Science-Light-Unit C Part 1

What are optical devices?

Technologies that use visible light, such as microscopes, telescopes, glasses, and binoculars.

Who invented the microscope?

Hans and Zacharias Jansen in 1596.

What is the primary use of a microscope?

To examine very small things.

Who was the first to use a microscope to study microorganisms?

Antonie van Leeuwenhoek.

Who invented the telescope?

Hans Lippershey in 1608.

What are the two main types of telescopes?

Reflecting (uses mirrors) and refracting (uses lenses).

What did Galileo improve in telescopes?

He improved the telescope to discover mountains on the moon and moons around Jupiter.

What is coherent light?

Light emitted by a laser that stays together in a straight ray.

What is light?

Electromagnetic radiation that behaves like both a particle and a wave.

What is a photon?

A particle of light that has no mass.

What is the electromagnetic spectrum?

The range of all possible wavelengths of light.

What is bioluminescence?

The production and emission of light by living organisms.

What is the difference between transparent, translucent, and opaque materials?

Transparent materials allow light to pass through, translucent materials allow some light, and opaque materials do not allow light to pass.

What is the law of reflection?

The angle of incidence equals the angle of reflection.

What is specular reflection?

Reflection of light from a smooth surface where parallel rays hit at the same angle.

What is diffuse reflection?

Reflection of light from a rough surface where rays scatter at different angles.

What is the Tyndall effect?

The scattering of light off particles in a fluid, used to distinguish mixtures.

What is incandescence?

Emission of visible light from a substance when heated.

What is luminescence?

Glowing of materials that are NOT being heated.

What is chemiluminescence?

Production of light by chemical reactions, such as in glow sticks.

What is photoluminescence?

Emission of light caused by the absorption of light.

What is electroluminescence?

Emission of light caused by electricity, as seen in LEDs.

What is the role of pigments in plants?

Pigments absorb specific wavelengths of light, reflecting others, which determines the color we see.

What is the significance of chlorophyll?

It absorbs most red and blue light for photosynthesis and reflects green light.

What did Pythagoras believe about light?

He believed light comes from our eyes, which was later proven false.

What did Euclid contribute to the understanding of light?

He described the law of reflection and that light travels in straight lines.

Who first quantified the speed of light?

Albert A. Michelson.

What did Isaac Newton discover about light?

He showed that white light is a mixture of colors using a prism.