1. How can we see things so small?
Microscopes
How can we see things so small?

2. History of Microscopes
During that historic period known as the Renaissance (about 1400’s until the 1600’s), there occurred the inventions of printing, gunpowder and the mariner's compass, followed by European travel to America. Bill Shakespeare was busy writing stories at this time too!
In Science the invention of the light microscope made visible the details of small objects.

3. What were they first used for?
A long, long time ago someone picked up a piece of transparent crystal thicker in the middle than at the edges, looked through it. They discovered that it made things look larger!

4. It was later learned that this could focus the sun's rays and set fire to a piece of paper or cloth. These crystals became known as “magnifiers”, "burning glasses“, or "magnifying glasses“.

5. Near the end of the 13th century people began using them in spectacles – or glasses!

6. Magnification
But what do things look like when magnified?

7. What are these?
Human Red Blood Cells
Snowflake

8. Section of human hair
A ‘split end’

9. Fly eyes!

10. ZOOM!!! Magnification Getting Bigger 1 10 100 1,000 10,000 100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
Getting Smaller 1
0.1
0.01
0.001
0.0001
Demo: Powers of 10

11. Make a VERY SIMPLE microscope!
What you’ll need:
A sheet of clear plastic
A few drops of water
Something to observe
eeeeeeeeeee

12. How do microscopes ‘work’?
Magnifying glass….

13. For example….. A lens with a magnification of 10 x (increases size by 10 times)
Magnifying glass
Original is
0.4 cm in size
We see
as 4 cm
in size

14. What does a real microscope look like
What does a real microscope look like? What do things look like under microscopes!
Virtual Microscope

15. 1590 – First Compound Microscope
Hans and Zacharias Janssen, Dutch eyeglass makers, made one of the first compound microscopes. Their microscope was simply a tube with a lens on each end.

16. 1660 – Hooke’s Compound Microscope
Robert Hooke improved on the compound microscope. The stand at the left holds oil for a flame, which shines on the specimen under the microscope.

17. 1683 – Leeuwenhoek’s Simple Microscope
Anton van Leeuwenhoek made a simple microscope – only one lens. BUT IT COULD MAGNIFY OBJECTS 266 TIMES!
He was the first person to see many one celled organisms, including bacteria.

18. 1886 – Modern Compound Light Microscope
German scientists Ernst Abbe and Carl Zeiss made a compound light microscope similar to the one pictured to the right. The mirror at the bottom focuses light up through the specimen.