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A License to Learn
LA
O
RY
35
T
BO RA
S
cientific discoveries often follow the development of new tools and technologies. This is certainly true in the case of infectious diseases. As you saw in Activity 33, “From One to Another,” researchers
Alexandre Yersin and Shibasaburo Kitasato independently used the microscope to identify the cause of the bubonic plague. Compound microscopes—microscopes that use more than one lens—were invented around 1595. These first microscopes usually magnified objects only 20–30 times their original size. But as you will learn in the next few activities, even this level of magnification was enough to discover a world of new scientific ideas.
By 1840, Italian physicist Giovanni Amici (a-MEE-chee) had invented the oil-immersion microscope which could magnify objects 6,000 times. In most middle schools, the highest level of magnification is usually about 400 times. Today, the transmission electron and scanning electron microscopes can magnify objects over 40,000 times!
CHALLENGE
What is the correct way to use a microscope?
C-22
© 2006 The Regents of The University of California.
Created by SEPUP, Lawrence Hall of Science, Berkeley, California. Adapted with permission. All rights reserved.
A License to Learn • Activity 35
MATERIALS
For each group of four students
1
cup of water
1
dropper
1
pair of scissors (optional)
For each pair of students
1
microscope slide
1
coverslip
1
microscope lens paper various materials, such as a comic strip, human hair, leaf, etc.
For each student
1
Student Sheet 35.1, “Microscope Review”
(optional)
1
Student Sheet 35.2, “What Does Magnification
Mean?” (optional)
PROCEDURE
Part One: Earning a License
1. Your teacher will demonstrate the different parts of a microscope, as shown in Figure 1. eyepiece objectives
stage coarse focus knob
stage clips diaphragm fine focus knob
light source
LA
O
RY
35
T
BO RA
S
cientific discoveries often follow the development of new tools and technologies. This is certainly true in the case of infectious diseases. As you saw in Activity 33, “From One to Another,” researchers
Alexandre Yersin and Shibasaburo Kitasato independently used the microscope to identify the cause of the bubonic plague. Compound microscopes—microscopes that use more than one lens—were invented around 1595. These first microscopes usually magnified objects only 20–30 times their original size. But as you will learn in the next few activities, even this level of magnification was enough to discover a world of new scientific ideas.
By 1840, Italian physicist Giovanni Amici (a-MEE-chee) had invented the oil-immersion microscope which could magnify objects 6,000 times. In most middle schools, the highest level of magnification is usually about 400 times. Today, the transmission electron and scanning electron microscopes can magnify objects over 40,000 times!
CHALLENGE
What is the correct way to use a microscope?
C-22
© 2006 The Regents of The University of California.
Created by SEPUP, Lawrence Hall of Science, Berkeley, California. Adapted with permission. All rights reserved.
A License to Learn • Activity 35
MATERIALS
For each group of four students
1
cup of water
1
dropper
1
pair of scissors (optional)
For each pair of students
1
microscope slide
1
coverslip
1
microscope lens paper various materials, such as a comic strip, human hair, leaf, etc.
For each student
1
Student Sheet 35.1, “Microscope Review”
(optional)
1
Student Sheet 35.2, “What Does Magnification
Mean?” (optional)
PROCEDURE
Part One: Earning a License
1. Your teacher will demonstrate the different parts of a microscope, as shown in Figure 1. eyepiece objectives
stage coarse focus knob
stage clips diaphragm fine focus knob
light source