping this standing, if possible, for good!
Tuesday, August 21, 2007
Sunday, August 5, 2007
An Eye for the Camera...
Here is a comparison between the Eye and the Camera... Although the concepts or principles concerning the camera is based on the functions and capabilities of the human eyes, it has advantages, similarities, differences and disadvantages as compared to our visual organ...
HUMAN EYES vs. CAMERA Human eyes have often been compared to cameras. They are alike in terms of structure, but they have one fundamental difference in functioning mechanism.
Similarities:
1. opening for light to enter aperture pupil
2. control the amount of light entering camera/eye diaphragm control size of aperture iris muscles control size of pupil
3. refract light glass biconvex lens mainly cornea ;
lens, aqueous & vitreous humor
4. object of light action to form image photosensitive chemicals on film photoreceptors(rods & cones) in retina
5. absorb excessive light to prevent multiple images formation dark internal surface pigmented, dark choroid
Difference:
1. focusing mechanism change distance between lens & film change focal length of lens using ciliary muscles
HUMAN EYES vs. CAMERA Human eyes have often been compared to cameras. They are alike in terms of structure, but they have one fundamental difference in functioning mechanism.
Similarities:1. opening for light to enter aperture pupil
2. control the amount of light entering camera/eye diaphragm control size of aperture iris muscles control size of pupil
3. refract light glass biconvex lens mainly cornea ;
lens, aqueous & vitreous humor
4. object of light action to form image photosensitive chemicals on film photoreceptors(rods & cones) in retina
5. absorb excessive light to prevent multiple images formation dark internal surface pigmented, dark choroid
Difference:
1. focusing mechanism change distance between lens & film change focal length of lens using ciliary muscles
And here's a short and brief origin of the modern cameras...
Camera obscura.
The forerunner to the camera was the camera obscura. The camera obscura is an instrument consisting of a darkened chamber or box, into which light is admitted through a double convex lens, forming an image of external objects on a surface of paper or glass, etc., placed at the focus of the lens.[4] The camera obscura was first invented by the Iraqi scientist Ibn al-Haytham (Alhazen) as described in his Book of Optics (1015-1021).[1] English scientist Robert Boyle and his assistant Robert Hooke later developed a portable camera obscura in the 1660s.[2]
The first camera that was small and portable enough to be practical for photography was built by Johann Zahn in 1685, though it would be almost 150 years before technology caught up to the point where this was possible. Early photographic cameras were essentially similar to Zahn's model, though usually with the addition of sliding boxes for focusing. Before each exposure, a sensitized plate would be inserted in front of the viewing screen to record the image. Jacques Daguerre's popular daguerreotype process utilized copper plates, while the calotype process invented by William Fox Talbot recorded images on paper.
The first permanent colour photograph, taken by James Clerk Maxwell in 1861.
The first permanent photograph was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris. Niépce built on a discovery by Johann Heinrich Schultz (1724): a silver and chalk mixture darkens under exposure to light. However, while this was the birth of photography, the camera itself can be traced back much further. Before the invention of photography, there was no way to preserve the images produced by these cameras apart from manually tracing them.
The development of the collodion wet plate process by Frederick Scott Archer in 1850 cut exposure times dramatically, but required photographers to prepare and develop their glass plates on the spot, usually in a mobile darkroom. Despite their complexity, the wet-plate ambrotype and tintype processes were in widespread use in the latter half of the 19th century. Wet plate cameras were little different from previous designs, though there were some models, such as the sophisticated Dubroni of 1864, where the sensitizing and developing of the plates could be carried out inside the camera itself rather than in a separate darkroom. Other cameras were fitted with multiple lenses for making cartes de visite. It was during the wet plate era that the use of bellows for focusing became widespread.
***Here are some site feeds from http://library.thinkquest.org/28030/eyeevo.htm and http://en.wikipedia.org/wiki/Camera... I just think the sources deserve due respect and recognition for their works as published in my blog... Please, do not support plagiarism... Just passin by... Leave a message on my tagboard if you wish to copy some posts in this blog and your site as well... thanks...
Saturday, August 4, 2007
A Post on "Fiber Optics" (ver. final)
Here is an advanced application of the concepts in optics as used in daily life and in technological advancements... the Fiber Optics...
First, how is the term defined?
*According to webopedia.com, a site I passed by during my surfs, here is what they say about it...
>A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
Fiber optics has several advantages over traditional metal communications lines:
Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
Fiber optic cables are less susceptible than metal cables to interference.
Fiber optic cables are much thinner and lighter than metal wires.
Data can be transmitted digitally (the natural form for computer data) rather than analogically.
The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more fragile than wire and are difficult to splice.
Fiber optics is a particularly popular technology for local-area networks. In addition, telephone companies are steadily replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will employ fiber optics.
The advantages of using fibre optics
Because of the Low loss, high bandwidth properties of fiber cable they can be used over greater distances than copper cables, in data networks this can be as much as 2km without the use of repeaters. Their light weight and small size also make them ideal for applications where running copper cables would be impractical, and by using multiplexors one fibre could replace hundreds of copper cables. This is pretty impressive for a tiny glass filament, but the real benefits in the data industry are its immunity to Electro Magnetic Interference (EMI), and the fact that glass is not an electrical conductor. Because fibre is non-conductive, it can be used where electrical isolation is needed, for instance between buildings where copper cables would require cross bonding to eliminate differences in earth potentials. Fibres also pose no threat in dangerous environments such as chemical plants where a spark could trigger an explosion. Last but not least is the security aspect, it is very, very difficult to tap into a fibre cable to read the data signals.
Fibre construction
There are many different types of fiber cable, but for the purposes of this explanation we will deal with one of the most common types, 62.5/125 micron loose tube. The numbers represent the diameters of the fibre core and cladding, these are measured in microns which are millionths of a metre. Loose tube fibre cable can be indoor or outdoor, or both, the outdoor cables usually have the tube filled with gel to act as a moisture barrier which stops the ingress of water. The number of cores in one cable can be anywhere from 4 to 144
Over the years a variety of core sizes have been produced but these days there are only three main sizes that are used in data communications, these are 50/125, 62.5/125 and 8.3/125. The 50/125 and 62.5/125 micron multi-mode cables are the most widely used in data networks, although recently the 62.5 has become the more popular choice. This is rather unfortunate, because the 50/125 has been found to be the better option for Gigabit Ethernet applications.
The 8.3/125 micron is a single mode cable which until now hasn't been widely used in data networking, this was due to the high cost of single mode hardware. Things are beginning to change because the length limits for Gigabit Ethernet over 62.5/125 fibre has been reduced to around 220m, and now, using 8.3/125 may be the only choice for some campus size networks. Hopefully, this shift to single mode may start to bring the costs down.
What's the difference between single-mode and multi-mode?
With copper cables larger size means less resistance and therefore more current, but with fibre the opposite is true. To explain this we first need to understand how the light propagates within the fibre core.
Light propagation
Light travels along a fiber cable by a process called 'Total Internal Reflection' (TIR), this is made possible by using two types of glass which have different refractive indexes. The inner core has a high refractive index and the outer cladding has a low index. This is the same principle as the reflection you see when you look into a pond. The water in the pond has a higher refractive index than the air, and if you look at it from a shallow angle you will see a reflection of the surrounding area, however, if you look straight down at the water you can see the bottom of the pond. At some specific angle between these two view points the light stops reflecting off the surface of the water and passes through the air/water interface allowing you to see the bottom of the pond. In multi-mode fibres, as the name suggests, there are multiple modes of propagation for the rays of light. These range from low order modes which take the most direct route straight down the middle, to high order modes which take the longest route as they bounce from one side to the other all the way down the fibre.
This has the effect of scattering the signal because the rays from one pulse of light, arrive at the far end at different times, this is known as Intermodal Dispersion (sometimes referred to as Differential Mode Delay, DMD). To ease the problem, graded index fibres were developed. Unlike the examples above which have a definite barrier between core and cladding, these have a high refractive index at the centre which gradually reduces to a low refractive index at the circumference. This slows down the lower order modes allowing the rays to arrive at the far end closer together, thereby reducing intermodal dispersion and improving the shape of the signal.
(click to see the diagram)
That'll be enough for now, I'm still reading about this things... hehehehehe... Just passin by...
First, how is the term defined?
*According to webopedia.com, a site I passed by during my surfs, here is what they say about it...
>A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
Fiber optics has several advantages over traditional metal communications lines:
Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
Fiber optic cables are less susceptible than metal cables to interference.
Fiber optic cables are much thinner and lighter than metal wires.
Data can be transmitted digitally (the natural form for computer data) rather than analogically.
The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more fragile than wire and are difficult to splice.
Fiber optics is a particularly popular technology for local-area networks. In addition, telephone companies are steadily replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will employ fiber optics.
The advantages of using fibre optics
Because of the Low loss, high bandwidth properties of fiber cable they can be used over greater distances than copper cables, in data networks this can be as much as 2km without the use of repeaters. Their light weight and small size also make them ideal for applications where running copper cables would be impractical, and by using multiplexors one fibre could replace hundreds of copper cables. This is pretty impressive for a tiny glass filament, but the real benefits in the data industry are its immunity to Electro Magnetic Interference (EMI), and the fact that glass is not an electrical conductor. Because fibre is non-conductive, it can be used where electrical isolation is needed, for instance between buildings where copper cables would require cross bonding to eliminate differences in earth potentials. Fibres also pose no threat in dangerous environments such as chemical plants where a spark could trigger an explosion. Last but not least is the security aspect, it is very, very difficult to tap into a fibre cable to read the data signals.
Fibre construction
There are many different types of fiber cable, but for the purposes of this explanation we will deal with one of the most common types, 62.5/125 micron loose tube. The numbers represent the diameters of the fibre core and cladding, these are measured in microns which are millionths of a metre. Loose tube fibre cable can be indoor or outdoor, or both, the outdoor cables usually have the tube filled with gel to act as a moisture barrier which stops the ingress of water. The number of cores in one cable can be anywhere from 4 to 144
Over the years a variety of core sizes have been produced but these days there are only three main sizes that are used in data communications, these are 50/125, 62.5/125 and 8.3/125. The 50/125 and 62.5/125 micron multi-mode cables are the most widely used in data networks, although recently the 62.5 has become the more popular choice. This is rather unfortunate, because the 50/125 has been found to be the better option for Gigabit Ethernet applications.
The 8.3/125 micron is a single mode cable which until now hasn't been widely used in data networking, this was due to the high cost of single mode hardware. Things are beginning to change because the length limits for Gigabit Ethernet over 62.5/125 fibre has been reduced to around 220m, and now, using 8.3/125 may be the only choice for some campus size networks. Hopefully, this shift to single mode may start to bring the costs down.
What's the difference between single-mode and multi-mode?
With copper cables larger size means less resistance and therefore more current, but with fibre the opposite is true. To explain this we first need to understand how the light propagates within the fibre core.
Light propagation
Light travels along a fiber cable by a process called 'Total Internal Reflection' (TIR), this is made possible by using two types of glass which have different refractive indexes. The inner core has a high refractive index and the outer cladding has a low index. This is the same principle as the reflection you see when you look into a pond. The water in the pond has a higher refractive index than the air, and if you look at it from a shallow angle you will see a reflection of the surrounding area, however, if you look straight down at the water you can see the bottom of the pond. At some specific angle between these two view points the light stops reflecting off the surface of the water and passes through the air/water interface allowing you to see the bottom of the pond. In multi-mode fibres, as the name suggests, there are multiple modes of propagation for the rays of light. These range from low order modes which take the most direct route straight down the middle, to high order modes which take the longest route as they bounce from one side to the other all the way down the fibre.
This has the effect of scattering the signal because the rays from one pulse of light, arrive at the far end at different times, this is known as Intermodal Dispersion (sometimes referred to as Differential Mode Delay, DMD). To ease the problem, graded index fibres were developed. Unlike the examples above which have a definite barrier between core and cladding, these have a high refractive index at the centre which gradually reduces to a low refractive index at the circumference. This slows down the lower order modes allowing the rays to arrive at the far end closer together, thereby reducing intermodal dispersion and improving the shape of the signal.
(click to see the diagram)
That'll be enough for now, I'm still reading about this things... hehehehehe... Just passin by...
Thursday, August 2, 2007
The Night After I Entered Hell (The Fragrant Aftermath)
Hahahahahahaha... The clock comes closer, the question hurled like a corny joke.
"What is the frequency of the second hand of the clock?" Sir, one! hahahaha...
Then moments passed, the real answered was finally processed, one over sixty!
And it was accepted...
I thought, I thought that our Graded Recitation would make my spirit leave my body in no time... But fate didn't showed it's ugly face on me... I fortunately answered the question from Sir Moski... It's not a fishbone stuck on my throat, It was a sword I pulled out of me seconds after I shot the real pellet unto them.... hahahahaha... I was expecting for my servants, SOH CAH TOA, to carry me away from that one... I just can't help but laugh at that one... Did I make it on my own or did somebody gave me the confirmation I was looking for...
Christmas doesn't come everyday, it's just a graded recitation... The REAL DOOMSDAY is about to grasp me on my... my... they'll hold me tight on my... my... constricted and sweating... my... neck... I know what you're thinking... Long Test II and Periodical Examinations I... waw... Titanic sounding huh? Well, these are bigtime pushers... of low scores... hahahaha...
Goodluck to your exams... Our Standard Operating Procedures, share your blessings... joke... Just passin by...
"What is the frequency of the second hand of the clock?" Sir, one! hahahaha...
Then moments passed, the real answered was finally processed, one over sixty!
And it was accepted...
I thought, I thought that our Graded Recitation would make my spirit leave my body in no time... But fate didn't showed it's ugly face on me... I fortunately answered the question from Sir Moski... It's not a fishbone stuck on my throat, It was a sword I pulled out of me seconds after I shot the real pellet unto them.... hahahahaha... I was expecting for my servants, SOH CAH TOA, to carry me away from that one... I just can't help but laugh at that one... Did I make it on my own or did somebody gave me the confirmation I was looking for...
Christmas doesn't come everyday, it's just a graded recitation... The REAL DOOMSDAY is about to grasp me on my... my... they'll hold me tight on my... my... constricted and sweating... my... neck... I know what you're thinking... Long Test II and Periodical Examinations I... waw... Titanic sounding huh? Well, these are bigtime pushers... of low scores... hahahaha...
Goodluck to your exams... Our Standard Operating Procedures, share your blessings... joke... Just passin by...
Wednesday, August 1, 2007
The Night Before I Enter Hell ( I Feel Like Posting)
Good day people of the Philippines!
This post was published on the given date, the date before doomsday's prequel---
THE GRADED RECITATION!!!
I just wanna post this one although it isn't really on my nerves.
It's just the thought of having my parents meet Mr. Moses King Mendoza
one of these days that sends shiver down my spine (yah, it's completed, intentionally...)
A battlefield of questions- ranging from the ever-reliable SOH-CAH-TOA to the
mind-boggling, eye swirling lenses under OPTICS...
How I wish I can just pick the questions up for my own benefits
(define and explain sohcahtoa... awesome!), but it's impossible alright.
Every clock seems to tick on my face, telling me how much time do I have to gather up my thoughts and say something in front of the Physics Jury...
I need help but I can't seem to find nor plunder anything from anyone...
DESPERATION ARISES! hehehe...
What's the use of eating thick books and ink-flooded notes if I can't absorb anything from them?
What's the use of asking my classmates or anyone around me if they don't have the answers I need?
Just askin... how nice...
Here's your question:
>What will you do if you just forgot the right answer?
>Oops! Time's up! Pass your papers! Late answers will not be accepted...
Have fun...
This post was published on the given date, the date before doomsday's prequel---
THE GRADED RECITATION!!!
I just wanna post this one although it isn't really on my nerves.
It's just the thought of having my parents meet Mr. Moses King Mendoza
one of these days that sends shiver down my spine (yah, it's completed, intentionally...)
A battlefield of questions- ranging from the ever-reliable SOH-CAH-TOA to the
mind-boggling, eye swirling lenses under OPTICS...
How I wish I can just pick the questions up for my own benefits
(define and explain sohcahtoa... awesome!), but it's impossible alright.
Every clock seems to tick on my face, telling me how much time do I have to gather up my thoughts and say something in front of the Physics Jury...
I need help but I can't seem to find nor plunder anything from anyone...
DESPERATION ARISES! hehehe...
What's the use of eating thick books and ink-flooded notes if I can't absorb anything from them?
What's the use of asking my classmates or anyone around me if they don't have the answers I need?
Just askin... how nice...
Here's your question:
>What will you do if you just forgot the right answer?
>Oops! Time's up! Pass your papers! Late answers will not be accepted...
Have fun...
A Very Very Very LATE POST on Vectors...
Just wonderin if I can still post this whole thing up... It's better late than never, ayt? Here's what I understood about that matter...
The component method of addition can be summarized this way:
+Using trigonometry, find the x-component and the y-component for each vector. Refer to a diagram of each vector to correctly reason the sign, (+ or -), for each component.
+Add up both x-components, (one from each vector), to get the x-component of the total.
+Add up both y-components, (one from each vector), to get the y-component of the total.
+Add the x-component of the total to the y-component of the total then use the Pythagorean theorem and trigonometry to get the size and direction of the total.
Let's take this all one step at a time:
>First, let's visualize the x-component and the y-component of d1.
>The two components along with the original vector form a right triangle.
>Therefore, we can use right triangle trigonometryto find the lengths of the two components.
>That is, we can use the 'SOH-CAH-TOA' type of definitions for the sine, cosine, and tangent trigonometry functions.
>Now, using trigonometry like this will not tell us the sign, (+ or -), of this component, (or any other).
The component method of addition can be summarized this way:
+Using trigonometry, find the x-component and the y-component for each vector. Refer to a diagram of each vector to correctly reason the sign, (+ or -), for each component.
+Add up both x-components, (one from each vector), to get the x-component of the total.
+Add up both y-components, (one from each vector), to get the y-component of the total.
+Add the x-component of the total to the y-component of the total then use the Pythagorean theorem and trigonometry to get the size and direction of the total.
Let's take this all one step at a time:
>First, let's visualize the x-component and the y-component of d1.
>The two components along with the original vector form a right triangle.
>Therefore, we can use right triangle trigonometryto find the lengths of the two components.
>That is, we can use the 'SOH-CAH-TOA' type of definitions for the sine, cosine, and tangent trigonometry functions.
>Now, using trigonometry like this will not tell us the sign, (+ or -), of this component, (or any other).
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