WITHOUT A MICROSCOPE OUR EYESIGHT CAN ONLY SEE CLEAR, DEFINED IMAGES OF THINGS THAT ARE 0.1 MM OR LARGER
This means we cannot see any microorganisms that could make us sick!
Created a lot of myths
MICRO-ORGANISMS FIRST DISCOVERED BY ANTON VAN LEEUWENHOEK.
Used lenses to look at blood samples
He made an object appear larger than it’s actual size…termed magnified.
Robert Hooke was looking at cork
Coined the term ‘cells’
TODAY’S MICROSCOPES:
2 General Types Used in Science Research
Compound Light Microscope (up to 2000 X magnification)
Electron Microscope (up to 2, 000, 000 X magnification)
MAGNIFICATION :
Ocular lens (usually 10x) X Magnification Lens (4x, 10x, or 40x)
FIELD OF VIEW: The entire area that can be seen when you look through a microscope DIAMETER OF FIELD: The diameter of the field of view, it's the distance between one side of the lens to another. Diameter of field depends on magnification!! Lets say at 10x magnification (AKA ocular lens only) your diameter of field is 20mm: At Low power the objective lens is 4x magnification. So the diameter of field is 4 times smaller : Diameter of Field / Objective lens magnification 20mm / 4 = 5mm At Medium power the objective lens is 10x magnification. So the diameter of field is 10 times smaller : Diameter of Field / Objective lens magnification 20mm / 10 = 2mm At High power the objective lens is 40x magnification. So the diameter of field is 40 times smaller : Diameter of Field / Objective lens magnification 20mm / 40 = 0.5mm
Magnification
Once the magnification of each individual lens is known, calculating total magnification is simple math.
- Multiply the magnification of the lenses together. - For example, if the eyepiece magnification is 10x and the objective lens in use has a magnification of 4x, the total magnification is 10 × 4 = 40.
The total magnification of 40 means that the object appears forty times larger than the actual object. If the viewer changes to the 10x objective lens, the total magnification will be the ocular's 10x magnification multiplied by the new objective lens's 10x magnification, calculated as 10 × 10, for a total magnification of 100x.