Four hundred years ago……… the world of the microscope was unexplored. The structure of plants...

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Transcript of Four hundred years ago……… the world of the microscope was unexplored. The structure of plants...

MicroscopeHistorical Timeline

Four hundred years ago………the world of the microscope was unexplored. The structure of plants and animals we could see was a mystery, and there were thousands more tiny plants and animals that were still unknown. The causes of disease could only be a guess and medical science was yet to be developed. The invention of the microscope brought about a revolution-a breakthrough in scientific knowledge that slowly leads us to where we are today……..

•It has been known for over 2000 years that glass bends light.

•The first accurate lenses were not made until about the year 1300.

Bending Glass

Then:

Now:

Glass Bending Light

Reflection: bounces awayRefraction: bends another direction

•The first accurate lenses were not made until about the year 1300.

•In spectacles, a pair of lenses placed a modest distance in front of the eye helps to focus images on the retina.

•For the average eye, the pupil is dilated to a diameter of only 2 to 3 millimeters in diameter under daylight conditions, so only the small central part of a spectacle lens actively assists direct vision.

•The remainder of the lens serves chiefly for orientation.

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• By the 1600’s, it was discovered that optical instruments could be made by combining lenses.

•When a lens serves as a telescope objective, it is placed a considerable distance from the eye and its entire surface forms the image of a distant object at its focal plane.

•An additional lens placed near the eye is required to see an enlarged image.

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•Credited with the invention of the first compound microscope with his father Hans. • Lived in Middleburg, Holland.

Antonie van Leeuwenhoek(1632-1723)

• Dutch scientist.• Made his own simple microscopes with a single lens that were handheld.

• Made many drawings of what he saw and historically became the first person to see bacteria, yeast, and living blood cells. (although he didn’t know what they were then) He called them “animalcules.” He drew the largest collection of microorganisms in any one scientists lifespan.

• He made a total of 419 microscope lenses. He ground them by hand himself. The last count yielded over 500.

Robert Hooke (1635-1703)• Was born on the Isle of

Wight, England.• Was a member of the

Royal Society.• Wrote a book called Micrographia

• Drew many organisms we find today.

• Coined the term “cell” from his cork bark drawings.

• All his microscopes and every accessory was handmade by himself.

Descriptions and Drawings

Microscopes Robert Hooke Developed

Robert Hooke’s Drawings

The Oxford Scientific Society

The Royal Society

From Past to Present