LIGHT

Coach Dave EdingerJ. C. Booth Middle SchoolPhysical Science (8A)

Light + Energy Visible light is a form of wave energy and the only

part of the electromagnetic spectrum that we can see.

The Light SpectrumLight waves of a specific energy level will emit a particular color.

Radio waves

Micro-wave Infrared

Ultra-violet X-rays

GammaRays

In physics, light refers to electromagnetic radiation. The light we normally talk about in everyday life refers to the visible spectrum (the part of the electromagnetic spectrum that the human eye can see).

Other animals can see parts of the spectrum that humans can’t. For example, a large number of insects can see ultraviolet (UV) light.

UV light can be used to show things the human eye can’t see, coming in handy for forensic scientists.

The wavelength of infrared light is too long to be visible to the human eye.

Scientists study the properties and behaviors of light in a branch of physics known as optics.

Light FactsWhen Albert Einstein developed his ideas of relativity, he stated that no object can accelerate to the speed of light or go beyond it. Essentially, light is a universal speed limit. Unfortunately, this means that science fiction spacecraft, like the Enterprise on Star Trek, couldn't really go warp 5.

Albert Einstein (1879-1955) was a physicist who is widely regarded as one of the most influential scientists of all time. He is best-known for his Special and General Theories of Relativity, but contributed in other areas of physics. He won the Nobel Prize in physics for his explanation of the photoelectric effect.

Light travels at 671 million miles per hour. Did you know?

The Speed of Light facts:How long does it take to get to the Moon?

Light travels the 380,000 kilometers (240,000 miles) between the Moon and the Earth in 1.3 seconds. It would take a person more than nine years of continuous walking to travel this distance.Light: 1.3 secondsElectron: 2.9 minutesSpace shuttle (orbital speed): 14 hoursSound (70° F): 13 daysPassenger jet: 18 daysNYC subway car (maximum speed): 220 days

How fast is light? Here are some comparisons.

Let’s make our own Light Spectrum (Prism)

What we will need:o A glass of water about 3/4 full.o White papero A sunny day

Instructions:Bring the glass of water and paper to a sunnypart of a room, by a window is ideal.Hold the glass of water above the paper and watchas the sunlight passes through the glass of the water.Look to see how the light bends/refracts and forms a rainbow of colors on the paper.What happens when you hold the glass at a higher height or hold the glass at different angles?

What’s happening?Like a rainbow in the sky, the sunlight passes through the raindrops and bends/refracts the light.When the sunlight refracts we see the colors red, orangeyellow, green, blue, indigo and violet.