Before the invention of the microscope it must have been hard for scientists to defend many of there theories with out verification. When the microscope was invented it gave scientists the ability for very extensive research and to prove the concepts with visual stimuli. This one invention opened up a realm of possibilities that was previously unavailable to researchers. The microscope provides the tool to visually see what is useable by the naked eye. For students in variety of fields we can see what is conceptually in textbooks. The microscope can be found today in a wide variety of professions ranging from scientist studying DNA to school teachers. If Zacharias Janssen could have foreseen the wide range of applications his simple (for the time) telescope would today be used for he would probably dismiss the thought as impossible.
At the very base function a telescope allows an individual to take something very small and magnify it a large number of times to see the very basic functions and chemical makeup of just about anything. For this lab I used a compound microscope, one of the most commonly used microscopes. The compound microscope is easy to use reliable and sturdy made from USA approved steel. This type of microscope uses light to show a two dimensional black and white image. It is easy to clean and maintain with basic equipment. The controls are fairly straight forward and again fairly simple to use and master.
Basic parts of compound microscope:
I will start the list of parts going from the ground up. As I discuss each part you can refer to the diagram for any clarification. Like any piece of scientific equipment the microscope has a base to support the entire structure, normally fairly heavy and sturdy. A compound microscope uses a light source for illumination so a power switch is normally found on the base. Just above the center of the base is the actual light source which looks straight up to the stage and the aperture. The light should be in good shape and not burned out or you will not have a crisp image. From the base up the arm is a very important structure connecting the major components to the sturdy base. From the arm there are a variety of adjustment knobs. The first is the fine adjustment knob followed by the coarse adjustment knob. You will always use the coarse adjustment knob first to raise the stage up and down. Raising the stage is your first attempt at getting an image of the specimen (while looking threw the eyepiece). Once a image of the specimen has been obtained the fine adjustment knob will be used to get a more detailed and crisp view. the fine adjustment knob will have to be reset every time you switch to a higher magnification objective. The stage sits on gears connected to the base by the coarse adjustment knob and using the knob will physically raise or lower the stage. The stage contains the aperture, stage clips, and diaphragm. The aperture is a hole in the stage with a glass piece inside allowing for light to illuminate the specimen sitting on top of the stage. the Diaphragm is the device which controls how much light from the source actually gets to the aperture. In general for the lower magnifications less light is need for the image. As you increase the magnification you will rotate the diaphragm to allow more light and better detail. The stage clips will be used to hold the slide with the specimen physically in place on the stage. As a note there are normally also controls (not in the diaphragm) which would be used to move the stage clips left and right or front to back to center the specimen over the aperture. Connected to the arm is a stage stop which can be used to keep the stage at the preferred height and not allow it to creep down making your view out of focus. The most important component of the microscope is the objectives. These have varying degrees of magnification normally 4x 10x and 40x magnification. You can rotate between these using the nosepiece. the objectives will need to be cleaned and properly maintained or the view you have of the specimen could be dirty and unusable. The body tube connects the eyepiece to the rest of the microscope. Normally the body tube can be adjusted so the eye pieces are more inline with you vision for a better view. The eyepiece is where all the magic happens. If all the other components are set correctly you will be able to look threw the eyepiece and get an amazing view of some foreign world so small only the microscope can show you these wonders.
Here is my 40x magnification for an onion root. Notice the clear bright image and crisp detail. I used the diaphram adjustment to get just the right amount of light. Using the fine adjustment knob gave me the clearest view of the onion root. I can clearly see the definition and texture of the cells making up the skin of the root.
I will start the list of parts going from the ground up. As I discuss each part you can refer to the diagram for any clarification. Like any piece of scientific equipment the microscope has a base to support the entire structure, normally fairly heavy and sturdy. A compound microscope uses a light source for illumination so a power switch is normally found on the base. Just above the center of the base is the actual light source which looks straight up to the stage and the aperture. The light should be in good shape and not burned out or you will not have a crisp image. From the base up the arm is a very important structure connecting the major components to the sturdy base. From the arm there are a variety of adjustment knobs. The first is the fine adjustment knob followed by the coarse adjustment knob. You will always use the coarse adjustment knob first to raise the stage up and down. Raising the stage is your first attempt at getting an image of the specimen (while looking threw the eyepiece). Once a image of the specimen has been obtained the fine adjustment knob will be used to get a more detailed and crisp view. the fine adjustment knob will have to be reset every time you switch to a higher magnification objective. The stage sits on gears connected to the base by the coarse adjustment knob and using the knob will physically raise or lower the stage. The stage contains the aperture, stage clips, and diaphragm. The aperture is a hole in the stage with a glass piece inside allowing for light to illuminate the specimen sitting on top of the stage. the Diaphragm is the device which controls how much light from the source actually gets to the aperture. In general for the lower magnifications less light is need for the image. As you increase the magnification you will rotate the diaphragm to allow more light and better detail. The stage clips will be used to hold the slide with the specimen physically in place on the stage. As a note there are normally also controls (not in the diaphragm) which would be used to move the stage clips left and right or front to back to center the specimen over the aperture. Connected to the arm is a stage stop which can be used to keep the stage at the preferred height and not allow it to creep down making your view out of focus. The most important component of the microscope is the objectives. These have varying degrees of magnification normally 4x 10x and 40x magnification. You can rotate between these using the nosepiece. the objectives will need to be cleaned and properly maintained or the view you have of the specimen could be dirty and unusable. The body tube connects the eyepiece to the rest of the microscope. Normally the body tube can be adjusted so the eye pieces are more inline with you vision for a better view. The eyepiece is where all the magic happens. If all the other components are set correctly you will be able to look threw the eyepiece and get an amazing view of some foreign world so small only the microscope can show you these wonders.
Here is my 40x magnification for an onion root. Notice the clear bright image and crisp detail. I used the diaphram adjustment to get just the right amount of light. Using the fine adjustment knob gave me the clearest view of the onion root. I can clearly see the definition and texture of the cells making up the skin of the root.
There have been many great inventions of the past couple hundred years, but with the exceptions of the wheel, fire in mans early life, and Coca-cola in modern society, has a device had such profound effects. The microscope has been used in almost all major scientific breakthroughs in the 20th century. If Robert Hooke was alive today and had a PH.D from MIT who knows what innovations he could have made for the next generation of microscopes.
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